Main journal

[Mopar Vinnie]

I bought a steel crankshaft. He said it was .010 over crank and I just want to make sure. How do i go bout this

 

[Fran Blacker]

Bet he meant .010 under. A micrometer for exact diameter or a dial caliper for close enough. If a factory undersize look on face of counter weigths.

 

[steve340]

The crank will be 10 thou undersize as it is ground down and the bearings will be 10 thou oversize.
Get a micrometer and find the standard journal size in the service manual.
Your crank should measure 10 thou less than standard size.

 

[BeepBeepRR]

Here is a great read,, should help you understand.
https://www.enginebuildermag.com/20...-crankshaft-better-020-020-030-030-field-exp/

 

[Mopar Vinnie]

It's a 440 crank stock stroke is 2.750 and mine is 2.732

 

[Mopar Vinnie]

That's .020

 

[69Bee]

Actually, it is 0.018". If your measuring device is accurate, it is probably a worn out 0.010" grind. I highly doubt a crank grinder would undergrind it by mistake.

 

[Mopar Vinnie]

Would u just put .010 under bearings in then and call it a dsy6

 

[69Bee]

Would u just put .010 under bearings in then and call it a dsy6

What the hell is a "dsy6"?

 

[Fran Blacker]

Crank needs to be reground -.020 if not out of round to much. Probably needs to go -.030.

 

[Hemirunner]

Would u just put .010 under bearings in then and call it a dsy6

You should probably take it to somebody with some accurate measuring equipment and get it double checked. It’s getting real hard to find .020 bearings and if it’s.030 under you might as well junk it and find another.

 

[33 IMP]

If it's truly .018 under, it's a mess and will need to be reground. 020 and 030 bearings are around, you just have to look harder. Cutting it to .030 wont hurt a mopar steel crank at all (unless it is cracked, of course). Mine is 30-30 and still goes 11s.
Edit: crank stroke is 3.75 for a 440, the main journal size is 2.750.
Re-edit: the FIRST thing to do is get it magnafluxed for cracks, before spending a cent on bearings, or getting it turned.

 

[33 IMP]

What the hell is a "dsy6"?

Typing error of "day?" ?

 

[69Bee]

Typing error of "day?" ?

Makes sense, thanks...

 

[69Bee]

I just had to get some for a 440 for a customer. Use Clevite MS2324P which is a full groove set. I can still get Std, 0.010", 0.020", and I think 0.030".

 

[Mopar Vinnie]

Thank u guys

 

[Garys1969RR]

The stock main journal size on a 440 crank is 2.750". A .010 undersize crank would have a journal diam of 2.740". A .020 undersize would be 2.730". Pretty sure the clearance is ground into the bearing. So it would be about .002" larger than the journal, for oil clearance. Take the crank to an engine builder who knows about crankshafts, and have him mike ALL the journals. Your rod journals will have a different diameter than the mains.
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