Inliners International Forums General Discussion Drive Train match for flywheel/clutch/pressure plate?

You may have caught my post in engines about prepping a Mercruiser 120 (62-70 Chevy 153) with a T5 trans from an S-10.
The back end of my block should match up with anything that would fit a sbc with a 2 piece rear main seal.
I have a flywheel from a mid-60's Chevy ll. It is made for a 9"clutch and the contact surface is slightly recessed.
Along with my 14 spline trans I have a new clutch kit for the S-10 it came from, (that would be from a 2.5l/4 or a 2.8l V6).
I laid out the flywheel and put the clutch on it, then sat the pressure plate on top. It sits flat! The clutch does seem to be pinned between them, but it doesn't seem there is any pressure to be gained from bolting the plate down.
I hope I am just 1 part away from a match, like a flat 153t flywheel drilled for the small clutch/pressure plate? A really thick clutch? A flatter pressure plate housing from a Chevy ll?
I have an adaptor on the way to mate the longer shaft of the 4/6 cylinder T5 to the engine and was hoping to get started.
Anyone have a suggestion that doesn't require me to sell a kidney?

First option that comes to mind is find a clutch shop and see what they reccomend.

We have one here (middle of nowhere Anchorage, Alaska) I have to believe there is at least one in Oregon still.

Second option, I have an afinity for Hays clutches, reputable brand that has been around longer than the parts you are working with.

You might check with them. http://haysclutches.com/

Third option, see if a machine shop is willing to surface the raised area off your flywheel.

I say that figuring that your flywheel recess shouldn't be too deep (1/8 - 3/16 if all the parts are touching).

If it were mine, and the other two options were a no go (and there was enough metal, ie starter ring won't fall off) I would take the flywheel to my local oilfield services machine shop (Unique Machine, if you're wondering) and have them stick it in their blanchard grinder and carve on it till it was flat.

An AG or heavy industry shop should be able to do the same.

I figure it would cost me (Alaska rates) between $70 and $120 to do that.

Of course you get to play the throw out bearing height game after that (you likely will anyway).


Other option is to use a different flywheel.

Why is the Chevy II flywheel desireable, extra mass, odd starter location that uses a "non standard" (for a SBC) ring gear, wierd pressure plate bolt pattern?

If it's a matter of odball pressure plate bolt pattern, I believe the 4.3 V6 flywheel had a common (to a SBC) pressure plate bolt pattern, and should fit the two piece seal crank flange.

If I recall correctly the 4.3 is internal balance as well.

Best of luck.

First drives are always the best!

All good suggestions, Nex! I should try to find out what flywheel was used on the 90 degree V6's from their introduction in '78 until the rear seals changed after '85.
While I'm here I'll ask if anyone knows if the Buick RWD 231 flywheel is interchangeable in case I come across one.
I went with the Chevy ll flywheel just because that originally came on these motors when in autos. Nothing so special, heavy, like I want it. I don't think milling the mounting surface will bother me weight wise, but what about having less threads for the pressure plate bolts to seat in?

Any idea how many threads you will have left after machining (if you go that route)?

I was taught that much past a bolt diameter and a half is unnecessary in Iron.

So if they are 1/4" bolts then 3/8 should be good (1/4 X 1.5 = 3/8).

I would even try 1 shank diameter, if that made the difference (especially since that particular pressure plate shouldn't be especially high pressure).

At least I would if that flywheel aligns the cover with dowl pins.

Good luck.

It only takes 5 threads to hold torque look at the nuts you have in your bin if its a 1/4 in nut it will be 1/4 intall and have five threads on course thread applications