Is this a cast or forged crank?

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C2ndLTpigeon

Mopar or no Car!
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Can someone help me id this crank. Almost looks like its steel and makes a good ring when you tap it. But I'm not to familiar with slant cranks. Heres a pic and part number.

20210516_110004.jpg
20210516_110137.jpg
 
Yeah, but he hasn't posted any close-up pictures of the 'parting' line for us to be able tell....
 
Looks forged if you tap it with a wood handle of a hammer does it have a "ring" to it or a dull "thud" I also think most Slants had forged or should I say they ran a forged crank for a long span of time...
 
It has a nice ring unlike some cast V8 cranks I have.
Yeah the ring means forged also the "forge" marks are wide and the cast seam is thin and raised. That looks forged to me but the photo is at a distance. I dont see any thin cast marks in it where they would be. More of a wide flat appearance which would also be forged.
 
Yeah that pic on the very left, you can make out the "wide" forging mark on the throw. That and the ring and the fact that most slants are forged I'd say its a yes.
 
The rounded edges of the counterweights are a good indication its a forged crank. Cast cranks are usually much more squared off at the edges.
 
Hey, very easy to check....if the mains measure over an inch wide and the thrust about 1.25 wide then you have a Forging! The cast cranks had smaller mains/thrust.............that looks like a forged crank to me.....forge on!!!!!!!!!!!!!! and Slant 6's RULE !
 
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You can easily tell from the very FIRST picture it's a forged steel crank.
 
I think so too, but the point was to get the OP to know how to tell which is why I asked him to zoom the pic. Then I hopefully informed him of what the wider forging marks looked like. I can only hope he understands. I'd post a pic of a cast crank,but right now the only one I have out of an engine is forged.
 
I think so too, but the point was to get the OP to know how to tell which is why I asked him to zoom the pic. Then I hopefully informed him of what the wider forging marks looked like. I can only hope he understands. I'd post a pic of a cast crank,but right now the only one I have out of an engine is forged.

And the info helped. Ive messed around with some 318's and they have all had cast cranks. I just wanted to be sure as I never would of expected there to be more forged cranks in the slants. But yes I do now understand what you meant looking at the marks, like I said I learned something new today.
 
I think so too, but the point was to get the OP to know how to tell which is why I asked him to zoom the pic. Then I hopefully informed him of what the wider forging marks looked like. I can only hope he understands. I'd post a pic of a cast crank,but right now the only one I have out of an engine is forged.

Yeah I get that, but he didn't ask HOW to tell. He asked if WHAT he HAS is forged. It is. But, since we do all want to spread information....at least I know I do, HERE is how you tell.
CAST VS FORGED.jpeg
 
You can easily tell from the very FIRST picture it's a forged steel crank.

Found this pic on line. I believe top is forged, bottom cast. If that is so (and I've never had a cast slant six crank physically in my hands), they do look different, but not in the way cast vs. forged V8 cranks do. Please correct me if the bottom pic is not a cast slant six crank. The pic came from a Hot Rod article on building a hot slant six, and the cast crank was chosen because it was strong enough and a lot lighter.

Chrysler Slant Six Cylinder Engine - Mopar Muscle Magazine

mopp_0602_03z-chrysler_engine-crank_shaft.jpg
 
Found this pic on line. I believe top is forged, bottom cast. If that is so (and I've never had a cast slant six crank physically in my hands), they do look different, but not in the way cast vs. forged V8 cranks do. Please correct me if the bottom pic is not a cast slant six crank. The pic came from a Hot Rod article on building a hot slant six, and the cast crank was chosen because it was strong enough and a lot lighter.

Chrysler Slant Six Cylinder Engine - Mopar Muscle Magazine

View attachment 1715738436

Both of those appear forged.
 
Both of those appear forged.

OK, I'm gonna stick my neck out and still say the bottom one is cast. Note that the center counterweight is significantly smaller. Also, the rod bearing widths are narrower. I'm not aware of any slant six forged cranks with a smaller center counterweight or smaller rod bearing widths (of course, I have been wrong before). Here's a pic that Dutra posted on Slant Six Org. a few years ago, when he was putting together an aluminum block slant six with a cast crank. Looks to me like the bottom crank above, albeit ground on (lightened) a bit:

crank-full.jpg


Another:
crank-weight.jpg
 
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