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Can you do some research on forged chrome molly 300M gun drilled/machined hollow crankshaft for high-performance cars with a modified racing engine. You should do a video on rare custom cnc machined forged 7068 aluminum alloy engine internal race parts (rods& pistons) Plus total seal gappless metal piston rings
Well depends on a multitude of factors. Such as WHEN it snaps. If at or near tdc in an interference engine? Possibly catastrophic. At high rpm? Same. Any other not so much. Sure there will be damage but its not the end.
@@Demonslayer20111 It will almost always snap at maximum force, which is at maximum RPM. Highest probabilities are near TDC and BDC because of the maximal acceleration at those points. Second derivative of a cosine is a negative cosine, so if one imagines TDC piston position as 1/2*displacement*cos(angle_shaft) then acceleration is negative to that and thus inward. How long elongation towards fracture takes is the question. Though if it is fatigue failure, I'd say instant snap as all the energy absorbtion in the material is no longer there.
I'm an engineer with carbon fibre experience and I absolutely agree with everything you said except for one thing. You can stack up layers of carbon fibre with different fibre orientation. This way it can sustain loads coming from different angles and making the part more isotropic. This doesn't change the final verdict though, CF parts are only economically feasible for very exotic cars.
Glad to read I had the right thought process! I was thinking the same thing while he was explaining that, "why dont they just rotate the carbon fiber sheet 90 degrees after every layer?" I figured there was some complicated mathematical or scientific explanation why they couldnt, but I guess not lol
He does mention orientation of the threads. My concern would be heat for the resin. Stuff like this gives me hope that traditional piston engines (and other engines, like wankels) will survive forever, even as they become hybridized, use waste-produced fuels or hydrogen, etc.
Iv actually been using carbon rods in my turbo bike for a year now.. it's working well at 60+psi of boost. It is chunky but seems to do fine so far. First version didn't do great but after some testing it's worked although with some less than conventional design. It doesn't have that many hrs at power so can't speak for long term.
@@oliverscorsim that's an absurd amount of boost. In a liter bike that would be like 600+ hp! In something like a Honda Valkyrie, it could be more! Do you have a TH-cam channel or something?
@@jessev9686 iv got a few old vids on this channel but Iv been grudge racing it aswell as developing it. But hoping to break the 100hp goal with 155cc. I will say the epoxies exist for the temps and forging is how I did it along with a few directional layers. My crank is pressed together so no rod bolts to strip. I do weld the pin after pressing. And I have a bushing in the small end. Making the part wasn't all that hard once I made the mold. As far as production it has to sit in the mold under pressure for too long in my opinion but it could happen. In my case I had forged steel rod and I started bending those went to some fancy billet that works but about half way through testing (maybe 50 Dyno pulls in) they would be done (stretched). So I tried carbon. After I fixed a few things I learned in the process and found the right resin I haven't hurt one yet but I am out of turbo for now.
A pro stock team experimented with carbon fiber connecting rods and found out that every time the car experienced tire shake it destroyed the rods. They decided the CF rods weren't worth the expense and were too fragile when subjected to the stress encountered in an imperfect world.
I put a motor in a tow rig for a race team that was competing at Heartland Park Topeka and they dropped a valve. Inside the truck on the console, they had some carbon fiber rods. This was in 1996 and I asked them wth they had and where they came up with them ? They told me they were working on them and had them to where they would handle the compression but couldn't handle being pulled apart at high RPMs. They also said I would be seeing them for sale within a few years.......... haven't seen them yet
One thing you didnt mention about aluminum rods are they are "Shock Absorbers". That is a big reason why they are used in racing engines. They lesson the "hit" on the bearings, ect. Top fuel rods actually shrink after a run. That is how much force is being put on engine connectiong rods.
@@woozledog And the top fuel engines op mentioned are rebuilt after every 1/4 mile. The spark plugs, seals, valve springs, pistons, rods etc are all literally consumable parts that are done after 1-4 passes.
When we see carbon fiber/carbon carbon connecting rods in Formula 1 engines, then we'll know that they have overcome the obstacles inherent with CF/CC. Until then, it is pretty cool to think about the performance advantages of such a lightweight and rigid material inside of a reciprocating engine.
@jacenharding2674true carbon fiber is very brittle also they use titanium connecting rods in F1 which are stronger than steel and stronger than aluminum and just about as strong as carbon fiber so. Unless I got my fax wrong I don't know maybe I made a mistake. I don't work at McLaren or something lol.
@@NebosvodGonzalezyou got your facts wrong. Titanium is not stronger than steel. It is very slightly less stronger than steel while weighing as much as aluminum which is what makes it a good metal on a lot of applications. Steel is slightly stronger but way heavier.
I'm not really a car buff, or especially interested in this subject, but I found your presentation absolutely fascinating, informative and easy to understand. Additional knowledge about anything, is never a waste of time. It is a brilliant video. Thanks.
You are a breath of fresh air, I build my own engines for Drag Racing and Road Racing. Every time I was Drag Racing at Fremont Drag Strip, when I came home I took the engine apart, at that time I was running a D/Gas 1955 chevy four door sedan, I ran a Chrysler 4 speed transmission and 1957 Pontiac Rear Axle, leaving the staring line at 10.000 RPM, I was able to lay a big gate job on my competition, 6-14 rear axle ratio, the 288 cubic inch chevy engine was screaming at the finish line. When I got home I found the Con Rod Bearings were moving a round, so I added a windage tray to the back of the pan, but when checked the Rods I had Boxed in I found the pistons were hitting the heads because the rods were Stretching even though I had right at 001. of and inch clearance. The next time I ran the Bearings looked great the windage tray worked, but the Pistons were hitting the heads too much. So I bought a new set of Carrilow, Steel Con Rods. Those Connecting Rods were So "Good", I was able to use those same Rods in other Engines I ran. Never "Broke" and Engine because of making sure I had "Good-Equipment" and that I checked the engine after hard Racing. I would like to get more information on the New "Carbon-Fiber" Rods being sold through Carrilow.
Why were you spinning a sbc to “10,000” rpm? Aint a sbc on earth making power that high especially in the old days with 23* angle heads. Also how can a piston hit the “head” “too much?” It shouldn’t hit it at all! I’m very confused here and the “ quoted” words you typed are misleading.
@@lambchopLSX87its a dragster engine. Uses a different fuel and is set up right on the limit. The con rods can stretch, meaning the pistons will touch the head.
@@soundmattersuk I know what it means, but they don’t hit the “head” so much as they would hit the valves! That in turn would destruct the engine. I’ve built all my own engines, I turn my current setup (stock bore and stroke 366 inch 6.0L iron block) to 7400 and it makes power to 7200 roughly, and the technology and flow of a modern engine far surpasses a standard sbc. I just can’t buy what the man is selling, it’s an outlandish claim to say it was having ptv contact and not self destructing. This is like a wild version of “my 327 had a 3/4 race cam, double hump heads, and it could hop a coke can! And Ricky couldn’t grab the $20 bill stuck to the dash when it was matted to the floor!”
Four things from a former aerospace composites M&P Engineer: 1 - “Forged Composites” is nothing more than compression molding, which has been done for decades in Aerospace for lower strength parts. We used ribs made from compression molded graphite in some ribs that didn’t see much load. 2 - The anisotropy of composites is not a detriment for connecting rods. The load is only in one direction: compression/tension with a little torsion and bending. Connecting rods could be made with properly aligned fibers (some along the length, some at 45 degree angles) to take any load in the engine. 3 - Epoxy would be not great for connecting rods, but BMI resin can handle the heat and oil very easily. 4 - Adding threaded inserts to composites for bearing loads has been done, and I don’t see an issue with this application. If I were tasked with designing composite connecting rods, I would use BMI resin with Resin Transfer Molding. This would allow for making the connecting rod hollow or foam filled, with precision placed inserts or metal sleeve inserts that can post machined later.
Addition from a carpenter: Your second point is exactly right, the anisotropic behaviour doesn't really matter since a carbon fiber part could (or probably already is) likely be made just like plywood. If you rotate the layers, such that in a top-down view they alternate horizontal and vertical, you get rid of almost all of the shrinking/expanding wood does when reacting to humidity. Not to mention that plywood-like materials are much, much more resilient compared to solid wood of the same species and thickness due to the crossed fibers spreading the load instead of shearing apart. This would apply to a carbon fibre part as well, I'd assume.
Thx from an aircraft mechanic. BUT connecting rods will primarily experience high compression loads. Those are not considered to be the strengths of fiber composites, as compression is mostly carried by the resin matrix. I doubt it would handle the pressure in modern forced engines.
@Alfred Wedmore lol. You should know by now that the trend these days is to make stuff up by claiming to be something related to the video topic. I can make up one right now that will be more believable. "in the most fake voice you can think of": As a former engine builder for a reputable company, blah blah blah blah blah...
@@BestMods168 yes as a living lego person I personally prefer acrylonitrile-butadiene-styrene for all my engineering. It’s a great durable thermoplastic that can take all the power a human child can throw at it.
@@mnxs They dont rebuild the engine. Not even top fuel dragsters get an engine rebuild after each race, thats a myth. They do get an engine inspection, they open it up and if the parts are good they go back in.
@@RadDadisRad All metals will suffer fatigue and catastrophic failure if there isn't enough material. Titanium is used in some rods. AML V8 for example. Aluminium doesn't stretch like bubble-gum, it has quite a low strain-to-failure. It has a finite fatigue life; no endurance limit and has a low fatigue strength/unit volume compared to steel (since mentioned in the article).
On that Lamborghini connecting rod sample, the bolts thread into that hunk of metal that makes up the logo. Also, you can just use nuts on the other side of connecting rod bolts, it’s not necessary to have the thread in the rod itself. Titanium rods usually are set up this way. 👌
I can not find a SINGLE issue with this video. It's not only great, it's amazing: the lack of any music helps the viewer focus on the actual matter at hand, the audio is clean and clear withour any noise or distortion, with perfect volume level. The subject is presented seamlessly in logically connected steps and progression, everything is well thought out and presented. Like a few commenters have already said, this level of quality and professionalism is EXTREMELY rare on TH-cam, and is up to par with professional documentary and educational videos. I was about to ask if you are a professor because you could definitely help a university student understand a subject matter. Keep up the amazing work! Subscribed!
There are bound to be some errors in details in a lengthy video, but my comment was regarding the quality of the video and presentation itself. It was very listenable and easy to follow.
@@dannyr3346 I don't think you've watched anything he's done lately cause the 4 rotor is running, driving and doing fan fuckin tastic. Bottom line... he's far more capable than you'll ever be.
I remember the fanfare of carbon-carbon pistons for two stroke engines (I worked in the motorcycle field for 30 years), and the unceremonious disappearance of the new "miracle material" almost as fast as its appearance. So many youtube channels get so much wrong that I was skeptical when I clicked on your video. I was wrong. Outstanding grasp of the subject matter and first rate ability to convey that knowledge. Well done, sir. Very well done.
@@überbooga psssh they paid us the cost of living and not a dollar more. So thank you for your thanks, that’s all I’ve gotten beyond an addition to my resume!
I was a little surprised that you didn’t include titanium rods in the video. I know they are available for several AMG engines and allow considerably higher revs.
Titanium is a great Material. And probably the real reason why we ll not see carbon fiber rods soon. Titanium rod weigh about the same as the claimed weight for carbon fiber rods in this video. Of course depending on the engine. But titanium ist so strong, that you simply need less material, while with carbon fiber you need more, due to the different forces in an engine.
They're great if you can keep them from galling the crank shaft. The Honda C engine has titanium rods, so does the LS7. But they have both had instances of galling, more so for the LS7. The surface coatings fail and that's that.
