Any have an opinion on the UR crank pulley? I have to replace my busted one and I don't know if this is such a good idea....because what I've read about the harmonic dampener...
However it is the harmonic dampener that busted on my car...so I don't know what to go with...please give me some opinions.
You sound like you are on the fence like me. I have an SS with 75k and am thinking about the UR crank pulley. Billy hates the thing, Dan Yi is afraid of it. Billy had engine damage that could be attributed to the pulley. Dan Yi spun a bearing but on the oppoiste sid eof the crank so he says its not the pulley. He also decided to play it safe and not run the crank pulley on his rebuilt motor. If a possible rebuild isn't in your budget I'd get the stock pulley. If you are like me and you don't really care, get the UR pulley. The gains of the crank pulley are pulling me towards it(damn SS). Basically, Billy is the only one that has had his engine torn down to show the effects of the crank pulley. I know it will increase engine wear, as will an mod, its how much it natters to you that is the question.
__________________
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07 Accord V6 6spd
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Ya I wish there was more examples from engine tear-downs. Although informative, Billy's case is a single one, which doesn't say a whole lot. You should never go on one case. I figure the company would be out of business if they really sucked as much as some people say.
You can credit me, too, for that article- I rewrote it a year or two ago when I reformatted the web site to include more of Larry Widmer's opinions and detail the damage a little better.
I just searched the web and found almost nothing on "crank pulley damage." I did find some-
Since I got a lot of mechanical engineering lectures a couple of years ago, I am familiar with the problem of damping harmful harmonic waves caused by the firing order. Unfortunately, the UR crank pulley lacks the harmonic damper found in the stock pulley. Moreover, the reduced weight of the alloy pulley will make the situation much worse (actually, I would prefer a heavy crome-vanadin-moly-steel pulley that provides the same momentum of inertia as the stock pulley), because it changes the complex natural vibration modes of the crankshaft assembly - this also happens if you switch to a lightened flywheel design.
There are two kinds of vibrations to be damped, torsional vibrations and bending vibrations, the later are only critical in two and some three cylinder designs and in general can be neglected in case of in-line fours with 5 main bearings. Torsional vibrations can only be reduced by either simple rubber or viscous damper pulleys, which transform vibration energy into heat or by absorber masses tailored to remove a certain harmonic without energy loss. What happens when removing the damper?
Worst case: fatigue failure of the crank - when you keep your engine at a critical speed for some time your crank may break due to exposure to very high dynamic stress - as far as I know, this will not happen to the extremely dynamic stress resistant SR20 crank, which consists of forged steel (tempered to provide toughness and ductility) that provides high bending stiffness and dynamic stress resistance (much higher than possible with tempered spherical graphite cast iron cranks).
But even if the crank withstand torsional vibrations, some other parts of the engine may not. Dependent on the tolerances, the oil pressure and the design of the bottom end inreased bearing wear of the main bearings is most likely.
Besides, timing chain stretching, valve train failure, sheared pulley and flywheel mountings are also possible side effects.
Why the heck am I up to install the pulleys if they are that dangerous to the engine? Without question removing the damper will increase engine wear, but I know some older German in-line 4 designs (no diesel), which completely lack a damper and heavy mass pulleys. These engines worked reliable up to 150k miles - such engine was in my first car, and I was not able to kill it. Looking at the design of the stock SR20 damper it appears to provide mainly high-frequency bending and torsional damping (thin rubber ring, low mass outer ring) to make the bearings happy at very high engine speeds (the first SR20 appeared in 1991 could be pushed to a respectable 7600 redline). Taking into account normal driving conditions and the high stock oil-pressure the bearings should stay in good shape without the stock pulley. At least no SR20 owner has reported unusual bearing wear after bolting an alloy pulley to the crank.
Warning: the more cylinders and the higher the maximum rpm the greater the risk of serious damage by undamped torsional vibrations. I would not ever remove a harmonic damper from a V6 engine. This engine type is kinda subject to torsional vibration problems. Many people have claimed excessive bearing wear from using lightened aftermarket pulleys on such engines.
