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Crank pulley w/o damper causes engine failure?

87K views 209 replies 40 participants last post by  team3d 
#1 ·
Preface, I am relatively new...HERE. Not to forums, Honda engines, or engineering for that matter. I have an issue to debate and this seems to be the place to tackle it. Issue: the excessive paranoia that is the use of a non-dampened crankshaft pulley on a Honda engine will cause it to fail.

In theory I agree with this notion. Yes the rubber ring in a stock pulley is designed to dampen vibration. I have read a number of theories on the issue and while all are plausible, and none of them seem to be supported by what I would call "real world" evidence. Call me the devil's advocate. Maybe I am in the dark. Link me to some examples. Help me out.

In practicality, I dispute the notion that your Honda engine will fail because of the removal of the damper. I'd argue that daily driven cars are not abused enough to show any ill effect of having a billet aluminum pulley installed, at least not within a engine's normal life. What does this mean? It means, the amount of life you stand to lose by removing the damper is negligible compared to the added joy you got from driving it that entire time. If you had a lot of added joy, you were in all likelihood driving harder which would certainly cause the need for a rebuild at some point regardless of what pulley was on it. Likewise, a more sane driver would not likely incur enough stress to cause damage that the driver would notice in the car's lifetime they could attribute specifically to the damper being gone. In other words, beating on the engine (in racing or on the street) causes more damage than the damper prevents. Note, the fluidampr part and anything sfi approved is really made for RACING. Racing is more stressful than street driving. The blanket recommendation of race parts for the street is, well, wrong.

Furthermore, while the K-series is an awesome power-plant, nothing makes it so special that it is somehow more impacted by the tried-and-true power mod of lightening accessory drivetrain components. It is an engine, and a damn well built one. If anything past engines would be more susceptible to the dangers of removing the cranker damper. Aluminum pulleys historically have not caused failures for Honda owners. Because if they did, wouldn't UR be out of business? Or, are the people driving engines with light aluminum crank pulleys too stupid to realize their engines are failing, and the engines are too stupid too, because they fail to fail? I've read the theory. I've read the warnings. I've read the dangers. I think it is all a scare tactic propagated by people who have an inherent need to lead others away from danger and be the preemptive savior.

Are there any documented cases of engine failure due to elimination of the damper in the crankshaft pulley? I'd love to see them. Because while an obsessive-compulsive engine builder might argue the outcome of removing the damper, most of the rest of us are different, and are not paying a price.

Prove me wrong, please :)

Marcus

**********Update 6/21/2012: In 10 pages and two and a half years nobody has convincingly made a case that there is actually an issue running an aluminum pulley on a K-series. I have been running a UR set on my TSX for more than 20K miles, driven daily, also taking a track day, and with regular oil sample tests am finding no reason not to run an aluminum pulley for the power benefit.
 
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#190 ·
I have had an underdrive aluminum pulley kit on my TSX for about 24,000 miles now. I have taken it to two track days, I have beat on it up the California coast twice, lots of stop and go as well as freeway driving.

My proof my engine is in good shape after all of this?

http://www.heeltoeauto.com/files/tech/HT SPEC TSX-2012-1007.pdf

The data is not totally complete there, the first few changes were all conventional oil, and one of the more recent ones were as well. We have one test where iron is pretty high, but I think this is because I had too many miles on that oil.

Overall, the engine is healthy, does not burn oil, does not have any excess wear at all.

Aluminum pulleys bad for K-series engines = MYTH!

Marcus
 
#191 ·
Nice oil stats, however this information is not conclusive. The effects of harmonic vibration are not easily visible, and certainly not identifiable by an oil change. A better indication of engine health would be something like bearing wear inspection, compression test, etc.

Also there is a big difference between "MYTH" and Science...
 
#192 ·
Oil analysis is a perfectly good method of checking for excess wear in the engine. For you to suggest that the engine might be wearing at al elevated rate yet no extra wear metals are shpwomg on the oil don't make sense at all.

There is also a difference between theory and reality.
 
#193 · (Edited)
Oil analysis is an intuitive tool, but it does not tell the full story. The kind of wear HV causes does not put the engine in immediate danger, and this has never been said. It's understood as a more gradual wear. To deny this is ignoring theory, reality, and science. Maybe the difference in the long run is minimal, but there is a difference and it would show with wear eventually and possibly sooner than later depending on driving habits. I see this is more of contest with you than an exchange of knowledge so /our discussion.

http://www.atiracing.com/products/dampers/damper_dinan.htm
 
#199 ·
1). I don't have the science in front of me, But if Honda felt the need to spend time and a lot of money fabricating and tuning a damper then their must be a reason.

2). It's not just about engine wear, the torsion of a crankshaft, twisting and rebounding increases parasitic lose and creates a rougher power delivery. ATI and Fluidampr have shown to increase horsepower over lighter Stock unites.