This channel has developed beautifully over several years, and keeps providing technically accurate observations and facts. Very well done, please keep up the great work that have been doing.
15:30 "When a small piece of foam fell off and hit the wing of the Columbia" - a small piece 60x40cm, weighing nearly a kilo, and travelling at hitting it at a relative speed of about 800km/h. Not much would have withstood that impact.
The carbon carbon failure also wasn't the source of the failure, the fact that the impact destroyed the insulating tile is what caused the catastrophic failure on reentry. To place blame on the carbon carbon, is both obscure given that there aren't that many applications of hot structure outside of shuttle, and an irresponsible recollection of history
Aluminum rods are used in topfuel racing because aluminum does not transmit the forces to the bearing, it acts like a shock absorber. A steel rod would destroy the the bottom end in a topfuel engine.
Not only are your statements technically accurate, your extremely precise selection of words, is utterly amazing. And I get the impression that English is not your primary language, so it's even more impressive.
Garage 54 (on TH-cam) made carbon fiber rods. They lasted about 15 seconds! Now they are just some guys in a garage but they have done some amazing things. Like adding 2 cylinders to a 4 cylinder to make an inline 6, and it worked!
Off-topic for carbon fibre, but adding only two cylinders? Check out the work that Allen Millyard does in his shed: th-cam.com/video/sjxiHLZdSGw/w-d-xo.html
@@billedifier8584 yeah that's pretty sick! The Garage 54 guys don't do any of the stuff they do excepting it to last, it's more of experiments. Definitely going to look through this guy's videos though! Thanks man! I'm always down for finding new interesting stuff on here...
“Your car costing $8k more, that’s definitely something you’re going to notice” Unfortunately, I think that’s a big part of the appeal for AWA’s target market. “Well sure yours has the teakwood dash, diamond encrusted shifter, and kangaroo leather seats, but does it have the carbon fiber connecting rods?” “Uh, what’s a connecting rod?” “Oh you poor peasant… remind me to take him off the guest list for the Christmas party”
well to be far spenting more on a rebuild of already expensive engine like a LSX-7/C7 corvettes or 572-hemi ford-camer/vodoo ect. might be worth it vs aluminium rod's as TBO's are way longer ect. 1k to 2k per rod/piston if i had my 50K to 100K or more job on my 2-gen hemi that's on the rebuilding stand it would be tempting and im a average joe in 🇺🇸 but my luck sofar im not buying anything right now as the last 2 years in a row iv made less than 5k to 10k usd aka poverty 😑
Your car will cost greater than $8K more because it will have no connecting rods at all. It will be electric, whether you want that or not. And the electric propulsion tech is such a drawback that most consumers don't want it, but it will be forced on you because klimate krisis. And if that result means you can't really afford a car at all under those terms, then that's even better because we ultimately want personal transportation to be less accessible to the masses for the greater good of our society. You're welcome.
@@onemoremisfit as a pro-mechanic 👨🔧and millwright / out of worker aka poverty, parts i would agree with you and yes up front sofar battery packaging to go 300+ miles is $$$ without a recharge but maintenance is as much ect. so ROI is a wash or a head and daily more convenient to drive, and my 80's Chevy truck ( that's already a painful experience to get tags for as 1970-1999~ gm sucked at thing's like smog testing ect. ) im considering having it a full BEV but like i said im a broke FM so not in the cards this year as for the charger no it's staying a V8 BBM / hemi-stick car so im not sure how im being "forced to change my 60's car" but fuel costs in 2022/6+-usd ⛽ vs my income don't help to afford to drive it longer distances ect.
We've used carbon composites like forged carbon fiber, in the medical field for a couple decades. They are not only light and strong but also conductive and radiolucent (for XRays). Excellent video.
in those top fuel cars the aluminum connecting rod in a sense acts as a shock absorber. spreading the load time so that the crank doesn't see such a spike in load pressure probably stopping it from blowing itself apart. by spreading that impact time out a bit. they measure the life cycle of those rods by how much they have been compressed (shortened). those cars are a balancing act of many different parts made of different materials for different reasons. I bet that those rods are aluminum for more than one reason. but in this case comparing carbon fiber and aluminum as rod material this shock absorption effect of the aluminum gives a big advantage to aluminum as being the choice "I Believe".... thanks for the video 👍
Was thinking the same thing watching the video. Selecting aluminum rods isn't always about weight. Nitro and nitrous motors often go aluminum for it's malleability which absorbs some shoick loads of more violent power adders. Some big displacement drag engines will go aluminum for lower weight but this has more to do with the length of stroke and trying to reduce reciprocating mass at high rpm for reliability than reducing parasitic losses.
Dang... I know I am walking away, with a much greater understanding of engine internals, and the life cycle of steel, aluminum as well as carbon fibre. I can also say, I now have a greater understanding of possible use case scenarios for carbon fibre and forged carbon composites. Kudos to D4A for putting together such a clear, concise informational piece. I loved the video and I am now a new Subscriber along with all others who have clicked on the magic button... #d4a
Your talking skills are awesome. I am not even near car mechanic and it was never my hobby, but man, u made me listen the whole video without skipping. Very unusual for me because I almost always fast forward videos.
Great visualization. Just had to note that the quoted strength for 4340 steel alloy is for annealed alloy, which is basically never used as is. Commonly used 4340 when tempered in useful, tough condition has almost double the tensile strength, so 1cm2 rod would withstand up to 15 tons before breaking. Strongest alloys, likely maraging steels, can have tensile strengths up to 30 tons of similar size. However, this may be semantics in a bigger scheme, so take it just as a sidenote.
I am speechless, so I'll write instead. This is the first video I've watched on the channel, and within the first minute I clicked the Subscribe button. You have so thoroughly and logically analyzed the topic that I can't help being impressed. You are also a very good presenter. I hope to enjoy many more of your videos. Well done!
I have a friend that is mech. Engineer with degree from GA Tech. Asked him this before and he said he had an assignment in college to determine this and the loss of braking surface for the holes /slots is actually worse than the brake cooling gain (and subsequent brake gain) from having drilled/slotted rotors. My thoughts (not a mech engineer and haven’t asked him this theory) is that the amount of carbon in the rotors is what matters the most…. But not sure how the carbon affects the cooling either. BUT the reduction in spinning weight might also be a factor in buying drilled and slotted rotors. A lot of dirt late models actually run scalloped rotors to save some rotating weight. I would definitely be interested in video covering all these factors though. Gotta get that advantage wherever we can!
Congratulations! You are awesome! Nobody has ever so perfectly illuminated me the differences of CF vs CC. It was driving me nuts. Now for my purposes I will use the correct resin along with CF. Thank you.
I subscribed solely because of how in depth you went with the diagrams and information on the mechanics of the materials and such. I am not a car guy by ANY means but if your channel has more information rich videos like this, I'm in.
Fantastic video! I love learning about the science, physics and material properties! Your videos are way more informative and educational than the usual car channels that only discuss the dumbed down, practical applications of tools and tech.
@@noahvdl3331 you hit the nail on the head. I’m definitely a layman but this video answered all the questions I had on using CF for internals and even questions I never thought to ask. Definitely subscribing
The newer materials like carbon fiber and Kevlar are amazing. and they keep getting stronger and more resilient every year. Absolutely love this video, Great Presentation and Narration.
There is also the aspect of stretching, when at high rotational speeds the traditional connecting rod stretches about 1.5% of its size, so this must be taken into account in the clearance of the deck and if the stretching can be reduced with carbon fiber parts, the compression ratio can be better optimized.
Respect! Your explanation is on point! I've worked and researched a lot on carbon fiber composites (Formula Student, Research projects, my masters thesis, research my students did, you name it) and your short presentation here is outstanding. Very well presented!
I'm glad that you covered anisotropic vs isotropic materials but I think tensile strength vs compressive strength is a VERY important distinction when talking about connecting rods. You even showed some footage of carbon getting crushed but it would be worth showing a graph of tensile vs compressive strength.
Carbon fiber sheets can be layered with 45 degrees rotation between layers, fixing the problem with different strengths directions. The mats you show are already weaved with 90 degrees directions, so they should be good enough already. A conrod does rotate, but the forces are mostly only in the piston direction, a conrod is always worn by the up and down motion never on side rotating forces.
The forces are mostly in the direction of piston travel only when the piston is at TDC or TBC. When the crankshaft is at 90 degrees from TDC the side forces are considerable..
Your videos teach more more in a couple of minutes than I have learned in years of school or even two semesters of auto class. Thank you for your service in free education.
That is by design. They make you take classes you don't need and the people teaching the classes are losers. Now then, enter the brainwashing and you have a dangerous element in our society. So to sum it up, save your money and seek your dreams and quit relying on a piece of paper to get you anywhere.
Literally you touched on everything we have thought about with CF rods, in regards to the limits of resin, adding Graphene (Graphite but better) but it's brittle...we tried and realized it would be insane R&D to make, and we're still a small Honda V6 J-SERIES performance parts company. Our HalferLand J35 4340 with our added revisions pushed the upper limits to 1300+HP, coming in at just $750 for a set of six, better HP to $ ratio then even Crower, Eagle (Chinese rods, if ya didn't know) and others. Our daily shop 06' Accord J35 makes 560whp on just 8psi. HalferLand Performance Products
Another reason aluminum rods are used in drag racing, and other high horsepower engines, is it absorbs some of the shock loads compares to steel, so the crank and other components don't take as much impact. Plastic internals may be more likely, and have been looked into for a long time. Polimotor had a mainly plastic engine that ran in IMSA in 1984/5 en.wikipedia.org/wiki/Plastic_automotive_engine
Back in 1995 I was involved with an off road racing team running the Mickey Thompson Stadium Racing series where we we were only limited to displacement and had an open design with all other components. Knew an engineer at the Shell Research Center in Houston who was able to get us 4 block of carbon fiber which we machined to crudely shaped connecting rods. They were as ugly as home made soap but as light as a feather. Needless to say rotating weight went down dramatically and acceleration sky rocketed! Which created the next problem of valve float with an engine now hitting 10,000 rpms. It was fun while the team lasted .
Forged CF is really nice for some applications. You can even "optimize" it using long unidirectional strands. I recently made a forged quadcopter frame using 3D printed molds and chopped CF. It turned out great. But I don't see it being mass-produced for engine parts. It is hard to achieve consistent parts. I don't know how you can easily automate CF forging. Maybe if you make some kind of carbon-resin paste and pre-mold it to some shape and then compress everything once it's uniformly placed in the compression mold. It is much faster than traditional cloth layup, and you can easily achieve variations in the thickness of the part. But you are also limited with the shape of the part since you have to open the mold and extract the part after forging. I'm closer to thinking that engine parts will be heavily optimized using various software simulations and 3D printed in mass using some new steel 3D printing tech.
If the sky is the limit of cost why not make it out of hot pressed ceramic. You'd have 90,000psi transverse rupture strength with conventional hot pressed.
@@dogchainsaw3923 Well after reading many many comments and experiences from people who owned them, subaru's are as reliable as respectable their owner is. Good maintenance will result in a long lasting engine. There was a period (before 2000) where WRX's where coming with faulty head gaskets so the rumor stayed with the cars. Any car will blow heads with poor maintenance and redlining it while cold or extremely hot. They are more prone to failure if left with old oils or running them low on oil vs an inline 4. Low oil or bad oil will damage a flat engine faster than an inline or V.