A crank is a long, rigid metal shape; if you tap with a hammer it "rings" (especially forged cranks; cast cranks have some internal dampening). So what? Well, a hammer hitting it is only ONE way to cause the crank to RESONATE and exhibit harmonic VIBRATIONS. Another way is to RUN the engine! The engine is a vibration factory (as we all know)...and if left undamped, crank harmonics can build up at certain (harmonic) rpms and these vibrations DON'T just disappear, they have to be DISSIPATED! The best way to dissipate them is via the SPECIFICALLY-DESIGNED-TO-DO-THIS "Harmonic Dampener" hanging off the front of the crank. It has an elastomeric (rubber) isolator between the hub and the HEAVY outer ring, and is as a unit, designed to damp harmonics at the critical frequencies seen by the crank.
The heavier the outer ring, the better it damps, and the higher its efficiency at damping. NASCAR LONGtrack engines use HEAVY dampeners, to allow the bearings to live the long race length; the shorter the race, the more often the bearings get changed (after EVERY RACE), the LIGHTER a dampener can be used because lighter is a little faster to accelerate the engine due to lower rotational inertia. You are trading bearing/crank life for speed. Where do YOU want to go on this? Are you lucky?
The OTHER way to damp harmonic energy (which MUST GO SOMEWHERE) is through the main bearings, into the main bearing saddles on the BLOCK. This can cause premature wear/fatigue/flaking of main bearings, and cracks in the main bearing saddles on the block. This is a poor tradeoff for "an underdrive pulley".
Does this ALWAYS happen? No. Some people may not push their cars very hard very often; some may not do longtrack racing; some may not keep their cars long enough to discover the bearing wear, or to crack anything; the underlying design may be robust enough to cover over this MISTAKE in parts selection. There is a pretty big industry in harmonic dampeners, different TECHNIQUES for dampening (Fluidampr, ATI, BHJ, "The Rattler", etc) but they ALL DAMPEN HARMONICS because it is important. There may be some FREQUENTLY REBUILT race engines (?CART) that are not using dampeners but IF you think their ENGINEERS have not taken crank harmonics into account in their multi-multimillion dollar engine design, THEN there are worthless bridges to be sold to you...and foolish pennywise-pound foolish _NON DAMPENING_ "PULLEYS" to be sold.
For as much information you find that says there there IS damage that will occur and explains WHY, there is as much or more from people saying that there is no damage. I only know of one vehicle (personally) that has run a UR pulley on an H22 for an extended period of racing w/o trouble... and he's got about 20k of HARD track miles on the car with it. So far, no problem. We were worried about a possible oil pressure problem (loss of VTEC), only to find out that it was fuel starvation (similar symptoms)... so, the thing is tip-top.
My personal opinion is that if Honda, who can save a LOT of money on a vehicle they make 200,000 a year by shedding $5, doesn't use one... they must have a good reason. Every dollar counts- manufacturing a sandwiched pulley design CANNOT be cheap, a solid one would be much cheaper. Even if it were balanced, even if it weighed more... they would do it. They do not, and there MUST be some reason.
I have no idea why your pulley failed but I have yet to see that happen personally. I would chalk it up to a freak event and happily replace it with a new factory one. I'm not willing to risk a solid unit on any of my engines, even the one I race. I don't want to rebuild if I don't have to!!!
3) "Isn't my stock crank/eccentric pulley a balancer, harmonic/torsional, or vibrational damper?"
A common misconception is that factory crank pulleys on certain vehicles are harmonic dampers. The fact is, on todays late model cars the factory crank pulley is designed to reduce NVH (noise / vibration / harshness), which does not affect crankshaft or bearing life. These are noises and vibrations from the engine compartment that may travel into the cabin of the vehicle when the engine is running and the stock crank pulley is used to reduce NVH for the occupants (similar to the use of resonators in the intake to quiet intake noise). We do not manufacture crank pulleys that replace or eliminate a damper in applications where the factory crank pulley is an actual harmonic damper (such as 90 degree V engines).
Our pulleys are lightweight, CNC-machined 6061-T6 aluminum and are by design "0" balanced. Because of this, owners have called to tell us how much smoother their engine feels after installing our pulleys. Unorthodox Racing has been manufacturing and selling pulleys for over 5 years without a single engine failure due to the replacement of the stock crank pulley. This is testament to the quality and reliability of our products.
