I have found a crank that the guy says is a 312. I am not sure it is a 312 as there is not a dimple on the rear of the crank flange.  Is there another way to identify a 312 crank that is out of the block.  The crank looks pretty good but would need ground.  He wants $200.00 for the crank. He has a number of older cranks from a machine shop that clased here.  Any help would be appreciated.  Larry  

Larry

Easy! Go to ford-y-block.com, scroll down and click on Technical Info, and the click on Crankshaft Identification. In your case, identification should be easy with the crank having been removed. 

easy spot from a distance - if the first two throws are in line with each other it is a 312. The only other crank that has the first two throws lined up with each other is the 292 steel forged but that it is an easy spot from both metallurgy and from the crank flange being entirely round with no crescents, dots, or anything else. Of course, you could also mic the mains.

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

While the presence of the aspirin sized dot on the flywheel flange is a positive identifier for a 312 crankshaft, not having that dot can also be a 312 crankshaft.  Here’s a pic of the aspirin size dot.
 
If no dot on the flywheel flange, then look for a casting identifier (EC, ECZ, MB, EBU, ECZ) on the outer edge of one of the end crankshaft counterweights.  EC would be 272 or 292, MB or EBU would be 239 & 256, and ECZ would be 312.  If those are not readable or not present, then look at the casting at front rod throw right behind the #1 main.  Smooth without any kind of cutout around the ‘lightening hole’ in the front journal, then it’s a 312.  If there is a cutout or ‘dip’ present around that hole, then it’s a 239, 256, 272, or 292 crankshaft.  Here are some pictures for more clarification.
   
   

    

Lorena, Texas (South of Waco)

Additional pictures.
  
The cast cranks have eight counterweights while the steel crankshafts (292 only) have six counterweights.
 

 

 

Lorena, Texas (South of Waco)

Thanks guys that is very helpful.  Larry

Larry