Can they make custom designed forged pistons? If so, forged is the way to go. I'd add a cast piston guide/sleeve at the base of the piston to negate the piston knock. Cast for no expansion and forged for the primary and durability.
u said cast was 8-10% & 4032 was 10-11% ... how come your charts shows cast wear still better than 4032 ... your chart is wrong then ... for wear from wat u are saying and correct form would be wear least hypereutectic >12.5% , Forged 4032 10-11% , Cast 8-10% , Forged 2618 1-2% ...
Crazycatman the GE and GTE are identical in the short block... the GTE head is allegedly a bit better, but honestly you can make more power than you'll even want (700 plus) with just a turbo setup along with a good fuel system and a standalone ECU. Good luck👍
This is an absolutely wonderful discussion. I live near Detroit, and one of my classmates is a piston design engineer. He loved this when I showed it to him. His only comment was that modern pistons are NOT poured when cast. Rather the mold is dipped into the liquid metal and a vacuum is created such that the liquid metal flows into the evacuated mold. There is no possibility of air pockets in the resulting piston. The narrator touches on this when he speaks of "modern" techniques at 11:50, but does not say it specifically. I was told that this process is used for two reasons, to exclude air pockets, and that liquid aluminum alloys will oxidize instantly, at their surface, when exposed to air, and this creates aluminum oxide (slag) that is horrible when inside the body of the casting. The older pouring methods depended on the slag floating on the liquid and not going into the mold. There was a certain amount that did get into the casting but until vacuum techniques were developed this was unavoidable.
@@rlguerrero2263 well your doubt has actually confirmed your intelligence. The piston liners and bores must always be from a material that is not the same as the pistons/rings, for that exact question you asked about the expansion of materials due to heat. Almost always the liners are made from iorn-chome alloy, vanadium and molybdenum. This offers the best thermal stability, and wear resistance, as iorn also contains graphite, a natural lubricant. You will find the piston rings are also made from iorn, or some similar iorn alloy. The reason pistons themselves are mostly made from aluminium is due to the low mass which is advantageous for a chunk of metal flying up and down a cylinder 80ft/s. There have been instances when manufactures have tried other materials for liners one being nikasil, which ended up oxidizing and killing engines. There was a brief moment in time when they used to use aluminium cylinder liners for race engines, and they tried to use them in road sports cars i think Alfa Romeo tried it but the bores wore out too quickly and the engine was junk after 10k miles.
Without this video out there I would had bought a car, turboed it and ran forged pistons. Just to daily it, I'll pass. You are helping a lot people in their future builds. Thank you!
1k likes from bots i daily mine with forged and yes it does have slap. But I’m finding ways to help it by pre oiling before start. Also my block builder informed me of ditching my cast for forged. Because of my goals he seen the ones I had break. But wast knocking them (no pun intended)
@@claudedottin1312 I would of thought the same thing, probably gotten the same advice. But if they tell you to switch from cast to forged it is most likely the type of tuning you apply.
Your friendly neighbor Stanley. You’ll be just fine Stanley just make sure they were STD (not what the neighbor has if you know what I mean) and save the money on getting the cylinders checked. They will expand and fill then just fine
Excellent discussion on the differences between these piston materials. Having had significant experience with all 3 in racing applications, the only thing I would add is that in comparison to forged, hypereutectic pistons are far more likely to shatter if anything significant goes wrong. For example, when a hypereutectic piston makes contact with a valve (say missed shift/valve float) that piston will often shatter and take every thing out--rods, block, crank, cam and heads. Often with forged pistons you are just dealing with a bent valve and a salvageable engine. Two thumbs up for this vid--you know your stuff.
I did NOT know any of that. I always thought forged was the way to go. Very good way of explaining this topic. Thank you for taking the time to put this together - I really benefited from it!
I'm a 35yr career mechanic & this short but fascinating video was so insightful. It's actually making me reconsider my current engine build project! You've highlighted so many variables based on final choice. Many thanks indeed. Subscribed 😉👍🏻
GREAT video, you give the FACTS about the most misunderstood component in a engine, most engines are DAILY drivers, while it might be "suped" up a bit w/ a bigger cam better heads you don't spend day after day at the track, another thing you have to ask yourself "How many times do you want to rebuild your motor?", I'm personally rebuilding my sbc 350 that has 439,906 miles on it, it still gets 17mpg and 12 if I'm loaded down(7,000gvrw+)the cylinders are a lil glazed but there is Zero ridge at the top of the bores but its starting to get more blow by on the rings than I care to tolerate. I'm upgrading my heads to better flowing ones along with my intake and exhaust(mid length headers to full length because they produce better power down low) but pistons will still be cast or hyper and I will use zero gap rings to further reduce contaminants in the bottom end getting into the oil. Yes most engine shows we all love to watch are dropping 1000.00 sets of forged pistons in like its nothing and flogging them on the dyno saying look at how much power I made at 6k rpm etc but this DOED NOT reflect the average guy who has a hot rod that likes to drive his car or suv on a daily basis. The true cost of doing a total rebuild is getting more and more expensive if you don't want imported cheep parts since our money is worth less and less every year, I personally like to drive my vehicles.
I really enjoyed your enthusiastic explanation, humor with your “Accent” on accuracy. As a retired ASE Master Tech who worked on factory turbo charged cars in 1980, then Grand National in 85, I used your information to reinforce my knowledge. Liked & subscribed!
When I saw the hypereutectic pistons, I was like, "they are making pistons out of cast iron?", this phrase is used in cast iron metallurgy; you have eutectic and eutectoid, the amount of carbon being below or above 8% respectively, but hypereutectic means it's right at 8%, which has characteristics different from less or more carbon, so I was a bit confused on this video. You did an awesome job explaining all this! People need to know the what and why, before they spend big bucks on their engine, daily driver, a bit more than that, it a full blown racer
Wankel engines still have pistons--the rotors themselves. A Wankel is a type of piston engine, it works using displacement. The motion is different, the function is the same. The original term for Wankel rotary engines was "rotating piston machine."
@@KontrolCZ ?? Not sure why you think I'm not letting people enjoy something, I had an RX-7 Turbo II for well over 10 years, modified it and drove it to work everyday. Pretty good little engine, fuel consumption was high though.
I used cast hypereutectic pistons in my engine build. My engine is a mild 40% power increase over stock so I didn't need anything over the top. My next engine build will have custom forged slugs, expecting a 95% increase in output over stock, not huge but the high rpm operation calls for something a bit stronger regardless.
I'll be honest, when I 1st saw the 1st few seconds of the clip, I thought that this would have been a waste of time… but this person is very knowledgeable and gave a lot of good information
The information on pistons and knowing why to choose each one in this video is OUTSTANDING! Even breaking down that there are still cons to having a forged pistons over a cast piston is amazing. This needs to be pinned!! To all piston video searches!
Perfectly explained. Well done. Now just get 7.5 billion people to watch it. I'll bet I spend an hour every day explaining the whys and wherefores of hypereutectic and forged pistons.
I love that you're diving into these deeply technical topics. I'd love to see more on different car components and what their advantages/disadvantages are for people considering them. A lot of people "over build" their car for what they're really doing with it, and videos like this might help them save money.
