help to identify crankshaft

[1970 duster]

I have a 340 crankshaft and would like to know if it is a cast or steel crank. I looked for a casting number no luck, the only numbers that i could locate were a 50 in a triangle with a capitail R above. not sure if this means anything to someonethanks in advance for any help

 

[387dart]

I have a 340 crankshaft and would like to know if it is a cast or steel crank. I looked for a casting number no luck, the only numbers that i could locate were a 50 in a triangle with a capitail R above. not sure if this means anything to someonethanks in advance for any help

If a cast crank the parting line on the counterweights will only be ±1/8". On a forged crank the parting line will be ±3/4" wide. Also if you strike a counterweight on a forged crank with a hammer it will have a "ting" sound to it vs a cast crank will be more like a "tong".
Hope this helps.

 

[demon seed]

Here, you can tell the difference by looking at it.
http://www.moparts.org/Tech/Archive/motor/8.html

Terry

 

[1970 duster]

Thanks, both of my cranks are steel, now off to buy a converter, Hughes ,ACC any suggestion

 

[340_833 dart]

Also if you strike a counterweight on a forged crank with a hammer it will have a "ting" sound to it vs a cast crank will be more like a "tong".
Hope this helps.

Actually, it's just the opposite. The cast crank will have a high pitched sound due to it not being as dense as the forged crank.