My 2 cents.
 
#202 ·
1). I don't have the science in front of me, But if Honda felt the need to spend time and a lot of money fabricating and tuning a damper then their must be a reason.
They are needed. Even on a flat 4 or 6 they are used. Why would the manufacture install them if they weren't?
I did not say there was not a reason for the rubber ring to be galvanized into the stock crank pulley. Earlier in this thread it was speculated that it is intended to dampen induced forces or vibration from the alternator, power steering pulley, and air conditioner's varying load. This makes a lot more sense than them putting it in to protect the bottom end from shaking itself appears or fracturing over time. Remember the CTR N1 pulley? Stock engine, no accessories, no damper in the crank pulley...

2). It's not just about engine wear, the torsion of a crankshaft, twisting and rebounding increases parasitic lose and creates a rougher power delivery. ATI and Fluidampr have shown to increase horsepower over lighter Stock unites.
Now that is intriguing! Where can I see those tests?
 
#200 · (Edited)
I have a set (2 pcs) of the NST pulleys from Marcus@Heel-Toe. Was one of the first Mods I had bought from him. I have had them in my car for approx. 60 tkm/3yrs now. just recently changed the belt due to further engine mods. The pulleys still look good, the only thing being that the grooves/splines seem to be 'rounded', not as 'sharp/pointed' as the were when new, but the new belt fits, slips not. Have never had problems, from what my butt-dyno says, it is an alright investment, abit pricey, for what it be, but still it seems as if my car revs quicker/lighter, i think it is/would be more noticeable, with an a/t, as is mine.
Mounty
 
#201 ·
They are needed. Even on a flat 4 or 6 they are used. Why would the manufacture install them if they weren't?

Engine block rigidity and uniform clearances should minimize any metal/metal contact that would show up in an oil analysis.

The main purpose of a damper is to dampen torsional vibrations of the crank. This isn't going to show itself as broken cranks. Most people see it as flywheel bolts backing out (ever seen a flywheel shoot off an engine?) or other bits of the engine loosening up.

Changing the flywheel, modifying the crank, or replacing damper will change the harmonics of the crank and when/where the torsional stress occurs.

Pretty good paper on the subject. They also make custom dampers.
http://www.bhjdynamics.com/downloads/pdf/tech/BHJDynamics_Damper_Info.pdf
 
#203 ·
Just to show I am not an argumentative PITA, a recent email exchange with a customer:


Customer:
Hey Marcus, I read from exeler8 I think on a message board said that the motors nowadays are internally balanced and that the cranks nowadays are not balanced such as the unorthodox pulleys, but why is the fluidampr one balanced?

Me:
Well, balance really is really not the issue. The Fluidpamr is trying to dampen internal shock and vibration cause by combustion in the engine. The crank's ability to cope with plastic deformation is what is in question. Personally I think the crank is stout enough and there has been no real link made between Honda engine failures and a non-dampened pulley.

Wanna waste a bunch of time on this topic and get my full feelings on the matter? Read here:
http://www.k20a.org/forum/showthread.php?t=70848

Customer:
That's a lot of info, so what would you recommend on a 800 to 900whp tsx? Fluidampr or unorthodox racing?

Me:
I'm assuming to get this you are running a significant amount of boost on an upgraded lower-end, probably with the stock crank. If you are running like this now I would rather consider the Fluidampr. You are stressing the crank a lot with this much power. The Unorthodox part, while I do not believe will be an on a car making less power, say up to about 300-400 whp, you are talking about a multitude more power that is probably getting to the limits of the stock crank's ability to cope with torsional fatigue. You have a drag-competition level of power there, and you need a part that is built to deal with that. That does not mean if it is good for an 800 hp engine is it is good for a 250 hp engine. You wanna get the right part for the setup, and I see no value in running a Fluidampr on much of anything this side of your ridiculously high power level.



-----------------------------------------------

I am not trying to say that a crank damper does not have value, but within a certain frame of view different things are going to be true. It's the same general reason I'd not recommend race pads on the street. Aside from the impracticality of the temperature window being totally inappropriate, the noise and rotor wear make the choice silly.

For the greatest percentage of us, we will never actually realize the benefit of running an upgraded or even the standard crank pulley.
 
#207 ·
This thread is very informative. I've been reading about these lightweight pulleys and issues all night at work.
First was the people over at AcuraZine a few years back that have the Cu2 TSX and had the UR pulley kit, and now this thread.
I've taken in a lot of info and knowledge.
I actually just purchased the RRC crank pulley and the RRC oil pump for my TSX.
Looking forward to seeing the difference in acceleration and engine response.
I also wanted to get a lighter aftermarket pulley but I'm getting a good deal on the OEM stuff.
 
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