I learned (on some corner of TH-cam) that the Subaru Boxer headgasket issue was due to the way (how much) the cilinders are supported at the cilinder head side. closed deck vs open deck design. Normal Impreza engines are built ~cheape~- more cost effective then their race/rally variants but that doesn't stop kids from painting stock Subaru's blue, slapping wings and golden rims om them and overtax theis engines into failure. Subaru builds reliable engines. I have driven three EN engines and am currently enjoying an EF engine and trust me when I say I (have to) run them hard as they make 41 to 54 horsepower at best and you will use them all. Best of all they do it on a service interval that makes a lot of Americans turn pale at the thought (oil/filter 12.500km/7770mi).
Your illustrations show the materials being "tested" and rated for strength in tension, but the vast majority of the force on a connecting rod is going to be in compression both directly down through the rod and laterally off to the sides. as the crankshaft rotates. Good video, thanks for sharing it.
Those top fuel drag cars actually produce an insane amount of heat in that short run. They don't get more than 1 run out of most of those engines. There is so much force involved in that one run that their clutch plates weld together by the end of the run. They have to rebuild the entire engine and drive train after every run usually.
Yeah but that's one run of incredible heat then the parts are replaced anyway, yeah dont get me wrong they have tough internals, but an average car has to deal with heat cycling, cold starts, infinitely variable driving conditions and loads, poor maintenance and the rest, which is where fatigue comes into play
@@hamstirrer6882 first off then use King bearings. Great for longjevity. Whereas clevites will eventually eat up a crank, but are good for short usage.
I think the NSX had titanium connecting rods. You show a picture of an NSX engine when talking about steel con rods. Not criticizing, just checking. Great video, as usual. 👍
Great video !! you do your research. The main reason for using aluminum in really high output engines is for the bearings the aluminum connecting Rod acts like a shock absorber during the combustion process. That reason is why you don’t find materials like steel,titanium and Carbon Fiber connecting rods in TOP FUEL engines and other high output drag racing engines
@@Bit-while_going I see what your thinking but in reality the more you compress the air fuel charge the more heat you generate. This is why high compression engines generally require a higher octane rated fuel to resist pre ignition because of the heat. This is also why you want a intercooler or a alcohol based fuel or both to remove heat from the charge on a turbo charged vehicle compressing the air causes heat. I hope I shed some light on this subject
After playing with CF engine components a number of years back there was always the problem with frictional wear. Another consideration especially with valvetrain parts was an absolutely predictable harmonic force that would explode the material. This could be worked around by changing RPM/ material thickness/ spring packages. At that time the gains were minimal for the investment of time and money. But always enjoy a learning experience.
My initial expectation was that it'd be due to the resin breaking down over time due to exposure to oil and exacerbated by the heat and heat cycling _(ignorance warning: I assume things that breakdown from petroleum-based oil, would do so with synthetics, too...)_ Hah... And he just covered the resin issue while typing! Followed by the assumption that CF wouldn't be _as good_ at sudden, massive compression loads like a conn rod would see. So to hear its fiction wear being the issue, is surprising, as if have envisioned most CF parts to incorporate metal bearings or surfaces at those junctions. After all, our conn rods have bearings, they're not directly contacting the crank since even with lube there's wearing going on. (and the bearing being easier/cheaper to replace than an entire rod) As an example, an intake valve being CF, would be given a steel interface at the rocker arm. Whether that's an insert added before resin is applied (therefore being anchored), or something more simple like a cap, might come down to the specific part getting remade in CF.
@@DUKE_of_RAMBLE I In the case of the connecting rods wear occurred at the crank cheeks and between the rods. All valvetrain components were capped or inserted with metal wear components. Oil breakdown of the resin never appeared to be a problem as the duration of use of failed parts varied sometimes by years. Another note on valvetrain any excessive lash which would never harm conventional parts quickly took out the CF parts.
Great presentation. Thank you for an informative and easy to watch explanation with some good old common sense thinking. Lots of work went into this and I commend your approach and determination.
The quest for lightweight internal parts is to reduce the reciprocating mass inside of the engine . The lighter the mass , the faster the engine goes from idle to redline rpm and that is what wins races . They've only been exploring the " plastic " con rod idea for fifty years now . Something most people don't realize about aluminum rods is that they stretch upon deceleration, especially down shifting, which is why they aren't used in road racing .
The stretch can be accounted for, it's simply the short cycle life before failure is the reason they aren't used for endurance engines such as circle track or road racing.
@@davelowets what you're calling a short life span, more times then not is the crew chief tunng the engine by swapping in a new set of slugs with a different wrist pin location to alter where top dead center is in the cylinder. Although 92% loads of nitromethane and 70% overdrive on the blower will take it's toll, the drivers in the other forms of racing aren't crazy enough to run such engine combos.
@@bobbrinkerhoff3592 I'm not sure where your trying to head with this, but road/circle racing and drag racing are two very different things. And yes, aluminum rods DO have a very short lifespan compared to a steel rod. Fatigue sets in very quickly with an aluminum rod, and they need to be changed or else a failure is inevitable. Some drag racers with N/A engines on gasoline wont run they're aluminum rods past 100 passes, because they've experienced failures shortly after 100 runs. That's only 25 miles. NO good for any kind of circle or road cars.
@@djstatyk1540 yes, and it changes the static compression ratio, which can be further altered by using different thickness head gaskets. Where it gets " interesting " is when you get into the staging lanes, and experience a delay, and the conditions that you have tuned for change on you. That's when you swap out blower pulleys in order to change the amount of cylinder pressure, or final compression ratio. Hope this helps you to understand, cause it can get complicated fast.
Fascinating stuff, presented so very clearly and detailed ... especially for a casual "watcher" of automotive stuff ... like me. Really neat. Thanks d4a guy, much appreciated! DT
The only Street application I can see for OEM carbon fiber engine internals is top of the line vehicles like Porsches GT RS models, or whatever Lamborghini and Ferrari are calling their top models now.
Any popular mechanics reader could have told you this but not nearly as elegantly, especially in the very last Era of the ICE...always appreciate all your vids, and your engineering for us dummies examinations...
Whenever I rotate, and reciprocate at the same time, I get dizzy. MIT recently developed 2DPA. It's a two dimensional pollimer that's supposed to be twice as strong as steel, and as light as plastic. Hopefully we'll be seeing this in all sorts of manufacturing. It's inexpensive, and can be used in injection molding.
Yes. I've been waiting . (( For REAL WORLD Brutal testing )) 40 years ago... "Advanced Hybrid Ceramic" engine blocks. ect, ect. Re: "Lamborghini .. Weather STOCK Performance cars, or Poupose built, Liquid cooled (Performances Race boat engines ) Are Soooo Unreliable. COOL, ?? Oh yeah ! But wherever you go, It would be recommended to have top tier mechanics & a truck W/ All possible replacement parts. Ironically Yamaha Has consistently brought industry changing tech to market. & AMAZING things that NEVER Came to market. & NOW, Manfactures forced to go Electric. & Technology ( Batteries & THE GRID ) Not ready.
Twice as strong as what steel? There is so many grades available. There's even a mold steel that in bulk form can hit 750 KSI tensile. Downside is yield strength is not much less. That is a strength to weight ratio better than any titanium alloy, bar none. Long live Iron !
Very interesting video! I do find it interesting though that you mainly mention CF in tension. Not giving too much thought to it, I believe the rods are subject to much higher compressive forces vs tensile (I have 0 knowledge of the internal forces that go on during the combustion cycle so the above statement could very well be wrong). CFRP are also much weaker in compression due to the epoxy matrix taking most of that load (at least that’s what I remember from my mechanics of composites class). Though, if you made a con rod from sheets of CF, you could make it quasi-isotopic depending on the layup
An excellent video! Great organization, great graphics, great explanations. Well done! I learned a lot about the use and the limits of carbon fiber. Thank you.
Pretty much bang on, cost is a big problem but only a minor one. Many motorsport engine manufacturers have dabbled with them over the years and each time they fire them up they last minutes if they're lucky (enough to get down the drag strip maybe) They just can't handle the heat, oil and vibration. C-C pistons are the worst. If they survive cranking they usually blow on the first WOT of the engine. Only bit you missed is the bearings / lubrication challenges of a rod. Fitting of the bearing is tricky in carbon, and also most modern rods carry oil up to the little end to lubricate that as well
A 24hr racing series would be a serious marker to lay down if they done something like that and survived while being competitive that would really make a big statement.
Great video. This reminds me if Ford's promises of high temperature plastics that they were going to make their engine blocks from, or GM's ceramics engine blocks. We have yet to find the other material that can compare and do everything that steel already does. I'm hoping someday we do come up with a material that does actually start to replace some metal that's cheap to make lightweight and very very durable and strong
I cringe when I think about the powered metal rods in my LS1 engine. It's different, just spelled Cheaper. Stupid people who think Billet is the solution to everything but if they actually knew anything about metallurgy they would know that it's crap in it's untreated form because of it's grain structure. That's why aluminum must be stretched out to it's yield point --3°.
It is also very brittle in cold temps. Ford focus’s used front lower carbon fiber suspension arms until they started shattering in cold temperatures. I can imagine a car parked outside in a cold climate then they shatter in the engine when the engine is started and the car owner revs it up a bit to get warm faster like so many do in cold areas.
"Revving a cold motor to warm it faster" -- that's the stupidest thing I've ever heard. Install a block heater if you need to. Protip: if you don't abuse your engine, it lasts longer. "I saved almost an hour of warm-up time over my working lifetime and it only cost me $10k in additional mechanic's fees!" Please, write in to Scotty Kilmer to say you do this so we can all get a laugh as he mocks you! 🤣
Actually you can forge CF and have something that can sustain 1000F. I believe Bonafab Customs put a blank of forged CF in a firing furnace at 1500F and it didn’t do anything.
Another piece of brilliant work, D4A! Could you make a video someday about your education/background? I'm guessing you have a MS in Mechanical Enginerding with a lot of hands on practical experience. Your content is always very well explained and easy to understand. Thank you for the great educational videos.
A very nice comparison of connecting rod materials and engine performance. I was waiting for you to address the effect of reduced inertia on the engine's ability to attain higher rpm along with it's ability to accelerate faster to this rpm-hence the drag-racing industry's intense interest in reducing the engine's reciprocating (especially) weight. As you are undoubtedly aware, inertia force increases as the cube of rpm. Therefore, even the smallest of weight reduction will allow significant increases in torque and bhp before material failure at these elevated speeds.
2009 f150 5.4l 4×4 160k one set of brakes. 2 batteries. 1 battery was just purchased. No other problems. Serviced very well. Very rarely went more than 3k between oil changes.
On Columbia, it wasn't just a little piece of foam; the foam had a lot of kinetic energy when it struck the wing. Even NASA thought that the tiles could survive such an impact, until they properly modeled it.
You really believe Columbia broke apart because of the piece of foam striking the wing? I have a bridge for sale! But really, that shuttle was taken out by something. There is video footage showing another vehicle or object shooting something at Columbia. I don't know what they did on that mission to piss someone or something off but it is what it is. And it wasn't a piece of foam on launch.
Sounds like good to try in a motorcycle engine. It might be more noticeable with a motorcycle platform. However, this not very cheap, but would show the longevity that they can with stand over time while is use.
Also any type of endurance orientated racing: NASCAR, Baja 1000, 24 hours at Le Mons... That sort of thing. Throwing the worst conditions know at the parts, for the longest times.
They researched carbon-carbon pistons for two stroke motorcycle engines in the 80s. They couldn't solve delamination under load. The pistons tended to shed their tops above the top ring groove.