Owners who have engines that use balance shafts must understand that if they eliminate their balance shafts their engines must be balanced and blueprinted if they expect to have no long-term engine problems with or without the use of our crank pulleys. This balance shaft elimination is rare and only happens on a few models that are modified for racing only (Eclipse/Talon/Laser/Galant VR4/Conquest TSI/Starion just to name a few).
4) "Will the underdrive pulleys cause my engine to have premature bearing wear ?"
This is a fear many prospective owners have and it is a valid concern since we are dealing directly with the rotating assembly. It is, however, a fear with no basis in fact. The fact is that our pulleys have the opposite effect on engine bearings. The combination of tight tolerances, quality control, perfect balance, and dramatic weight loss versus the stock pulleys reduces the stress on your engine extends the total service life you can expect from your engine. Engine bearing problems are purely associated to poor engine maintenance, use of heavier than factory recommended oils, improper engine building practices which includes poor balancing, excessively revving engines when they are cold, and owners expecting their factory oil pumps to handle engine HP outputs 2-3 times over stock HP levels.
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This is what THEY say, but you can take it for what it's worth. Who made Billy's pulley?
Me personally I'm with Red98Lude, I was looking into a turbo rebuild for my car in the near future anyway, so if it does fail I won't be too upset...but no one wants it to happen regardless of whether you have the $$ to fix it.
I already picked up a UR crank pulley, it will be installed tomorrow. My car had a terriblt vibration before the crank pulley failure...so we'll see if it's gone tomorrow.
And manufacturer's never lie to sell products, right?
When I offered to help pay for an informal "test" between UR's pulley and a stock pulley UR didn't reply. Take that for what it's worth.
If you planned on buying the UR pulley anyway, why bother asking others' opinions?
A solid crank pulley is a solid crank pulley. Unless it was made on a machine with horrible tolerances, it shouldn't matter who made it. Mine was not a UR, so take however you want.
Right now, nothing has been scientifically proven on H22 engines. I have seen plenty of evidence on other engines, though. My bearings and oil pump on my H22 is evidence enough for me, but I wouldn't expect others to think that it's enough. The H22 is not special by any means, and if a solid crank pulley causes damage to other engines, why would the H22 be immune?
From what I have heard from friends (not seen with my own eyes), some Suby and DSM owners are finding that their knock sensors are detecting false knock after installing solid crank pulleys. Interesting fact, if you ask me. Tells me that more vibration is making its way into the block.
As for tearing your car down for an engine rebuild, if you let the damage go for a long time (without a catastrophic failure) eating bearings will eventually ruin the crank, and if you spin a bearing, you could destroy the block. So, if buying a new engine doesn't bother you for your turbo build-up, I say go for it.
You will note that an unorthodox emplyee ("unorthodox") contributed. Other than a few posts, he has yet to be heard from again.
I seriously doubt that UR balances all their pullies, or that their lathe is any more exacting or precise than anyone elses. I covered this and other manufacturing concerns in the above thread. You will also notice that the UR person never directly addresses any of our comments, other than to regurgitate their marketing comments that you read on their site. THEY HAVE NO DATA TO BACK THEIR CLAIMS. If they do, this is a challenge for them to present it.
There is a preponderance of evidence that crank pullies cause problems. Whether or not it will for you or anyone else remains to be seen. To me, the preponderance is enough that it isn't worth the 5HP or so gain that you will get. Spend your money on something else, or accessory pullies which is the SMART way to do it!
Originally posted by 71dsp And manufacturer's never lie to sell products, right?
When I offered to help pay for an informal "test" between UR's pulley and a stock pulley UR didn't reply. Take that for what it's worth.
If you planned on buying the UR pulley anyway, why bother asking others' opinions?
I never planned to buy it, I had a stock crank pulley on order, but a friend msg me last night to say he had the UR ones in his basement.
I'm going to read the other thread. I'm not denying your evidence, just looking for more evidence.
Just as a counter: DSM owners have to remove their balancer shaft to install these, so it makes sense if they haven't blueprinted the engine this could happen. Also it's a solid pulley, so it makes sense more noise is being transmitted, part of the function of the harmonic dampener is to quiet the engine sounds...
