SBM Crank Identification Help!
Can you post a couple pictures of each?
I have found some some crank ID’s in the past by doing an online search. Have you tried that and no hits?
I have 4 SBM cranks here and I do not have any way of knowing what they were used in.
Is there a chart somewhere showing casting numbers or a way to ID them?
1 is marked 2658278. 1.8 crank register. 2.49 main
1 has a partial number, 46577 on the number 2 main counterweight. 1.5 crank register. 2.50 main.
Last one has no number. It has a double roller crank sprocket. 1.8 crank register. 2.49 main.
I was able to ID this one:
1 is marked 3418640. 1.8 crank register. 2.78 main. This is a 360 cast crank.
Any help?
Your first crank, the mains have been cut .010 as they measure by your account 2.49, standard is 2.50, with no pictures I can not tell you if it is cast or forged; you can figure that out just by looking at it; (reference your 360 crank parting line is narrow, cast) wide parting line (forged), narrow parting line (cast). Possibly came out of a late 273, maybe 318, 340.
Your second crank, with the small register could be 273, or 318 Poly, most likely has wide parting line (forged), mains measure, buy your account, standard
Your third crank, mains have been cut .010, the double roller crank sprocket is of no real importance, chain and gear set could have been changed out long ago. Check for wide, or narrow parting line, just another ordinary small block crank.
The crank you have identified as a 360 crank has had the mains cut .030, as you have measure them at 2.78, standard is 2.81, we know it is cast, look for the letters CFD cast into it, allegedly these were better cranks, who knows
Does this help?
