r u guys sure that early A-12s had forged cranks in them? till what yr they came forged?
and r they actually better then late model A-12s or not?
barpk

I'm surprised we haven't nailed this down tight ...

Jaime's book said A14s have a forged crankshaft,the A15 does not ... and Nissan Competition at least offered forged cranks for A12-A15. Forged Steel Cranks i A15's

ca18dat_man said "A14 and A15 engines ... will rev reliably to 7500 if built properly the A14 would rev to 8000rpm with no real problems. The A15 I had only had cast pistons" dizzy's

sagemanone, the racer from Utah said "[A14 and A15] engines use a Forged steel crankshaft" Help on Coupes (engine mods)

I guess we could use the J-type pistons in the A-type engine: Flat top pistions

No not all a12 pistons are flat tops. The ones that I just pulled out of my a12 were the dish style. I had them decked to make them flat top and lower compression.

Craig

DD how do you know the a14 is forged??
I only found that pre 74 or early a12 cranks are forged. The only pistons I heard of are forged are the flatties on original gx engines.
early 1975 excellent a14 engines might be forged but I havent found were this info is from. I heard that nissan and toyota mass casting techniques of cranks improved strength and therefore budgets in the mid seventies and many companies adopted casting to better detect engine abuse in the warranty period using researched data of stress fractures on cast internals.

Are any/all A12 factory pistons forged?

Are all stock A12 pistons flat-tops, or do some have a dish like the A14/A15 pistons?

I understand the A12 and A14 crankshafts are forged, but the A15 is not.