Thank you, glad to hear you feel that way. I have actually planned more videos like this in the future, they will cover various different engine components and principles. Thanks for watching and hope you stay tuned for more.
it seems 25 people had to downvote this because they paid for forged pistons in their daily driver that never sees the track. Nice explanation man. Everything was spot on. I really wasn't expecting that!
I bought a set of drop in forged pistons for my motorcycle. They increased the compression due to a higher dome, and increased the power and torque. Problem was my air cooled motorcycle would then overheat in traffic on 100 degree days, and they were noisy in a way that made it sound like the engine was about to grenade. I put the stock pistons back in, they are beautiful, cast coated pistons. They aren't noisy, they run cooler, and the bike sounds way better. Riding for me is about an enjoyable overall experience, not just sheer performance. Better sound and reliability create a better overall experience.
This channel rules. This is all information I’ve researched before when selecting the pistons on my 3S-GTE’s and also on my 1UZ-FE, but it was awesome hearing the results of your research because they matched my own. Makes me feel justified in my piston choices for my cars: 1990 MR2T - cast pistons, daily driven 1994 Celica GT4 - forged pistons, track weapon 1997 LS400 - Stock hyper-eutectic, rarely driven 😝
Thank You...I was given a 55 Chevy...6 banger...I drove it over 300,000 miles...replaced pistons once with a .040 over bore...but the crank was only half a 1,000 out...awsome... your point well taken Sir!!
I was going to use a forged 2618 Mahle piston in my EJ207, but watched a few vids and went for a CP 4032 instead. So vids like this one do help us to make better choices.
Can you share the part numbers of the CP 4032 pistons for Subarus? I've never seen a 4032 from CP, while Mahle is known for their 4032 PowerPak pistons.
You have to be one of the most intelligent young men I have came across in my 53 years... This is by far the best explanation on piston ever produced on the web. Great job...
I was looking for why hypereutectics pistons created heat, but found this great tutorial instead. Without your great knowledge in showing us this video, we wouldn't have got your audience. Well done. 😁
One of the most reliable B18C engines I put in my civic kept the Hypereutectic pistons but better rods in NA config. I went between Vegas and LA for years without any issues on that engine. It was amazing.
What's your setup and power? Did you drive it aggressive often? Most Honda engine is reliable. Even b20 Frankenstein build will later at lease two years it said it's one of the unreliable build.
Well done, just what I was after, informed, logical and easy to understand while still giving more in-depth answers than others on what the differences and tradeoffs are between the different piston options, liked the visuals etc, it all made for a somewhat entertaining lesson. I really liked the little round up at the end reminding us that the best choice really comes down to knowing how you will use the motor and what characteristics will be most advantageous, many thanks from Down under.
It's interesting that the aftermarket industry offers either cast or forged pistons to raise power potential, yet they really lack on hypereutectic piston applications. It's like the middle ground, where going cast is risky, yet forged is overkill. Just an observation.
@@JoseRivera-ym3wj If you can't find any good info then call/email the people that make them. They should tell you the alloy and silicon percentage. If they don't then find a less shady company to make your pistons.
@@JoseRivera-ym3wj really have to research these things. As he said the terms get thrown around in quite the general fashion, though upon looking there is a lot of alloy play today. Any reputable business with give all that info.
Thank you very much for this. Simple, straight and informative. I've long been confused about how to prepare for an anticipated project to rebuild my trusty 'pedestrian-but-wonderfully-reliable' 86 Ford 300 straight six now that I'm retired and the truck has turned over 1/2 million km. Its achieved this (and I have never seen the inside of the motor during the past 35 years except to renew 2 valve cover gaskets and replace one exhaust manifold gasket) and it still doesn't use oil between changes but that wonderful engine is deserving of major TLC and I'm currently having to weigh (financially) what is 'wanted' vs what's actually 'needed'.
Alright you Zlatan Ibrahimovic of engineering! This is some serious knowledge of production processes, material science and machining. Great job, I'm gonna check all your videos!
Very nicely done. I almost bought forged pistons thinking i was getting an upgrade. My machine shop guy mentioned that forged pistons are noisy, now I know why. Thanks for the info.
Hehe, I like how you point out Silicon(e), now all that is missing is the pronunciation. Silicone silly cone Silicon sille kan My buddy and I were debating what type of pistons to put into our little project and I couldn't remember the name of the Si-pistons. So after googling, the answer became clear, and this video was attached. Thanks! Hypereutectic pistons all the way man. The time of the forged piston is over. Those are only good in professional racing machines, where they tear into the engine every day.
Hypereutectic are alright but there is absolutely nothing wrong with forged pistons. They will not damage an engine in any way. If the tune in an engine is not correct the forged piston as more forgiving. Not matter what kind of piston they all need to be sent to a machine shop and have the oil clearances sized accordingly to the application. Poor machining and tunning is what kills engines along with improper maintenance.
To be completely honest i was thinking this video will not be any better then we see other TH-cam videos, but i was wrong. Finally someone here knows that how things actually work and the details were spot on... well done 👍🏼
I came across this channel and i find it really amazing on how this guy explained everything detail by detail.... i do racing myself for more than a decade but listening with his explanation i begin to understand more the important things that i needed in engine building.
Thank you for such a clear and interesting dissertation on what could be considered a rather dull subject. You have an incredible way of lecturing and that is a gift.
Sure appreciate your good sense of humor when acknowledging silicon/silicone. Been clicking away at your videos, I'm on a learning binge. Thanks for all the top quality info here.
You doing a great job my name is Steve from Annapolis Maryland I come across your videos and I religiously watch you all the time morning afternoon evenings keep up the good work
Excellent video and information. You are absolutely correct with the analogy of engines and shoes. My bugeye WRX was fitted with forged pistons, forget rods and steel crank when it was professionally rebuild by the previous owner. The piston slap was very evident when the engine was running cold once I rectified the valve tappet clearances. It's my daily driver.
Thank you! Not even halfway through and already subscribing! That was, by far, the best explanation I have heard to date regarding the difference between these. Not only from a metallurgical standpoint, but also as it pertains to the most practical intended application for the engine they are going in. It's quite annoying to encounter someone boasting about their engine's forged pistons in a vehicle they use to drive back and forth to work or school everyday (and never the track), only to see the disbelief on their face at your blasphemy of disagreeing with such a piston choice. I'll be saving a link to this video and sharing it whenever I encounter such a person.
Very well explained, I spent countless hours researching online about the different piston types trying to decide what I needed. This sums it up perfectly in just 15 minutes. Good job.
@@DStead2239 like richard holdner said youre both right Why buuld the engine up like that when the junkyard ls will respond to a small turbo and cam? And why waste time on a junkyard ls and just build it right? You're both right. They both have their places
Best vid I've seen so far on the differences between these 3 options. You're absolutely right, the internet loves to tell all that forged is superior in every way. Thanks for all the clarification!
@@unclegeorgesspeedandfeed The contents of the video talk about how the choice would be situation and usage dependent, not as black and white as better or worse.
I just found this video. I am glad I did. I am in the beginning stages of building a 4.9l il6. I thought forged pistons would be the way to go, but after watching this video, I'm leaning towards the Hypereutectic pistons. This really helped me decide not only on a better choice, but also cost reduction. ty d4a!
