Lightweight Crank Pulley Check-In

[95blackGsTurbo]

I have seen problems with just bolting these things on time and time again. I also have seen them have no problems if they are used properly. The last motor rebuild I did for a customer, I took the lightweight pulley in to have it balanced with the rotating assembly. Though the machine shop did say that the pulley definitely made a big difference in how far it was off. It still balanced perfect and everything is running great so far.

 

[dsm-onster]

So in some instances, the one piece pulley has been out of balance or throws the assembly off balance (Well that means it was out of balance). . . That may happen with a damped pulley. OEM or fluidamper? I doubt.

 

[tkelly27]

The big boys use lightened, aluminum pulleys. At the end of the day, I take their knowledge and experience as proof over the many over-opinionated, undereducated, cheap and scared people of the internet.

Not true.

evolutionm.net - View Single Post - So let's finally set it straight with aftermarket crank pulleys...

After finding uneven main bearing wear Buscher won't run them. There used to be a page with pictures. He said it started happening when he switched to an UD pulley, and went away when he went with a fluidampr.

Run one if you want. I feel there are better ways to make power.

 

[ramsack]

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That's all I need to stay with a damped pulley.

 

[viprez586]

An undampened crank will have more deflection due to torsional harmonics, which directly leads to increased wear on the main bearings. The effect can be more or less pronounced depending on engine geometry and power levels.

Enough cylinder pressure will break any crank if it's the weakest link; an undampened crank is just more susceptible due to the increased harmonic vibration.

I've seen cars run the same timing belt for over 200,000 miles. So is it safe to say that they only need to be changed at 200,000 miles because 1 or 10 made it that far? Or do you use some engineering and a bit of theoretical MTBF (mean time between failure) data, and recommend changing them at 60,000 miles?

Engineers spend lots and lots of hours with their heads in books for a reason. It's up to you if you want to tempt the laws of physics, or trust what the math tells us.

Best said phrase in this thread. --^

To all the non-believers - go argue your points with a certified engine assembly technician at a plant(any OEM)- better yet the guy who designs and tests them. Let me know if you win that argument.

Yes the "big dogs" run them(un-dampened). The "big dogs" also have the cash to teardown their motor after a season/whenever they feel like it. So go be "like" the "big dogs" no one is stopping you.

It's your car - you take the risk - you beat the snot out of it - you test it's limits. Who care's? Not I.
I'll stick with what's been tested and proven in a facility with more (than you or most people would be willing the spend) material, manpower, machinery and endless amount of funds to support their test results.
So the factory H.B. Failed? Common problem? Ever heard of contamination? Recall? TSB?
How about that nut behind the wheel banging through every gear squeezing out every couple of HP he can get out of it. (Esp. you who shift @ rev limiter)

 

[dsm-onster]

They don't do it to squeeze every horsepower out of their setup. They do it to to squeeze every penny out of their setup. Stock or fluidamper is so expensive

 

[viprez586]

They don't do it to squeeze every horsepower out of their setup. They do it to to squeeze every penny out of their setup. Stock or fluidamper is so expensive

I was referring to us. The ones who modify it to 285-500+ HP and then some.
Then are puzzled/angry when they have little reliability issues. - Like(in fact) the OEM designed the H.B. to handle that kind of load(repetitive racing/abuse).

But very true - they build cars as cheap as possible now-a-days. Any short-cut to reduce production cost at the expensive of the consumer and us technicians.

I bought an OEM one btw, think I scored it for $100. That's cheap IMHO.

 

[Boosted98gsx]

I bought an OEM one btw, think I scored it for $100. That's cheap IMHO.

I think that's normal price.

 

[SpawnedX]

Not true.

evolutionm.net - View Single Post - So let's finally set it straight with aftermarket crank pulleys...

After finding uneven main bearing wear Buscher won't run them. There used to be a page with pictures. He said it started happening when he switched to an UD pulley, and went away when he went with a fluidampr.

Run one if you want. I feel there are better ways to make power.

Didn't realize David Buschur made up the entirety of all DSM big boys. I am sure there are plenty of people who didn't know that.

