Harmonic balancer..

[Luni]

No, I think this discussion is good. As long as we keep mudflinging out of it and we just have an intelligent discussion this type of stuff is good on a messageboard. This is what the place exists for.

[Luni]

Oh yeah and it isnt a Harmonic BALANCER, its a Dampener. Which is a totally different ballgame.

So from what Ive gathered, dampening pulleys direct the harmonic dissonance caused by engine operation down it directionally where it can be absorbed by rubber.

So why cant we use some thick, hardcore rubber washers and a rubber gasket of some sort between the crank and the balancer.

I dunno. Sorry guys, Im taking this way too seriously I think.

[shimric]

There are pieces of rubber between the balancer and the pulleys that are pressed on.

[shimric]

Well, I ordered the UR pulley. Go ahead and call me a douche or an idiot or w/e your clever minds can think of. At least i'm being mature.


I'll also start a thread about it and keep you guys updated on it's preformance and characteristics of the UR pulley vs the stock one.

[shimric]

Actually, after doing some mild research it clearly says in the BGB crankshaft pulley. NOT harmoinc balancer. So by that deffinition I just bought a replacement for my crank pulley. I'm sure if it was a harmonic balancer it would be called so in the BGB.

[Bak@EMSPowered]

ya'll are cute.... how fun to watch people go against every piece of advice anyone gives them.... kinda like teenagers

[shimric]

People give shitty advise everyday. Mainly because they don't have REAL WORLD facts to back up their advise.

[Bak@EMSPowered]

Have fun with your car. I wish you the best with the new pulley.

[Luni]

Dude dont be bagging on me. I have done more research on this topic and provided more data for and against it than anyone on this thread. Ive been very informative and objective about the subject throughout the thread so dont go getting asshurt with me about it.

[mrturrari]

When I was rebuilding my enigne I asked my machine shop this question. Their opinion was that it will cause no ill effects as long as the motor has the proper oil clearances and is well maintained. These guys have been doing this for 30 years including many full out race motors and more recently performance imports so I trust their expertise.

My own opinion is that Toyota's manufacturing process has certain margins for error and the "balancer" was put there to compensate for those instances when errors happened to add to each other to create a failure causing sitution. Most engines will not have a problem but you never know unless you have it checked. I played it safe on mine and had the whole assembly balanced to less then 1 gram from pulley to clutch. The balancing cost only $130, less then most UD pulleys.

[wesnemo]

Bringing this post back from the recent dead. Yes, I have to admit (unashamedly) that I have joined the douche bags and gotten an Unorthodox pulley. While cost benefit analysis told me not to buy one at full price, I was lucky to get one at a price I could not refuse.

I looked at all the posts I could find on this board and the OC board and concluded there is a fair amount of misinformation and speculation out there.

Kudos to Luni for shedding some important light on the subject. The 5s is internally balanced so shedding the stock pulley is no loss other than dead (and some minor rotating) weight. A little extra NVH in a build is not a negative. Mrturrari makes an important and often overlooked point. Get the whole rotating assembly balanced. Don't just hang things on there assuming they will help.

[TomsMR2]

someone got a UR pully and filled it with urethane.

ive seen no conclusive proof that the UR pully causes engine failure. ive also seen no conclusive proof that the ur pully actually does anything. the pully is reletively small.. rotational weight that close to the centerline has much less significance than weight further out, like on a flywheel.. ill keep the stock pully for the sole reason that i dont think adding a UR pully will help with power or response.

[AndrewMcG]

Originally Posted by TomsMR2

someone got a UR pully and filled it with urethane.

That was me. Here is my post:

This has been discussed a few times with some people saying that pulleys need to be dampened or harmonic balanced and others say its not going to rip the motor apart or do anything negative to the motor. From my experience at an engine machine shop that Ive been working at for over a year, Ive found that harmonics can be harder on bearings if not treated. I have no specific findings with mr2's, just engines in general.

I am swapping a 5vzfe V6 into my mr2 and it does in fact have a harmonic balancer on the engine. It has a rubber ring in the middle of the crank pulley to help with harmonic vibrations. In the swap you must use a 3s or 5s pulley so my only pulley I had laying around was an Unorthodox Aluminum pulley that weighed about 1/2lb. compared to the stock 5vz weighing in at ~9lbs. I tapped the 5vz crank on the ground and it made a solid "thud" noise. I then tapped the Unorthodox Racing aluminum pulley and got a high pitch ring that lasted 3-4 seconds. I thought that cant be good at all. So I came up with a plan.

I went out and bought 3M Window Weld at Autozone, the same stuff we use to fill our motor mounts with. Its a poly urethane that is sticky and rubbery when dries. I then filled the entire inside of the pulley with the urethane. It now is about twice as heavy, just shy of 1lb. and absolutely has ZERO vibration noise to it when I tap it on the concrete as before. I am going to bring the pulley into work tomorrow and put it on our engine balancer and rebalance it. I would not recommend this process without rebalancing it, as you could make matters worse because it will be impossible to make the urethane completely even all around. Here are some pics. Please give me your input as to whether this was a good idea or completely retarded, thanks.

[Luni]

The question Andrew is, whether or not youre actually doing anything by muffling/muting the resonance. Unless we know for sure the resonation is moving INTO the unorthodox pulley, and is transferred into the 3m which doesnt resonate very well and basically absorbed as heat energy. If it absorbs the energy and transferrs into heat energy and released (which is what they do in acoustics, in relatively the same fashion, for the same reason), then its a very good thing and you may have stumbled onto something very valuable.

[wesnemo]

In the Carpathian Mountains they hang garlic around their necks to keep away vampires. It works. They never encounter any.

I like garlic, but don't hang any around my neck. I have never encountered a vampire either.

I'm not real convinced that filling the lighter pulley with urethane acomplishes anything but if it makes you happy, do it.

[AndrewMcG]

Im still not completely comfortable with the idea, but the urethane does make me feel better. At least because I tried.

[CyFi]

Originally Posted by shimric

People give shitty advise everyday. Mainly because they don't have REAL WORLD facts to back up their advise.

+1, lots of people say lots of things without really knowing. Im sure ive done it before, we all have, but you cant rest your full decision in what people THINK

[wesnemo]

Amen to that.

[biorchang]

Ok...

I know I am digging up an old grave here, but my crank pulley is shot and I am seriously considering an underdrive setup.

Check out:

http://www.gofastbits.com/index.php?...qs_pulley_kits

If I read this correctly, the fact that I have a new lightened flywheel and new lightened Eagle Rods has already thrown the stock harmonic (frequency) dapening out of whack.

I guess I don't really see what I have to loose here? Is there anyone with any real world experience out there that royally screwed up their motor by using an underdrive pulley?

I mean look at the WRX stuff on their site...those things sound like they are awesome!

[Gairloch]

I would think that if you got the rotating masses balanced altogether it wouldn't be a problem.