Ok, so I purchased this 83 rx7 that supposedly has a 1974 rebuilt 4 port truck motor in it. It has dual weber carbs and racing beat exhaust. I need to replace the clutch. Does anybody have a clue what clutch and year is compatible with this motor? Not sure if it has the truck flywheel or a 7 one. I do know this, the tranny looks identicle to a 12a, even the slave cylinder is identicle. Is there a way to tell what I might have, or am I going to have to take it out before I order my parts?

 

i would pull it out first..just to be sure, i wouldent want to be stuck with a clutch that i cant use..

:AA:

 

The clutch plates are the same for any engine up till 82, 13B or 12A. If the guy that built the engine had any sort of brain, then he/she used the flywheel built for that engine, which would be a 74 13B flywheel. The flywheel has the counterweights built into it, and if you mix the flywheels between years and engine size , 13B and 12A, the counterweight won't be right and the engine will not last long. The easiest way to tell what clutch you need is to take the clutch disk out and measure it. There are 3 sizes, 215mm, 225mm, and 235mm. All have the same center spline size and number of splines.

 

Awesome, thanks man. I was trying to avoid having to pull it out first, looks like Im going to have to limp it till winter.

 

All correct except for one thing. The 235mm clutch has a different spline.

 

If it's the old school 13B, then it's a 215 mm clutch. There is no 235 mm. The TII clutches are 240mm and have a different spline count and input shaft diameter.

 

If it has a REPU flywheel, the clutch and pressure plate are incompatible with any other. If it has 9 bolts, it's REPU.

You aren't out of options. Take the tranny out and take a look at everything.

 

So what are the chances that when the motor was built, they changed the flywheel? Here is the only info I have on the car................

1ST GEN MAZDA RX-7 AUTOCROSS/TRACK DAY/DRIFT CAR; REBUILT 13-B ENGINE with twin Weber Carb setup (engine rebuilt by Rotary Performance/Bret DePedro of Manassas Va about 4,000 miles ago), Rotary Engineering intake, Racing Beat Exhaust; Rollbar with 5 point racing harnesses in both seats; 5 way adjustible Tokico shocks, Eibach springs & CarboTech brake pads; NEW 15" ROH Snyper wheels with 205/50/15 Falken Azenis ($800 in wheels/tires purchase last year); Short throw shifter & competition steering wheel; Great beginner car that you can drive to and from the track, autocross or drifting event; rear wheel drive is fun to learn for high performance driving and the light weight and excellent balance of a rotary engine car makes this an easy car to drive fast. See the car in action with 8 photos at Summit Point at the EUROIMAGE.US website; click dropdown box under "choose a past event" and go to "Summit 10 23-24'04"; click HPDE3 run group and car #52. BMW's, Vett's, Porsche's are too much money. Drive something that you can afford to fix if something breaks or wears out. Located in central Virginia in Culpeper about 1 1/2 hours south of Washington, DC or about 45 minutes west of Interstate 95; Paint is weakest part of the car; repainted Subaru Rally Blue by previous owner but some previous Mazda vinyl stickers, BF Goodrich & car numbers on door shaded areas remain in the right light; right front fender has a couple of dents; interior door panels removed along with rear hatchback trim (lighter & faster). Needs a new exterior paint job to be a beautiful car. I've enjoyed the car for 6 years and about 6,000 miles; purchased in 1999 from original NASA-Virginia director; 13-B engine and Weber carb setup purchased from Chris Cobetto, current NASA-Virginia/MidAtlantic director.

 

Oh yeah, so say I needed a tranny also. What would you seasoned guys suggest I get for a replacement? I have a 12a tranny available for free. And I have an 86 tranny and clutch available for $75. How hard would it be to put the 2nd gen tranny and clutch in? Am I getting back to diferent spline counts? If it is a repu flywheel in which the pressure plate is held on with 9 bolts, whats my option for clutches? Do they even make a stock replacement?

 

Stick with a 12A tranny, or spend lots of time researching the 2nd gen tranny swap.

Seeing how many things have been changed on the car, I'm willing to bet the flywheel is no longer stock. That heavy flywheel does not suit a sports car.

Check to see that it has 6 bolts. Remove the pressure plate and measure the disc diameter. The two choices are 215mm or 225mm. Let us know which it is. We'll go from there.

 

Im thinking it might have a lightened flywheel. I dont remember any past 12a I had drop revs as fast as this one does. I would imagine the truck flywheel would be pretty heavy though. So Im looking for 9 or 6 bolts, thanks a lot guys, you have been most helpful.

 

Take the top inspection cover off. Look down inside. If you know what you're looking for, you'll quickly be able to tell whether you have a light aftermarket flywheel or stock. You can probably also count the bolts as you turn the engine over by hand. Use a 22mm wrench or the equivilant (7/8"?) on the alt pulley. It makes rotating the engine easy.

 

Right on man. Thats a lot easier than takin the tranny out.