 

[ramsack]

Bushur makes products and sells them. I'm sure they do research on things. What other "big boys" are there that do R&D? Anyone who is saying not to run them are published scientifically and it was lab researched, just like the people who designed our engines. Everyone who is saying just slap an aluminum pulley on are basically just people who say that they lucked out. I really don't get the mentality that makes people think Mitsubishi used a damper for no reason. They handle stock power just fine, and there are alternatives out there meant for higher power output. V8s were around long before our engines. It's not like the Japanese invented the 4g63 out of nothing. It was based on what was created before they made it. As everyone has said, run at your own risk, and don't come crying here when things go to shit.

 

[SpawnedX]

Bushur makes products and sells them. I'm sure they do research on things. What other "big boys" are there that do R&D? Anyone who is saying not to run them are published scientifically and it was lab researched, just like the people who designed our engines. Everyone who is saying just slap an aluminum pulley on are basically just people who say that they lucked out. I really don't get the mentality that makes people think Mitsubishi used a damper for no reason. They handle stock power just fine, and there are alternatives out there meant for higher power output. V8s were around long before our engines. It's not like the Japanese invented the 4g63 out of nothing. It was based on what was created before they made it. As everyone has said, run at your own risk, and don't come crying here when things go to shit.

When someone can provide to me proof outside of the same 5 pictures of turned cranks snapping. Then everything there will matter.

Until then, I stand behind that the "increased risk" of these pulleys is highly exaggerated and are probably no more dangerous than a stock pulley.

 

[Locke]

We cited well established and very accepted theories of classical mechanics that do explain these phenomena. "I don't (want to) believe it" and "It didn't happen to me!" seem to broadly sum up rebuttals.

There is an increased risk, but how much would at this point be pure speculation without further data. Shoving the notion aside would be irrational.

I am done with this thread, it is becoming circular.

 

[dsm-onster]

I wholeheartedly concur. I've never seen a picture of a blackhole (would be fairly hard to see I gather). But, I've seen cosmologists bring out proof that there's one in the center of our galaxy based on the movement of the star cluster close to the center of the galaxy. Likewise, I've never seen a crank flex (would be fairly hard to see I gather). But, Buschur and the gentleman on the evom forum brought their proof to the table of the bearing wear that mysteriously developed with the non damped pulley and then it further mysteriously left with the removal of it. The mechanics behind the theory is sound enough for Mitsu to install a damper on ALL their motors. The risk goes up without a two piece damper. Else, economy over waste; Mitsu is in it for the money.

Quantify the risk? There's two gentlemen we've referred to that had failures. How many motors did Buschur deal with that had bearing wear from no damping? take all those numbers and divide them in to the total who've spoke up here plus those failures. More have run an undamped pulley, the crank is fine, and not spoke. Same goes with those that have had failures, and not spoke. This is a poll to get a picture of the whole.

Is the stock damper worthless at X torque? Again quantify the risks yourself. don't come out with a broad statement that 'well it didn't fail with me and the failures were all on cut cranks so it's a non issue'. NOTHING is cut and dry without proper consistant repetable data.

ALL the failures were cut cranks? again was buschurs crank or cranks cut? we need more information. But I'll tell you this, Coltboostin and Kevin Jewer run cut cranks. Theirs didn't break with VERY high torque numbers. They run fluidampers? Someone go find out. If a damper saves a cut crank (including Buschur's if his were cut) then you see that there IS an increase in flex when a damper is not used. A smaller crank fails first. If dampers saved their cut cranks and mitsu puts dampers on oem cranks, there's a healthy enough risk for me to be installing a damper always.

 

[SpawnedX]

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There is a picture of Jewer's build, he has a Fluidampr. Want to see a picture of my Fluidampr as well? Because the point is being sorely lost on people here.

Your pictures and theories mean nothing to me and many people. Unless you can ask that crank what exactly happened, you can only make assumptions. Of the pictures circulating here, that originated on the NABR forums, you read those threads and you will find out they were turned cranks. How much of this added to the outcome?

