Rosko

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Missing Gears &raquo;</TD></TR><TR><TD CLASS="quote">

as far as the fluidampr, i as well as several others have had bad luck w/ that unit because it uses an aluminum hub and will actually start to twist the groove where the keyway sits in the pulley. im not sure if fluidampr has corrected this problem yet or not. the ATI piece uses a steel hub just like the factory pulley and works very well. ATI is actually the only brand damper allowed to be used in NASCAR because they have proven themselves to hold up so well.

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Interesting, I saw the ATI unit at the PRI show 2 years ago, it was for the b-series as the H wasnt out yet, and it looked like a real nice piece.

Missing Gears

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rosko &raquo;</TD></TR><TR><TD CLASS="quote">


Interesting, I saw the ATI unit at the PRI show 2 years ago, it was for the b-series as the H wasnt out yet, and it looked like a real nice piece.</TD></TR></TABLE>

yeah, the b series pullys have been out for a while and keep in mind that you probably wont see an h series pully because it is not offered off the shelf. it has to be custom ordered, but they do offer them. and they are very nice.

Missing Gears

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paulwithap

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rosko &raquo;</TD></TR><TR><TD CLASS="quote">

So what was the outcome?</TD></TR></TABLE>

here is the overboost study on crank pulleys: http://www.overboost.com/story.asp?id=1283

Rosko

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by paulwithap &raquo;</TD></TR><TR><TD CLASS="quote">

here is the overboost study on crank pulleys: http://www.overboost.com/story.asp?id=1283</TD></TR></TABLE>

Thanks... thats pretty interesting.

94Vtecluder

Well they got one thing right.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Note that we've avoided the topic of underdrive pulleys, one of the most hotly debated items on automotive chat forums. Not that underdrive pulleys are a bad thing in and of themselves, but most of the pulleys out there are not dampened, and that's what leads to hot arguments online.</TD></TR></TABLE>

I guess the bottom line to take away from this is there is a chance you take when using pulleys. We can sit here and argue till your bleu in the face you can't just say that pulley's themselves cause trouble because there are people who have used them with years for success. HOWEVER that being said there are people who have ran into problems with them. So I think the only think you can take away from this argument is there seems to be a postive correlation between pulley's and problems. Use at your own risk.

Chris F

I don't suppose that we've reached a consensus on this, a year or two later?

kb58

I read the OP's post, and jumped straight to the end.

Okay, you're using companies that want your money as a source of "research"? That's no good since they're biased. Ever notice how Orthodox and ATI say opposite things? And what they say happens to back what each of them sell? I went through the same thing as you, but what you did was like asking a McDonald's employee at the front counter if you should buy their hamburger.

To get some unbiased information, I contacted automobile makers. I got a reply from on, that said this:

“I talked to our engine builder who builds high performance V8s. He occasionally builds engines without vibration dampers, but only for hill climbing / sprinting. He recommends that the crank is replaced after no more than 4 seasons racing due to the fact that it will eventually fail. The overall milage covered is therefore very low over 4 seasons.

I've been checking out every other possible lead that I have and one of the most interesting is the fact that &lt;mfg name removed&gt; will use the production damper on the new V6 racing engine. The engine is based around a production block and crank and will be used for circuit racing. The milages will be higher than sprinting but not so great. The engineers think that the damper can be improved slightly, (probably reduced mass), but not deleted altogether. This is interesting because with a 6 cylinder engine or multiples of 6 it is possible to achieve perfect primary and secondary balance. The pulses through the crank from each cylinder is what is clearly being damped as you probably already knew by now.

A failure related to the damper will result in a broken crank, possible pressure plate etc rather than bearing damage. I think that any failed bearings etc are as a result of general abuse and not down to the vibration damper.

I think that it is clear that any vehicle that will cover moderate milages should have a vibration damper to prevent the risk of crank failure.”

No discussion on four-cylinder engines, but enough for me. Instead, I built a car that weighes 1600lbs for my H22A1. If I end with 5hp less, I'm willing to deal with it. For me, the risk just wasn't worth it. But, hey, if you want to use one, go ahead, but if something happens, don't expect Orthodox to voluteer to fix your engine. They'll tell you that you caused that damage yourself. How can you ever prove otherwise?

team3d

i have use light weight underdrive pulley on all of my modified honda since 1997 (20yrs), none of my car have explode it yet, even with nos......

i also know many l.a. locals daily their honda/acura for over 150k with underdrive pulley and their cars haven't exploded yet...