Hello all

I'm working on a decidedly non-rotary mazda project, but I'm hoping an RX7 pressure plate might allow me to have a shorter overall flywheel/clutch stack height. I am having issues with my current setup being too tall and hitting the inside of the transmission bellhousing (long story).

The step height is huge on my standard flywheel (20mm). If an RX7 pressure plate will bolt to my flywheel then i can have my step height machined down to match the RX7 spec, and easily shorten my clutch setup by whatever the difference is. Based on photos online the step height looks smaller... and the clutch disc used is the same diameter as mine, so I'm hopeful this will work out.

Anyway, the information I am looking for can be measured off of any FC N/A 13B flywheel. I need:

1. Flywheel step height (friction surface to pressure plate mounting point)
2. Dowel pin pattern, center to center, pin to pin.
3. Bolt hole pattern, center to center, straight across.

I would be interested in this information for the turbo flywheel too, however the likelihood of it working for my application is much lower since the disc is larger. I assume the bolt/pin pattern will also be larger but who knows.

If anyone has a worn out flywheel and pressure plate that they would send me for the cost of shipping, that would also work.

Thanks!!

 

the stock flywheels are cast and weighted(as they also balance the engine), they also are rotary specific in how they mount to the engine. it's unlikely you'll manage to use a stock flywheel without tons of work done to it. ie, look at the backside of one of our flywheels and you will see the problem.

of all the cars i worked on prior to rotaries, the rotary flywheel has always been rather odd due to the large single nut and taper retention system.

 

I am not planning to use the rotary flywheel at all, just the pressure plate. I could figure all this out myself by just ordering a 13B pressure plate but I'd like to have more than just a hunch before I do so...

I'm trying to determine if the pressure plate mounting bolt pattern on the 13B is the same as that of a Mazda BP engine. I suspect that it will be, since both setups utilize a 225mm diameter clutch disc and were manufactured around the same time.

From there I'll machine the step height on my BP flywheel down to match that of the 13B flywheel, whatever it is. Combine my modified flywheel with a 13B pressure plate & hopefully I'll end up with a flywheel/pressure plate assembly that's not quite as thick.

 

These are the dimensions I'm looking for.

 

ill throw you a bone since i doubt anyone else will, even though im getting tired of doing this stuff for free all the time.

1) 15mm
2) 8 5/8"
3) 10"

 

Thank you! The step is 5mm less than the BP flywheel which i think will be enough to get me the clearance I need.

Time to go compare the other dimensions against my spare flywheel!

 

Damn... the bolt pattern doesn't match up, 13B pattern is slightly larger than the BP. The search continues...

 

sorry for the bad luck.

 

No problem, it's not the first time an idea like this hasn't panned out. Happens a lot when your car is a reverse engineered mish-mash of parts from ~15 different cars from 3 different makes

I appreciate the help.