aluminium flywheels
 

I was told that I can't just put an aluminium flywheel on my 86 gt, I was told I have pull the motor and have it all balance to that flywheel otherwise I will have vibration... is this true? or couldn't I just use the harmonic balancer?

Doesn't sound right. The crank, rods, and pistons are already balanced to 50 oz. The balancer and flywheel are spec'd for 50 oz. imbalance. Replacing the flywheel should be fine, as long as you use a flywheel with the same imbalance as the old.

FWIW, I bought a Fidanza SFI aluminum flywheel which I am installing on a new stroker. The Fidanza is a zero balance flywheel, but has bolt-on weights for 28 and 50 oz.

So I can add the weights up? cause the flywheel is balanced to 0 also, but what would the benifits be in adding the weight back onto the flywheel? I thought the idea was to get away from that weight?

Zero balance is preffered. But the balance on the flywheel and balancer have to match balance on the crank/rods/pistons. They all have to be 50 oz. Or they can all be 28 oz., or 0 oz.

If you have stock crank/rods/pistons, then your balance is 50 oz. You should add the corresponding weight to the flywheel.

I'm not certain about adding weights up (?)

I was (am) thinking that adding the weights would be making the flywheel the same weight as the one I would be taking off, defeating my purpose to have a light flywheel, but by reading what you wrote it looks like it is just for balancing right not making the flywheel as heavy that was my problem... and yes it is all stock down there

Yes, the aluminum flywheel is almost half the weight of the stock flywheel, even after adding the 50 oz. weight to it. It should help the engine rev...someone said it was worth 10 hp...I don't know if that is true or not.

Ya thats what I was told also about getting the RPM's up faster... thanx for the help

If it was balanced with a stock flywheel, you HAVE TO USE a 50 oz imbalance flywheel. If it was balanced neutral, use no imbalance, 28 for 28.

Make sure you use what your engine was balanced for or it will shake itself to death.

Think of it as a wheel on a car. Whether you have a steel wheel or lightweight racing wheel, as long as you balance it, the TOTAL MASS doesnt really matter, as long as the BALANCE MASS is what you started.

FYI, I used this RAM in mine:
http://www.dariusrudis.com/mustang/t.../flywheel1.jpg

Same flywheel I have. Very nice piece.

E

Have any of you tested the alum at the track? I saw the test in MM&FF and it was all for the alum. But what have you all seen for results? I was firm on getting one for the new stroker, and my engine builder talked me out of it. He said that he would be happy to take my money, but he would rather see me with the steel unit.

Did he say why? A lot of old-school types don't like aluminum in general....they claim it work-hardens, becomes brittle, then breaks. I believe that's true in some applications, but not all.