I have to honestly admit that I've just started to be prejudiced about your looks. But I have to admit, that your knowledge is very advanced and the video is very valuable to me.
Very nice video.I just learned in university about hypereutictic alloys in general and it was really nice that i knew what you were talking about :D :D :D
Awesome , Very Informative Video !! Once had a .060 over 350 with stock heads that were lightly ported and cleaned up with .010 off the bottom , stock rods resized , king bearings , Comp. 270 cam , edelbrock intake & carb . With Cheap Silvolites down in the hole .... This was an experimental low budget buddy build bracket racer that made hundreds of passes until it let go with a broken crank !! Pistons are Very Strong , Even those Silvolites Never gave it up !! Hard to go wrong with K.B. Hyper tho. !! So , Watch your piston speed , communicate with your machine shop , double check all measurements , spend money on better fasteners , especially the rod caps because that's the most stressed part of any engine , and work to smooth the flow in the heads , over work the short side radius , that's where you make power !! 😆
That's some great advise! Thumbs up!!! Regarding cast pistons, i would say, from experience, the stock cast pistons in NA cars 90-2015 can easy handle a low boost conversion (max 10 psi). My mate decided to go for 500+ bhp on a 2JZ-GE for a club rally season '14, stock internals, worked fine :)
EXCELENT PRESENTATION ON TEACHING US THE BENEFIT AND DISADVANTAGE OF FORGED, CAST AND HYP PISTONS.THANK YOU👍I HAVE FORGED PISTON ,CONROD,AND CRANKSHAFT ON MY 400 CHEVY SMALL BLOCK.AND YES PISTON SLAP IS PRESENT AT COLD START.
Just wanted to say you have some really great videos. I've watched them all, and even forwarded a few to some friends. Good stuff! Looking forward to your next videos!
Was about to buy some forged pistons for my ej255 wrx build, but with your video now I know that with cast pistons will work fine for my daily basis, thanks for your video!
Awesome vid! Great info. Keep it up 👍 For anyone who might not know, Silicon- It is a hard and brittle crystalline solid with a blue-grey metallic lustre. Silicone- Squishy stuff that makes boobs big.
Good info! Old mopar cast pistons were quite good. They were made by TRW. Carroll Shelby said that in a big block there was no reason to switch to forged unless you were going to extremes. They had long heavy skirts, short strokes and long rods. I have seen blown 440s run factory pistons at 650 hp for years, and a built cast crank stock piston '78 440 with a tunnel ram launched at 7500 rpm for 3 years until a stock rod stepped out. Those pistons had steel expansion struts cast in them. What I miss is tin plating. The new coatings wear off much quicker. Also, most OEM cast pistons have offset pins to reduce slap. Most forged do not. We would reverse the cast pistons in our big blocks to get a straighter push on the crank. It definitely freed things up. Unless the engine was severely worn I didn't notice any extra slap. Hypereutectic pistons from the major supplier for a big mopar in my mind are inferior to the old cast ones, but better than cheap new cast ones. I have seen many of the hypereutectic crack probably because they are more brittle and have shorter thinner skirts. Also, hypereutectic pistons require larger ring gaps because they transfer more heat to the rings. I didn't know that about the two alloys for forged ones. I suppose my blown 572 hemi dragster motors custom pistons are the low silicon alloy. I don't care about slap!
Watching your early videos, I thought, this guy should speak out more. Nowadays, different story :D Seriously though, thanks for another informative vid!
This guy could have helped me out a lot in the 1960's when I took my apprenticeship. He put this in simple understandable terms, that a chimpanzee could understand (one that speaks english that is). Good content and accurate.
I’m an old school long time hot rodder and have built many engines from Jeep to GM to Porsche motors. Natural and forced, so I’ve done my homework and have to say you are as spot on as anyone on your video here. I even learned (or at least refreshed) so I want to pass on a thanks for educating not only yourself about the differences but passing on the knowledge. Oh and it is pernounced silicon no need to explain but I’m from the south soooooo😂👍🏻👍🏻👍🏻
MIM/PSM aka: “metal-injection-molded”/“powdered-sintered-metal” pistons and rods are becoming somewhat common now as well. They can be even more precisely made than cast and are stronger than cast components, often with strength comparable or better than billet and with significantly less machining to finish
Please forgive me for decade old info on a material, but MIM parts have a negative stigma in the gun world. Manufacturers use MIM to make small parts with detail or texture. Things like safety levers, mag releases and bolt catches. Small parts that are constantly hit with fingers or palms. They break all the damn time and are replaced with machined parts in anything past a budget build. So please, have there been some big improvements or was it just the small size? Not trying to be an asshole, honestly curious.
cody blea Believe it or not, I know what you are referring to, it used to be my job. The number of Remingtons with broken MIM parts that came in every month was ridiculous. The extractors were usually first to go. But yes, a large part of it is that they aren’t re-designing the geometry of the parts to fit the desired material, but rather re-using the shapes of machined or forged parts that aren’t really suited to the random grain structure of MIM parts. It is much like heat-treating: It can be done quite well or very poorly depending on the technology used. Also the metals used in many gun parts are often cheaper and lower-quality than those used by many modern MIM manufacturers; hence the poor reputation. The technology has gotten very good, but most manufacturers aren’t going to invest in it when they still make a profit off of their old (already paid off) technology. “A customer can have their critical parts in whatever material they choose, so long as they choose MIM.” -basically Remington
@@codyblea3638 Sintered parts are generally not heat treated to make production easy and cheap. Air pockets are usually present in them depending on the mesh size of sintered powder. Their grain structure is random and they lack fatique strength.
You left out a few things bud about forged pistons of today and even cast pistons. Let’s talk about ristpin offset and cam ground skirts. Depending on how you are building a engine you can today get forged pistons that are cam ground that virtually eliminate cold start piston slap; also it doesn’t take long for pistons to expand during warmup maybe 90 sec . Now let’s talk about cast pistons; they are cam ground and have off set rist pins this eliminates cold start up noise but the wear surface area in the skirt is about 2/3tds less then at full expansion. So the main cause of shorter engine life in any engine is no warmup. People get in their car start the engine and go and putting full load stress on the cylinder wall with a cast piston , I’ve seen it on engine overhauls there are wear lines in the cylinder bores from this it happens. So what I do is I always warm up my engine until the internal water temperature gets to about 110 degrees or you see the needle come up on your temperature gauge. My startup routine for any engine is the same as for large Diesel engines ask any truck driver about cold start warmups.
Also talk about the thermal expansion of the alloys used because the expansion difference is usually minimal to none. The reason you get piston slap is because forged pistons take longer to heat up and expand
What if the manual says no cold start warmups needed? Oh, no cars come out of the factory with forged pistons thus there's no requirement for cold warm ups before driving off....
My dad would get in his car and floor it in drive before the starter even stopped spinning on a regular basis, it ran fine over 200k miles. He also did oil changes every 10-15k with dino so it goes to show it's all about the design and manufacture, not the use and abuse.
