mjr46

I'm doing a t-5 conversion in my 66 coupe and I 'm upgrading to a 10.5 inch clutch(86-93 style) and I'm going to use a aluminum flywheel. so I know I need to stick with the 28 oz. unbalance however companies like ford racing, fidanza and f1 racing all offer the flywheel that has add on weights, so heres the question ford racing says theirs is 28.2 oz fidanza says 28.8 and f1 racing says 28.5 so which do I use and does it matter the less than 1/2 once difference between the three????? help me anyone!! I have a 74 302 in it that's mildly built.

Scott H.

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JMD

Truth be told,,,,,,,, I would buy the one I thought was the best value and pretend the imbalance was the same on all three. But,,, all else being the same I would buy the Ford Racing one, because it is Ford and probably made for stock applications, and sincethe imbalanceis the lightest, I would assume that there is little or no "extra meat" to machine off for balancing a new engine.

That is what I would do,,,, I have always been lucky that way though.

gothand

[ol][*]Why aluminum in a mild '74302?[*]Are you trying to use a diaphragm pressure plate? I had a diaphragm pressure plate on an early engine that bolted to the existing holes on my flywheel. Before getting too far ahead of yourself, take your flywheel down to a speedshop and see what they can fit up to it.[/ol]
Good luck!

mjr46

well I don't know what you consider mild but to me this is what's done to it block .040 whith h.o rods reconditioned and forged light weight pistons with 69 heads ported and polished with manley 1.94/1.50 valves, roller rockers, rotating assembly was also balanced,rpm air gap intake, 650 double pumper and a crane .500/.500 lift cam, headers and 3.50 gears. It ran a best of 13.69 @ 102mph with a single track 2.80 gears. anyway to me this is mild but the flywheel is roasted as 2.80 gears didn't help not smoking the clutch. but also I figured with the tranny out an aluminum flywheel would help it rev even quicker and maybe pick up some time at the track?? but the reason I want to upgrade the flywheel to the late model style is it has provisions for dowl pins for added strength as the car does see minimal track time once or twice a year. the stock one doesn't also price for the aluminum ones is relatively cheap online. so if you have any ideas on the unbalance issue or experience any advice is appreciated thanks for the reply!!!

Norm Peterson

You're even more likely to overheat things with a light flywheel, as it doesn't store as much energy to help get you off the line (so you'll slip it even more).

It's true that the lighter flywheelcan help out, but only if the total combination is set up for it. Given what you've described, you need deeper axle gears anyway, and they'd need to be deeper still to compensate for a light flywheel. You may get some help from the T5 if 1st gear in it is deeper than 1st is in whatever tranny is in there now.

For an upper limit on axle gearing, I'd suggest axle gearing that is not so deep that you'd ever have to shift into 5th at the strip, which should put your overall gearing in 5th not too far from where 4th is now.


Norm

JMD

I have never used an alum. Flywheel, but to my uninformed mind, it seems that an alum. Flywheel would be more susceptible to heat damage than a steel flywheel, am I right about this?

Norm Peterson

The potential is there to do more damage, if you insist on slipping it under heavy load for an extended length of time or having it repeatedly slip without giving things a chance to cool off. But most of the immediately-generated heat only gets as far as the the steel friction surface. Even though the steel is in firm contact with the aluminum, heat transfer between two mating surfaces isn't nearly as good as through a single solid piece, so the aluminum will not heat up as quickly or see the same peak surface temperature as the clutch disc side of the steel friction plate. Ultimately though, it's a heat balance kind of thing, where you don't want to be adding heat consistently faster than it can dissipate. That's about as specific as I can get.


Norm

mjr46

I'm not installing a t-5 because I need an extra gear at the strip. If I hit fifth at the strip then my gears would be way to tall.the 4 speed that was it there was a wide ratio t-10 meaning 1st was way to tall with 2.80 gears I could take 1st to 45 mph before shifting and even with 3.50 gears I still could take 1st to high which was the problem for clucth slippage as I could not launch hard because the tranny was geared tall in first very low in2nd and 3rd and 4th fell on it's face.
the t-5 has a low 1st 3.35 ratio and 2nd through 4th is close too. all I want 5th for was cruise on highway as with 3.50 gears with the 4 speed rpm's were close to 3400 at 65mph. higher than I like for cruising speeds. anyway I just ordered the fidanza aluminum flywheel so hopefully by saturday evening I'll be cruising again and hopefully this combo will work out.

JamesW

I found a 50oz stock 5.0 flywheel on the cheap, then took it, along with my original 28oz flywheel down to a machine shop and had it match balanced. The balanced, and surfaced the 5.0 flywheel for about 75 bucks and it worked perfectly.