So I have this billet steel race flywheel. The problem is, it's .640" from the crank flange to the friction surface, with a .346" thick mount pad. So even with the short ARP bolts, the bolt heads hit the springs in the clutch disc by about .050".

So we put the 6 bolts in the lathe and cut .010" off the tops, then we put the flywheel in the lathe and we cut .120" out of the hub/mount pad. So now the center is .226" thick.

Now, I googled this and people have done it, the machinest that helped me do it said it would be fine, and I figure it's still 3 times thicker than a flexplate.

Any thoughts concerns?

The only other issue. is the bolts now have to be cut down by at least .100 to clear the back of the block...

-- Joe

 

probably should ask this first, are you countersinking for a tapered head bolt, or just machining a pocket for the regular flywheel bolts to sit down into? I think the latter would be the better bet.

 

I machined the pocket where the bolt holes are down by .120", then I tapered it outward.

The specs of the flywheel are:

crank hub to friction surface: .640"
Crank hub to bolt flange: .346"

So that left .294" for a pocket for the bolts. On an OE type clutch disc with 6 springs, the fat springs hit the bolts.

So I took .120" out of the bolt pocket, which leaves the flywheel thickness at .226" thick where it bolts to the crank.

The flywheel I have is not hays, but happens to be the exact same as a hays 10-130. Same specs, dimensions, etc. I called hays and asked them, and they told me to use their disc with a different hub design. He said he wouldn't cut anything out of the flywheel. Well I already own the brand new clutch set.

I called the folks who made the flywheel, and they said I can countersink it. I did some searching online and I found some threads where folks have done the same thing. But I'd like the thirdgen.org opinion.


Like I said, .226" is probably 2-3 times as thick as a flexplate, which was my machinest's opinion on the matter. However I'd still like some other opinions.

-- Joe

 

Seriously.. Nobody has any comments on this?

-- Joe

 

How much does it weigh that it was worth the machine work?

If you were willing to take .120" off the flywheel to crank mounting surface, why not have taken .050" off the other side at the face of the bolt holes and solved the clearance problem?

 

I think you misunderstood.

I woudn't compare to a flexplate but rather to a factory flywheel for the thickness(apples to apples). Billet is stronger metal and can support some thinner demensions but how much is the question. taking .120 off is only .005 away from an 1/8th of an inch thats a lot of metal in my opinion to remove from a posible grenadeing sawblade near your ankles

 

We removed material from the inside of the pocket where the bolt heads rest, which made the pocket .120" deeper, pushing the bolt heads farther away from the friction surface.

Been thinking that. I called the guys at RAM but they couldn't tell me the dimensions of their flywheel. From what I can tell, hays, and most companies use the same .640" height, so I'm not sure what to do at this point. I don't want to use a stock iron flywheel for the same reason you stated. I like my feet.

-- Joe

 

Thank you for clarifying that.


I don't know how to calculate safe dimensions for a given item / RPM / rotating weight, which would be nice to have in the thread.

That said,
If you are worried about your machined flywheel, you need a scattershield.
If you are worried about a stock unmachined flywheel, you need a scattershield.

Net, I think you wasted time on this flywheel. Keeping in mind, I run a T5 clutch and flywheel in front of an LT1 T56 with mechanical linkage so I like wasting time. Sorry to be a hater.

 

I don't think they make a scattershield though that bolts to an SBC and offers a mopar transmission bolt pattern.. The one I have is kinda unique.

-- Joe

 

so your t-56 is from mopar look to ddperformance.com for part # C191LS. it is a scatter shield from Quiktime to mate the Viper T56 to an LS1 which has the same bolt patern save for 1 bolt which can be drilled out or just left out, your choice.

 

I'm not running a T56, I'm running a mopar A833, however I will look into it and see if it happens to have the same bolt pattern.

What I probably should do, is get a saginaw/muncie pattern lakewood, and drill it and weld nuts on the inside for both the mopar pattern, and the TKO, and maybe chevy T56 while i'm there...

-- Joe