Thank you for the video! I learned a lot about the pistons then I ever knew. I have a 289 engine that a machine shop is installing hyperuetecic pistons in to it. The guy recommended it and I was researching them because I didn't have a clue. I feel a lot better now. The 289 is original in my 1967 mustang. Thanks again
This guy is very intelligent. This is why you see NASCAR teams preheating the oil before they start the engine. If you go with a forged piston always allow the engine to come up to temp at an idle. This pretty much eliminates piston slap concerns. They also make 12 volt heat probes for wet sump oil pans and water jackets in the engine block which helps the engine come to operating temperature in a couple of minutes.
Excellent video with great information. Wish I had this explained to me years ago. I've heard of the Hypereutectic pistons but I didn't know much about them. Using Silicon (Aka Glass) in aluminum would give it some extra strength much like wrought iron or steel. But I have to say casting has come a long way from the start of engine building. The old way of casting was making a mold out of sand and pouring molten metal into it. Known as sand casting, it produced cheap parts, but the castings were usually weak in strength and could require a good bit of machining as the cast parts would be a bit rough. These early castings could have microscopic air bubbles and the metal could have large grains causing them to be weaker that forged pistons. You could see the large grains in a broken part. Newer casting processes like investment casting and spin casting made the parts have much smaller grain size, eliminated all air pockets of any size, made the parts much stronger and cut final machining to a minimum. Many parts that are made using these processes come out with much closer tolerances and smooth finishes. As for forged pistons and piston slap causing wear in the cylinder bore, I've never noticed that in any engine I've rebuilt. Even after well over 100K on the engine. I would imagine the piston would wear more that the cylinder walls. Even in the aluminum blocks they have a silicon carbide lining in the cylinder walls that make the walls much harder than aluminum alloy. One thing I kind of wish he did talk bout are the completely machined pistons from solid stock aluminum alloys. I've heard some of the same praises from forged pistons on these machined pistons. So many talk about how good a machined part from a solid billet is compared to machining from solid stock. Like the claim made about something made from aircraft grade aluminum. Most have no idea about what they are talking about and is usually some kind of an advertising gimmick from someone that doesn't know anything about metal. I've been a machinist over 40 years and I laugh at people when they come in talking about stuff like this. First a billet is nothing more than a cast or rolled shape of metal that usually requires a bit more process at a refinery. But really it is nothing more than common solid metal stock. As for aircraft grade aluminum, that is another gimmick. As there are many grades of aluminum used in aircraft construction, all have advantages and disadvantages depending on what the metal is used for. Common grades for aircraft use can be 2024, 6061, 5052, 7075 and a lot more. Then there is the harness or Temper of the aluminum that is identified by a T indication. It is most commonly given as T1 to T10 or O. O is soft and T10 would be harder than T1 and all that also depends on the alloys in the aluminum. When someone trys to sell you something and they say it is made from aircraft grade aluminum, have some fun and ask them what aircraft grade is it and what T hardness is it. They look at you like a dear in headlights or they will repeat, "But it's aircraft grade" like it is something special. I have a lot of fun with that. Sometimes I ask for an MSDS or SDS on the item and tell them that it contains hazardous materials just to blow their minds.
Excellent video my man! Definitely helping clear up info and dispel a lot of myths. Idea for another video that you can connect back to this one. Talk about knock, what causes it, and why different piston types are more or less susceptible to damage under knock. The hyperuetectic pistons in the STI engine come up a lot when people talk about ring land failure. Of course, 90% of them have no idea what they are talking about, so videos like this really help clear the air.
Serious information presented in a very digestible format. You just covered thirty years of knowledge I learned the hard way racing Turbo motors! Great presentation young man!
I taught physics for seven years and understand complex things but I never became astute in metallurgy or any type of blacksmithing on up this is the best explanation and even for the simplest of thought processes it really does explain and get to the heart of it all excellent well done beautiful
I run hypereutectic pistons in my truck. I've always liked them better than forged. The only thing forged are good for is if you have detonation in the cylinders ( the fuel explodes to soon) they can take that punch better than hypertectic but as long as you dont have detonation hypereutectic are they way to go
In a world of insanely simple car bolt on videos, your content is a welcome change. Your videos can even teach a seasoned mechanic some of the finer points of powerplant engineering. I appreciate your content, so if you have a Patreon, please share so we can contribute!
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Can they make custom designed forged pistons? If so, forged is the way to go. I'd add a cast piston guide/sleeve at the base of the piston to negate the piston knock. Cast for no expansion and forged for the primary and durability.
There are exceptions. Audi and vw have been using forged for over 2 decades in factory motors.
You forgot L-series pistons :/
u said cast was 8-10% & 4032 was 10-11% ... how come your charts shows cast wear still better than 4032 ... your chart is wrong then ... for wear from wat u are saying and correct form would be wear least hypereutectic >12.5% , Forged 4032 10-11% , Cast 8-10% , Forged 2618 1-2% ...
Crazycatman the GE and GTE are identical in the short block... the GTE head is allegedly a bit better, but honestly you can make more power than you'll even want (700 plus) with just a turbo setup along with a good fuel system and a standalone ECU. Good luck👍
This is an absolutely wonderful discussion. I live near Detroit, and one of my classmates is a piston design engineer. He loved this when I showed it to him. His only comment was that modern pistons are NOT poured when cast. Rather the mold is dipped into the liquid metal and a vacuum is created such that the liquid metal flows into the evacuated mold. There is no possibility of air pockets in the resulting piston. The narrator touches on this when he speaks of "modern" techniques at 11:50, but does not say it specifically. I was told that this process is used for two reasons, to exclude air pockets, and that liquid aluminum alloys will oxidize instantly, at their surface, when exposed to air, and this creates aluminum oxide (slag) that is horrible when inside the body of the casting. The older pouring methods depended on the slag floating on the liquid and not going into the mold. There was a certain amount that did get into the casting but until vacuum techniques were developed this was unavoidable.
Thank you for sharing that. Once you told me, it stands to reason.
It is so refreshing to hear someone actually understand materials engineering and their application. Subscribed
Thank you :)
Are you kidding me? This fruitcake is a starbucks manager or something. He doesn't know sh!t.
@@JustForFun77077 Educate us, then.
So, if you don't mind a layman doubt..
What if the cylinders are done forged with the same material of the pistons, with the same expansion ratio?
@@rlguerrero2263 well your doubt has actually confirmed your intelligence. The piston liners and bores must always be from a material that is not the same as the pistons/rings, for that exact question you asked about the expansion of materials due to heat. Almost always the liners are made from iorn-chome alloy, vanadium and molybdenum. This offers the best thermal stability, and wear resistance, as iorn also contains graphite, a natural lubricant. You will find the piston rings are also made from iorn, or some similar iorn alloy. The reason pistons themselves are mostly made from aluminium is due to the low mass which is advantageous for a chunk of metal flying up and down a cylinder 80ft/s. There have been instances when manufactures have tried other materials for liners one being nikasil, which ended up oxidizing and killing engines. There was a brief moment in time when they used to use aluminium cylinder liners for race engines, and they tried to use them in road sports cars i think Alfa Romeo tried it but the bores wore out too quickly and the engine was junk after 10k miles.
Without this video out there I would had bought a car, turboed it and ran forged pistons. Just to daily it, I'll pass. You are helping a lot people in their future builds. Thank you!
