51 merc block?

[bwood53]

Can only locate one set of numbers. 08201. Am I missing another indicator of who made the block? Has 8cm heads and for 8ba intake. Rather not take the crank out. Thanking you in advance...

[19Fordy]

The only way you will be able to tell for sure that it's a Merc block is if it has a Merc 4 inch crank. You don't have to take the crank out. Just remove one head and measure the maximum stroke from bottom dead center to top dead center. Ford is 3 3/4 in. Merc is 4 inches. Even then, there is the chance that it's an 8BA block with a Merc crank. Merc and Ford blocks were the same for 1949-53 with no distinguishing markings differentiating one from the other. You might get lucky if the date code is stamped on the intake surface of the block like this:
https://www.fordbarn.com/forum/showth...ead+date+codes

Another indicator would be if you find parts with Merc part numbers on them still on the engine. Folks would not normally change these parts. For instance, here is then oil pump idler gear cover for a 1951 merc engine. It is on the back of the engine.

[Mike51Merc]

You don't have to take the crank out. You can measure the piston stroke or visually inspect the crank by taking the oil pan off.

[bwood53]

Thanks guys...

[Karl Wolf]

Originally Posted by Mike51Merc

You don't have to take the crank out. You can measure the piston stroke or visually inspect the crank by taking the oil pan off.

Look for the plugs in the ends of the crank throws... 5/8" plugs will mean it's a 4" crank. If you find 3/8" plugs it still could be a 4" crank
(more rare), but you would have to measure piston travel- one piston tracked from bottom center to top center- certainly hard to do from under the car...

Karl

[Ol' Ron]

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Right now good blocks are more important than 4' cranks.

[Flowmeister]

My 51 Merc block has 1CM cast into the back, by the bell housing,
It's on my heads too.

[moefuzz]

Just my humble opinion but

1CM indicates Canadian production Mercury but there is no real garuntee that it has a 4" crank unless you put it in there yourself. Most of the 4" cranks never made it back into rebuilt (even factory authorized rebuilt) Ford/Mercury engines.

look here:
https://www.fordbarn.com/forum/showpo...6&postcount=21



jmho

.

[Flowmeister]

Actually I was wrong on my previous post
The block is cast C1BA, the heads are cast 1CM
It also has an Engine Rebuilders tag riveted to it
It does have a 4" crank, i've pulled a head and measured.
I'm pretty sure mine is a real 51 Merc engine.

[mtflat]

The hot ticket was a merc car engine with EAB heads for highest comp with stock parts.

I bought my merc engine with a ford intake from a '46 grain truck. The only way to know for sure is to unbolt things and measure.

IIRC, it's been shown that merc trucks in Canada came with 239 ford engines.

[moefuzz]

In the back of my mind I was thinking EAB and 1CM but it all translated somehow to 8CM.
Thanks for the note, I will fix the post to read correctly before more than just myself is confused.