Help newbie on l20b motor

[DATSUN671]

I'm rebuilding a l20b motor. I have a couple questions.

 

I have scratches on the crankshaft and is it ok to reuse it?

 

I have been researching on the Frankenstein l20b and I came across the big bore 2.4. My question is what kind of performance camshaft can I use to run with the ka pistons?

 

Has anyone done this set up and what were the results?

 

Thanks for the help

[RTB]

It will be a 2.3 not a 2.4. And some of those big bore motors don't have the best rod/stroke ratios.

[datzenmike]

I imagine you can run any cam you like in it. The KA pistons have very little dish but they also stop 1.55mm from the top of the bore. The trouble with long duration cams is they make power but run crappier at low RPMs where you drive most of the time.

 

Rod/stroke ratios mean less to a street car motor than a race motor. No matter what the ratio, it will run and run well. There is less deceleration/acceleration at TDC as the rod length increases and this reduces stress on the rod and piston... but this is at extremely high RPMs. The big bore motor will be the exact same rod/stroke ratio as the Z22 motor and it runs just fine. I wouldn't worry about it.