1k likes from bots i daily mine with forged and yes it does have slap. But I’m finding ways to help it by pre oiling before start. Also my block builder informed me of ditching my cast for forged. Because of my goals he seen the ones I had break. But wast knocking them (no pun intended)
@@claudedottin1312 I would of thought the same thing, probably gotten the same advice. But if they tell you to switch from cast to forged it is most likely the type of tuning you apply.
1k likes from bots tis be correct sir
@@claudedottin1312 well good luck on your set up
1k likes from bots lol it’s been 5 years ☺️🤙🏽
I’ve Been a car guy since the early 80s. And this might be the best piston content I’ve ever seen. Well done!👍
I've been working on cars most of my adult life, and I learned something today. Thank you, very well explained!
So. You're telling me I probably shouldn't put those 1000 dollar forged pistons i bought yesterday into my 89 corolla wagon with 251000 miles? Dammit.
Lol!
😂
actually if you got stock bore size it might be perfect hahah seal up that worn out bore
Your friendly neighbor Stanley. You’ll be just fine Stanley just make sure they were STD (not what the neighbor has if you know what I mean) and save the money on getting the cylinders checked. They will expand and fill then just fine
Your friendly neighbor Stanley just use it for drag racing as suggested.
Excellent discussion on the differences between these piston materials. Having had significant experience with all 3 in racing applications, the only thing I would add is that in comparison to forged, hypereutectic pistons are far more likely to shatter if anything significant goes wrong. For example, when a hypereutectic piston makes contact with a valve (say missed shift/valve float) that piston will often shatter and take every thing out--rods, block, crank, cam and heads. Often with forged pistons you are just dealing with a bent valve and a salvageable engine. Two thumbs up for this vid--you know your stuff.
I did NOT know any of that. I always thought forged was the way to go. Very good way of explaining this topic. Thank you for taking the time to put this together - I really benefited from it!
I'm a 35yr career mechanic & this short but fascinating video was so insightful. It's actually making me reconsider my current engine build project! You've highlighted so many variables based on final choice. Many thanks indeed. Subscribed 😉👍🏻
GREAT video, you give the FACTS about the most misunderstood component in a engine, most engines are DAILY drivers, while it might be "suped" up a bit w/ a bigger cam better heads you don't spend day after day at the track, another thing you have to ask yourself "How many times do you want to rebuild your motor?", I'm personally rebuilding my sbc 350 that has 439,906 miles on it, it still gets 17mpg and 12 if I'm loaded down(7,000gvrw+)the cylinders are a lil glazed but there is Zero ridge at the top of the bores but its starting to get more blow by on the rings than I care to tolerate.
I'm upgrading my heads to better flowing ones along with my intake and exhaust(mid length headers to full length because they produce better power down low) but pistons will still be cast or hyper and I will use zero gap rings to further reduce contaminants in the bottom end getting into the oil. Yes most engine shows we all love to watch are dropping 1000.00 sets of forged pistons in like its nothing and flogging them on the dyno saying look at how much power I made at 6k rpm etc but this DOED NOT reflect the average guy who has a hot rod that likes to drive his car or suv on a daily basis. The true cost of doing a total rebuild is getting more and more expensive if you don't want imported cheep parts since our money is worth less and less every year, I personally like to drive my vehicles.
I really enjoyed your enthusiastic explanation, humor with your “Accent” on accuracy. As a retired ASE Master Tech who worked on factory turbo charged cars in 1980, then Grand National in 85, I used your information to reinforce my knowledge. Liked & subscribed!
When I saw the hypereutectic pistons, I was like, "they are making pistons out of cast iron?", this phrase is used in cast iron metallurgy; you have eutectic and eutectoid, the amount of carbon being below or above 8% respectively, but hypereutectic means it's right at 8%, which has characteristics different from less or more carbon, so I was a bit confused on this video. You did an awesome job explaining all this! People need to know the what and why, before they spend big bucks on their engine, daily driver, a bit more than that, it a full blown racer
You are mixing steel and cast iron Fe-C phase diagram, also it goes from 0,01% C to aprox. 2% C for steel and from 2% to 6,67% C for cast iron.
There is HYPOeutectic (meaning less), eutectic (menaing on the spot) and HYPEReutectic (meaning more) when dealing with Aluminium-Silicon alloys.
"What piston is best for your engine"
Me driving rotary : "why am I watching this?"
Wankel engines still have pistons--the rotors themselves. A Wankel is a type of piston engine, it works using displacement.
The motion is different, the function is the same. The original term for Wankel rotary engines was "rotating piston machine."
@@devilsoffspring5519 let people enjoy things
@@KontrolCZ ?? Not sure why you think I'm not letting people enjoy something, I had an RX-7 Turbo II for well over 10 years, modified it and drove it to work everyday. Pretty good little engine, fuel consumption was high though.
Because you might learn something.
@@d.haroldangel241 Better answer than my jibba-jabba, A+ for content if not effort :)
I used cast hypereutectic pistons in my engine build. My engine is a mild 40% power increase over stock so I didn't need anything over the top.
My next engine build will have custom forged slugs, expecting a 95% increase in output over stock, not huge but the high rpm operation calls for something a bit stronger regardless.
I'll be honest, when I 1st saw the 1st few seconds of the clip, I thought that this would have been a waste of time… but this person is very knowledgeable and gave a lot of good information
Anyone else here because they didnt know wtf a hyper eautectic something is
The only reason I'm here
Just wanted to see how in-depth and accurate he was. Spot-on.
Same here!
YES! can't even spell it. Hyperautomatic? What?
Apparently they’re wet biscuits
The information on pistons and knowing why to choose each one in this video is OUTSTANDING! Even breaking down that there are still cons to having a forged pistons over a cast piston is amazing. This needs to be pinned!! To all piston video searches!
Perfectly explained. Well done. Now just get 7.5 billion people to watch it. I'll bet I spend an hour every day explaining the whys and wherefores of hypereutectic and forged pistons.
I love that you're diving into these deeply technical topics. I'd love to see more on different car components and what their advantages/disadvantages are for people considering them. A lot of people "over build" their car for what they're really doing with it, and videos like this might help them save money.
Thank you, glad to hear you feel that way. I have actually planned more videos like this in the future, they will cover various different engine components and principles. Thanks for watching and hope you stay tuned for more.
it seems 25 people had to downvote this because they paid for forged pistons in their daily driver that never sees the track.
Nice explanation man. Everything was spot on. I really wasn't expecting that!
Thank you!
Great job explaining the differences and why sometimes throwing the most expensive parts at your engine build can be a waste of money.
I bought a set of drop in forged pistons for my motorcycle. They increased the compression due to a higher dome, and increased the power and torque. Problem was my air cooled motorcycle would then overheat in traffic on 100 degree days, and they were noisy in a way that made it sound like the engine was about to grenade. I put the stock pistons back in, they are beautiful, cast coated pistons. They aren't noisy, they run cooler, and the bike sounds way better. Riding for me is about an enjoyable overall experience, not just sheer performance. Better sound and reliability create a better overall experience.
This channel rules.
This is all information I’ve researched before when selecting the pistons on my 3S-GTE’s and also on my 1UZ-FE, but it was awesome hearing the results of your research because they matched my own. Makes me feel justified in my piston choices for my cars:
1990 MR2T - cast pistons, daily driven
1994 Celica GT4 - forged pistons, track weapon
1997 LS400 - Stock hyper-eutectic, rarely driven 😝
I've been building engines since 1967 and today I learned something new. Thanks for a concise and informative presentation.
