Building a fast car? Get $400 OFF the VIP package and never pay for another course, EVER: hpcdmy.co/vipy20 50% OFF your first engine building course. Enrol now: hpcdmy.co/offery20 🙋♂ Want some insight into how harmonics are considered during the engine design phase? You will LOVE this! (or you won't, but I bet a chocolate fish that you will): hpcdmy.co/4b5556 TIME STAMPS: 0:00 - Introduction 0:30 - Misconception of harmonic dampers 3:10 - Solid alloy front pulleys 4:45 - Internal vs externally balanced engines 7:05 - What is a damper, and what does it do? 8:20 - Similar in its function to a suspension damper 9:40 - Effects of torsional twist 11:10 - Why do some stock engines not have dampers? 15:10 - Problems with factory dampers 18:55 - Aftermarket dampers 23:00 - Dampers and engine balancing 24:40 - Questions
My father built race engines all his life, the super damper was essential part of the recipe... we'd watch other people lose engines all the time... While ours would win races and last
MotoIQ just made a FANTASTIC, indepth video on this as well. By the way. The last Steve Morris Podcast was great, but not long enough, gotta have him back :)
One point to make, this (FD) should not be something you only consider on high HP builds. Added this to my daily driver and it has made a massive difference on drivability and even smoothness. There are almost no visible vibrations moving through steering wheel from the engines only the road.
@@zzzz1192 I wouldn't worry about it for an aircooled VW. As Andre mentioned, the problem shows up when the engine runs at a speed that resonates. For most engines this is a high frequency (high speed). This is a product of torsional rigidity, which is largely affected by crankshaft length. Longer crankshaft, lower resonant freqeuncy. For example old American inline 6s, you will either see them as torquey builds under 6k rpm, or as screaming race engines well past that speed. This is because their cranks are long enough that the destructive harmonic is down around 6k rpm. Now with a stubby VW crankshaft, it's not a problem at all, that resonant frequency is so far out of the range. Spend your money elsewhere on the engine.
I had a different experience - the ATI damper broke a just built engine (M52B28) already on the dyno bench. After the dyno, there was a strong vibration in the engine at 2500 and 5000 rpm, so that the whole car was shaking. We took the engine apart again, the crankshaft bearings were like driven 400,000km on a brand new engine. We even sent the crankshaft to another country for balancing (just in case, to find out if it was still balanced before) but everything was fine. The engine was repaired and worked again properly with the OEM damper. We put ATI and immediately felt the same vibration at 2500 and 5000 rpm. Whole story was told to ATI and then ATI replaced this damper but same issue with new damper. Currently the car is running with an OEM damper and there is no vibration. Also I found in one BMW forum exactly the same issue with another M52B28 engine.
wow. i had run my turbo b28 now 3 years with stock damper and no problems. would be really interesting to know what cause that with ati damper. M54 platform ati has been proven many times to work well.
It might help some to think of the crankshaft as a torsion spring, being twisted by the inertial loads of the pistons and rods, and firing impulses. Every spring has a frequency, or speed, it will 'flex' at, and it's sometimes called the "critical frequency", "resonant frequency", or even "harmonic frequency". Most of the time, the loads on the crankshaft are not at, or near, this critical frequency, and there's little variation in the crankshaft's twisting forces. However, at some engine speeds and/or torque values, these forces will co-incide with the twisting and increase the specific loads, or stresses, at specific points of the crankshaft - this is often referred to as "positive feedback", it's not quite right, but it means it increases the forces over time, possibly to the point where the mechanical strength of the crankshaft can't resist the stresses on it and it breaks. In extreme cases it can happen almost immediately, but what's more common is the formation of cracks that slowly weaken the crank' to the point where it fails. Think of it as someone swinging on a swing - under normal swings one just has a nice regular swing, but if someone comes up behind and gives a little extra push at the right time, and keeps doing it, that little extra push over time can have a big affect over a fairly short number of swings. Can't recall if it was mantioned, but a common sign of excess crankshaft deflection, twisting, is when flywheel bolts keep working loose - the twisting crankshaft is working against the inertia of the flywheel. Some engines are prone to this, such as the Pinto and Barra, and a good harmonic damper/dampener can drastically improve this.
I bought into the whole "ATI is the best" garbage. 665" Chevy on alky. Continually had issues with rocker arm adjusting nuts coming loose, flexplate bolts coming loose, and other severe valve train issues. All were signs of either severe detonation or out of control harmonics. There was also damage on the bearings that is caused by either detonation or out of control harmonics. Also ran a belt drive. However, there were ZERO signs of detonation on the piston crowns, chambers, or spark plugs. Methanol engines (mine is) are very hard to get into detonation unless something is very wrong. Mine had a very safe tune in it as well....When it broke a rod, it was determined that the damper was not sufficiently controlling the vibrations in the crank. I called ATI and told them what I found, they told me that I had the wrong damper on my engine. The damper I had was the one THEY told me was the correct one for my combo. There was also significant micro welding on the snout where the damper was also indicating it was moving and not dampening. Press fit was dead on spec as indicated. After looking at all this, and talking with ATI, I'm going back to Fluidampr. Ran them in the past with ZERO issues, for decades on racing and street engines. Never once did I have the issues that I had with an ATI.
I really love stuff like this even though i cant currently spend any money on my car and my car cant really be tuned meaningfully i find this very interesting and i've always loved the idea of building a car that has all of these little things that can free up more power that is currently there but wasted by heavier components and is just over all really responsive, thanks for sharing your Knowledge!
Very interesting. A friend of mine ruined his 2JZ crankshaft (crack on the 6th conrod journal) and we actually suspected that happened because the damper pulley he used was a mere aluminum pulley (in fact not damping anything at all).
