4A cranshafts, whats interchangable?

[ae93_sx]

Okay, basically i have a bigport 4agze with a stuffed crank. I purchased a 20v silvertop crank thinking that they were interchangable. My Machinist compared the 2 cranks and the 20v ones seems to have larger bigends.

So basicaly what i need to know is what version of the 4A i can pinch a crankshaft from.

alternatively, do you think the 20v one could be machined down to match? i'll contact my machinist and ask the question later today.

[Trls250s]

Bigport cranks are only interchangable with bigports.

Smallport, and both 20v have the same crank dimensions.

[ae93_sx]

bugger! so would an NA bigport and a GZE bigport have the same crank?

[slighty_sykotic]

Bigport cranks are only interchangable with bigports.

Smallport, and both 20v have the same crank dimensions.

What?

Thats not right.

Bluetop bigport is the only different one. Redtop bigport is the same.


EVERY CRANK IS THE SAME EXPECT BLUETOP.

Tell your mechinic to check again. Unless you have a crazy 4agze butilt with 40mm journals....

[ae93_sx]

I thought early NA bigports were the only different version to! had a couple of people confirm that a 20v crank would suit my needs before i purchased it only to be told otherwise at the machineshop once measured

I'll give my machinist a call

[xsspeed]

yeah i'm sure only bluetops run the 40mm crank

[ae93_sx]

turns out that it was the right crankshaft. i misinterpreted the bloke. he meant the journal was too small because it had spun a main bearing and there was a fair bit of meat missing.

so now i need to find yet another crank

[Trls250s]

Sorry i forgot there was a redtop bigport.

They are yucky so i dont even consider them.....