Are all 1.8 cranks equal
 

Be gentle guys :)
I'm starting a turbo build, I have a BP4W with spun big ends, so the crank is not looking good unless it's ground and polished I assume.
I have a BP05 with a good crank. Wanting the use the BP4W block with BP05 crank.

Other than the obvious short vs long nose.
Question - are all the 1.8 cranks identical in construction and size?

I did do about an hour of searching, In the past I'm sure I read they are the same somewhere but can not find a define answer ATM.

as far as size, yes, the BP ones are the same. (well, the commonly available ones, and in the US i doubt you'll be finding an old Familiar GT-AE in a wrecking yard)

Construction wise, I recall reading in one of the older MX5/Miata books that the one in the Miata is forged, where the cranks in the 323/Laser etc are not (other than the Familia GTR)

In saying that, I've never actually seen any evidence to confirm that, and really cant see why Mazda would bother spending the extra cost on a forged crank for a car that is only making marginally more power than the 323 it came from.

Miata 1.8 cranks are forged and interchangeable. Protege and other 1.8 Mazda (Kia and Ford) are cast and don't have the same counterweighting.

Thanks guys for your response. awesome I can start to move forward with the build.