I put an aluminium pulley on my rb20, ran it at two events and swapped it out for a romac balancer - the aluminium had weird peening marks at the crank snout shoulder like it had been hit with a tiny hammer and the crank bolt was still tight
Indeed. Vibrations are known to create kind of micro peening, sometimes causing the assembly almost impossible to separate. The 2JZGTE I am talking about has been used for drifting. The aluminum damper did its pulley job as long as the engine was under light boost, issue occurred at third event after the engine received new turbo setup for more serious boost (~700hp). We are rebuilding for next event. Stock damper will be used that time
You can measure the torsional vibrations with a rotational laser vibrometer. They’re not cheap but also not expensive, I borrowed one from a friends shop. It will show you where you will have resonance issues in the engine. I also have a hypothesis that certain materials (forged vs, cast etc.) are more prone to having resonance issues. We built a high revving boxer engine and measured huge resonance issues when going above 8k rpm, but later on changed the setup and it showed almost no resonance with the new billet crankshaft, so we opted for a simple alloy pulley, and it’s been fine. It might not even be the manufacturing process, but rather down to the alloy used in each case, who knows.
Thank you HPA for this master class. One thing i didn't hear mentioned in the class or in the comment section were considerations for engines that have balance shafts to counter-balance certain engine masses (as written in the factory service manual). I'm particular I'm referring to a 1999 Chrysler 4 cylinder, 2.4 liter engine that's similar to the Mitsubishi 420a engine except the head flow is reversed (intake manifold is in the front, exhaust manifold in the rear). I've turbocharger this engine adding forged pistons and rods on the OEM crank. I built this engine when i was younger and dumber and removed the counter balancers and the OEM dampener for a billet aluminum crank pulley. This is a street driven engine making a little more than double the stock power to the wheels. My questions is Are engines with counter balance shafts at less risks of harmonic damage? Thanks Pantyeatr1
Balance shafts are for reducing NVH due to the pistons going up and down. Mass dampers reduce twisting in the crankshaft due to the combustion process.
@@PANTYEATR1 usually in the Evo and DSM world they balance shafts are deleted by turning the bearing over. I’ve heard way too many stories on engine catastrophes because of plz keeping them on their higher HP builds.
@@Andrew49683 the Chrysler 2.4L engine i have is now a forged turbo engine. I'm looking to make 475 whp with it. I'm not sure if that's considered high HP. I'm currently pushing 336 whp and i haven't had a problem yet. This engine's job is strictly street duty. Thanks for your reply.
casue the engine is already tunned,, inside..the weight iside can treat the bibrations you dont need thayt crap super damper,, if you respect the original build. engine machinsit and builder.,
It's, usually, semantics but not only do you need a harmonic damper but if it doesn't have a really significant amount of mass on the outside you also need a belt load on it. The mass and inerta of accessories is also part of the equation.
Cummin's 5.9L in pulling truck's like to break the crank into three pieces when you sit about 3500rpm-4500rpm but if you rev it right threw that zone and get it up to 6000rpm they run just fine but beware of that rpm while running down the track because there is no way to get rid of it, only just shooting threw that range!
The Sterling Damper, TCI Rattler in the U.S., seems to be a better solution as it works with a specific order of vibration rather than a specific frequency.
Agreed with almost everything except I've always looked at the cause of crankshaft torsional vibration from another perspective. My understanding of what you were saying was that is caused by the torsional twist within the length of the crank (which could cause resonance) whereas I've always believed (rightly or wrongly) it was caused by the crankshaft slowing down during compression stroke and speeding up on the power stroke and +/- neutral for the other 2 strokes. Obviously this effect would be greatly increased on a 1 cyl engine and reduced with more cylinders. As I say, this is just how I've always looked at it and I may well be wrong. I welcome input from others.
Hey Andre it was a b20 engine not b18c lol. Block was a b18c but internals b20. Probably made no difference anyway and I'm glad ya saved it when ya did. 😅
Would like to get your input regarding the notion of a dual mass flywheel provide some level of harmonic dampening? Also, a bit of an experience to share. I had swapped to a light weight flywheel on my BMW Z4 M-Coupe, a car that does not have a harmonic crank pulley damper, but does have a factory dual mass flywheel. I noticed some negative effects with the light weight, single mass flywheel to something called gear lash rattle, or gear noise, which I had believed were related to some level of torsional harmonics of the crankshaft. The symptoms were experienced as a lighter rattling sound, when the clutch was out, and the car was in gear, often encountered with low speed, low load driving often encountered when traversing thru a parking lot. I had swapped back to a stock dual mass flywheel as I had concerns with prolonged use with no harmonic dampening on the crankshaft. You mentioned that Porsche is a company that often omits harmonic pulley dampers, and I'd go out on a limb to speculate that those cars all had a dual mass flywheel, or comparable dampening towards the flywheel side of the engine.
Thought I had heard of the oscillations making their way into a manual transmission as well, and the cheaper non-dual mass flywheels (on engines that used them OEM) having odd drivetrain noises or even gear wear. Also heard of just non sprung hubs doing similar but can't recall the source
I replaced my Harmonic balancer with a brand new stock one when i built/stroked my Rb26. Only aimed for 400-450rwkw. (Billet crank, rods, pistons, stroker, head work etc.. ) Did i make a mistake going with a standard balancer? I actually never properly investigated balancers or pulleys until watching your video and now I'm thinking if i made the right choice. Primarily a street car with some track days (1-2 a year).
