[RallyBob]

So can the step in the flywheel be removed and the stock clutch disc and pressure plate used?

If a stock Opel cast iron flywheel is machined flat (to the bottom of the groove defining the high/low step), then redrilled ( six bolts, not four) for an S-10 Chevy clutch, it works fine. I've done that for many years. A little bit of material can be removed from the backside and the flywheel weight drops to about 14-15 lbs. Very streetable.

The real advantage of the aluminum flywheel vs. the stock cast iron one is it can take a LOT more power and torque. You will never scatter an aluminum flywheel no matter what power and rpms you have. Cast iron has it's limits, and if you've ever seen a cast iron flywheel explode it is downright scary....I nearly lost a foot from such as explosion. Pieces of iron went through the bellhousing, through the floor, and halfway through the carpeting and hit my foot....couldn't walk right for 3 days from the bruising. Other pieces went through the hood!

So if you have a sub 150 hp engine and keep the revs below 7000 normally you'll be fine with the stock cast iron flywheel. But a 200 hp, 8000 rpm engine needs a bit more security than that, better stick to aluminum or billet steel. If you are drag racing (hard launches), using nitrous, or pumping a bunch of boost through a stock flywheel, think real hard about how much you like your feet and legs.....

Bob

 

[RallyBob]

$325 is a very, very good price for a custom aluminum flywheel with a steel friction insert and a new ring gear.

Duane (MantAscona) had the first one of these custom made as a one-off years ago, and it cost him about $550.

The first group buy we did was rather large, and yet they cost $409 each plus shipping.

I wouldn't pass on these at that price!

Hmmm, now if I could just find 32,500 pennies under my car seat....

 

[RallyBob]

Do they actually make the ring gear as well? Yes $325 is a very nice price for this amount of material and machine work.

I'm only assuming they are supplying ring gears again. They did previously, not sure what the source is, but apparently they found a common ring gear that fits an Opel.

Bob

 

[RallyBob]

I will also take one, if it will accept an Opel Clutch. Let me know were to send the money.
jc

AFAIK, they only have dimensions for a 9.125" Chevy S-10 clutch fitment. I had sent them a stock flywheel for reference a few years ago, and a billet steel flywheel I had custom made to fit the S-10 clutch, and they copied the design (somewhat) but in aluminum.

Bob

 

[RallyBob]

Any takers on the one remaining unit?

Todd

If I had the money, I'd be all over it. Maybe next time.

 

[RallyBob]

Hmm...maybe we can work something out...would you be interested in working on another cylinder head? I have the 2.4 valves left over from the head you reworked...

Todd

Depends on your lead-time Todd, I need to find a workshop and get settled in first. Right now I'm not taking on any more workload.

Bob

 

[RallyBob]

OK Todd I'm taking this last one,
So that's two flywheels I pay to you.
Hiro

Swiped away from me by our French Connection!

Just kidding Hiro, I don't need to be spending money on anything right now!

Bob

 

[RallyBob]

what is the size & rating of this clutch?
is it a 6 bolts mounting pattern or 4 bolts?
Hiro

Hiro, the clutch is 7" (178 mm), and is not rated for much power. But with an updated disc it will work fine for most applications. Spline is the same as Getrag 240.

The pressure plate is a good design with 6 mounting bolts...much better than the standard Opel 200 mm design!

Bob

 

[RallyBob]

Bob, exactly what "updated" clutch is shown in your post? Looks very different from mine.

Custom disc made by Action Clutch Exchange. Full metallic pads with a solid-center hub, for racing use only!