Do u mean steam engines?
So refreshing to see someone making videos with common sense.
Thank You...I was given a 55 Chevy...6 banger...I drove it over 300,000 miles...replaced pistons once with a .040 over bore...but the crank was only half a 1,000 out...awsome... your point well taken Sir!!
I was going to use a forged 2618 Mahle piston in my EJ207, but watched a few vids and went for a CP 4032 instead. So vids like this one do help us to make better choices.
Can you share the part numbers of the CP 4032 pistons for Subarus? I've never seen a 4032 from CP, while Mahle is known for their 4032 PowerPak pistons.
Ivan Delos Santos bingo. I’ve got Mahle for my SBF, they’re 4032. Don’t expand much, can run tighter clearances
The ej207 is factory with forged pistons tho ?
@@alexjaxon9928 Depends on the year/version. STi V7 used forged pistons. V8 and above went to cast hypereutectic.
@@19minorthreat69 no!! ...all sti 2 liters after sti v6, hypereutectic pistons .
for spec c .... I do not remember anymore
You have to be one of the most intelligent young men I have came across in my 53 years... This is by far the best explanation on piston ever produced on the web. Great job...
I really opened this expecting you to get get half of it incorrect. You did a very good job explaining this topic in a way it could be understood.
Why? 7 billion people in the world and only you know pistons? Arrogant.
I was looking for why hypereutectics pistons created heat, but found this great tutorial instead. Without your great knowledge in showing us this video, we wouldn't have got your audience. Well done. 😁
all these comments and no one says how awesome his shirt is?! awesome shirt champ ;)
Finally!!!
Beat me to it by a few days. :P
lokiiddqd SONIC 💥 😆👍🏾😎
I thought they where anime H
@@joemango9782 those are characters from Street Fighter , i can see Ryu, Ken, Chun Li and Cammy
One of the most reliable B18C engines I put in my civic kept the Hypereutectic pistons but better rods in NA config. I went between Vegas and LA for years without any issues on that engine. It was amazing.
What's your setup and power? Did you drive it aggressive often? Most Honda engine is reliable. Even b20 Frankenstein build will later at lease two years it said it's one of the unreliable build.
Are you still active? Currently building 2 b16 motors
Well done, just what I was after, informed, logical and easy to understand while still giving more in-depth answers than others on what the differences and tradeoffs are between the different piston options, liked the visuals etc, it all made for a somewhat entertaining lesson. I really liked the little round up at the end reminding us that the best choice really comes down to knowing how you will use the motor and what characteristics will be most advantageous, many thanks from Down under.
As a machinist and engine building hobbiest for the last 25 years,
Great video 👍
It's interesting that the aftermarket industry offers either cast or forged pistons to raise power potential, yet they really lack on hypereutectic piston applications. It's like the middle ground, where going cast is risky, yet forged is overkill.
Just an observation.
Most cast aftermarket Pistons are hypereutectic alloy
@@doddgarger6806, how can one be sure? Say I want to turbo a Nissan KA engine. How would I know if the cast piston is hypereutectic?
@@JoseRivera-ym3wj If you can't find any good info then call/email the people that make them. They should tell you the alloy and silicon percentage. If they don't then find a less shady company to make your pistons.
@@JoseRivera-ym3wj really have to research these things. As he said the terms get thrown around in quite the general fashion, though upon looking there is a lot of alloy play today. Any reputable business with give all that info.
Thank you very much for this. Simple, straight and informative. I've long been confused about how to prepare for an anticipated project to rebuild my trusty 'pedestrian-but-wonderfully-reliable' 86 Ford 300 straight six now that I'm retired and the truck has turned over 1/2 million km. Its achieved this (and I have never seen the inside of the motor during the past 35 years except to renew 2 valve cover gaskets and replace one exhaust manifold gasket) and it still doesn't use oil between changes but that wonderful engine is deserving of major TLC and I'm currently having to weigh (financially) what is 'wanted' vs what's actually 'needed'.
Alright you Zlatan Ibrahimovic of engineering! This is some serious knowledge of production processes, material science and machining. Great job, I'm gonna check all your videos!
Very nicely done. I almost bought forged pistons thinking i was getting an upgrade. My machine shop guy mentioned that forged pistons are noisy, now I know why. Thanks for the info.
Hehe, I like how you point out Silicon(e), now all that is missing is the pronunciation.
Silicone silly cone
Silicon sille kan
My buddy and I were debating what type of pistons to put into our little project and I couldn't remember the name of the Si-pistons. So after googling, the answer became clear, and this video was attached. Thanks! Hypereutectic pistons all the way man. The time of the forged piston is over. Those are only good in professional racing machines, where they tear into the engine every day.
Hypereutectic are alright but there is absolutely nothing wrong with forged pistons. They will not damage an engine in any way. If the tune in an engine is not correct the forged piston as more forgiving. Not matter what kind of piston they all need to be sent to a machine shop and have the oil clearances sized accordingly to the application. Poor machining and tunning is what kills engines along with improper maintenance.
To be completely honest i was thinking this video will not be any better then we see other TH-cam videos, but i was wrong. Finally someone here knows that how things actually work and the details were spot on... well done 👍🏼
Great video! I never knew forged piston expand more under heat and Hypereutectic piston have less expansion then cast pistons.
I came across this channel and i find it really amazing on how this guy explained everything detail by detail.... i do racing myself for more than a decade but listening with his explanation i begin to understand more the important things that i needed in engine building.
Thank you for such a clear and interesting dissertation on what could be considered a rather dull subject. You have an incredible way of lecturing and that is a gift.
Sure appreciate your good sense of humor when acknowledging silicon/silicone. Been clicking away at your videos, I'm on a learning binge. Thanks for all the top quality info here.
You doing a great job my name is Steve from Annapolis Maryland I come across your videos and I religiously watch you all the time morning afternoon evenings keep up the good work
One of the most informative videos I’ve seen relating to the topic. 10/10
This is the best explanation I have ever heard
Glad to see someone along the time to explain in depth but in an easy to understand for people of not knowing of these things.
Was thinking about this the other day , cool to see you go into more depth with it
Excellent video and information. You are absolutely correct with the analogy of engines and shoes. My bugeye WRX was fitted with forged pistons, forget rods and steel crank when it was professionally rebuild by the previous owner. The piston slap was very evident when the engine was running cold once I rectified the valve tappet clearances. It's my daily driver.
That may be the best t-shirt I've ever seen in my life!
Thank you! Not even halfway through and already subscribing!
That was, by far, the best explanation I have heard to date regarding the difference between these. Not only from a metallurgical standpoint, but also as it pertains to the most practical intended application for the engine they are going in.
It's quite annoying to encounter someone boasting about their engine's forged pistons in a vehicle they use to drive back and forth to work or school everyday (and never the track), only to see the disbelief on their face at your blasphemy of disagreeing with such a piston choice.
I'll be saving a link to this video and sharing it whenever I encounter such a person.
Great video man, been doing this for 35+ years and you answered a few questions that I had about hypereutectics 🤘
Great video. Just the right amount of information to explain everything without losing people with the technical.