Andre, what is your experience of putting Fluid dampers on a Subaru boxer engine and have you noticed any difference between a Fluid Damper and ATI damper on a 4G63 engine
I haven't had much experience on that platform sorry. We built one EJ25 based drag engine many years ago and used an ATI damper. I can't really give a thorough comparison of ATI vs FD sadly as we just don't have enough data points. I've used both and had good results with both but can't say one is better than the other - Andre
Hi. This isn't a vehicle engine but it a 4 cylinder engine from a Waverunner that operates as high as 10,000 RPM's were it sits on the set rev limiter. I've noticed with a lot of the Yamaha MR-1 engines that have spent a Conrad out of it's block it's from number one cylinder. I'm wondering if this is due to resignation vibration.
yes, yamanha numer one.. not only yammah ,, car engines have it too. sometimes number 4, had a problem with a racing engine... built by me pilot says wehn he passed over a bridge the he felt engine strage, (couldnt be the engine couase i try to build tehm PErfect) , after analising it, found that the bridge vibrated a lot.. it had metal sheets on some parts.. so when car passed over it it ressoanted. avoid thsoe superdampers its crap,, you need to build your engine accordling and analise them.. buiding a engien reqeuires a lot of knowledgment i mount them , machine them adn study them for 25 years,, and i dont know everything , iam closer.. ;)
What about harmonic balancers with clutch fan’s attached to them like a rb25. Do you recommend switching to thermon fans to take weight off or oem replacement ok. Cars making 340kw doing circuit racing and street driving
Is my stock HB for a Gen v lt1 enough for a lt1 Gen v 416 stroker Whipple 800-1000HP? Been waiting for a super damper for 4 months now with a Mid Jan 24 delivery. If not are there others that u can recommend for a quicker delivery? Thanks. A one year build now waiting on parts
Do you think race engines at Lemans, wether in LMP/ HyperCar, GTE/GT2 classes run super Dampers as well? I’m definitely going to be running it. I heard it saves your main bearings.
They might not depending on the engine design and development, but you will find plenty that do. If you can get your hands on any maintenance schedules (more likely for GTE and GT3 class cars) of a specific engine you are interested in you will even see when they life/replace them. This interview is also really good at covering off what engineers can do at the engine design stage that we can not with our road car turned race engines - Taz. th-cam.com/video/ZX4TR6SgRRY/w-d-xo.html
Why do some engines have no damper from the factory? My experience is with the old Alfa 'Nord' 4 cylinder and the Maserati V6 biturbo 90 degree odd-fire 4 valve engine - no damper on either? That said, the much later Stelvio/Giulia QV V6 does have a harmonic damper, but has almost same displacement and firing order as the Maserati. Would a damper improve the early engines?
Also I had the same theory on the PRV 90 degree Odd fire V6.... it may be beneficial for an odd fire V6. I even found an original 1975 SAE study for this engine, & they did acknowledge the oddfire harmonics but wasn't feasible to counteract due to cost per unit. I can only wonder of the gains, but a torsional vibration study needs to be done so they can properly tune the damper, & is very expensive! See my common above...
In the ATI range they often offer different options for the likes of 'race only' or street with and without accessory drives. Might be worth a look - Andre
I have a question and honestly, it causes A LOT of arguments on the forums. The Suzuki Cappuccino F6A has a harmonic balancer (the car comes with A/C). the Autozam AZ1 using the exact same motor, was sold with a solid pulley, no AC. The harmonic balancer for the cappuccino is extremely hard to come by, whereas the solid az1 pulley is cheap and everywhere. If the harmonic balancers are so important, how can the exact same motor be sold with and without one? The only difference is A/C...
We didn't design that engine so can't answer that for you, however, we do all know that OEMs have put cost reduction to fit price brackets over quality and reliability in many instances in the past. I'd say you could find an example from every OEM of this if you look for it. It's also fair to say OEMs are not perfect and all of them have made outright mistakes. I'm not saying either is the case here, I just feel the way you worded the question implies the OEM knows exactly what they are doing, always, and never put a foot wrong so there must be a good and perfect explanation for this situation, and there simply might not be. Outside of that, have a listen to this interview to help you understand what they are and why they occur. From there you can make your own decision on which path you take and the risk vs reward - Taz. www.hpacademy.com/blog/88kg-500hp-10500rpm-hayabusa-v8-radical-sportscars-rpe-v8-tech-talk/
copy copy, thanks for the reply. Suzuki designed the engine as Mazda only bought the engines from them so it makes sense Mazda could have ditched the balancer for cost... they are kei cars at the end of the day... I'll have a listen to the interview. I've been loving the efi turning course btw. @@hpa101
Great video, I have a questions. Does an ati pulley balance on a machine that balances engine parts ? Do we balance the engine parts without the ATI pulley and mount the pulley once the engine is finished ? thx
This deals with harmonics, not the balance of your parts, no. Different things 🤘 This video will clear up what harmonics are from an engine design standpoint: www.hpacademy.com/blog/88kg-500hp-10500rpm-hayabusa-v8-radical-sportscars-rpe-v8-tech-talk/ - Taz.
if your engine to not have bad ahrmonoics you dont need this,,a dn if he has you ahve to be carefull cause probably it will not solve your problem, you need changes in the pulley
A few people have had that issue. Some have tried group buys through groups associated with their specific vehicle, but that must be a real ball ache! - Taz.
I did the same....the preliminary run was for 100 units, & $5000 a day for torsional analysis, up to 2 days, plus cost of travel, plus cost of a dyno facility. Didn't yet get a quote for each unit!!!!!!!! My theory it may be beneficial for an old Odd-Fire V6. I even found an original 1975 SAE study for this old engine, & they did acknowledge like I thought that this oddfire engine had severe harmonics but wasn't feasible to counteract due to cost per unit. I can only wonder what measurable gains would be gained.
A DMF is primarily intended to reduce vibration an shock being transferred into the gearbox. I can't speak from personal experience on it's affect on the actual engine in terms of mitigating harmonics though sorry - Andre
This is specific to harmonic dampers, not harmonic damper brands. There will be more we didn't mention, but not because they might not be a great option for you. If Ross Performance ticks all the boxes for you, grab one, I'm sure they're great too 😎 - Taz
Not familiar with the L series but all engines have harmonics and for performance applications, especially those that are raced, it's worth looking into. Get in touch with the likes of ATI, Fluidampr or similar and they can help you figure out if you need one for your intended use, and if they have something that suits. In some cases and aftermarket damper might not be available for some engines off the shelf - Taz.
