Identify 312 Crankshaft


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By lalkie - 2 Months Ago
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  
By 55blacktie - 2 Months Ago
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. 
By Daniel Jessup - 2 Months Ago
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.
By Ted - Last Month
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.
http://forums.y-blocksforever.com/uploads/images/2ade9651-9a34-457c-b242-dfc5.jpg 
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.
http://forums.y-blocksforever.com/uploads/images/ed3115dd-3c44-47c6-a57f-c7eb.jpg  http://forums.y-blocksforever.com/uploads/images/ba9d97a3-cb0a-4e34-84da-c6ba.jpg 
http://forums.y-blocksforever.com/uploads/images/b90c96c2-0c48-471e-af8f-9027.jpg  http://forums.y-blocksforever.com/uploads/images/1a08d065-65af-4c0f-a686-1417.jpg 

http://forums.y-blocksforever.com/uploads/images/6e324b48-ad07-4908-97bf-7814.jpg  http://forums.y-blocksforever.com/uploads/images/86408e6a-187c-4c8f-bb2d-579c.jpg  

By Ted - Last Month
Additional pictures.
http://forums.y-blocksforever.com/uploads/images/e2cb8012-e03b-4abd-b88e-fc21.jpg  
The cast cranks have eight counterweights while the steel crankshafts (292 only) have six counterweights.
http://forums.y-blocksforever.com/uploads/images/7510de88-c601-485a-93c0-24d1.jpg 

http://forums.y-blocksforever.com/uploads/images/7848f50f-ecba-445e-99f8-0df3.jpg 

http://forums.y-blocksforever.com/uploads/images/dcebefc1-bfa1-46bd-8dc1-8910.jpg 
By lalkie - Last Month
Thanks guys that is very helpful.  Larry