Bulk buy for 1st Gen Lightweight Pulley - NOT Underdrive

[moebius]

Since the F2/F2T is not a balanced engine, the pulley on the engine needs to be damped. A damped pulley is more tolerant of imperfect balance. Not only that, but it really helps to smooth out the engine vibrations.

Getting an undamped pulley, e.g. a solid billet aluminum pulley, is a bad idea.

But then again, damped and lightweight are kinda sorta, mutually exclusive, you tend to have to add "expensive" to the mix, to make it happen - see Fluidampr® Harmonic Dampers Made in U.S.A. for gas and diesel engines for more information. Same goes for an underdrive pulley.

Seriously, a lightweight, undamped pulley is just bling.

IF it were a *real* lightweight and *damped* pulley, for $70, shoot, even, $90, I'd buy it.

But it isn't.
There you go.

[defiler]

I don't have one in my possession, but weren't the PP pulleys also dampened?

[Jake]

Originally Posted by defiler

I don't have one in my possession, but weren't the PP pulleys also dampened?

No, it is just a solid chunk of aluminum.
And I would think f our engines arent balanced, then a lighter weight pulley would help, not hurt the vibration.
My goal is to get the revs up faster. If you add a damper, you just turn your lightweight pulley back into a stock pulley.

[moebius]

*sigh*

Undamped pulleys put uneven stresses on your crankshaft.
If you want to make more power, you want that power as even as possible, because the more power you make, the more stress you have on your crank shaft, the more stress on your crankshaft, the more stress on your bearings. The worse the vibrations on your bearings and crankshaft, the sooner these things wear out and break.

Yes, with a lighter pulley, it will allow the engine to accerlerate and decellerate faster. If you are going to have a track *only* car, then this is a good thing. BUT, you will be rebuilding your engine, far more often.

The stock damped pullies are quite good. They are damped for a reason.

The new MZR engines from Mazda have balancer shafts, they don't need as much damping, and will benefit from a lightened pulley. Not so with our mazda F series engines. The F series from Honda have a balancer shaft, you can get away with a lightweight pulley there.

I'm telling you, it is a bad idea.

IF you are going to do it, do it right.
Don't put a $90 part in, which will cause a $700 rebuild. It's just not a good idea.

Sure, you can run with a lightweight pulley, for a while, but it will damage your bearings, and it will reduce the maximum amount of power that you can safelty make on a particular engine.

Here is a nice description,
Harmonic's In The L Series In-line 6 Cylinder Engines
but realize, they are talking about 6 cylinder engines, which are inherently balanced internally, much like boxer style engines.

For more good information about engine smoothness, and why and which engines are and are not balanced see:
AutoZine Technical School - Engine

for four cylinder engines specifically:
AutoZine Technical School - Engine

[Jake]

None of those 3 articles talk specifically about pulleys or a lightweight pulley's effect. If you are going to post links to support your arguement, please find something that goes along the lines of... "Dont use lightweight pulleys because...".

Have you personally had any experience with the effects of a lightweight pulley on an MX6 engine?

Originally Posted by moebius

*sigh*

Harmonic's In The L Series In-line 6 Cylinder Engines
but realize, they are talking about 6 cylinder engines, which are inherently balanced internally, much like boxer style engines.

For more good information about engine smoothness, and why and which engines are and are not balanced see:
AutoZine Technical School - Engine

for four cylinder engines specifically:
AutoZine Technical School - Engine

[moebius]

No, I'm talking about engine balance. Not having a damper affects engine balance. I wanted people to understand a little more about engine balance, hence the links I choose. You know, connect the dots. What honda owners and V8 owners say about undamped lightweight pulleys *DOESN'T* apply to us. We don't have a balanced engine - they do. They can get away with not using a damped pulley, we can't.

I have not had any personal experience with a lightweight undamped pulley, mostly, because they cost around $400, and the benefit is pretty marginal. IF I was trying to make a FE-DOHC spin to 9,000 rpm, then I would be using a FluidDampr pulley, you betch-yer-best-buttons I would.

There is a wonderful video, which I was unable to find in a timely fashion, which shows the difference a damper makes on crankshaft vibrations.