@@termonostruman any useful information? Or just regurgitating what you've heard from your buddies? 4 cylinders have inherent harmonics and mass manufacturing doesn't go to the length to minimize it to the extent of not needing a balance shaft assembly. But hey I guess you're smarter than all the engineers across multiple manufacturing models and have a better solution. 🙄🙄🙄🙄🙄🙄🙄🙄
Most modern engines are actually not properly balanced, they rely on production tolerances which are too loose and have a plus and minus factor, which leaves most engines in poor balance. Also there are primary, secondary balances just as a start, after that hat when hitting high rpm (12,000) rpm and above, lots of extra problems occur. When hitting very high rpm, you will end up needing individual dampers on the cams to prevent them literally exploding at certain frequency ranges....
In any production engine there are tolerances for internal balance of the components. In modern production engines these tolerances are actually pretty reasonable, however they're usually not as tightly controlled as we'd use when building a race engine. As per the video though, it really doesn't matter if every component in the engine was balanced to within 0.00001 grams - The engine will still produce vibrations in the crankshaft that need to be damped out - Andre
I've been lucky enough to be part of engine design in many disciplines, and the affects of engine pulse, as in firing order, to address harmonics, its a complicated situation thar usually ends up in a compromise, for example, you know you will use your engine at a certain frequency/rpm, so you design around that rpm/frequency range with the aim of longevity of the components in its required state. Ultimately, even chassis design and stiffness has to be considered when looking at balance of the engine and the vehicle to give a pleasant environment for the squishy bag of bones that we are to make the best of what we are piloting at the time.. It's not just about engine life, a race car is best thought of as a grand piano, every key needs to be 'in tune' and compliment, or else you end up with a very powerful, but un-driveable lump of metal and carbon that cost a lot of money and achieves very little....
yes they are, thats way they are rpm limited. well about new engines we dont know, they build it not to last we ahve to change this amrket need a big guarantee from the factory....
I have 05 k24a2 motor with with type s pump and vtc intake cam gear and I have unorthodox raceing damper on my k24a2 would it throw more power ??? And is it worth it for the k24a2
You won't make more power as a result of a specific damper. A light weight damper however is no different to reducing the weight of other parts of your rotating assemebly (pistons, rods etc) so the engine can accelerate faster. You won't see this as a result on a dyno but the car can potentially accelerate faster for this reason. That being said, from a quick google it looks like that 'damper' isn't a damper at all and is just a billet light weight pulley which I absolutely wouldn't recommend - Andre
@@hpa101 thanks you so it just light weight pully just make the motor rev a little faster cuse its light weight and I have 1000zz injectors blox raceing and 54mill itbs too 450 fuel welboro pump on stock motor im gonna try to make 265hp on stock motor 05 k24a2 twin lope vteck hopefully it makes good power
If you have stock internals you should run a stock crank pulley, Honda crank pulleys are usually 2 peace. The outer ring of the pulley is bonded to the inner with a layer of rubber, this is sufficient to absorb the crank harmonics for a stock internal K24. If you are using aftermarket forged internals, an ATI or a Fluidamper is best, because they are more capable of absorbing more harmonics which will happen because the aftermarket internals are beefier and therefore can create more harmonic vibrations within the crank, even when perfectly balanced. For you, I’d throw the Unorthodox pulley in the trash, like Andre said, it does no damping AT ALL, put on a stock damper and get a lighter flywheel and clutch if you want a rev-happy K24. BTW, I built a turbo B18C2 in the early 2000s with all aftermarket internals making 400hp for years, it had a Fluidampr from the start, so I can recommend it from perfect 1st person experience.
@@martindworak oh I have full k24a2 05 tsx motor its not a k24a lol k24a is oddysee motor I have 05 k24a2 its a jdm twin lope vteck engine its way different then oddysee motor k24a and yeah I have full brand new exedy stage 2 clutch full raceing flywheels too everything is new on motor well we see if this unorthodox damper works on my stock motor its on the motor already not going to change it we gonna see if it does a difference if not then we will know on dyno numbers I get it tuned next month didn't want to get it tuned in summer time September gets cold out here east side so we see I will go live on dyno not gonna hide nothing lol
@skunk Please don't start attacking people. Let's keep HPA free of that. You can talk about a subject without getting personal even when you strongly disagree with someone. Yes it can be hard, but give it a crack 😎 - Taz.
Expensive yes,needed ? Absolutely.. save your money fellas and get one. The less vibration saving a lot money of yours,especially dude who loves flooring 😅
Building a fast car? Get $400 OFF the VIP package and never pay for another course, EVER: hpcdmy.co/vipy20
50% OFF your first engine building course. Enrol now: hpcdmy.co/offery20
🙋♂ Want some insight into how harmonics are considered during the engine design phase? You will LOVE this! (or you won't, but I bet a chocolate fish that you will): hpcdmy.co/4b5556
TIME STAMPS:
0:00 - Introduction
0:30 - Misconception of harmonic dampers
3:10 - Solid alloy front pulleys
4:45 - Internal vs externally balanced engines
7:05 - What is a damper, and what does it do?
8:20 - Similar in its function to a suspension damper
9:40 - Effects of torsional twist
11:10 - Why do some stock engines not have dampers?
15:10 - Problems with factory dampers
18:55 - Aftermarket dampers
23:00 - Dampers and engine balancing
24:40 - Questions
My father built race engines all his life, the super damper was essential part of the recipe... we'd watch other people lose engines all the time... While ours would win races and last
so do i need a damper?
MotoIQ just made a FANTASTIC, indepth video on this as well. By the way. The last Steve Morris Podcast was great, but not long enough, gotta have him back :)
It's always a challenge trying to extract all the info while being respectful of the guests time. Glad you enjoyed it - Andre
@@hpa101 Oh, i could tell. You two could dive into one of your topics you had written down for a whole podcast each.
One point to make, this (FD) should not be something you only consider on high HP builds. Added this to my daily driver and it has made a massive difference on drivability and even smoothness. There are almost no visible vibrations moving through steering wheel from the engines only the road.
