My old car has few, or no, options for a lightweight flywheel. A civic fly has the same number of teeth and same outside diameter, but is only 6 bolt. According to one rockauto brand, the holes are in the same radius, and Honda is pretty consistent with this type of thing so I believe it. I've put their pics into gimp and compared with some transparency.. 4 bolts would have holes all to themselves, the other 4 would overlap the pre-existing holes by about 10-20%. I will throw the pic on imgur later, I'm at work now and can't go there.

Any comments on this? Laughs? Tears for the future exploded bell housing?

My stock fly is 22lbs and has a huge step around the edge. There is one option for the carb flywheel that is a normal 'flat' one, but it is still 20lbs and I don't believe a machine shop can take enough off to bring it where I want. (like 12-15)

 

Now posting this I realize I should have color coded the holes, but I think this still gets the message through. The 2 that line up as is, the 2 that would fall in unused space, and the 4 that overlap a bit.

 

Machine some plugs for the holes from the same material, Loctite them in place, drill new holes...

Grant
CLUTCHTAMER.COM

 

Yes, I had thought of that last night as well.. Use plugs to take up the space and hopefully any stress from it not being solid and then leave it be. And this won't be any crazy turbo build so shouldn't be much to worry about. Thanks for the confirmation.

 

 

It probably won't explode and send shrapnel through your passenger.
You could also probably jump from a rolling vehicle and live.

 

I have some flywheels I can measure for you. b-series, k-series and h-series. Let me know.

 

I say take the flywheel you want to a fabrication shop and have them weld the holes shut,. Plug or not they need to be welded shut. Then have it machined flat, drill holes, then have it rebalanced.

IIRC OEM spec ITR flywheels are 12lbs.

 

You DO NOT want to weld the holes. If it's an aluminum flywheel, welding will weaken the aluminum. Even if it's steel, it will distort the flywheel face.

As said above, machine some interference shrink-fit slugs, loctite in place, then redrill.

Or just buy an 8-bolt flywheel.