I had heard that Mercury of Canada used them towards the end of production.
Any ideas ?

Thanks,Oldmics

not in cars thats for sure.there were always rumors about trucks with 312s having them but nobody ever produced one.

I think this myth is because most people who don't know Y-Blocks tend to refer to them as 312s, even if they're not, you know, all Y-Blocks are 312s when they are for sale.
No 312s in trucks from the factory and no 312 forged cranks.  If either of these were true, there would be proof by now.


Lawrenceville, GA

Well I might just have the proof ??? This crank has come out of a 292 block that was built for a blower and also has a Harman & Collins roller cam.
Can anyone tell me how to ascertain if this crank that I have is forged or cast? This thing rings like a bell when I tap on it !
I know about the steel 292 cranks having six counterweights and the cast having eight counterweights.
What I have is definatly a 312 crank with 8 counterweights but it has some peculiarities I have not seen when compared to other 312 cranks.

Suggestions??

Oldmics

How about some pictures?

The forged cranks I've seen for any pushrod v8 are of a 6 counterweight variety.  Is the engineering number still on it?

I think you can tell forged from cast by the parting lines created by the forging dies or moulds but I'm not well versed on that.


Lawrenceville, GA

I have two Mercury flathead 4" cranks. One rings when struck, the other gives a dull thud. There is a difference in finish between the two. The gurus in the know say ford didn't make a forged crank for the Mercury. So I still don't know the cause. I used the ringing crank for the engine in my car. If I ever use the other I'll have it checked thoroughly for cracks or defects.

The cranks pretty rusty and crappy looking. EXCEPT for the journals. (Figure that ???)
Im going to wire wheel the majority of the rust off before posting pictures.
It has ECZ 1 stamped on the frontmost counterweight with the number 55 in a box also stamped in the same area.

Oldmics

ECZ sounds like a standard cast 312 crank.  I would expect a later unit to also have a later id, as the 292 forged crank did, C1TE instead of EC.


Lawrenceville, GA

i would put forged 312 cranks on the same level as bigfoot.

A forged crankshaft will have a wide parting line that is sometimes 3/8" wide and varies in width, whereas a cast crankshaft will be a very thin line and straight.  A good cast crankshaft will ring like a bell if it is does not have a crack, or lots of crud in the journals and balance holes.  Joe-JDC

JDC