I'm trying to get a one made for the aircooled vws, I work on ... love that you've done to this to a daily, and notice a difference
@@zzzz1192 I wouldn't worry about it for an aircooled VW. As Andre mentioned, the problem shows up when the engine runs at a speed that resonates. For most engines this is a high frequency (high speed). This is a product of torsional rigidity, which is largely affected by crankshaft length. Longer crankshaft, lower resonant freqeuncy. For example old American inline 6s, you will either see them as torquey builds under 6k rpm, or as screaming race engines well past that speed. This is because their cranks are long enough that the destructive harmonic is down around 6k rpm. Now with a stubby VW crankshaft, it's not a problem at all, that resonant frequency is so far out of the range. Spend your money elsewhere on the engine.
I had a different experience - the ATI damper broke a just built engine (M52B28) already on the dyno bench. After the dyno, there was a strong vibration in the engine at 2500 and 5000 rpm, so that the whole car was shaking.
We took the engine apart again, the crankshaft bearings were like driven 400,000km on a brand new engine. We even sent the crankshaft to another country for balancing (just in case, to find out if it was still balanced before) but everything was fine. The engine was repaired and worked again properly with the OEM damper. We put ATI and immediately felt the same vibration at 2500 and 5000 rpm.
Whole story was told to ATI and then ATI replaced this damper but same issue with new damper.
Currently the car is running with an OEM damper and there is no vibration.
Also I found in one BMW forum exactly the same issue with another M52B28 engine.
Woww was wondering same thing with m50🤷🏼♂️
@@madmanwheelies6157 you had same issue in same rpm range?
@@laurihaasma1501 no but saw someone had issue i almost ordered kit and read the same thing
wow. i had run my turbo b28 now 3 years with stock damper and no problems. would be really interesting to know what cause that with ati damper. M54 platform ati has been proven many times to work well.
@@Jakedelus maybe with m54 is different
It might help some to think of the crankshaft as a torsion spring, being twisted by the inertial loads of the pistons and rods, and firing impulses.
Every spring has a frequency, or speed, it will 'flex' at, and it's sometimes called the "critical frequency", "resonant frequency", or even "harmonic frequency".
Most of the time, the loads on the crankshaft are not at, or near, this critical frequency, and there's little variation in the crankshaft's twisting forces.
However, at some engine speeds and/or torque values, these forces will co-incide with the twisting and increase the specific loads, or stresses, at specific points of the crankshaft - this is often referred to as "positive feedback", it's not quite right, but it means it increases the forces over time, possibly to the point where the mechanical strength of the crankshaft can't resist the stresses on it and it breaks. In extreme cases it can happen almost immediately, but what's more common is the formation of cracks that slowly weaken the crank' to the point where it fails.
Think of it as someone swinging on a swing - under normal swings one just has a nice regular swing, but if someone comes up behind and gives a little extra push at the right time, and keeps doing it, that little extra push over time can have a big affect over a fairly short number of swings.
Can't recall if it was mantioned, but a common sign of excess crankshaft deflection, twisting, is when flywheel bolts keep working loose - the twisting crankshaft is working against the inertia of the flywheel. Some engines are prone to this, such as the Pinto and Barra, and a good harmonic damper/dampener can drastically improve this.
Some of the best information I've found on the internet on the subject thank you
Glad it was helpful!
I bought into the whole "ATI is the best" garbage. 665" Chevy on alky. Continually had issues with rocker arm adjusting nuts coming loose, flexplate bolts coming loose, and other severe valve train issues. All were signs of either severe detonation or out of control harmonics. There was also damage on the bearings that is caused by either detonation or out of control harmonics. Also ran a belt drive. However, there were ZERO signs of detonation on the piston crowns, chambers, or spark plugs. Methanol engines (mine is) are very hard to get into detonation unless something is very wrong. Mine had a very safe tune in it as well....When it broke a rod, it was determined that the damper was not sufficiently controlling the vibrations in the crank. I called ATI and told them what I found, they told me that I had the wrong damper on my engine. The damper I had was the one THEY told me was the correct one for my combo. There was also significant micro welding on the snout where the damper was also indicating it was moving and not dampening. Press fit was dead on spec as indicated. After looking at all this, and talking with ATI, I'm going back to Fluidampr. Ran them in the past with ZERO issues, for decades on racing and street engines. Never once did I have the issues that I had with an ATI.
I really love stuff like this even though i cant currently spend any money on my car and my car cant really be tuned meaningfully i find this very interesting and i've always loved the idea of building a car that has all of these little things that can free up more power that is currently there but wasted by heavier components and is just over all really responsive, thanks for sharing your Knowledge!
Very interesting. A friend of mine ruined his 2JZ crankshaft (crack on the 6th conrod journal) and we actually suspected that happened because the damper pulley he used was a mere aluminum pulley (in fact not damping anything at all).
I put an aluminium pulley on my rb20, ran it at two events and swapped it out for a romac balancer - the aluminium had weird peening marks at the crank snout shoulder like it had been hit with a tiny hammer and the crank bolt was still tight
Indeed. Vibrations are known to create kind of micro peening, sometimes causing the assembly almost impossible to separate.
The 2JZGTE I am talking about has been used for drifting. The aluminum damper did its pulley job as long as the engine was under light boost, issue occurred at third event after the engine received new turbo setup for more serious boost (~700hp).
We are rebuilding for next event. Stock damper will be used that time
You can measure the torsional vibrations with a rotational laser vibrometer. They’re not cheap but also not expensive, I borrowed one from a friends shop. It will show you where you will have resonance issues in the engine.
I also have a hypothesis that certain materials (forged vs, cast etc.) are more prone to having resonance issues. We built a high revving boxer engine and measured huge resonance issues when going above 8k rpm, but later on changed the setup and it showed almost no resonance with the new billet crankshaft, so we opted for a simple alloy pulley, and it’s been fine. It might not even be the manufacturing process, but rather down to the alloy used in each case, who knows.
next time build your engine the right way
Thank you HPA for this master class. One thing i didn't hear mentioned in the class or in the comment section were considerations for engines that have balance shafts to counter-balance certain engine masses (as written in the factory service manual).