I want people to know, that if the put an undamped pulley on their engine, that there is a good chance it will significantly shorten the life of their engine, especially under high power situations.

So, go for the undamped pulley, and let me know how much you enjoy changing your main bearings.

Oh, and please post before and after 1/4 runs, so people realize how much difference it doesn't make to have a lightweight pulley.

More ... relevant links:
Welcome to ATI Performance Products.com
and
Team3S- Dodge Stealth Mitsubishi 3000GT Owners Pages
and
Pinkcore BBS: light weight pulley problem?

Mostly first hand reports from other (non-MX6) internally unbalanced engine owners who have used, or thought about and are warning others against an undamped lightweight pulley.

[Jake]

Yes I did find a few postings about lightweight pulleys, but it seems like there are just as many for it as against it.

Also, you can get a lightweight pulley for the mx6 1st gen a lot cheaper than that, that is, if they still made them. I just bought one from Performance Probe for $90.

I suppose I could see about adding a fluiddampr to the pulley assebly. OR just not worry about it, because frankly, Id personally be okay with a shortened engine life in trade for faster spinup. This is a weekend car, not a daily driver, and I will probably outgrow the novelty before I have to replace the engine.

SO maybe I will just make them with the caveat that it may shorten engine life.

[moebius]

Originally Posted by Jake

Id personally be okay with a shortened engine life in trade for faster spinup. This is a weekend car, not a daily driver, and I will probably outgrow the novelty before I have to replace the engine.

SO maybe I will just make them with the caveat that it may shorten engine life.

As long as people know what they are getting themselves into, then by all means, go do it!

I'm mostly trying to provide information for the lazy butts out there who:
1) think this will add like 50 hp to the car
2) think this will knock 1 second off their quarter mile run
3) think this will help the engine last longer/be more efficent/whatever

Lots of people do things without knowing why.

Jake, obviously you are capable, and informed, but there are many immature people on the board who could be counting on their car as their only vehicle.

A lightweight undamped pulley is not something you put on your *only* car -- perfect for weekend drag cars however.

Don't forget the lightened flywheel too -- that'll make a far bigger difference than a lightweight pulley. With a lightened flywheel, it ought to be easier to notice the difference that a lightened flywheel makes. Hopefully, if you are doing that much, then the AC and PS deletes are not far behind, nor is a significantly larger turbo -- because of all that extra under hood room, you realize. I mean, you can't have that space going to waste!

[LMB__]

but if i mount my pulley on the crankshaft with a fidenza flywheel and clutch and send it to a shop to get it balanced, then it will be no problem?

[moebius]

Very good question.

I think you, LMB___, mean : crankshaft - not camshaft. The Flywheel and the main pulley are attached to the crankshaft. The camshaft operates the valves. I don't mean to be rude, I just want to be absolutely clear, in case there is any translation misunderstanding.


It will help, *BUT* even having a balanced crankshaft, will not change the fact that the engine in the F2/F2T is inherently unbalanced. Hence the links to the engine smoothness in a previous post.

This is why the stock engine comes with a damped pulley.

I would strongly recommend against doing this on a daily driver. For a track only, or weekend only, or some other second car sort of situation, it should be okay. Realize that the F2/F2T/FE-DOHC are all unbalanced, and for maximum engine life, a damped pulley is required.

Having a fully balanced Flywheel/Crankshaft/Pulley will help to reduce vibrations, but it is impossible to avoid them in the F2/F2T/FE-DOHC engines.

[LMB__]

i ment crank, just wrote wrong.. hehe :P,

[LMB__]

any news on this?

[Jake]

Well... here is what Im gonna go do. Im gonna go get Sam to copy the one I have, so then he has the program. I will get 3 made and sell the 3 to whoever wants them. But im not gonna annodize or balance them. I will let the buyer do that. Im ONLY doing it so that in case someone wants one in the future, we will have the CNC programming already done to dupe it.

[proberider]

w/out the ps and ac section?

[Jake]

Originally Posted by proberider

w/out the ps and ac section?

No, with.
Its easier to delete a section from the program than add.