Hypereutectic sounds like a special move in Street Fighter 2
This is fantastic. Someone finally made a video that explains it all in brilliant detail. Good job!
Now that's a really unique content. Just thanked Jesus I found this channel.
Amen
Very well explained, I spent countless hours researching online about the different piston types trying to decide what I needed. This sums it up perfectly in just 15 minutes. Good job.
My stock Supercharged Camaro with the LSA engine came with Hypereutectic. Now I know why. Thanks
Yes, because Chevrolet are cheap bastards
@@DStead2239 yet everyone and their mom wants a junkyard Ls to put a turbo on...
@@KingJT80 maybe in the U.S, here Bogans use junk yard barra's and the rest of us build proper engines..
@@DStead2239 like richard holdner said youre both right
Why buuld the engine up like that when the junkyard ls will respond to a small turbo and cam?
And why waste time on a junkyard ls and just build it right?
You're both right. They both have their places
@@DStead2239 It's funny how you see a crap load of Ford's with LS engines and gm transmissions 🤣
Ok. your channel is excellent. There are too many amateur channels with no real knowledge of mechanics or metallurgy. this one is pretty an exception
Best vid I've seen so far on the differences between these 3 options. You're absolutely right, the internet loves to tell all that forged is superior in every way. Thanks for all the clarification!
Forged pistons are the best way to go. The quality of a cast piston to a forged is night and day
@@unclegeorgesspeedandfeed The contents of the video talk about how the choice would be situation and usage dependent, not as black and white as better or worse.
I just found this video. I am glad I did. I am in the beginning stages of building a 4.9l il6. I thought forged pistons would be the way to go, but after watching this video, I'm leaning towards the Hypereutectic pistons. This really helped me decide not only on a better choice, but also cost reduction. ty d4a!
This was really enjoyable! (edit) “Engines are just like shoes” is now one of my favorite metaphors.
Thanks for makeing it more clear to me the difference between those pistons.
I have to honestly admit that I've just started to be prejudiced about your looks. But I have to admit, that your knowledge is very advanced and the video is very valuable to me.
What a weird comment.
What the fuck did I just read
As always, a very informative video. I don't know why I am watching it four years after its upload. Thank you.
Very nice video.I just learned in university about hypereutictic alloys in general and it was really nice that i knew what you were talking about :D :D :D
Awesome , Very Informative Video !! Once had a .060 over 350 with stock heads that were lightly ported and cleaned up with
.010 off the bottom , stock rods resized , king bearings , Comp. 270 cam , edelbrock intake & carb . With Cheap Silvolites down in the hole .... This was an experimental low budget buddy build bracket racer that made hundreds of passes until it let go with a broken crank !! Pistons are Very Strong , Even those Silvolites Never gave it up !!
Hard to go wrong with K.B. Hyper tho. !! So , Watch your piston speed , communicate with your machine shop , double check all measurements , spend money on better fasteners , especially the rod caps because that's the most stressed part of any engine , and work to smooth the flow in the heads , over work the short side radius , that's where you make power !! 😆
Learned so much about this subject and didn't even get off my couch to learn. Thank you so much. Subscribed 👍
Brilliant
I am an engine builder and you have put the information across very well
That's some great advise! Thumbs up!!!
Regarding cast pistons, i would say, from experience, the stock cast pistons in NA cars 90-2015 can easy handle a low boost conversion (max 10 psi). My mate decided to go for 500+ bhp on a 2JZ-GE for a club rally season '14, stock internals, worked fine :)
EXCELENT PRESENTATION ON TEACHING US THE BENEFIT AND DISADVANTAGE OF FORGED, CAST AND HYP PISTONS.THANK YOU👍I HAVE FORGED PISTON ,CONROD,AND CRANKSHAFT ON MY 400 CHEVY SMALL BLOCK.AND YES PISTON SLAP IS PRESENT AT COLD START.
Just wanted to say you have some really great videos. I've watched them all, and even forwarded a few to some friends.
Good stuff!
Looking forward to your next videos!
Was about to buy some forged pistons for my ej255 wrx build, but with your video now I know that with cast pistons will work fine for my daily basis, thanks for your video!
Do this video for rods! Heaps of good info here, thank you
Thank you for making these videos with real engineering understanding. It’s refreshing to see clear and coherent thoughts.
Awesome vid! Great info. Keep it up 👍
For anyone who might not know, Silicon- It is a hard and brittle crystalline solid with a blue-grey metallic lustre.
Silicone- Squishy stuff that makes boobs big.
Good info! Old mopar cast pistons were quite good. They were made by TRW. Carroll Shelby said that in a big block there was no reason to switch to forged unless you were going to extremes. They had long heavy skirts, short strokes and long rods. I have seen blown 440s run factory pistons at 650 hp for years, and a built cast crank stock piston '78 440 with a tunnel ram launched at 7500 rpm for 3 years until a stock rod stepped out. Those pistons had steel expansion struts cast in them. What I miss is tin plating. The new coatings wear off much quicker. Also, most OEM cast pistons have offset pins to reduce slap. Most forged do not. We would reverse the cast pistons in our big blocks to get a straighter push on the crank. It definitely freed things up. Unless the engine was severely worn I didn't notice any extra slap. Hypereutectic pistons from the major supplier for a big mopar in my mind are inferior to the old cast ones, but better than cheap new cast ones. I have seen many of the hypereutectic crack probably because they are more brittle and have shorter thinner skirts. Also, hypereutectic pistons require larger ring gaps because they transfer more heat to the rings. I didn't know that about the two alloys for forged ones. I suppose my blown 572 hemi dragster motors custom pistons are the low silicon alloy. I don't care about slap!
Watching your early videos, I thought, this guy should speak out more.
Nowadays, different story :D
Seriously though, thanks for another informative vid!
Man this made me laugh... Thank you :)
Damn what an informative video. I was under the assumption that forged pistons were just hands down better. Now I know better.
This guy could have helped me out a lot in the 1960's when I took my apprenticeship. He put this in simple understandable terms, that a chimpanzee could understand (one that speaks english that is). Good content and accurate.
I’m an old school long time hot rodder and have built many engines from Jeep to GM to Porsche motors. Natural and forced, so I’ve done my homework and have to say you are as spot on as anyone on your video here. I even learned (or at least refreshed) so I want to pass on a thanks for educating not only yourself about the differences but passing on the knowledge. Oh and it is pernounced silicon no need to explain but I’m from the south soooooo😂👍🏻👍🏻👍🏻
Thank you. I knew half of the things you said, but you filled me in with the other half, so damn informing
i enjoyed being schooled on this topic.
good share!
larry
MIM/PSM aka: “metal-injection-molded”/“powdered-sintered-metal” pistons and rods are becoming somewhat common now as well. They can be even more precisely made than cast and are stronger than cast components, often with strength comparable or better than billet and with significantly less machining to finish
Glad the technology is improving!
Please forgive me for decade old info on a material, but MIM parts have a negative stigma in the gun world. Manufacturers use MIM to make small parts with detail or texture. Things like safety levers, mag releases and bolt catches. Small parts that are constantly hit with fingers or palms.
They break all the damn time and are replaced with machined parts in anything past a budget build.
