I know the 312 ECZ-6015C blocks are very difficult to find in good, uncracked, usable condition but thought I would ask if anyone has one for sale.  I finished restoration of my father's supercharged Custom last summer and used the only good 312 block that I could find, a B9AE block.  I had five ECZ 312 blocks but all were cracked at the main bearings.  Correctness of the car is very important to me so, if anyone has or knows of a block for sale that has passed a magnaflux test please let me know by a PM.  Thanks, Randy

Where are you located?

Butch Lawson

Manchester,  TN

Pittsburgh, PA

Randy  If you don`t have any luck in finding one  I may be able to help you out , call me   Harry Hutten 513-868-3311  S/W Ohio  Cinci.

This crack issue brings up a question.. For say street use only & assuming the block isn't badly damaged, is there any reasonable way to repair one?  


Paul

For street use, and also for my supercharged '57 drag car, I have drilled and tapped the hole deeper and used a longer bolt.  Be careful that the bolt isn't too long and blocks the side oil passage.  And don't torque to 140 ft. lbs. like the factory did in '56.  Use 90-100 pounds.

John - "The Hoosier Hurricane"

John: Wow!  Just drilled & threaded for a longer main cap bolt. No attempt to weld the block or plate the crack area ?. And used in a race car.  It would seem those blocks are just as tough as I've suspected..  


Paul

I have a 312 I just bought last week.   Can you magnaflux-or die test the block while its still assembled?   I hate to knock it apart if the bottom end is actually good.   It's been bored to ,0425 by a rebuilder.   You can still see the crosshatch marks in the bores.
Interesting about tapping the holes deeper,  how deep can you  go?

Unfortunately you didn't contact this site before you bought the engine.. All supposed 312 blocks should be inspected one way or the other before purchase, especially 1956 engines, partly because of the issue of cracks & also because they are difficult to check out when assembled as to what they actually are. As some one once commented, there are more 312 engines (particularly 1956's) advertised for sale then were originally built!.. Not quite true, but often what is advertised as a 312 is actually a 292 or even a 272 engine.! Casting letters/numbers on Y-Blocks don't necessarily differentiate between the displacements..You need to see the crankshaft & Con rods for the ECZ markings to confirm an original 312 engine.. Good luck with your buy..
P.S.- maybe I'm missing something, but and I'm not understanding the overbore numbers you posted?..


Paul

Ted, If I understand your post, you have successfully used blocks with cracked main webs by tapping the bolt holes deeper?  Two engine builders in my area, granted neither with much y-block experience, strongly recommended not to use these blocks even with studs installed in deeper holes.   If some of the cracked 312 blocks can be used that would be good news.

Randy