Your explanation is very well done without complicated math and jargon like when I was getting my Ph.D. in material science back in the 80-ties. The world has a lot more collective experience and sharing of information today than back 40 years ago. Like one of the famous scientists said, we have now reached the level of increasing the IQ of our planet by 10 points because of the WWW with "FACT BASED INFORMATION" sharing and content like yours. Greetings from USA
Considering we are making 4 cylinder engines that produce well over 1000hp these days (some make around 2000hp at the crank), if the claims that AWA are making are true, there is some real desirability in the racing world. In fact if I could afford a set, I would love to swap out my forged rods for some carbon fiber rods. As of right now my forged rods are the limiting factor in how much power my engine can make.
Those high power drag race engines with billet aluminum rods use aluminum not just because its lightweight but also its a softer material than steel and acts a little bit like a shock absorber to damped harmonic forces that would otherwise be detrimental to the rod bearings
Great video, keep it going! 😎 However there is one point worth mentioning: metal components have tolerances because of thermal expansion and wear, while carbon fiber not really (please correct me if I’m wrong). This means that if we isolate the rods, at different temperatures there will be a certain tension between metallic and composite parts, assuming the engine is stationary to keep it simple. And this would lead to complications to all the assembly points and components like bearings, piston pin and the fact that you can’t thread the carbon fiber for the rod caps, therefore you would either need metal inserts or use a self-locking screw-nut assembly. But again, how would thermal expansion affect that? There was something else I had in mind, but I can’t recall it at the moment 😅
Full roller bearings in self-contained oils for the mains via seals. The rods in there own self contained chambers. Be hard to manufacture but i suspect it would work
Great video. I'm not that interested in cars and engines in and of themselves but I loved how you describe how the strengths and weaknesses of different materials determines their real-world application.
Long ago I worked for AMOCO... 1980s... "Metal components included cylinder sleeves, combustion chamber tops, piston crowns, bearings, valves and seats and a standard crankshaft. The block, piston skirts and even connecting rods were made from glass-reinforced polyamide-imide thermoplastic resins marketed under the name Torlon. Output was published as 318 HP at 9200 RPM, and weight as just 152 pounds-nearly 265 less than its standard, iron-blocked counterpart. Polimotor 2 was installed in a Lola T616 and raced extensively in 1984 and 1985 IMSA Camel GT Championship seasons, the car earning many top-five finishes as well as a podium in the form of third-in-class at 1985’s Lime Rock 2 Hours....
Carbon fibre rotors in an EV motor would be interesting. Also, (vacuum) metal vapour deposition might be able to apply a protective coating to the resin.
High efficiency requires tight clearances between the magnetic poles. The limit on the clearance is bearing wear and tolerances. Carbon fibre just gets in the way (unless you are using it to hold the soft copper rotor windings in at high rotation speeds).
@@allangibson2408 it appears to be a wrap around the circumference of the rotor, looked pretty thin in photos. Sandy Munro did a tear down on his channel if you’re curious.
Awesome video. Carbon fibre has been completely revolutionary for some purposes e.g. making fishing rods and tennis racquets. So I guess the natural engineering tendency is to try to extrapolate this success into other uses where strength to weight ratio matters.
Wouldn't this mean that carbon fiber could be a useful material for a rotor in a wankle style engine? The load is a lot less complex in its distribution, and the weight savings could dramatically increase the high rpms that rotaries can already reach. Maybe im wrong but i feel as though it could be a real breakthrough for that market.
Since the crankshaft just rotates, it doesn't move, the benefits of it weighing less are not much, saving a few kgs is never a bad thing, but I don't think doing it with a carbon crankshaft is worth it in any situation. The pistons and rods on the other hand are constantly forced to accellerate and deccalarate up and down, if they weigh less they have less inertia meaning it takes a lot less energy to do this. The crankshaft has to accelerate and decallarate too, but it's not a hundred times a second.
@@dido1803 Torsional stresses are just tensile and compressive stresses at a 45° angle. So this can be solved by just changing the direction of the carbon fiber to the optimal direction (45° w.r.t. the length of the shaft).
"A failed head gasket could lead to a snapped rod" This can happen for regular engines in some circumstances, but no, you still do not want this. For the record, early adopters of aluminum engines also had to contend with being picky about coolant, as many early blocks and heads were slightly porous or could become porous over time and letting coolant inside. This is why the famous GM DexCool exists - To replace the ancient alcohol and ethylene glycol based coolants of the 1920s and 1950s I'm by no means an expert on the subject, but I do wonder if there's a way to make partial carbon fiber or partial carbon carbon parts, since there's nothing saying we have to rely entirely on it's properties alone. Why not make the pistons out of carbon carbon but plate them in a reasonable thickness of aluminum to share the decreased weight but keep their rigidity?
Dex-cool is the worst thing to happen to vehicles. It gels and corodes inside the water jackets of the motor. Everytime I rebuilt a chevy motor that used dex-cool it was a horror show. We had to hot tank the block and heads before we could even start working on it. I always refilled it with standard coolant if it is a passenger vehicle or red line water wetter and straight water for performance vehicles. So pretty much you need a motor rebuild after running dex cool it was cost you another $1-3k for cleaning and labor. I usually just get long blocks from the manufacturer and deck the heads, it's about he same price.
Dexcool exists to destroy engines so GM sells more parts and cars. All it does is eat up everything (plus the Chinese parts quality), so they leak, which leads either to big repairs or blown up engine. Every single engine is the same story starting as low as 20k miles. Meanwhile....a 20 yrs old, 200k+ mi Japanese car has no leaks, original hoses, original water pump, etc. Green coolant and 180* t-stat does wonders. Funny how the first Japanese and German cars with aluminum blocks/heads never had a single issue... And they're still running today without a single major repair.
Because carbon is still brittle. And aluminum and carbon don't mix, the parts you see combining the 2 will have a barrier between the 2 or corrosion will happen. Then the strength of whichever metal you choose, will be weaker because there is less mad of it, allowing it to flex more, further stressing the carbon, and since there's less carbon, then the overall part would be weaker
You cannot compare the challenges of chemicals to Carbon Fiber vs Aluminum. It's a whole other league of challenging. We are talking about like exposure to these chemicals will rapidly compromise the rod. Like hours at most, minutes at soonest. Depending on the epoxy resin used. This is not even close to the challenges to aluminum porosity, which I am familiar with. It can happen in the home model engine engineering world with cast parts and if the aluminum is not the right type or not cast correctly and get a lot of porosity. I think it be amazing to engineer the issues out, but definitely a DRASTICALLY more difficult task. As he pointed out in the vid very well. I also design model engines for a hobby, at some point I will build them. So while not a full fledged engineer, I do understand what he is saying about the problems with carbon rods and more. The fact they can make them work at all is an INCREDIBLE engineering feat! I'm surprised that they were even able to do it at all at any level.
And actually, carbon fiber composites are known not to like compressive forces. They are better in traction than compression, so basically the opposite of what a rod has to do. We've even been proved recently that CF doesn't like pressure with the little Titan submersible...
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Can you do some research on forged chrome molly 300M gun drilled/machined hollow crankshaft for high-performance cars with a modified racing engine. You should do a video on rare custom cnc machined forged 7068 aluminum alloy engine internal race parts (rods& pistons) Plus total seal gappless metal piston rings
please check more the greek manufacture his totall scam do and inside in his car chaos
Could you make a video explaining the advantages in terms of power of having different amount of cylinders for the same displacement?
You are comparing apples an oranges. You should be asking why there isn't graphene steel alloys...
IF.. you want to retain credibility when you present calculations.. do it RIGHT!.. seven point "EIGHTY FIVE".. WTF is that
Technically, Aluminium connecting rods will also last the life of the engine --- considering the consequences of a rod snap
Not even funny, not a joke either - but im laughting LOUD
LoL
Well depends on a multitude of factors. Such as WHEN it snaps. If at or near tdc in an interference engine? Possibly catastrophic. At high rpm? Same. Any other not so much. Sure there will be damage but its not the end.
@@Demonslayer20111 It will almost always snap at maximum force, which is at maximum RPM. Highest probabilities are near TDC and BDC because of the maximal acceleration at those points. Second derivative of a cosine is a negative cosine, so if one imagines TDC piston position as 1/2*displacement*cos(angle_shaft) then acceleration is negative to that and thus inward. How long elongation towards fracture takes is the question. Though if it is fatigue failure, I'd say instant snap as all the energy absorbtion in the material is no longer there.
I see what you did there......
I'm an engineer with carbon fibre experience and I absolutely agree with everything you said except for one thing. You can stack up layers of carbon fibre with different fibre orientation. This way it can sustain loads coming from different angles and making the part more isotropic. This doesn't change the final verdict though, CF parts are only economically feasible for very exotic cars.
Glad to read I had the right thought process! I was thinking the same thing while he was explaining that, "why dont they just rotate the carbon fiber sheet 90 degrees after every layer?" I figured there was some complicated mathematical or scientific explanation why they couldnt, but I guess not lol
He does mention orientation of the threads. My concern would be heat for the resin. Stuff like this gives me hope that traditional piston engines (and other engines, like wankels) will survive forever, even as they become hybridized, use waste-produced fuels or hydrogen, etc.
Iv actually been using carbon rods in my turbo bike for a year now.. it's working well at 60+psi of boost. It is chunky but seems to do fine so far. First version didn't do great but after some testing it's worked although with some less than conventional design. It doesn't have that many hrs at power so can't speak for long term.
@@oliverscorsim that's an absurd amount of boost. In a liter bike that would be like 600+ hp!
In something like a Honda Valkyrie, it could be more!
Do you have a TH-cam channel or something?
@@jessev9686 iv got a few old vids on this channel but Iv been grudge racing it aswell as developing it. But hoping to break the 100hp goal with 155cc. I will say the epoxies exist for the temps and forging is how I did it along with a few directional layers. My crank is pressed together so no rod bolts to strip. I do weld the pin after pressing. And I have a bushing in the small end. Making the part wasn't all that hard once I made the mold. As far as production it has to sit in the mold under pressure for too long in my opinion but it could happen. In my case I had forged steel rod and I started bending those went to some fancy billet that works but about half way through testing (maybe 50 Dyno pulls in) they would be done (stretched). So I tried carbon. After I fixed a few things I learned in the process and found the right resin I haven't hurt one yet but I am out of turbo for now.
A pro stock team experimented with carbon fiber connecting rods and found out that every time the car experienced tire shake it destroyed the rods. They decided the CF rods weren't worth the expense and were too fragile when subjected to the stress encountered in an imperfect world.
Thank you
I just commented above that carbon fiber is much to rigid. Then I see your comment 👍🏼
I put a motor in a tow rig for a race team that was competing at Heartland Park Topeka and they dropped a valve. Inside the truck on the console, they had some carbon fiber rods. This was in 1996 and I asked them wth they had and where they came up with them ? They told me they were working on them and had them to where they would handle the compression but couldn't handle being pulled apart at high RPMs. They also said I would be seeing them for sale within a few years.......... haven't seen them yet
for sure I agree. the compression effect of the aluminum is needed 👍
the advantage of steel/aluminum is that they’re flexible, even if they’re forged they still have that small flex that cushions vibrations
One thing you didnt mention about aluminum rods are they are "Shock Absorbers". That is a big reason why they are used in racing engines. They lesson the "hit" on the bearings, ect. Top fuel rods actually shrink after a run. That is how much force is being put on engine connectiong rods.
He also forgot heat. It gets hot in engines.
@@Delt4_Cr4wfishHe mentioned that it gets hot in engines. If you had watched the whole video.
@@juanc5149 i did
They're used in racing engines because racing engines are built to last like 10,000 miles lol
@@woozledog And the top fuel engines op mentioned are rebuilt after every 1/4 mile. The spark plugs, seals, valve springs, pistons, rods etc are all literally consumable parts that are done after 1-4 passes.