I'm particular I'm referring to a 1999 Chrysler 4 cylinder, 2.4 liter engine that's similar to the Mitsubishi 420a engine except the head flow is reversed (intake manifold is in the front, exhaust manifold in the rear). I've turbocharger this engine adding forged pistons and rods on the OEM crank. I built this engine when i was younger and dumber and removed the counter balancers and the OEM dampener for a billet aluminum crank pulley. This is a street driven engine making a little more than double the stock power to the wheels. My questions is
Are engines with counter balance shafts at less risks of harmonic damage?
Thanks
Pantyeatr1
Balance shafts are for reducing NVH due to the pistons going up and down.
Mass dampers reduce twisting in the crankshaft due to the combustion process.
@@dontfeelcold thanks for explaining. I'll see if i can get a dampener for this old 4 cylinder
@@PANTYEATR1 usually in the Evo and DSM world they balance shafts are deleted by turning the bearing over. I’ve heard way too many stories on engine catastrophes because of plz keeping them on their higher HP builds.
@@Andrew49683 the Chrysler 2.4L engine i have is now a forged turbo engine. I'm looking to make 475 whp with it. I'm not sure if that's considered high HP. I'm currently pushing 336 whp and i haven't had a problem yet. This engine's job is strictly street duty. Thanks for your reply.
Got a 02 s2000 ap1 9k redline has 250k miles,it has a lightweight crank pulley ,no issues.
Great to hear you haven't had issues. Long may that last 😎 - Taz.
casue the engine is already tunned,, inside..the weight iside can treat the bibrations
you dont need thayt crap super damper,, if you respect the original build.
engine machinsit and builder.,
It's, usually, semantics but not only do you need a harmonic damper but if it doesn't have a really significant amount of mass on the outside you also need a belt load on it.
The mass and inerta of accessories is also part of the equation.
Cummin's 5.9L in pulling truck's like to break the crank into three pieces when you sit about 3500rpm-4500rpm but if you rev it right threw that zone and get it up to 6000rpm they run just fine but beware of that rpm while running down the track because there is no way to get rid of it, only just shooting threw that range!
The Sterling Damper, TCI Rattler in the U.S., seems to be a better solution as it works with a specific order of vibration rather than a specific frequency.
Agreed with almost everything except I've always looked at the cause of crankshaft torsional vibration from another perspective. My understanding of what you were saying was that is caused by the torsional twist within the length of the crank (which could cause resonance) whereas I've always believed (rightly or wrongly) it was caused by the crankshaft slowing down during compression stroke and speeding up on the power stroke and +/- neutral for the other 2 strokes. Obviously this effect would be greatly increased on a 1 cyl engine and reduced with more cylinders. As I say, this is just how I've always looked at it and I may well be wrong. I welcome input from others.
As far as I'm aware, the torsional twist is caused by exactly what you described. Same big picture just different parts zoomed in on
Hey Andre it was a b20 engine not b18c lol. Block was a b18c but internals b20. Probably made no difference anyway and I'm glad ya saved it when ya did. 😅
Would like to get your input regarding the notion of a dual mass flywheel provide some level of harmonic dampening?
Also, a bit of an experience to share. I had swapped to a light weight flywheel on my BMW Z4 M-Coupe, a car that does not have a harmonic crank pulley damper, but does have a factory dual mass flywheel. I noticed some negative effects with the light weight, single mass flywheel to something called gear lash rattle, or gear noise, which I had believed were related to some level of torsional harmonics of the crankshaft. The symptoms were experienced as a lighter rattling sound, when the clutch was out, and the car was in gear, often encountered with low speed, low load driving often encountered when traversing thru a parking lot. I had swapped back to a stock dual mass flywheel as I had concerns with prolonged use with no harmonic dampening on the crankshaft. You mentioned that Porsche is a company that often omits harmonic pulley dampers, and I'd go out on a limb to speculate that those cars all had a dual mass flywheel, or comparable dampening towards the flywheel side of the engine.
Thought I had heard of the oscillations making their way into a manual transmission as well, and the cheaper non-dual mass flywheels (on engines that used them OEM) having odd drivetrain noises or even gear wear. Also heard of just non sprung hubs doing similar but can't recall the source
I replaced my Harmonic balancer with a brand new stock one when i built/stroked my Rb26. Only aimed for 400-450rwkw. (Billet crank, rods, pistons, stroker, head work etc.. ) Did i make a mistake going with a standard balancer? I actually never properly investigated balancers or pulleys until watching your video and now I'm thinking if i made the right choice. Primarily a street car with some track days (1-2 a year).
Are you going to put a fluid damper on your rx7?
missed this live. I would have asked, do you find stock bonded ones quickly fail with supercharger belt loads....??
Andre, what is your experience of putting Fluid dampers on a Subaru boxer engine and have you noticed any difference between a Fluid Damper and ATI damper on a 4G63 engine
I haven't had much experience on that platform sorry. We built one EJ25 based drag engine many years ago and used an ATI damper. I can't really give a thorough comparison of ATI vs FD sadly as we just don't have enough data points. I've used both and had good results with both but can't say one is better than the other - Andre
Hi.
This isn't a vehicle engine but it a 4 cylinder engine from a Waverunner that operates as high as 10,000 RPM's were it sits on the set rev limiter.
I've noticed with a lot of the Yamaha MR-1 engines that have spent a Conrad out of it's block it's from number one cylinder.
I'm wondering if this is due to resignation vibration.
yes, yamanha numer one.. not only yammah ,, car engines have it too.
sometimes number 4,
had a problem with a racing engine... built by me
pilot says wehn he passed over a bridge the he felt engine strage, (couldnt be the engine couase i try to build tehm PErfect) , after analising it, found that the bridge vibrated a lot.. it had metal sheets on some parts.. so when car passed over it it ressoanted.
avoid thsoe superdampers its crap,, you need to build your engine accordling and analise them..
buiding a engien reqeuires a lot of knowledgment i mount them , machine them adn study them for 25 years,, and i dont know everything , iam closer.. ;)
Dont buy a theories as truth , theory is differetn from practise.
