What should I buy?

Transmission to Rear-end

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autogear
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Re: What should I buy?

Post by autogear » Mon Apr 10, 2017 1:19 pm

Paul;

You'd find, that a high RPM engine coupled with an ultra lightweight flywheel; will NOT like the M20 (2.54 1st) and sub-3.73 rear axle.
Routinely, when doing these types of applications, you'd want something in the 12-14:1 total gear reduction (rear gear x 1st gear); to overcome the lack of inertia of the lightweight flywheel.

Go with the standard weight or slightly lighter weight (36-lb from Mcleod I think) and the car will exhibit more "punch" off the line. Otherwise you'll be winding the motor up at every stopsign and dumping the clutch/ Now, cruising the burger stand, it'll RPM like a demon, but it'll be a paper tiger.

Reach out to Jody?

pdq67
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Re: What should I buy?

Post by pdq67 » Mon Apr 10, 2017 2:11 pm

As always Auto gear, you come through.

I am just going to roll it outta the hole easy, (my stock M-20 and 3.31 posi- with probably 25.5" tall, wide tires), so that once I hit say, 3,000 rpm, nail it and go up as high as I want to, then shift and repeat!

I know that this is by no stretch a drag race type of take-off, but whatever, I am not going to put it in competition anyway. If I was to do that, I figure that at a min, 4.88's would be my friend!

But you know something, regardless a what the gear is that once the little sucker is, as the 2-stroke guys say, "up on the pipe", it runs like a, "scalded dog"! This is what I dearly loved about my ol' junk301!! It was a hoot up top.. I know that my ol' Strong-Arm 406 was way more powerful than my ol' junk301, but it just lacked that way up top, top end change!

My ol' junk301 at 7,500 rpm with new points and a week later, only 7,000 rpm up top sort a deal. And I have, "double sprung", my Delco points and did fine for a week , then once the, "plastic", follower wore back from going above 7,500 rpm, new points!

And I used a worn, thin silver dime to set my points back then!!

pdq67

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Re: What should I buy?

Post by novadude » Wed Apr 12, 2017 9:58 am

The Ram steel flywheel is a nice piece. I had issues with balance on a hays steel flywheel.

A Question for autogear regarding the Luk "repSet" clutches:

Would a cheap clutch set just use a grey iron pressure ring? I know the "performance" brands often advertise a ductile iron pressure ring, but maybe all clutch sets include this?

I'd be a little worried about a grey iron ring coming apart at 8000 rpm.

Why not consider a 10.5" clutch like the Z28 used? Not a lot of torque here, so the 11" probably isn't necessary. The 10.5" stuff will be lighter.

autogear
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Re: What should I buy?

Post by autogear » Wed Apr 12, 2017 4:35 pm

I don't have enough expertise to say one way or the other RE: grey iron vs. ductile; Im sure you could reach out to Luk directly; and see what they're actually building.
I just helped a local remove a Centerforce II clutch and its stamped "Sachs Automotive Brazil"; painted orange and has a Centerforce sticker on it.

I do often effort to get my customer to try for a 10.5" clutch, for the reasons you stated. Sometimes its hard to find your needs in a 26-spline 10.5" setup though. Hays does have some stuff there.

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