Who knows how many bearings were worn on Buschur's motor, thanks for telling us he had a crank balance issue. You can replace bearings once every 6 months to a year, what any person running real power should do. What is in question here, is whether or not cranks snap because of those pulleys. The answer is short, you or I will never know.

My theory, something else contributed to those few and far in-between problems, because if the pulley was solely responsible, then we would see A LOT more cases. You have a better chance of crankwalking.

Other theories? Some engineers who make their money selling dampers told me so. Well Unorthodox racing tells me the other way. Guess what? Both are self-serving arguments.

Again the bottom line, do whatever the eff you feel like, it's your motor.

 

[dsm-onster]

Who knows how many bearings were worn on Buschur's motor, thanks for telling us he had a crank balance issue. You can replace bearings once every 6 months to a year, what any person running real power should do. What is in question here, is whether or not cranks snap because of those pulleys. The answer is short, you or I will never know. . .

. . .Other theories? Some engineers who make their money selling dampers told me so. Well Unorthodox racing tells me the other way. Guess what? Both are self-serving arguments.

Buschur's cranks were causing bearing wear with out a damper. Same cranks did not show bearing wear with damper. Same with the evom guy. Cranks wern't out of balance, because a damper doesn't alter balance. The issue is that the cranks flexed enough to wear the bearings. does it lead to breakage? Who started this theory that a cut crank is weak enough for such flexing to break it?

I don't want my crank flexing enough to cause bearing wear. Even if I pull it down after every race. Altering the timing between the cylinders isn't ideal; and repetitive bending of metal with enough frequency over enough time does what?

My crank is cut. All your theory is really saying is that one running a cut crank should CERTAINLY have a proper damper.

With respect to selfserving expert opinion, a neutral authority to site is Mitsubishi. They build their motors with dampers. Though it would be a bit more cost effective not to.

 

[SpawnedX]

Buschur's cranks were causing bearing wear with out a damper. Same cranks did not show bearing wear with damper. Same with the evom guy. Cranks wern't out of balance, because a damper doesn't alter balance. The issue is that the cranks flexed enough to wear the bearings. does it lead to breakage? Who started this theory that a cut crank is weak enough for such flexing to break it?

I don't want my crank flexing enough to cause bearing wear. Even if I pull it down after every race. Altering the timing between the cylinders isn't ideal; and repetitive bending of metal with enough frequency over enough time does what?

My crank is cut. All your theory is really saying is that one running a cut crank should CERTAINLY have a proper damper.

With respect to selfserving expert opinion, a neutral authority to site is Mitsubishi. They build their motors with dampers. Though it would be a bit more cost effective not to.

Mitsubishi is a notorious over/under engineering company that cuts corners when they shouldn't and overpads when there is no need. All my theory is saying is I don't care about your (not you dsm-onster, just your in general) crap, I do what I want. And what I want is to run a Fluidampr because I am ok with not reinventing the wheel, but rather forging it from aluminum rather than carve it from wood and slap a tire on it.

 

[ramsack]

Mitsubishi is a notorious over/under engineering company that cuts corners when they shouldn't and overpads when there is no need

This is evident by that retarded rubber piece on the 2g driver's side motor mount. On mr2s there is a triangular rubber piece on the subframe that touches nothing else.

 

[viprez586]

This is evident by that retarded rubber piece on the 2g driver's side motor mount. On mr2s there is a triangular rubber piece on the subframe that touches nothing else.

It's for vibration dampening/absorption.
Lexus tends to stick a few more all over the car for smoothness & lowering noises you'd normally hear.
Some even have two on the exhaust.

 

[kimcheefists]

Here's a video that shows the difference between the two types of pullies. Even though the FSM straight up tells us why we need a dampened pulley, well, here's another resource.

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I didn't make this video.

 

[SpawnedX]

, there is nothing scientific about that video and it really proves nothing.

I still stand behind that this issue is blown out of proportion. I still have my Fluidampr though. I doubt the aluminum frees up that much power.

 

[ramsack]

This Pool Can Create Waves In Any Shape You Want

Around 3 minutes in see what the water does, this is resonance.