Yo .



Rebuilding a twin dizzy 12a ,



using rx-7 FB 12a rotors , front counterweight , and flywheel .



Issue , i havent seen the the rx-2 gearbox or flywheel yet , so my question is : How does the rx-7 flywheel match up with the rx-2 gearbox , and top mounted starter , and is there some differences regarding clutch / release bearing ?





Thanks!

 

Early stuff uses a small diameter flywheel / flexplates and removable bell housings. Later engines use large diameter flywheels/ flexplates and cast in place bell housings.



Except for the RX-4 and Rotary pickup truck. With large diameter flywheels/flexplates, side mount starters and bolt to early transmissions.



RX-2 and RX-3 use a removable belhousing (small diameter top starter mount)



If you have real RX-2 irons and housings, the RX-7 flywheel will be too big to fit inside the RX-2 bellhousing. One way around the problem would be to balance the whole assembly with the RX-2 flywheel installed, then everything goes together same/same.



Or, make a simple flywheel to fit over a stock RX-7 counterweight and an RX-2 automatic trans flexplate. I did this at first. Used a Porsche super 90 pressure plate 7" very light and cheap as a rebuilt item. Then the RX-2 bell housing and trans goes right on.



Or, build the engine with the RX-7 rear iron. You may have to plug a case bolt hole or two. And alter the intake manifold flange a bit. Then the RX-7 flywheel will work fine, but you will need a RX-7 transmission,

Or, use a RX-4 bell housing which has the big diameter to bolt to the RX-7 iron and bolts to the early transmissions. You will need to notch either bell housing to clear the top mounted starter.



Or, make a 1/4" steel plate adaptor to fit the back of the RX-2 or RX-7 iron and a Small GM bell housing, like the S-10 and then use any GM transmission. Or the Richmond Gear road racing 5 speed, which is what I use. You need a Racing Beat catalogue, which has this kind of data in it. The stock release bearing and lever should work in all cases.



Lynn E. Hanover

 

good info! i forget pre 73 is different.

 

Hey !



Thanks for sharing Lynn ,!



-very apreciated :-)



The owner of the car wants to keep his original gearbox .