So please, have there been some big improvements or was it just the small size? Not trying to be an asshole, honestly curious.
cody blea Believe it or not, I know what you are referring to, it used to be my job. The number of Remingtons with broken MIM parts that came in every month was ridiculous. The extractors were usually first to go. But yes, a large part of it is that they aren’t re-designing the geometry of the parts to fit the desired material, but rather re-using the shapes of machined or forged parts that aren’t really suited to the random grain structure of MIM parts.
It is much like heat-treating: It can be done quite well or very poorly depending on the technology used. Also the metals used in many gun parts are often cheaper and lower-quality than those used by many modern MIM manufacturers; hence the poor reputation. The technology has gotten very good, but most manufacturers aren’t going to invest in it when they still make a profit off of their old (already paid off) technology.
“A customer can have their critical parts in whatever material they choose, so long as they choose MIM.”
-basically Remington
@@codyblea3638 Sintered parts are generally not heat treated to make production easy and cheap. Air pockets are usually present in them depending on the mesh size of sintered powder. Their grain structure is random and they lack fatique strength.
You videos are super easy to understand and a great comprehensive guide for starters! Thank you🙏
You left out a few things bud about forged pistons of today and even cast pistons. Let’s talk about ristpin offset and cam ground skirts. Depending on how you are building a engine you can today get forged pistons that are cam ground that virtually eliminate cold start piston slap; also it doesn’t take long for pistons to expand during warmup maybe 90 sec . Now let’s talk about cast pistons; they are cam ground and have off set rist pins this eliminates cold start up noise but the wear surface area in the skirt is about 2/3tds less then at full expansion. So the main cause of shorter engine life in any engine is no warmup. People get in their car start the engine and go and putting full load stress on the cylinder wall with a cast piston , I’ve seen it on engine overhauls there are wear lines in the cylinder bores from this it happens. So what I do is I always warm up my engine until the internal water temperature gets to about 110 degrees or you see the needle come up on your temperature gauge. My startup routine for any engine is the same as for large Diesel engines ask any truck driver about cold start warmups.
I baby my car: I will drive on a cold engine but
Also talk about the thermal expansion of the alloys used because the expansion difference is usually minimal to none. The reason you get piston slap is because forged pistons take longer to heat up and expand
What if the manual says no cold start warmups needed? Oh, no cars come out of the factory with forged pistons thus there's no requirement for cold warm ups before driving off....
My dad would get in his car and floor it in drive before the starter even stopped spinning on a regular basis, it ran fine over 200k miles. He also did oil changes every 10-15k with dino so it goes to show it's all about the design and manufacture, not the use and abuse.
Word
Thank you for the video! I learned a lot about the pistons then I ever knew. I have a 289 engine that a machine shop is installing hyperuetecic pistons in to it. The guy recommended it and I was researching them because I didn't have a clue. I feel a lot better now. The 289 is original in my 1967 mustang. Thanks again
Damn, I didn’t just liked it. Very well explained and I now know the differences.
This guy is very intelligent. This is why you see NASCAR teams preheating the oil before they start the engine. If you go with a forged piston always allow the engine to come up to temp at an idle. This pretty much eliminates piston slap concerns. They also make 12 volt heat probes for wet sump oil pans and water jackets in the engine block which helps the engine come to operating temperature in a couple of minutes.
Well thank you tuner brother because I just actually always learn new things from your videos man keep up with the wonderful work here tuner brother
Excellent video with great information. Wish I had this explained to me years ago. I've heard of the Hypereutectic pistons but I didn't know much about them. Using Silicon (Aka Glass) in aluminum would give it some extra strength much like wrought iron or steel. But I have to say casting has come a long way from the start of engine building. The old way of casting was making a mold out of sand and pouring molten metal into it. Known as sand casting, it produced cheap parts, but the castings were usually weak in strength and could require a good bit of machining as the cast parts would be a bit rough. These early castings could have microscopic air bubbles and the metal could have large grains causing them to be weaker that forged pistons. You could see the large grains in a broken part. Newer casting processes like investment casting and spin casting made the parts have much smaller grain size, eliminated all air pockets of any size, made the parts much stronger and cut final machining to a minimum. Many parts that are made using these processes come out with much closer tolerances and smooth finishes.
As for forged pistons and piston slap causing wear in the cylinder bore, I've never noticed that in any engine I've rebuilt. Even after well over 100K on the engine. I would imagine the piston would wear more that the cylinder walls. Even in the aluminum blocks they have a silicon carbide lining in the cylinder walls that make the walls much harder than aluminum alloy.
One thing I kind of wish he did talk bout are the completely machined pistons from solid stock aluminum alloys. I've heard some of the same praises from forged pistons on these machined pistons. So many talk about how good a machined part from a solid billet is compared to machining from solid stock. Like the claim made about something made from aircraft grade aluminum. Most have no idea about what they are talking about and is usually some kind of an advertising gimmick from someone that doesn't know anything about metal. I've been a machinist over 40 years and I laugh at people when they come in talking about stuff like this. First a billet is nothing more than a cast or rolled shape of metal that usually requires a bit more process at a refinery. But really it is nothing more than common solid metal stock. As for aircraft grade aluminum, that is another gimmick. As there are many grades of aluminum used in aircraft construction, all have advantages and disadvantages depending on what the metal is used for. Common grades for aircraft use can be 2024, 6061, 5052, 7075 and a lot more. Then there is the harness or Temper of the aluminum that is identified by a T indication. It is most commonly given as T1 to T10 or O. O is soft and T10 would be harder than T1 and all that also depends on the alloys in the aluminum.
When someone trys to sell you something and they say it is made from aircraft grade aluminum, have some fun and ask them what aircraft grade is it and what T hardness is it. They look at you like a dear in headlights or they will repeat, "But it's aircraft grade" like it is something special. I have a lot of fun with that. Sometimes I ask for an MSDS or SDS on the item and tell them that it contains hazardous materials just to blow their minds.
Excellent video my man! Definitely helping clear up info and dispel a lot of myths. Idea for another video that you can connect back to this one. Talk about knock, what causes it, and why different piston types are more or less susceptible to damage under knock. The hyperuetectic pistons in the STI engine come up a lot when people talk about ring land failure. Of course, 90% of them have no idea what they are talking about, so videos like this really help clear the air.
Serious information presented in a very digestible format. You just covered thirty years of knowledge I learned the hard way racing Turbo motors! Great presentation young man!
Thank you, that means a lot.
Thanks, I learned something today. Nice clear straightforward explanation.
I taught physics for seven years and understand complex things but I never became astute in metallurgy or any type of blacksmithing on up this is the best explanation and even for the simplest of thought processes it really does explain and get to the heart of it all excellent well done beautiful
I run hypereutectic pistons in my truck. I've always liked them better than forged. The only thing forged are good for is if you have detonation in the cylinders ( the fuel explodes to soon) they can take that punch better than hypertectic but as long as you dont have detonation hypereutectic are they way to go
In a world of insanely simple car bolt on videos, your content is a welcome change. Your videos can even teach a seasoned mechanic some of the finer points of powerplant engineering. I appreciate your content, so if you have a Patreon, please share so we can contribute!
mate you are a jet at explaining this...subbed!