When we see carbon fiber/carbon carbon connecting rods in Formula 1 engines, then we'll know that they have overcome the obstacles inherent with CF/CC. Until then, it is pretty cool to think about the performance advantages of such a lightweight and rigid material inside of a reciprocating engine.
Well said.
@jacenharding2674true carbon fiber is very brittle also they use titanium connecting rods in F1 which are stronger than steel and stronger than aluminum and just about as strong as carbon fiber so.
Unless I got my fax wrong I don't know maybe I made a mistake.
I don't work at McLaren or something lol.
@jacenharding2674not just brittle. The epoxy will never be able to handle the heat inside an engine.
@@NebosvodGonzalezyou got your facts wrong. Titanium is not stronger than steel. It is very slightly less stronger than steel while weighing as much as aluminum which is what makes it a good metal on a lot of applications. Steel is slightly stronger but way heavier.
CF has poor compressive strength
I'm not really a car buff, or especially interested in this subject, but I found your presentation absolutely fascinating, informative and easy to understand. Additional knowledge about anything, is never a waste of time. It is a brilliant video. Thanks.
On the contrary, I'm here just for the well deserved digs at the Lamborghini corporate :-D
An incredible video, thanks! Never asked for it, but definitely loved it and helped me to understand the theory behind it
love your video too
I wanna see CarbnFibr woven into an Escutoid pattern, then locked into shape via resin.
th-cam.com/video/MkfmCLiJ6kI/w-d-xo.html
so awsome to have the master as a companion
Gud comment. And gud vid also.
Greatness meeting greatness!
You are a breath of fresh air, I build my own engines for Drag Racing and Road Racing. Every time I was Drag Racing at Fremont Drag Strip, when I came home I took the engine apart, at that time I was running a D/Gas 1955 chevy four door sedan, I ran a Chrysler 4 speed transmission and 1957 Pontiac Rear Axle, leaving the staring line at 10.000 RPM, I was able to lay a big gate job on my competition, 6-14 rear axle ratio, the 288 cubic inch chevy engine was screaming at the finish line. When I got home I found the Con Rod Bearings were moving a round, so I added a windage tray to the back of the pan, but when checked the Rods I had Boxed in I found the pistons were hitting the heads because the rods were Stretching even though I had right at 001. of and inch clearance. The next time I ran the Bearings looked great the windage tray worked, but the Pistons were hitting the heads too much. So I bought a new set of Carrilow, Steel Con Rods. Those Connecting Rods were So "Good", I was able to use those same Rods in other Engines I ran. Never "Broke" and Engine because of making sure I had "Good-Equipment" and that I checked the engine after hard Racing. I would like to get more information on the New "Carbon-Fiber" Rods being sold through Carrilow.
Why were you spinning a sbc to “10,000” rpm? Aint a sbc on earth making power that high especially in the old days with 23* angle heads. Also how can a piston hit the “head” “too much?” It shouldn’t hit it at all! I’m very confused here and the “ quoted” words you typed are misleading.
Have you looked into titanium ?
do you have a brain damage or something?
@@lambchopLSX87its a dragster engine. Uses a different fuel and is set up right on the limit. The con rods can stretch, meaning the pistons will touch the head.
@@soundmattersuk I know what it means, but they don’t hit the “head” so much as they would hit the valves! That in turn would destruct the engine. I’ve built all my own engines, I turn my current setup (stock bore and stroke 366 inch 6.0L iron block) to 7400 and it makes power to 7200 roughly, and the technology and flow of a modern engine far surpasses a standard sbc. I just can’t buy what the man is selling, it’s an outlandish claim to say it was having ptv contact and not self destructing. This is like a wild version of “my 327 had a 3/4 race cam, double hump heads, and it could hop a coke can! And Ricky couldn’t grab the $20 bill stuck to the dash when it was matted to the floor!”
Four things from a former aerospace composites M&P Engineer:
1 - “Forged Composites” is nothing more than compression molding, which has been done for decades in Aerospace for lower strength parts. We used ribs made from compression molded graphite in some ribs that didn’t see much load.
2 - The anisotropy of composites is not a detriment for connecting rods. The load is only in one direction: compression/tension with a little torsion and bending. Connecting rods could be made with properly aligned fibers (some along the length, some at 45 degree angles) to take any load in the engine.
3 - Epoxy would be not great for connecting rods, but BMI resin can handle the heat and oil very easily.
4 - Adding threaded inserts to composites for bearing loads has been done, and I don’t see an issue with this application.
If I were tasked with designing composite connecting rods, I would use BMI resin with Resin Transfer Molding. This would allow for making the connecting rod hollow or foam filled, with precision placed inserts or metal sleeve inserts that can post machined later.
Addition from a carpenter:
Your second point is exactly right, the anisotropic behaviour doesn't really matter since a carbon fiber part could (or probably already is) likely be made just like plywood.
If you rotate the layers, such that in a top-down view they alternate horizontal and vertical, you get rid of almost all of the shrinking/expanding wood does when reacting to humidity. Not to mention that plywood-like materials are much, much more resilient compared to solid wood of the same species and thickness due to the crossed fibers spreading the load instead of shearing apart. This would apply to a carbon fibre part as well, I'd assume.
Thx from an aircraft mechanic.
BUT connecting rods will primarily experience high compression loads. Those are not considered to be the strengths of fiber composites, as compression is mostly carried by the resin matrix.
I doubt it would handle the pressure in modern forced engines.
@@hanswurstusbrachialus5213 very much agree.
@Alfred Wedmore lol. You should know by now that the trend these days is to make stuff up by claiming to be something related to the video topic. I can make up one right now that will be more believable. "in the most fake voice you can think of": As a former engine builder for a reputable company, blah blah blah blah blah...
@@BestMods168 yes as a living lego person I personally prefer acrylonitrile-butadiene-styrene for all my engineering. It’s a great durable thermoplastic that can take all the power a human child can throw at it.
Aluminum rods are also used in big boost applications because of their ability to take the shock away from the crankshaft.
Only downside they have to be inspected and replaced more often than the other options
@@jaycqc8136I think the implication here is high-end racing; they'd be rebuilding the thing all the time anyway.
I heard that in top fuel dragsters the rods are replaced every half dozen runs because they become shortened.
@@mnxs They dont rebuild the engine. Not even top fuel dragsters get an engine rebuild after each race, thats a myth. They do get an engine inspection, they open it up and if the parts are good they go back in.
@@rykehuss3435top fuel cars rebuild the engine between runs and replace whatever is needed including rods...
Would have been interesting to see titanium rods compared as well, such as those found in the LS7
Titanium rods suffer from fatigue and catastrophically fail. Aluminum stretches like bubble gum and is micrometered for reference after runs.
I also remember reading, a long time ago, about ceramic connecting rods.
I was under the impression that titanium is the strength of MILD steel and weight of aluminum. Not actually as strong as hardened steel.
@@RadDadisRad
All metals will suffer fatigue and catastrophic failure if there isn't enough material. Titanium is used in some rods. AML V8 for example.
Aluminium doesn't stretch like bubble-gum, it has quite a low strain-to-failure. It has a finite fatigue life; no endurance limit and has a low fatigue strength/unit volume compared to steel (since mentioned in the article).
@@RadDadisRad not really, 917 had titanium rod and they still managed to make 24 hours at full throttle, heck some even had titanium crankshaft
On that Lamborghini connecting rod sample, the bolts thread into that hunk of metal that makes up the logo. Also, you can just use nuts on the other side of connecting rod bolts, it’s not necessary to have the thread in the rod itself. Titanium rods usually are set up this way. 👌
Agreed it's just another failure point
I can not find a SINGLE issue with this video. It's not only great, it's amazing: the lack of any music helps the viewer focus on the actual matter at hand, the audio is clean and clear withour any noise or distortion, with perfect volume level.
The subject is presented seamlessly in logically connected steps and progression, everything is well thought out and presented.
Like a few commenters have already said, this level of quality and professionalism is EXTREMELY rare on TH-cam, and is up to par with professional documentary and educational videos.
I was about to ask if you are a professor because you could definitely help a university student understand a subject matter.
Keep up the amazing work!
Subscribed!
I prefer no music so i can play my own in the background.
well, he didn't get in to the cost and manufacturing overhead which imo, is the prime deciding factor when choosing a material.
4340 at 1cm2 cs can not withstand 75000n. Thats the only thing.
the tiles on the Columbia were not carbon carbon, there aerogel and 98% air....thats a flaw
There are bound to be some errors in details in a lengthy video, but my comment was regarding the quality of the video and presentation itself.
It was very listenable and easy to follow.
"Nothing like a thick black strong rod..." - Rob Dahm.
That's what she said.
I could see Rob trying to pioneer carbon rotors.
@@deciplesteve how, he can’t even get a car to run right…
@@dannyr3346 I don't think you've watched anything he's done lately cause the 4 rotor is running, driving and doing fan fuckin tastic. Bottom line... he's far more capable than you'll ever be.
Thats a Myth needs exposing 😂…th-cam.com/video/YnQSYYw3aeU/w-d-xo.html
I remember the fanfare of carbon-carbon pistons for two stroke engines (I worked in the motorcycle field for 30 years), and the unceremonious disappearance of the new "miracle material" almost as fast as its appearance. So many youtube channels get so much wrong that I was skeptical when I clicked on your video. I was wrong. Outstanding grasp of the subject matter and first rate ability to convey that knowledge. Well done, sir. Very well done.
Composite Technician here: Very well explained. Absolutely well done.
Man after watching this video I just wanna say - thank You for your service!
@@überbooga psssh they paid us the cost of living and not a dollar more. So thank you for your thanks, that’s all I’ve gotten beyond an addition to my resume!
I was a little surprised that you didn’t include titanium rods in the video. I know they are available for several AMG engines and allow considerably higher revs.
They are factory in some of the LS corvette engines.
He has an older video where he compares titanium connecting rods to steel and aluminum ones
@@bobsbillets good to know
Titanium is a great Material.
And probably the real reason why we ll not see carbon fiber rods soon.
Titanium rod weigh about the same as the claimed weight for carbon fiber rods in this video. Of course depending on the engine.
But titanium ist so strong, that you simply need less material, while with carbon fiber you need more, due to the different forces in an engine.
They're great if you can keep them from galling the crank shaft. The Honda C engine has titanium rods, so does the LS7.
But they have both had instances of galling, more so for the LS7. The surface coatings fail and that's that.
This channel has developed beautifully over several years, and keeps providing technically accurate observations and facts. Very well done, please keep up the great work that have been doing.
15:30 "When a small piece of foam fell off and hit the wing of the Columbia" - a small piece 60x40cm, weighing nearly a kilo, and travelling at hitting it at a relative speed of about 800km/h. Not much would have withstood that impact.
Would anything survive after something like that? lol
@@ridezosmon2306 A Toyota Hilux.
@@yapod9061 Or a ´94 Celica.
@@ridezosmon2306 an old Nokia phone
The carbon carbon failure also wasn't the source of the failure, the fact that the impact destroyed the insulating tile is what caused the catastrophic failure on reentry. To place blame on the carbon carbon, is both obscure given that there aren't that many applications of hot structure outside of shuttle, and an irresponsible recollection of history
Aluminum rods are used in topfuel racing because aluminum does not transmit the forces to the bearing, it acts like a shock absorber. A steel rod would destroy the the bottom end in a topfuel engine.
Not only are your statements technically accurate, your extremely precise selection of words, is utterly amazing.
And I get the impression that English is not your primary language, so it's even more impressive.