Here's my question, this article was written about the BMW straight 6, which has a very long crank. If there is one car that needs excellent balancing and dampening, it's that car! Just a thought about why it's a much bigger deal on an E36 than a Prelude comparitively.
Thoughts?
Also what can I tell Honda to check for bearing damage...should I pay up and have them open up the bottom and check it out or not?
What are you talking about w/Honda and bearing damage? Are they the ones doing the work?!
You can pull the oil pan and remove a cap and check one half of a bearing set at a time.
I don't doubt that other engines need a harmonic balancer more than ours do. I also don't doubt ours might need one the least of all engines, especially with balance shafts. What I do doubt is that UR has not done any real research into this, and likely doesn't even have anyone on staff that's an ME that really understands the forces at work.
As far as I'm concerned, the evidence is in and the jury is out. Until I see more info that says that it's OK, it's not going on any of my motors.
Why don't you try it and let us know in a hundred thousand miles?
Would you really see a big difference in HP levels by changing to an UR pulley? I know a lot of ppl with Auto or SS transmissions would like to gain anything they can... but it seems more like a gamble at this point.
What kinda DYNO numbers are people seeing with a lighter, solid crank pulley installed?
__________________ Dan
2003 350Z GONE :'( -- AIM: neurCLOsis
Originally posted by Neur0sis Would you really see a big difference in HP levels by changing to an UR pulley? I know a lot of ppl with Auto or SS transmissions would like to gain anything they can... but it seems more like a gamble at this point.
What kinda DYNO numbers are people seeing with a lighter, solid crank pulley installed?
Originally posted by marcucci What are you talking about w/Honda and bearing damage? Are they the ones doing the work?!
You can pull the oil pan and remove a cap and check one half of a bearing set at a time.
I don't doubt that other engines need a harmonic balancer more than ours do. I also don't doubt ours might need one the least of all engines, especially with balance shafts. What I do doubt is that UR has not done any real research into this, and likely doesn't even have anyone on staff that's an ME that really understands the forces at work.
As far as I'm concerned, the evidence is in and the jury is out. Until I see more info that says that it's OK, it's not going on any of my motors.
Why don't you try it and let us know in a hundred thousand miles?
Hehe I will!!
Ok here's another for you....about a month ago I had the recall work done on my front balancer shaft oil seal...is it possible that they screwed it up, which cause the engine to be more unblanced and cause my crank pulley to fail?? I think I should make them check it out? But I'm trying to think of how they could screw up the balancer shaft when replacing the oil seal on the end...?
To change the oil seal, the balancer belt has to be removed. It's possible that they didn't set the balancer to TDC when the belt was installed. That could cause excessive vibration.
That would probably not have caused any problems with your pulley, though. What could have caused problems with the pulley is if the tech removed the pulley and didn't torque it properly when he/she reinstalled it.
Would they have had to remove the crank pulley to do the recall? Something sounds fishy here.....I was getting excessive NOTICEABLE engine vibration since the seal fixed...I didn't notice it until I had the downpipe replaced a week later cause it was making excessive noise...
I even went into the dealership and said I thought it was vibrating excessively (the engine) but I could not pinpoint the cause, until now!
What seal? Anything on the front (front main, front balance shafts, front cam) would have require t-belt removal and thus the crank pulley. If it was siezed on (wouldn't be surprised with the age of your car) they would have needed a puller to get it off.
Originally posted by marcucci What seal? Anything on the front (front main, front balance shafts, front cam) would have require t-belt removal and thus the crank pulley. If it was siezed on (wouldn't be surprised with the age of your car) they would have needed a puller to get it off.
What I am saying is that I brought my car in for recall work 4 weeks ago. The Front Balancer Shaft Oil Seal Recall.
What I think, based on what Billy has said, is that if the T-belt and everything has to come off for that it is entirely possible they did not properly torque the Crank Pulley Bolt when they replaced everything.
This would explain why I immediately noticed the vibration...I could feel it through the pedal at a constant RPM....and when I went back to Honda they said it was fine...and now this....points to the oil seal replacement. Todd can you confirm that the crank pulley would have to be removed to get at the balancer shaft?
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