New Flywheels?

[Trstno1]

Are the flywheels available for our engines new anymore? If so, what is the cross reference part. I will simply be re-surfacing my flywheel, but just incase the ppl at the machine shop screwed up the step I wanted to know if there were a different avenue in order to purchase one. I sort of cringe letting anyone work on a NLA part. Makes me nervous....

[Josh]

there are no new or xref flywheels. I could make more, but i don't really see there being a market for it. if you ask your favorite vendor for a flywheel they would likely be able to sell you a good used one.

make sure you have the spec right though, you are looking for a 0.020" step for the clutch running surface.

[Bitsyncmaster]

If you still see the fly cutter cut marks on the surface your flywheel should be fine. On mine all I did was sand it a little with 120 grit silicon carbide sand paper. I did the sanding on a granite surface block but the sanding does not really remove much, surface rust and glaze.

I had posted what my step was in my thread when I did mine. I think it was less than 0.020" (can't find that post).

Flywheels are machined with a fly cutter and not done on a lathe. I guess they want the cross grooves for better grip.

[David T]

The flywheel should only need to be ground if you have cracks, blue spots or scoring. You should be able to see that even before you remove it. When you take it to the machine shop they should be able to tell you what it needs and how much they have to remove, if anything. All they may need to do is a "clean-up" cut (a very light cut). Let them know they must maintain the step (when they see it they should know what to do). That means whatever they remove from the clutch face, they must also remove from the step. I would not worry about them damaging the flywheel. Any good shop has done so many that they know what they are doing. It is a simple machining operation. You should inspect the ring gear. if you have damaged teeth you may need to get them welded up and ground, replace the ring gear, or find a used flywheel. If the ring gear is damaged you should replace the roller clutch drive (bendix) on the starter too. Flywheels can be cut with a fly cutter but the better shops use a Blanchard centerless grinder. Much more precise and does a flatter, smoother job.

[Trstno1]

Thanks for the feedback everyone! I'll be getting my flywheel resurfaced here soon. I really just curious what one would do if the machine shop screwed up my flywheel.

[Josh]

Thanks for the feedback everyone! I'll be getting my flywheel resurfaced here soon. I really just curious what one would do if the machine shop screwed up my flywheel.

its a pretty simple surface grinding job, it will be fine.

once again, because there is doubt for some reason, the step size is 0.020"

[Bitsyncmaster]

its a pretty simple surface grinding job, it will be fine.

once again, because there is doubt for some reason, the step size is 0.020"

I found my post about the step I had. Post #46
I had 0.016"

http://dmctalk.org/showthread.php?16661-Clutch-replace/page5&highlight=step

Also my flywheel had red locktite on the bolts. I used an impact wrench to remove them.

[Josh]

I found my post about the step I had. Post #46
I had 0.016"

http://dmctalk.org/showthread.php?16661-Clutch-replace/page5&highlight=step

Also my flywheel had red locktite on the bolts. I used an impact wrench to remove them.

Flywheels wear overtime, so the step size will decrease. Maintaining the step as measured on a used flywheel is silly. Its like putting different tires on your car that are just as worn as the last ones.

I have machined flywheels with a 0.040" step to get more clamping force out of the pressure plate. Going less than 0.020" could cause slipping. Not likely with a PRV, but a consideration.

[Trstno1]

Flywheels wear overtime, so the step size will decrease. Maintaining the step as measured on a used flywheel is silly. Its like putting different tires on your car that are just as worn as the last ones.

I have machined flywheels with a 0.040" step to get more clamping force out of the pressure plate. Going less than 0.020" could cause slipping. Not likely with a PRV, but a consideration.

I will let them know .020!

[BABIS]

I have machined flywheels with a 0.040" step to get more clamping force out of the pressure plate.

my engine shop advised me the same for a turbo install :thumbup:

[Delorean Industries]

Flywheels wear overtime, so the step size will decrease. Maintaining the step as measured on a used flywheel is silly. Its like putting different tires on your car that are just as worn as the last ones.

I have machined flywheels with a 0.040" step to get more clamping force out of the pressure plate. Going less than 0.020" could cause slipping. Not likely with a PRV, but a consideration.

You are right. Going less will cause slipping. .040 is a good height for PRV's producing over 300 ft lbs of torque. .020 is the correct number for a stock drive train configuration.

We will be producing another batch of flywheels with replaceable inlays. We ran through our Fidanza units from 2014 and will be producing these in house moving forward. Not suitable for K jet cars as the idle system doesn't have the ability to catch itself efficiently.

[Josh]

You are right. Going less will cause slipping. .040 is a good height for PRV's producing over 300 ft lbs of torque. .020 is the correct number for a stock drive train configuration.

We will be producing another batch of flywheels with replaceable inlays. We ran through our Fidanza units from 2014 and will be producing these in house moving forward. Not suitable for K jet cars as the idle system doesn't have the ability to catch itself efficiently.

You are the one I got the tip from, thanks Josh.
I had a flywheel machined for a turbo ecotec car, sitting in the high 200s, figured it would be an excellent time to use the increased step height.

[Josh]

I was testing the clamping force of various pressure plates the other day. Increasing the step size DOES NOT increase the clamping pressure. This previous information is incorrect.