What about harmonic balancers with clutch fan’s attached to them like a rb25. Do you recommend switching to thermon fans to take weight off or oem replacement ok. Cars making 340kw doing circuit racing and street driving
Is my stock HB for a Gen v lt1 enough for a lt1 Gen v 416 stroker Whipple 800-1000HP? Been waiting for a super damper for 4 months now with a Mid Jan 24 delivery. If not are there others that u can recommend for a quicker delivery? Thanks. A one year build now waiting on parts
Do you think race engines at Lemans, wether in LMP/ HyperCar, GTE/GT2 classes run super Dampers as well? I’m definitely going to be running it. I heard it saves your main bearings.
They might not depending on the engine design and development, but you will find plenty that do. If you can get your hands on any maintenance schedules (more likely for GTE and GT3 class cars) of a specific engine you are interested in you will even see when they life/replace them.
This interview is also really good at covering off what engineers can do at the engine design stage that we can not with our road car turned race engines - Taz.
th-cam.com/video/ZX4TR6SgRRY/w-d-xo.html
Why do some engines have no damper from the factory? My experience is with the old Alfa 'Nord' 4 cylinder and the Maserati V6 biturbo 90 degree odd-fire 4 valve engine - no damper on either? That said, the much later Stelvio/Giulia QV V6 does have a harmonic damper, but has almost same displacement and firing order as the Maserati. Would a damper improve the early engines?
11:20
Cause all the engine you mentioned are shit.
Also I had the same theory on the PRV 90 degree Odd fire V6.... it may be beneficial for an odd fire V6. I even found an original 1975 SAE study for this engine, & they did acknowledge the oddfire harmonics but wasn't feasible to counteract due to cost per unit.
I can only wonder of the gains, but a torsional vibration study needs to be done so they can properly tune the damper, & is very expensive! See my common above...
I bought one for my car but it doesn't have a pull for thr powersteering pump 😅 so if I want to use it I guess I gota delete ps 😢
In the ATI range they often offer different options for the likes of 'race only' or street with and without accessory drives. Might be worth a look - Andre
Lots of electric power steering pump conversions out there too, those actually WILL gain you a few hp by reducing parasitic losses
I have a question and honestly, it causes A LOT of arguments on the forums. The Suzuki Cappuccino F6A has a harmonic balancer (the car comes with A/C). the Autozam AZ1 using the exact same motor, was sold with a solid pulley, no AC. The harmonic balancer for the cappuccino is extremely hard to come by, whereas the solid az1 pulley is cheap and everywhere. If the harmonic balancers are so important, how can the exact same motor be sold with and without one? The only difference is A/C...
We didn't design that engine so can't answer that for you, however, we do all know that OEMs have put cost reduction to fit price brackets over quality and reliability in many instances in the past. I'd say you could find an example from every OEM of this if you look for it. It's also fair to say OEMs are not perfect and all of them have made outright mistakes.
I'm not saying either is the case here, I just feel the way you worded the question implies the OEM knows exactly what they are doing, always, and never put a foot wrong so there must be a good and perfect explanation for this situation, and there simply might not be.
Outside of that, have a listen to this interview to help you understand what they are and why they occur. From there you can make your own decision on which path you take and the risk vs reward - Taz.
www.hpacademy.com/blog/88kg-500hp-10500rpm-hayabusa-v8-radical-sportscars-rpe-v8-tech-talk/
copy copy, thanks for the reply. Suzuki designed the engine as Mazda only bought the engines from them so it makes sense Mazda could have ditched the balancer for cost... they are kei cars at the end of the day... I'll have a listen to the interview. I've been loving the efi turning course btw. @@hpa101
Great video, I have a questions. Does an ati pulley balance on a machine that balances engine parts ? Do we balance the engine parts without the ATI pulley and mount the pulley once the engine is finished ? thx
This deals with harmonics, not the balance of your parts, no. Different things 🤘
This video will clear up what harmonics are from an engine design standpoint: www.hpacademy.com/blog/88kg-500hp-10500rpm-hayabusa-v8-radical-sportscars-rpe-v8-tech-talk/ - Taz.
if your engine to not have bad ahrmonoics you dont need this,,a dn if he has you ahve to be carefull cause probably it will not solve your problem, you need changes in the pulley
Has anybody any experience with Ross Performance Parts dampers?
Hello. I have one installed on my s50b32 . It's fine for now . Had a couple of track days already. I did install a duct to keep it cooler.
my experience says if you need a damper your in serious troubles.
Contacted FluidDampr about one for the JB-JL in my '97 Mira TR-XX, but they need at least 150 to make a batch 😓
A few people have had that issue. Some have tried group buys through groups associated with their specific vehicle, but that must be a real ball ache! - Taz.
I did the same....the preliminary run was for 100 units, & $5000 a day for torsional analysis, up to 2 days, plus cost of travel, plus cost of a dyno facility. Didn't yet get a quote for each unit!!!!!!!!
My theory it may be beneficial for an old Odd-Fire V6. I even found an original 1975 SAE study for this old engine, & they did acknowledge like I thought that this oddfire engine had severe harmonics but wasn't feasible to counteract due to cost per unit.
I can only wonder what measurable gains would be gained.
The dual mass flywheel, can actually help to mitigate hamonic balance?
A DMF is primarily intended to reduce vibration an shock being transferred into the gearbox. I can't speak from personal experience on it's affect on the actual engine in terms of mitigating harmonics though sorry - Andre
@@hpa101 thinking about it probably not, because is very loose in the middle.