Garage 54 (on TH-cam) made carbon fiber rods. They lasted about 15 seconds! Now they are just some guys in a garage but they have done some amazing things. Like adding 2 cylinders to a 4 cylinder to make an inline 6, and it worked!
They lasted 15 seconds because thier carbon lay up process was a joke.
Off-topic for carbon fibre, but adding only two cylinders? Check out the work that Allen Millyard does in his shed: th-cam.com/video/sjxiHLZdSGw/w-d-xo.html
@@billedifier8584 yeah that's pretty sick! The Garage 54 guys don't do any of the stuff they do excepting it to last, it's more of experiments.
Definitely going to look through this guy's videos though! Thanks man! I'm always down for finding new interesting stuff on here...
“Your car costing $8k more, that’s definitely something you’re going to notice”
Unfortunately, I think that’s a big part of the appeal for AWA’s target market.
“Well sure yours has the teakwood dash, diamond encrusted shifter, and kangaroo leather seats, but does it have the carbon fiber connecting rods?”
“Uh, what’s a connecting rod?”
“Oh you poor peasant… remind me to take him off the guest list for the Christmas party”
well to be far spenting more on a rebuild of already expensive engine like a LSX-7/C7 corvettes or 572-hemi ford-camer/vodoo ect. might be worth it vs aluminium rod's as TBO's are way longer ect.
1k to 2k per rod/piston if i had my 50K to 100K or more job on my 2-gen hemi that's on the rebuilding stand it would be tempting and im a average joe in 🇺🇸 but my luck sofar im not buying anything right now as the last 2 years in a row iv made less than 5k to 10k usd aka poverty 😑
@@richardprice5978 i hope things get better for you
@@posadist681 thank you. me two
Your car will cost greater than $8K more because it will have no connecting rods at all. It will be electric, whether you want that or not. And the electric propulsion tech is such a drawback that most consumers don't want it, but it will be forced on you because klimate krisis. And if that result means you can't really afford a car at all under those terms, then that's even better because we ultimately want personal transportation to be less accessible to the masses for the greater good of our society. You're welcome.
@@onemoremisfit as a pro-mechanic 👨🔧and millwright / out of worker aka poverty, parts i would agree with you and yes up front sofar battery packaging to go 300+ miles is $$$ without a recharge but maintenance is as much ect. so ROI is a wash or a head and daily more convenient to drive, and my 80's Chevy truck ( that's already a painful experience to get tags for as 1970-1999~ gm sucked at thing's like smog testing ect. ) im considering having it a full BEV but like i said im a broke FM so not in the cards this year as for the charger no it's staying a V8 BBM / hemi-stick car so im not sure how im being "forced to change my 60's car" but fuel costs in 2022/6+-usd ⛽ vs my income don't help to afford to drive it longer distances ect.
We've used carbon composites like forged carbon fiber, in the medical field for a couple decades. They are not only light and strong but also conductive and radiolucent (for XRays). Excellent video.
in those top fuel cars the aluminum connecting rod in a sense acts as a shock absorber. spreading the load time so that the crank doesn't see such a spike in load pressure probably stopping it from blowing itself apart. by spreading that impact time out a bit. they measure the life cycle of those rods by how much they have been compressed (shortened). those cars are a balancing act of many different parts made of different materials for different reasons. I bet that those rods are aluminum for more than one reason. but in this case comparing carbon fiber and aluminum as rod material this shock absorption effect of the aluminum gives a big advantage to aluminum as being the choice "I Believe".... thanks for the video 👍
Was thinking the same thing watching the video. Selecting aluminum rods isn't always about weight. Nitro and nitrous motors often go aluminum for it's malleability which absorbs some shoick loads of more violent power adders. Some big displacement drag engines will go aluminum for lower weight but this has more to do with the length of stroke and trying to reduce reciprocating mass at high rpm for reliability than reducing parasitic losses.
Also the fact that those high end race motors aren't made for more than a few miles of use.
@@frankbliss2924 Usually those engines are only spun about 1200 revolutions from start up to finish line !!
Dang... I know I am walking away, with a much greater understanding of engine internals, and the life cycle of steel, aluminum as well as carbon fibre. I can also say, I now have a greater understanding of possible use case scenarios for carbon fibre and forged carbon composites. Kudos to D4A for putting together such a clear, concise informational piece. I loved the video and I am now a new Subscriber along with all others who have clicked on the magic button... #d4a
Great presentation! Clear, orderly, logical -- no extraneous material. Loved it.
Your talking skills are awesome. I am not even near car mechanic and it was never my hobby, but man, u made me listen the whole video without skipping. Very unusual for me because I almost always fast forward videos.
Great visualization. Just had to note that the quoted strength for 4340 steel alloy is for annealed alloy, which is basically never used as is. Commonly used 4340 when tempered in useful, tough condition has almost double the tensile strength, so 1cm2 rod would withstand up to 15 tons before breaking. Strongest alloys, likely maraging steels, can have tensile strengths up to 30 tons of similar size. However, this may be semantics in a bigger scheme, so take it just as a sidenote.
Which is why gun barrels are made from it, as are bolt carriers
I am speechless, so I'll write instead. This is the first video I've watched on the channel, and within the first minute I clicked the Subscribe button. You have so thoroughly and logically analyzed the topic that I can't help being impressed. You are also a very good presenter. I hope to enjoy many more of your videos. Well done!
You found gold welcome
Amazing channel, you won't regret.
One of the best out there.
You're in for some comfy binge-watching brother. Go straight to his "iconic engine" series. Good stuff.
OH You will love the engine balancing series!!!
At first I tought this was going to be a long and tedious story but NO , this is really well explained and worth watching !
I sure wish I had a guy like you around when I was young, a lot of headaches could have been avoided. Keep up the amazing videos brother
I'd love a video on advantages/disadvantages of drilled vs slotted vs drilled and slotted vs normal rotors.
I have a friend that is mech. Engineer with degree from GA Tech. Asked him this before and he said he had an assignment in college to determine this and the loss of braking surface for the holes /slots is actually worse than the brake cooling gain (and subsequent brake gain) from having drilled/slotted rotors. My thoughts (not a mech engineer and haven’t asked him this theory) is that the amount of carbon in the rotors is what matters the most…. But not sure how the carbon affects the cooling either. BUT the reduction in spinning weight might also be a factor in buying drilled and slotted rotors. A lot of dirt late models actually run scalloped rotors to save some rotating weight. I would definitely be interested in video covering all these factors though. Gotta get that advantage wherever we can!
Congratulations!
You are awesome!
Nobody has ever so perfectly illuminated me the differences of
CF vs CC.
It was driving me nuts.
Now for my purposes I will use the correct resin along with CF.
Thank you.
Just found this channel. Some of the best content I've ever seen. No fat. Clear and complete explanations.
I subscribed solely because of how in depth you went with the diagrams and information on the mechanics of the materials and such. I am not a car guy by ANY means but if your channel has more information rich videos like this, I'm in.
Fantastic video! I love learning about the science, physics and material properties! Your videos are way more informative and educational than the usual car channels that only discuss the dumbed down, practical applications of tools and tech.
I agree, fantastic video. Accessible to the layman but also interesting for the more technically inclined people. Nice work, keep it up D4A!!!
@@noahvdl3331 you hit the nail on the head. I’m definitely a layman but this video answered all the questions I had on using CF for internals and even questions I never thought to ask. Definitely subscribing
The newer materials like carbon fiber and Kevlar are amazing.
and they keep getting stronger and more resilient every year.
Absolutely love this video, Great Presentation and Narration.
yes but no. this amazing materials actually not changed their properties since their development in mid-sixties.
Wow, I love how you explain all of this stuff to all of us, so easy to understand. Thanks!
4:11 I love that you are teaching engineering materials science in an interesting and engaging manner
There is also the aspect of stretching, when at high rotational speeds the traditional connecting rod stretches about 1.5% of its size,
so this must be taken into account in the clearance of the deck and if the stretching can be reduced with carbon fiber parts, the compression ratio can be better optimized.
wow that's a massive amount of stretch i could never imagine it that big
Way to go, Stockton Rush watched this video and now 5 people are one with the ocean.
😂
Omg you just killed me😅😅😅😅
Respect! Your explanation is on point! I've worked and researched a lot on carbon fiber composites (Formula Student, Research projects, my masters thesis, research my students did, you name it) and your short presentation here is outstanding. Very well presented!
You are the Anton Petrov of engineering! Your content is top notch!
I'm glad that you covered anisotropic vs isotropic materials but I think tensile strength vs compressive strength is a VERY important distinction when talking about connecting rods. You even showed some footage of carbon getting crushed but it would be worth showing a graph of tensile vs compressive strength.
Carbon fiber sheets can be layered with 45 degrees rotation between layers, fixing the problem with different strengths directions.
The mats you show are already weaved with 90 degrees directions, so they should be good enough already.
A conrod does rotate, but the forces are mostly only in the piston direction, a conrod is always worn by the up and down motion never on side rotating forces.
The forces are mostly in the direction of piston travel only when the piston is at TDC or TBC. When the crankshaft is at 90 degrees from TDC the side forces are considerable..
@@cousinfester4621 The piston is still trying to press the conrod together or apart, even at 90 degrees on the crankshaft.
Bro the way you explain things is incredible😍👍 and easy to understand
Your videos teach more more in a couple of minutes than I have learned in years of school or even two semesters of auto class. Thank you for your service in free education.
That is by design. They make you take classes you don't need and the people teaching the classes are losers. Now then, enter the brainwashing and you have a dangerous element in our society. So to sum it up, save your money and seek your dreams and quit relying on a piece of paper to get you anywhere.
Just don't make a submarine out of carbon fiber.
Why not
@@chud1187cuz it fuckin floats
@@chud1187last time someone did it, it imploded quite violently
Literally you touched on everything we have thought about with CF rods, in regards to the limits of resin, adding Graphene (Graphite but better) but it's brittle...we tried and realized it would be insane R&D to make, and we're still a small Honda V6 J-SERIES performance parts company. Our HalferLand J35 4340 with our added revisions pushed the upper limits to 1300+HP, coming in at just $750 for a set of six, better HP to $ ratio then even Crower, Eagle (Chinese rods, if ya didn't know) and others. Our daily shop 06' Accord J35 makes 560whp on just 8psi. HalferLand Performance Products
re: "Our daily shop 06' Accord J35 makes 560whp on just 8psi" nooiicee...!!! good to see somebody reppin' the J-series. 👍
Can I get that in an awd oddessy?
Another reason aluminum rods are used in drag racing, and other high horsepower engines, is it absorbs some of the shock loads compares to steel, so the crank and other components don't take as much impact.
Plastic internals may be more likely, and have been looked into for a long time. Polimotor had a mainly plastic engine that ran in IMSA in 1984/5
en.wikipedia.org/wiki/Plastic_automotive_engine
Ok now this is wacky, I love it!
Exactly,weight has little to för with it.
In top fuel they change the rods when they get tio short!!
Back in 1995 I was involved with an off road racing team running the Mickey Thompson Stadium Racing series where we we were only limited to displacement and had an open design with all other components. Knew an engineer at the Shell Research Center in Houston who was able to get us 4 block of carbon fiber which we machined to crudely shaped connecting rods. They were as ugly as home made soap but as light as a feather. Needless to say rotating weight went down dramatically and acceleration sky rocketed! Which created the next problem of valve float with an engine now hitting 10,000 rpms. It was fun while the team lasted .
you Sir are a storehouse of knowledge and professionalism. Thank you for sharing this information and keep this level of information coming.
Outstanding presentation…the best I’ve seen on a highly technical subject intended for the average viewer!
