2.2 L upgrade to 70.4 mm crank
 

Hi. I've got a stock 1970 911T that never has been apart and needs a rebuild. It leaks like a sieve. All the O rings have turned to dust.
While rebuilding, I have the opportunity to install a 70.4 mm crank and rods from a 2.7 liter.
Lets assume the original pistons and cylinders are reusable. (Cast iron cylinders honed and new rings.)
What compression ratio will this combination create?

Also, will the original flywheel bolt up to the 70.4 mm crank.
Thanks

Compression would change upward to 9.2 but youll need to modify the skirts of the Pistons to clear the counterbalance of the crank. You're pistons are castings and don't have the strength of the E or S Pistons.
I believe I would save the crank and build back "T"
Flywheel will bolt up.
Bruce

Thanks but why build back to T?

Assuming P/Cs are in good condition 2,2T upgrade to 70,4 works well.
Depends on the pistons you have check the skirts' clearance to crank.
I did it it once with no need for machining.

Put solex cams in it also and this will be a great torque engine that will rev out too.S

In that case valve pockets should be checked for valve clearance.

Should I use solex or E cams?
Thanks