No mention of the Aussie Ross performance dampers 😢
This is specific to harmonic dampers, not harmonic damper brands. There will be more we didn't mention, but not because they might not be a great option for you. If Ross Performance ticks all the boxes for you, grab one, I'm sure they're great too 😎 - Taz
I remember @GetaDomTune made a video on this years ago and a large portion of the Subaru community tried to dismiss his claims.
At their own peril sadly - Taz.
Is dual mass flywheel basically a harmonic balancer?
if you remove it you will need a damper for sure.
Please help! Would these work and/or be beneficial on non keyed ford L series motors?
Not familiar with the L series but all engines have harmonics and for performance applications, especially those that are raced, it's worth looking into.
Get in touch with the likes of ATI, Fluidampr or similar and they can help you figure out if you need one for your intended use, and if they have something that suits.
In some cases and aftermarket damper might not be available for some engines off the shelf - Taz.
i would bet you dont need it, but .. jsut testin..
@@termonostruman since balance shaft delete is common for these engines, I was just wondering if it would be a benefit and/or make a difference
@@popomomo12 fisrst engines shouldnt have balace shfts the are bad build.
second should never delete them
yor asking for destruction
@@termonostruman any useful information? Or just regurgitating what you've heard from your buddies? 4 cylinders have inherent harmonics and mass manufacturing doesn't go to the length to minimize it to the extent of not needing a balance shaft assembly. But hey I guess you're smarter than all the engineers across multiple manufacturing models and have a better solution. 🙄🙄🙄🙄🙄🙄🙄🙄
Most modern engines are actually not properly balanced, they rely on production tolerances which are too loose and have a plus and minus factor, which leaves most engines in poor balance.
Also there are primary, secondary balances just as a start, after that hat when hitting high rpm (12,000) rpm and above, lots of extra problems occur.
When hitting very high rpm, you will end up needing individual dampers on the cams to prevent them literally exploding at certain frequency ranges....
In any production engine there are tolerances for internal balance of the components. In modern production engines these tolerances are actually pretty reasonable, however they're usually not as tightly controlled as we'd use when building a race engine. As per the video though, it really doesn't matter if every component in the engine was balanced to within 0.00001 grams - The engine will still produce vibrations in the crankshaft that need to be damped out - Andre
I've been lucky enough to be part of engine design in many disciplines, and the affects of engine pulse, as in firing order, to address harmonics, its a complicated situation thar usually ends up in a compromise, for example, you know you will use your engine at a certain frequency/rpm, so you design around that rpm/frequency range with the aim of longevity of the components in its required state.
Ultimately, even chassis design and stiffness has to be considered when looking at balance of the engine and the vehicle to give a pleasant environment for the squishy bag of bones that we are to make the best of what we are piloting at the time..
It's not just about engine life, a race car is best thought of as a grand piano, every key needs to be 'in tune' and compliment, or else you end up with a very powerful, but un-driveable lump of metal and carbon that cost a lot of money and achieves very little....
yes they are, thats way they are rpm limited.
well about new engines we dont know, they build it not to last
we ahve to change this amrket need a big guarantee from the factory....
I have 05 k24a2 motor with with type s pump and vtc intake cam gear and I have unorthodox raceing damper on my k24a2 would it throw more power ??? And is it worth it for the k24a2
You won't make more power as a result of a specific damper. A light weight damper however is no different to reducing the weight of other parts of your rotating assemebly (pistons, rods etc) so the engine can accelerate faster. You won't see this as a result on a dyno but the car can potentially accelerate faster for this reason. That being said, from a quick google it looks like that 'damper' isn't a damper at all and is just a billet light weight pulley which I absolutely wouldn't recommend - Andre
@@hpa101 thanks you so it just light weight pully just make the motor rev a little faster cuse its light weight and I have 1000zz injectors blox raceing and 54mill itbs too 450 fuel welboro pump on stock motor im gonna try to make 265hp on stock motor 05 k24a2 twin lope vteck hopefully it makes good power
If you have stock internals you should run a stock crank pulley, Honda crank pulleys are usually 2 peace. The outer ring of the pulley is bonded to the inner with a layer of rubber, this is sufficient to absorb the crank harmonics for a stock internal K24. If you are using aftermarket forged internals, an ATI or a Fluidamper is best, because they are more capable of absorbing more harmonics which will happen because the aftermarket internals are beefier and therefore can create more harmonic vibrations within the crank, even when perfectly balanced. For you, I’d throw the Unorthodox pulley in the trash, like Andre said, it does no damping AT ALL, put on a stock damper and get a lighter flywheel and clutch if you want a rev-happy K24.
BTW, I built a turbo B18C2 in the early 2000s with all aftermarket internals making 400hp for years, it had a Fluidampr from the start, so I can recommend it from perfect 1st person experience.
@@martindworak oh I have full k24a2 05 tsx motor its not a k24a lol k24a is oddysee motor I have 05 k24a2 its a jdm twin lope vteck engine its way different then oddysee motor k24a and yeah I have full brand new exedy stage 2 clutch full raceing flywheels too everything is new on motor well we see if this unorthodox damper works on my stock motor its on the motor already not going to change it we gonna see if it does a difference if not then we will know on dyno numbers I get it tuned next month didn't want to get it tuned in summer time September gets cold out here east side so we see I will go live on dyno not gonna hide nothing lol
@skunk Please don't start attacking people. Let's keep HPA free of that. You can talk about a subject without getting personal even when you strongly disagree with someone. Yes it can be hard, but give it a crack 😎 - Taz.
JTT#31‽
Expensive yes,needed ? Absolutely.. save your money fellas and get one. The less vibration saving a lot money of yours,especially dude who loves flooring 😅
really ??
did you tested it to sentence what your saying??
@@termonostruman ever experience the crank pulley burst off to two pieces? If yes then you know what i am talking about.
@@CelebesViking yes you experience it your sofukindumb
Yeah any engine over 1k HP is never going to be safe to drive normally. lol Even with a harmonic dampener, it would save it from quick wear and tear.
in europe they dont use dampers they try to build engiens more prefectly.