ok, stumbled upon a 13b that I think came out of a repu and I want to put it in my '82 gsl to replace the worn out 12a. The mounts look the same, I know I gonna have to do something with the exhaust, what do I need to do on the clutch/bellhousing end of things?

It has an AT bellhousing and flexplate, the seller offered a flywheel and counterweight from a n/a s5 but I've yet to collect it. Before I yard out my original engine, can anyone tell my what parts I should buy?

Will my 82 flywheel and pressure plate bolt up? RB site says all 72-82 EXCEPT PU will fit, but then doesn't specefy anything for REPU. I'm on a pretty big time cruch, I'd appreciate any input... thanks!

 

Iirc, the REPU had a very heavy flywheel. I have one, but it's an auto too. You might PM Jeff20B, he's up on them quite well and you might post your question on the REPU forum.

http://mazdarepu.com/

and see what they have to say. I have doubts that the S5 parts will work, but take them anyway.

 

Since the engine came out of an auto, it has a rear counterweight that is correct for the rotating assembly. Purchase a light steel flywheel from Racing Beat or Mazdatrix and you can use the 215mm disc and pressure plate from your '82. That's how I would do it.

Otherwise you'd have to know precisely which rotating assembly is in your engine to know what flywheel would work correctly with it. If it is not matched, you run the risk of damaging bearings over time at least, and severe engine vibrations as well as destroyed bearings at worst.

The stock REPU flywheel is 30 pounds like all the other old school Mazdas except is also has a funny offset making it unique. Only a rotary truck disc and pressure plate will work with a rotary truck flywheel. Don't bother trying to source these parts unless you know 100% for sure that you have the right rotating assembly, and the parts are in good, useable condition. It's better to go with let's say a GSL-SE flywheel and a stock disc with a street strip pressure plate. That's probably the closest you'd get to stock REPU clutch action but with newer, more easily available parts. I'm sure it can tow just as well, too. If I was short on stock REPU parts, that's what I'd use.

 

so, what I got out of that was a flywheel will solve my problem, and that I would reuse the stock conterbalance.

Is there a way to verify that this came out of a pickup?

thanks

 

Does it have the MAZDA on the rotor housings? If not, it's not a truck engine.

 

I'll check tommorow, hopefully with some pics.

fwiw, heres a clip of it running...

http://www.youtube.com/watch?v=5TGfvtbdcVs

 

theres some pics, says 'mazda' on the housings

 

This is what mine looked like.

 

mines different than that, has the lower case 'mazda' and says 13B and automobiles.

So, I guess the only differences are gonna be small port differences and rotors, right?
Don't suppose it matters, I bought a flywheel and am putting it in my car anyways.

 

Couldnt one use a matching flywheel and counter weight from any 13b motor or even a 12a if the set came from the same motor? I hear the PR guys do this w/ no issues on n/a motors.

 

I have a set of those "Automobiles" rotor housings.

Small port differences indeed. The rotors are all the same. Any 13B flywheel from '74 to '85 will work, as will any 13B rear counterweight from '74-'85.

My rotor housings have GSL-SE spec echaust port timing. They also have a thermal reactor air bleed. So do yours, hence the reason for the header flange.

One thing for you to be made aware: there is a chance your intermediate plate could have tiny little intake ports. They're the same size an NO plates and GSL-SE. If so, it's best to swap in a Y intermediate plate from a '79-'85 12A because they're plentiful and have tall ports and normal port timing.

 

Please read this thread for more information. https://www.rx7club.com/forum/showth...=648208&page=1

 

thanks for the link, lots of anfo and pics in there!
I'm dropping the motor in as-is tommorow, later on I'll pull the intake and decypher exactly what I have. Maybe my retired 12a will become a donor at that point. Whenever I have time to do that I'm sure I'll tackle some porting...