bbc steel cranks

[slotracer]

how do you tell if it is a steel crank?
thanks pat(slotracer) :D

[058]

Look for the wide parting line. Cast cranks have a very narrow parting line.

[Froggystyle]

IF you bang it lightly with a hammer, you should hear a ringing sound. Cast will just give you a "dunk" sound.

[slotracer]

well i tapped it with a ball penned hammer and it sounded like a ring. but i checked the numbers on mortec and it say's it is a nodular
iron crank. so much for the ringing sound being a steel crank. lesson i learned is check the casting numbers. pat(slotracer) :D

[Floored]

if the crank is out look on the rod throws for either a thin casting parting line or a ground down ( about a 1/2 inch wide ) forging flash. on early ( 2piece rear seal) cranks on the flywheel flange you will find the same parting lines. 1/2 inch wide = forged- thin flash line cast crank if you position it with the snout upward and tap each counterweight with a hammer and get a resonant ring then there is an excellent chance of no cracks. flip crank over for the last counterweight or you will get a false ring with the flange down. if you get a dull thud on one then it may be broken cheap hint

[DetroitJim]

Slot, you already know what you have but as a post script I have found that on a BBC you can look down the distributor hole and see the crank throw to determine if it has a cast (narrow parting line)or forged (wide parting line) crank without pulling the pan or believing what you are told.
DJ

[shockwaveharry]

SLOTRACER:
...so much for the ringing sound being a steel crank. lesson i learned is check the casting numbers. pat(slotracer) :D If you ever get a cast and forged crank in the same room together, give 'em a tap. You'll definately be able to tell the difference.

[Fiat48]

Wide forging mark on the front throw is steel..little parting line is cast. Ringing doesn't always work. Many steel cranks dull thud..depends on balancing metal/operation.