How do you tell if the crankshaft you have is forged or cast, and internally or externally balanced? I'm trying to figure out what crank I have so I can find an identical replacement.
How to ID Crankshaft
- Thread starter patmckinneyracing
- Start date
- Status
tap the crank with a hammer....if it's a dull sound then it's cast...if it's a crispier more echoing sound like a bell it's forged. As for the crank being internally balanced does it have a 2 piece rear main?...if so it should be internally balanced and you should see evidence of that on the crank...
Here is a pic I found on another forum:
According to his post the one on the right is an early sbc crank that is internally balanced. The one on the right is the one out of my motor. The motor I have is a 350 out of a 78-79 chevy truck. I cannot remember but I'm pretty sure we re-used the stock crank and had it turned 10/10.
Here is the page I got the pic and info from: http://www.hotrodders.com/forum/lt1-148558.html
It's the last post at the bottom of the page.
Pontiacgp, do you tap the crank on the large weights or on the journal?
According to his post the one on the right is an early sbc crank that is internally balanced. The one on the right is the one out of my motor. The motor I have is a 350 out of a 78-79 chevy truck. I cannot remember but I'm pretty sure we re-used the stock crank and had it turned 10/10.
Here is the page I got the pic and info from: http://www.hotrodders.com/forum/lt1-148558.html
It's the last post at the bottom of the page.
Pontiacgp, do you tap the crank on the large weights or on the journal?
just tap it on a the first counter balance....I found this which is a better explanation than I could ever give..
http://www.youtube.com/watch?v=xIBG0hfR9v8
http://www.youtube.com/watch?v=xIBG0hfR9v8
a cast crank generally has a casting seam down the middle a forged crank does not have this cast also has a more gritty looking textue on the parts that are not machined forged is almost smooth. In the pic the crank on the left is an 86 and up one piece rear seal cast crank the one on the right is a early 80's and down two piece rear main seal crank that appears to be a forged crank notice it has no seam
That answered the forged/cast question. Based on that post I read mine is internally balanced. I just need to get home and hit the old one with a hammer to see what it is. By the looks of the two in the video, mine is cast.
So what flywheel would I get with an internally balanced cast crank?
Chevy 2480, I referenced the pic above because my flange is identical to the earlier 2 piece crank on the right.
So what flywheel would I get with an internally balanced cast crank?
Chevy 2480, I referenced the pic above because my flange is identical to the earlier 2 piece crank on the right.
I understand that. I was explaining an easier way of telling if it was forged rather than taking a hammer to it. It is easier to tell then people would think.patmckinneyracing said:
chevy....if you have 2 cranks side by side it's easy to tell the difference but when there is only one crank tapping it with a hammer is an easy and quick way of determining if it is cast or forged..
I dont need two cranks to tell the difference i know what i am looking at . Anyway dont know why you keep coming back with smart *ss replies just trying to give you the comin knowledge off what to look for. Maybe you should take that into consideration or just dont ask a ? if you dont want any answers.pontiacgp said:
- Status
