Lightened Allison Flywheel vs others

[ward00]

On Allison's site they say their 2.0 liter lightened flywheel weighs 8.5 pounds, the other competitors dont state a weight or state weights on the order of 13 pounds, what up with the big difference. Any recommendations?

[jon8christine]

I just bought the aluminum flywheel Allison's sells. It's made by Aasco and according to my kitchen scale weighs 7lbs 15.2oz. When I get around to putting it on I'll weight the OEM one. Contemplating doing the clutch while I'm in there and wondering which one to buy?

[Nut124]

I installed the Allison/AASCO aluminum flywheel in my "hot" 1800 build recently.

All my sources say the stock Valeo clutch is good for 200HP. That is what I installed. No problems so far.

[jon8christine]

Just for completeness and because I said I would I weighed the stock flywheel on my 1800 after pulling the engine for my build. 18 lbs 2 oz., so the aluminum one is over 10 lbs lighter. I also weighed the stock steel crank pulley, which came in at 3lb 6oz. I think they claim 1.5 lbs for the aluminum pulley, so I'm not sure that really makes much of a difference.

[RRoller123]

Combine the crank pulley with the adjustable cam pulleys and there is a significant reduction in weight and rotational mass, even with the cams at half speed.

[Nut124]

The lighter flywheel could allow the engine to increase rpm a bit quicker but will not nothing to add power.

The reason to use it is, if you plan on operating at over 6500rpm, that it is stronger and safer. It will not disintegrate and come thru the sheet metal into the foot compartment.

[SteinOnkel]

Lightened flywheels are one thing, aluminum flywheels something else. The former is simply the stock flywheel with material taken off. The latter is something I would strongly recommend against. The friction material of your clutch is designed to work in conjunction with cast iron and not aluminum. It will chew through that flywheel rather quickly. Which is fine if you are happy to replace it frequently.

For a racecar sure, for a street build it doesn't make sense.

[RRoller123]

The flywheel from Allison (now AR) is 2-part, not all aluminum. I have one in my car, the car accelerates a lot faster. Fantastic upgrade, well worth it, along with other things like CR, large valves, headers, wheels, etc.

[Nut124]

... The friction material of your clutch is designed to work in conjunction with cast iron and not aluminum. It will chew through that flywheel rather quickly. Which is fine if you are happy to replace it frequently.

For a racecar sure, for a street build it doesn't make sense.

Like RRoller said, the AASCO/Allison flywheel has a steel friction surface. I had doubts but I called AASCO and talked to them. It is proven, quality stuff.