Forged CF is really nice for some applications. You can even "optimize" it using long unidirectional strands. I recently made a forged quadcopter frame using 3D printed molds and chopped CF. It turned out great.
But I don't see it being mass-produced for engine parts. It is hard to achieve consistent parts. I don't know how you can easily automate CF forging. Maybe if you make some kind of carbon-resin paste and pre-mold it to some shape and then compress everything once it's uniformly placed in the compression mold.
It is much faster than traditional cloth layup, and you can easily achieve variations in the thickness of the part. But you are also limited with the shape of the part since you have to open the mold and extract the part after forging. I'm closer to thinking that engine parts will be heavily optimized using various software simulations and 3D printed in mass using some new steel 3D printing tech.
If the sky is the limit of cost why not make it out of hot pressed ceramic. You'd have 90,000psi transverse rupture strength with conventional hot pressed.
The question is why ?? 99% of the people wont notice the diference, and its cost more, it dont need to be mass produced.
@@jimsperlakis5634
For the same reason why cf rods don't do well for connecting rods. They both lack the necessary yield strengths
The Lamborghini employee "this guy.. driving - quattro - something" really killed me! :D
Extremely well researched and expertly presented. I learned a ton ! Thank you.
22:50 Having an STI engine as the first example of engine reliability while showing dozens of engines, makes me proud as a subie owner.
Subarus aren’t reliable though. They always got head gasket issues
@@dogchainsaw3923 Well after reading many many comments and experiences from people who owned them, subaru's are as reliable as respectable their owner is.
Good maintenance will result in a long lasting engine.
There was a period (before 2000) where WRX's where coming with faulty head gaskets so the rumor stayed with the cars.
Any car will blow heads with poor maintenance and redlining it while cold or extremely hot.
They are more prone to failure if left with old oils or running them low on oil vs an inline 4. Low oil or bad oil will damage a flat engine faster than an inline or V.
I learned (on some corner of TH-cam) that the Subaru Boxer headgasket issue was due to the way (how much) the cilinders are supported at the cilinder head side. closed deck vs open deck design. Normal Impreza engines are built ~cheape~- more cost effective then their race/rally variants but that doesn't stop kids from painting stock Subaru's blue, slapping wings and golden rims om them and overtax theis engines into failure.
Subaru builds reliable engines. I have driven three EN engines and am currently enjoying an EF engine and trust me when I say I (have to) run them hard as they make 41 to 54 horsepower at best and you will use them all. Best of all they do it on a service interval that makes a lot of Americans turn pale at the thought (oil/filter 12.500km/7770mi).
LOL
I immediately thought about this video when I heard about the Titan sub tragedy.
Your illustrations show the materials being "tested" and rated for strength in tension, but the vast majority of the force on a connecting rod is going to be in compression both directly down through the rod and laterally off to the sides. as the crankshaft rotates. Good video, thanks for sharing it.
Those top fuel drag cars actually produce an insane amount of heat in that short run. They don't get more than 1 run out of most of those engines. There is so much force involved in that one run that their clutch plates weld together by the end of the run. They have to rebuild the entire engine and drive train after every run usually.
Yeah but that's one run of incredible heat then the parts are replaced anyway, yeah dont get me wrong they have tough internals, but an average car has to deal with heat cycling, cold starts, infinitely variable driving conditions and loads, poor maintenance and the rest, which is where fatigue comes into play
@@hamstirrer6882 Completely get where you are coming from, I was just pointing out there is more stress and heat involved than he speculates.
Three plugs a cylinder. Which one is going to melt ?
@@hamstirrer6882 first off then use King bearings. Great for longjevity. Whereas clevites will eventually eat up a crank, but are good for short usage.
Matching parts to applications is key.
I think the NSX had titanium connecting rods. You show a picture of an NSX engine when talking about steel con rods. Not criticizing, just checking. Great video, as usual. 👍
Correct. Same with the f430
Great video !! you do your research. The main reason for using aluminum in really high output engines is for the bearings the aluminum connecting Rod acts like a shock absorber during the combustion process. That reason is why you don’t find materials like steel,titanium and Carbon Fiber connecting rods in TOP FUEL engines and other high output drag racing engines
Maybe it also helps that these are high compression and therefore they produce less heat for the power output?
@@Bit-while_going I see what your thinking but in reality the more you compress the air fuel charge the more heat you generate. This is why high compression engines generally require a higher octane rated fuel to resist pre ignition because of the heat. This is also why you want a intercooler or a alcohol based fuel or both to remove heat from the charge on a turbo charged vehicle compressing the air causes heat. I hope I shed some light on this subject
Fun to watch this video, this is a lovely way of linking up the classes I had in university for my engineering degree to cars.
After playing with CF engine components a number of years back there was always the problem with frictional wear.
Another consideration especially with valvetrain parts was an absolutely predictable harmonic force that would explode the material. This could be worked around by changing RPM/ material thickness/ spring packages. At that time the gains were minimal for the investment of time and money. But always enjoy a learning experience.
My initial expectation was that it'd be due to the resin breaking down over time due to exposure to oil and exacerbated by the heat and heat cycling _(ignorance warning: I assume things that breakdown from petroleum-based oil, would do so with synthetics, too...)_
Hah... And he just covered the resin issue while typing!
Followed by the assumption that CF wouldn't be _as good_ at sudden, massive compression loads like a conn rod would see.
So to hear its fiction wear being the issue, is surprising, as if have envisioned most CF parts to incorporate metal bearings or surfaces at those junctions. After all, our conn rods have bearings, they're not directly contacting the crank since even with lube there's wearing going on. (and the bearing being easier/cheaper to replace than an entire rod)
As an example, an intake valve being CF, would be given a steel interface at the rocker arm. Whether that's an insert added before resin is applied (therefore being anchored), or something more simple like a cap, might come down to the specific part getting remade in CF.
@@DUKE_of_RAMBLE I
In the case of the connecting rods wear occurred at the crank cheeks and between the rods.
All valvetrain components were capped or inserted with metal wear components.
Oil breakdown of the resin never appeared to be a problem as the duration of use of failed parts varied sometimes by years. Another note on valvetrain any excessive lash which would never harm conventional parts quickly took out the CF parts.
Very well made video. Very educational and explained in a way that anyone can understand.
Great presentation. Thank you for an informative and easy to watch explanation with some good old common sense thinking. Lots of work went into this and I commend your approach and determination.
@22:51 literally the best engine montage on all of TH-cam 🤤🤌 This man knows motors. Respect brother. 🤘
The quest for lightweight internal parts is to reduce the reciprocating mass inside of the engine . The lighter the mass , the faster the engine goes from idle to redline rpm and that is what wins races . They've only been exploring the " plastic " con rod idea for fifty years now . Something most people don't realize about aluminum rods is that they stretch upon deceleration, especially down shifting, which is why they aren't used in road racing .
The stretch can be accounted for, it's simply the short cycle life before failure is the reason they aren't used for endurance engines such as circle track or road racing.
@@davelowets what you're calling a short life span, more times then not is the crew chief tunng the engine by swapping in a new set of slugs with a different wrist pin location to alter where top dead center is in the cylinder. Although 92% loads of nitromethane and 70% overdrive on the blower will take it's toll, the drivers in the other forms of racing aren't crazy enough to run such engine combos.
@@bobbrinkerhoff3592 I'm not sure where your trying to head with this, but
road/circle racing and drag racing are two very different things. And yes, aluminum rods DO have a very short lifespan compared to a steel rod. Fatigue sets in very quickly with an aluminum rod, and they need to be changed or else a failure is inevitable. Some drag racers with N/A engines on gasoline wont run they're aluminum rods past 100 passes, because they've experienced failures shortly after 100 runs. That's only 25 miles. NO good for any kind of circle or road cars.
@@bobbrinkerhoff3592 altering where top dead center is, would allow for more air / fuel for bigger combustion correct?
@@djstatyk1540 yes, and it changes the static compression ratio, which can be further altered by using different thickness head gaskets. Where it gets " interesting " is when you get into the staging lanes, and experience a delay, and the conditions that you have tuned for change on you. That's when you swap out blower pulleys in order to change the amount of cylinder pressure, or final compression ratio. Hope this helps you to understand, cause it can get complicated fast.
Fascinating stuff, presented so very clearly and detailed ... especially for a casual "watcher" of automotive stuff ... like me. Really neat. Thanks d4a guy, much appreciated!
DT
The only Street application I can see for OEM carbon fiber engine internals is top of the line vehicles like Porsches GT RS models, or whatever Lamborghini and Ferrari are calling their top models now.
Any popular mechanics reader could have told you this but not nearly as elegantly, especially in the very last Era of the ICE...always appreciate all your vids, and your engineering for us dummies examinations...
Whenever I rotate, and reciprocate at the same time, I get dizzy. MIT recently developed 2DPA. It's a two dimensional pollimer that's supposed to be twice as strong as steel, and as light as plastic. Hopefully we'll be seeing this in all sorts of manufacturing. It's inexpensive, and can be used in injection molding.
Yes. I've been waiting . (( For REAL WORLD Brutal testing )) 40 years ago... "Advanced Hybrid Ceramic" engine blocks. ect, ect. Re: "Lamborghini .. Weather STOCK Performance cars, or Poupose built, Liquid cooled (Performances Race boat engines ) Are Soooo Unreliable. COOL, ?? Oh yeah ! But wherever you go, It would be recommended to have top tier mechanics & a truck W/ All possible replacement parts. Ironically Yamaha Has consistently brought industry changing tech to market. & AMAZING things that NEVER Came to market. & NOW, Manfactures forced to go Electric. & Technology ( Batteries & THE GRID ) Not ready.
Pp
Twice as strong as what steel? There is so many grades available. There's even a mold steel that in bulk form can hit 750 KSI tensile. Downside is yield strength is not much less. That is a strength to weight ratio better than any titanium alloy, bar none. Long live Iron !
Very interesting video! I do find it interesting though that you mainly mention CF in tension. Not giving too much thought to it, I believe the rods are subject to much higher compressive forces vs tensile (I have 0 knowledge of the internal forces that go on during the combustion cycle so the above statement could very well be wrong). CFRP are also much weaker in compression due to the epoxy matrix taking most of that load (at least that’s what I remember from my mechanics of composites class). Though, if you made a con rod from sheets of CF, you could make it quasi-isotopic depending on the layup
The highest forces on the rod and piston are at the very top of the stoke when the piston and rod are changing directions
An excellent video! Great organization, great graphics, great explanations. Well done! I learned a lot about the use and the limits of carbon fiber. Thank you.
Pretty much bang on, cost is a big problem but only a minor one. Many motorsport engine manufacturers have dabbled with them over the years and each time they fire them up they last minutes if they're lucky (enough to get down the drag strip maybe)
They just can't handle the heat, oil and vibration. C-C pistons are the worst. If they survive cranking they usually blow on the first WOT of the engine.
Only bit you missed is the bearings / lubrication challenges of a rod. Fitting of the bearing is tricky in carbon, and also most modern rods carry oil up to the little end to lubricate that as well
A 24hr racing series would be a serious marker to lay down if they done something like that and survived while being competitive that would really make a big statement.
Great video.
This reminds me if Ford's promises of high temperature plastics that they were going to make their engine blocks from, or GM's ceramics engine blocks.
We have yet to find the other material that can compare and do everything that steel already does.
I'm hoping someday we do come up with a material that does actually start to replace some metal that's cheap to make lightweight and very very durable and strong
I cringe when I think about the powered metal rods in my LS1 engine. It's different, just spelled Cheaper. Stupid people who think Billet is the solution to everything but if they actually knew anything about metallurgy they would know that it's crap in it's untreated form because of it's grain structure. That's why aluminum must be stretched out to it's yield point --3°.
