what are the advantages and disadvantages of these types. I would think that with the aluminum the weight concentration would be near the center. and I would think that the chromoly would have higher heat resistance but I really dont know much about these

-non

 

oh come on nobody knows anything

 

Aluminum can't be resurface like the chromolly so when you change your clutch you'll have to buy a new flywheel if its aluminum, not a big deal though.

 

Aluminum will get hot and expand faster than chrome molly. Chrome molly is a little heavier, but just that more safer. It all deppends on what you are doing with the car. I have both and not had a problem with either.

thanks,
Greg

 

I won't install an Al flywheel on my car. The chrome molly is much safer (at least enough to me that I won't risk my legs).

 

Aluminum flywheels are always multiple pieces. This leaves room for error during assembly. Sounds rediculous right? But yea, I have seem plenty of aluminum flywheels come apart, but 99.9% of them are fine. But yea the starter ring gears I have seen put on backwards, which is not a huge problem other than the fact that by the time you realize it you have to pull the transmission back out and send the flywheel back for another. I have also seen the hardware that holds the friction surface to the flywheel come off.

You cannot resurface EITHER. An aluminum one you can replace the friction surface tho. But I would throw it out and get a new one before I changed the friction surface because I would be affraid that the hardware may come off after I changed it. Not only that but the aluminum itself probably warped by the next time I have the tranny off.

Chromoly is always a pound or two heavier in the same configuration, but its not like you will ever notice a 1lb difference in the flywheel on a street car. Do not resurface a chromoly flywheel. I always thought it was a rumour that their heat treating was only surface deep... until my friend resurfaced his chromoly wheel and it was worthless only a couple months later.

I would not even consider the reuseability of a flywheel when purchasing anyway. If you are rich enough to be wearing out clutches fast enough that you have the tranny off and need to resurface your flywheel, then you can afford to just replace the flywheel, they are only a couple hundred bucks.

When the time comes for a clutch I will be using a chromoly flywheel. Until the time comes for a clutch, I would never bother removing the tranny JUST for a flywheel install. The gains are too slim for all that labor.

-Charles

 

One more thing I wanted to say... DO NOT, DO NOT, allow a machine shop to lighten your stock flywheel. This is a very dangerous practice. Many factory flywheels have plenty of material that COULD be removed to save weight, but do not trust your machine shop to do it right. It is NOT pretty at all when flywheels shatter. Depending on engine speed when it happens... the fragments will not only destroy anything in their path, but they WILL destroy YOU if your in the path. I have seen photos of an incident where a flywheel shattered in a shop when they were just reving the engine and chunks of the flywheel were embedded deep in the concrete floor amoung other places.

-Charles