[86turb]

hi i just bought this motor and i wanted to know what kind of crank is in it, if its a 4340 forged or cast crank i was told it was a 4340 any help would be great thanks ken

 

[BOOSTED-SS-ELKY]

Turn it over I can't tell.

 

[Chuck Stevens]

Cast iron crank.

 

[86turb]

 

[BOOSTED-SS-ELKY]

Sorry bud, I'm no help. I was hoping I'd be able to see casting marks around the rod journals. I know it is not a 4340. It does look like a really nicely done cast crank. Look for some markings (numbers).

 

[86turb]

thanks for the help

 

[Manic Machinist]

Usually a crank that heavily shot peened is cast. I had a Scat cast steel crank that was peened heavy like that. Never saw a 4340 crank that heavy.

Scat and many others put their info on the fron of the fron counterweight. Its hard to see with the front main cap in the way sometimes. Might need to remove it.

 

[86turb]

i was told it was a scat crank it is about 7 years old i looked with a flash light it has no stamping on it

 

[86turb]

if it was a cast steel crank what kind of hp can it hold it is a 331 ford

 

[BOOSTED-SS-ELKY]

Usually a crank that heavily shot peened is cast. I had a Scat cast steel crank that was peened heavy like that. Never saw a 4340 crank that heavy.

Scat and many others put their info on the fron of the fron counterweight. Its hard to see with the front main cap in the way sometimes. Might need to remove it.

Yeah, if you can pull that front cap off and look for some casting marks.

 

[Manic Machinist]

I was also looking at the drilled holes in the counterweight. Looks like softer metal from the lines.

 

[BOOSTED-SS-ELKY]

if it was a cast steel crank what kind of hp can it hold it is a 331 ford

I think Scat rates (HP) all their products on their website, but I havent looked. I know Eagle does....

 

[86turb]

I'm going to pull the front main cap off tonight to see if I see a part number

 

[RCM Racing engines]

I have seen only one other crank like that, came from Doug herbert.... supposed to be a 4340.......

are all the rod throws gun drilled like the one in the pics...... i am fairly sure you have a herbert 4340 OFF shore crank....... no -name....... who ever they get them from

in fact it looks totally like one of there rotating assemblies....for about $1200.00

do yourself a favor and put a better crank in it.......

 

[86turb]

the part # on the crank is 302 3250 5400 5140 y0307

 

[RCM Racing engines]

the part # on the crank is 302 3250 5400 5140 y0307

That ther is a 302 main, 3.250 stroke, 5.400 long rod
5140 steel material made on march of 2007

Herbert crank all the way.......off shore crank........