It is also very brittle in cold temps. Ford focus’s used front lower carbon fiber suspension arms until they started shattering in cold temperatures. I can imagine a car parked outside in a cold climate then they shatter in the engine when the engine is started and the car owner revs it up a bit to get warm faster like so many do in cold areas.
"Revving a cold motor to warm it faster" -- that's the stupidest thing I've ever heard. Install a block heater if you need to. Protip: if you don't abuse your engine, it lasts longer. "I saved almost an hour of warm-up time over my working lifetime and it only cost me $10k in additional mechanic's fees!" Please, write in to Scotty Kilmer to say you do this so we can all get a laugh as he mocks you! 🤣
glad we have a bunch of carbon fiber submarine material scientists here
I'm going to assume the resin in the cf rod is the limiting factor. Closest you can get with cf would probably be high carbon metals.
Actually you can forge CF and have something that can sustain 1000F. I believe Bonafab Customs put a blank of forged CF in a firing furnace at 1500F and it didn’t do anything.
@@RadDadisRad well yes there are high heat resins but I'm saying resins are brittle and will shatter
Should invest in a better engine
Imagine a spaceship welding it self mid air or an aircraft 😳
idk arent there stealth planes with cf around the exhaust?
Why not just make the entire vehicle cf, minus the con rods?
Another piece of brilliant work, D4A! Could you make a video someday about your education/background? I'm guessing you have a MS in Mechanical Enginerding with a lot of hands on practical experience. Your content is always very well explained and easy to understand. Thank you for the great educational videos.
A very nice comparison of connecting rod materials and engine performance. I was waiting for you to address the effect of reduced inertia on the engine's ability to attain higher rpm along with it's ability to accelerate faster to this rpm-hence the drag-racing industry's intense interest in reducing the engine's reciprocating (especially) weight. As you are undoubtedly aware, inertia force increases as the cube of rpm. Therefore, even the smallest of weight reduction will allow significant increases in torque and bhp before material failure at these elevated speeds.
2009 f150 5.4l 4×4 160k one set of brakes. 2 batteries. 1 battery was just purchased. No other problems. Serviced very well. Very rarely went more than 3k between oil changes.
On Columbia, it wasn't just a little piece of foam; the foam had a lot of kinetic energy when it struck the wing. Even NASA thought that the tiles could survive such an impact, until they properly modeled it.
You really believe Columbia broke apart because of the piece of foam striking the wing? I have a bridge for sale! But really, that shuttle was taken out by something. There is video footage showing another vehicle or object shooting something at Columbia. I don't know what they did on that mission to piss someone or something off but it is what it is. And it wasn't a piece of foam on launch.
@@danielfouardlibertarianono8017 I worry about your smooth brain…please unplug.
Sounds like good to try in a motorcycle engine. It might be more noticeable with a motorcycle platform. However, this not very cheap, but would show the longevity that they can with stand over time while is use.
Yep, motorcycle racing seems like a good application for them.
Also any type of endurance orientated racing: NASCAR, Baja 1000, 24 hours at Le Mons... That sort of thing. Throwing the worst conditions know at the parts, for the longest times.
They researched carbon-carbon pistons for two stroke motorcycle engines in the 80s. They couldn't solve delamination under load. The pistons tended to shed their tops above the top ring groove.
Your explanation is very well done without complicated math and jargon like when I was getting my Ph.D. in material science back in the 80-ties. The world has a lot more collective experience and sharing of information today than back 40 years ago. Like one of the famous scientists said, we have now reached the level of increasing the IQ of our planet by 10 points because of the WWW with "FACT BASED INFORMATION" sharing and content like yours. Greetings from USA
whyd they make you wear those ridiculous ties?!
But then we found out that garbage spreads faster than facts and rationality
The way you explain these things in a ELI5 way are magnificient, subscribed :)
Considering we are making 4 cylinder engines that produce well over 1000hp these days (some make around 2000hp at the crank), if the claims that AWA are making are true, there is some real desirability in the racing world. In fact if I could afford a set, I would love to swap out my forged rods for some carbon fiber rods. As of right now my forged rods are the limiting factor in how much power my engine can make.
4G63 crowd is making over 2000whp in a few different cars.
The "new thing" is actually 3 cylinder engines!
@@marcelogouveia9614 3 cylinders aren’t new. Triumph motorcycles has been doing 3 cylinders for a while.
Those high power drag race engines with billet aluminum rods use aluminum not just because its lightweight but also its a softer material than steel and acts a little bit like a shock absorber to damped harmonic forces that would otherwise be detrimental to the rod bearings
Great video, keep it going! 😎
However there is one point worth mentioning: metal components have tolerances because of thermal expansion and wear, while carbon fiber not really (please correct me if I’m wrong). This means that if we isolate the rods, at different temperatures there will be a certain tension between metallic and composite parts, assuming the engine is stationary to keep it simple.
And this would lead to complications to all the assembly points and components like bearings, piston pin and the fact that you can’t thread the carbon fiber for the rod caps, therefore you would either need metal inserts or use a self-locking screw-nut assembly. But again, how would thermal expansion affect that?
There was something else I had in mind, but I can’t recall it at the moment 😅
You might be able to lay up the CF in situ around its journal on the crank.
Come to think of it, that might be the way to get maximum strength.
Full roller bearings in self-contained oils for the mains via seals. The rods in there own self contained chambers. Be hard to manufacture but i suspect it would work
Great video. I'm not that interested in cars and engines in and of themselves but I loved how you describe how the strengths and weaknesses of different materials determines their real-world application.
Long ago I worked for AMOCO... 1980s... "Metal components included cylinder sleeves, combustion chamber tops, piston crowns, bearings, valves and seats and a standard crankshaft. The block, piston skirts and even connecting rods were made from glass-reinforced polyamide-imide thermoplastic resins marketed under the name Torlon. Output was published as 318 HP at 9200 RPM, and weight as just 152 pounds-nearly 265 less than its standard, iron-blocked counterpart.
Polimotor 2 was installed in a Lola T616 and raced extensively in 1984 and 1985 IMSA Camel GT Championship seasons, the car earning many top-five finishes as well as a podium in the form of third-in-class at 1985’s Lime Rock 2 Hours....
Carbon fibre rotors in an EV motor would be interesting. Also, (vacuum) metal vapour deposition might be able to apply a protective coating to the resin.
@L W In the Model S Plaid motor they use carbon fiber to wrap the rotor add strength, allow for higher rpm.
High efficiency requires tight clearances between the magnetic poles. The limit on the clearance is bearing wear and tolerances.
Carbon fibre just gets in the way (unless you are using it to hold the soft copper rotor windings in at high rotation speeds).
@@allangibson2408 exactly that. Enables the higher speeds of the motor. 20k rpm if I remember correctly.
@@wwatts In that case the carbon fibre needs to be in the rotor slots and nowhere else.
@@allangibson2408 it appears to be a wrap around the circumference of the rotor, looked pretty thin in photos. Sandy Munro did a tear down on his channel if you’re curious.
Awesome video. Carbon fibre has been completely revolutionary for some purposes e.g. making fishing rods and tennis racquets. So I guess the natural engineering tendency is to try to extrapolate this success into other uses where strength to weight ratio matters.
Wouldn't this mean that carbon fiber could be a useful material for a rotor in a wankle style engine? The load is a lot less complex in its distribution, and the weight savings could dramatically increase the high rpms that rotaries can already reach. Maybe im wrong but i feel as though it could be a real breakthrough for that market.
So much good info in your videos, but my favourite part to date is your impersination of a Lamborghini employee. Gold.
What about a CF crankshaft ?
Seems as though that would pose less challenges
since CF driveshafts are a common thing now, I believe we'll see crankshafts, too
Since the crankshaft just rotates, it doesn't move, the benefits of it weighing less are not much, saving a few kgs is never a bad thing, but I don't think doing it with a carbon crankshaft is worth it in any situation. The pistons and rods on the other hand are constantly forced to accellerate and deccalarate up and down, if they weigh less they have less inertia meaning it takes a lot less energy to do this. The crankshaft has to accelerate and decallarate too, but it's not a hundred times a second.
@@bacon.cheesecakeOne reason I believe cf is not good for crankshaft is because cf can't handle torsion stress well.
@@dido1803 Torsional stresses are just tensile and compressive stresses at a 45° angle. So this can be solved by just changing the direction of the carbon fiber to the optimal direction (45° w.r.t. the length of the shaft).
@@bacon.cheesecake well, yes. one could say the same about the driveshaft, but it's nevertheless used in racing, so... why not?
"A failed head gasket could lead to a snapped rod"
This can happen for regular engines in some circumstances, but no, you still do not want this.
For the record, early adopters of aluminum engines also had to contend with being picky about coolant, as many early blocks and heads were slightly porous or could become porous over time and letting coolant inside. This is why the famous GM DexCool exists - To replace the ancient alcohol and ethylene glycol based coolants of the 1920s and 1950s
I'm by no means an expert on the subject, but I do wonder if there's a way to make partial carbon fiber or partial carbon carbon parts, since there's nothing saying we have to rely entirely on it's properties alone. Why not make the pistons out of carbon carbon but plate them in a reasonable thickness of aluminum to share the decreased weight but keep their rigidity?
With Partial Carbon there might be a problem with different thermal behaviour/expansions
Dex-cool is the worst thing to happen to vehicles. It gels and corodes inside the water jackets of the motor. Everytime I rebuilt a chevy motor that used dex-cool it was a horror show. We had to hot tank the block and heads before we could even start working on it. I always refilled it with standard coolant if it is a passenger vehicle or red line water wetter and straight water for performance vehicles. So pretty much you need a motor rebuild after running dex cool it was cost you another $1-3k for cleaning and labor. I usually just get long blocks from the manufacturer and deck the heads, it's about he same price.
Dexcool exists to destroy engines so GM sells more parts and cars. All it does is eat up everything (plus the Chinese parts quality), so they leak, which leads either to big repairs or blown up engine. Every single engine is the same story starting as low as 20k miles.
Meanwhile....a 20 yrs old, 200k+ mi Japanese car has no leaks, original hoses, original water pump, etc. Green coolant and 180* t-stat does wonders.
Funny how the first Japanese and German cars with aluminum blocks/heads never had a single issue... And they're still running today without a single major repair.
Because carbon is still brittle. And aluminum and carbon don't mix, the parts you see combining the 2 will have a barrier between the 2 or corrosion will happen. Then the strength of whichever metal you choose, will be weaker because there is less mad of it, allowing it to flex more, further stressing the carbon, and since there's less carbon, then the overall part would be weaker
You cannot compare the challenges of chemicals to Carbon Fiber vs Aluminum. It's a whole other league of challenging. We are talking about like exposure to these chemicals will rapidly compromise the rod. Like hours at most, minutes at soonest. Depending on the epoxy resin used. This is not even close to the challenges to aluminum porosity, which I am familiar with. It can happen in the home model engine engineering world with cast parts and if the aluminum is not the right type or not cast correctly and get a lot of porosity.
I think it be amazing to engineer the issues out, but definitely a DRASTICALLY more difficult task. As he pointed out in the vid very well. I also design model engines for a hobby, at some point I will build them. So while not a full fledged engineer, I do understand what he is saying about the problems with carbon rods and more. The fact they can make them work at all is an INCREDIBLE engineering feat! I'm surprised that they were even able to do it at all at any level.
And actually, carbon fiber composites are known not to like compressive forces. They are better in traction than compression, so basically the opposite of what a rod has to do. We've even been proved recently that CF doesn't like pressure with the little Titan submersible...