The Ford Barn

Fredb_ · 02-09-2015, 02:08 PM

Just wondering what the differences are between the '49-'53 Ford / Mercury engines. I understand the Mercury has a crankshaft with 4" stroke and different pistons. I've also read about some Ford blocks come with replaceable exhaust valve seats. Are the main and rod bearings interchangeable? Is the stock camshaft the same in both? Other differences? Thanks!

Russ/40 · 02-09-2015, 05:55 PM

Correct about the stroke and pistons. No difference in any of the bearings. Cams are slightly different, but not enough to be perceptible in performance. Mercury heads are lower in compression. '49 blocks have both intake and exhaust seat inserts. Later in 50 the intake valve seats were deleted and by 53 blocks had no replaceable seats. It is my opinion, the early 49 blocks are the most desirable. They can be identified by them not having a fuel pump rod bushing. JMHO

19Fordy · 02-09-2015, 07:28 PM

Russ, Do 50 Merc blocks have a fuel pump rod bushing?

Walt Dupont--Me. · 02-09-2015, 07:56 PM

Quote:

Originally Posted by 19Fordy

Russ, Do 50 Merc blocks have a fuel pump rod bushing?

The only engine I've seen with out a fuel pump push rod bushing is 48 pickup with the first 8BA style engine, a few other things, head studs instead of bolts, no pump bushing, 1/8 pipe plug behind the flywheel so to drill a small hole through the push rod hole into the main oil line, probably some other things. I've had 2-3 of those engines. Walt

Russ/40 · 02-11-2015, 02:11 PM

Quote:

Originally Posted by 19Fordy

Russ, Do 50 Merc blocks have a fuel pump rod bushing?

Yes they do.
My original unrestored '49, never touched with 60k miles had no fuel pump rod bushing. That likely confirms Walts observation as well. The first 8BA's did not have the bushing. I suspect that changed some time in '49, as those blocks were depleted from stock. I cannot attest to what Canada did.

FRANK PKNY · 02-11-2015, 02:52 PM

Sponsored Links (Register now to hide all advertisements)

Is there any casting numbers that differentiate the Ford from Mercury?

Karl Wolf · 02-11-2015, 07:04 PM

Nope.

Karl

Karl Wolf · 02-11-2015, 07:07 PM

[QUOTE=Karl Wolf;1032125]Nope.

Not on the block, that is. Cylinder heads on the Ford, 8BA... Merc had 8CM, and a few others- guess I don't know all of them... The heads will exchange, you can't count on them being original.

Karl

Fredb_ · 02-13-2015, 01:52 PM

I bought 11 flatheads for $1000. Two were mercury blocks with the 4" stroke crank. One of the Merc blocks was busted badly behind the water pumps (probably froze). The other appears to be in good stock condition, never bored or machined. It's been a learning experience parting them out with different oil pans, timing covers, intake and exhaust manifolds, etc. I've enjoyed the greasy task and so far tripled my cash investment. I wanted to know how the experienced hot rodders use the Merc parts on their Ford blocks. thanks for the feedback guys, it is appreciated as always.

02-09-2015, 02:08 PM	#1
Fredb_ Senior Member Join Date: May 2013 Location: Coos Bay, OR Posts: 641	Ford / Mercury Flathead differences Just wondering what the differences are between the '49-'53 Ford / Mercury engines. I understand the Mercury has a crankshaft with 4" stroke and different pistons. I've also read about some Ford blocks come with replaceable exhaust valve seats. Are the main and rod bearings interchangeable? Is the stock camshaft the same in both? Other differences? Thanks!

02-09-2015, 05:55 PM	#2
Russ/40 Senior Member Join Date: May 2010 Location: Santee, California Posts: 3,505	Re: Ford / Mercury Flathead differences Correct about the stroke and pistons. No difference in any of the bearings. Cams are slightly different, but not enough to be perceptible in performance. Mercury heads are lower in compression. '49 blocks have both intake and exhaust seat inserts. Later in 50 the intake valve seats were deleted and by 53 blocks had no replaceable seats. It is my opinion, the early 49 blocks are the most desirable. They can be identified by them not having a fuel pump rod bushing. JMHO

02-09-2015, 07:28 PM	#3
19Fordy Senior Member Join Date: May 2010 Location: Coral Springs FL Posts: 11,017	Re: Ford / Mercury Flathead differences Russ, Do 50 Merc blocks have a fuel pump rod bushing?

02-11-2015, 02:52 PM	#6
FRANK PKNY Senior Member Join Date: May 2010 Location: POUGHKEEPSIE NY 12601 Posts: 1,019	Re: Ford / Mercury Flathead differences Sponsored Links (Register now to hide all advertisements) Is there any casting numbers that differentiate the Ford from Mercury? __________________ [email protected]

02-11-2015, 07:04 PM	#7
Karl Wolf Senior Member Join Date: May 2010 Location: Mill Valley,Ca. Posts: 1,509	Re: Ford / Mercury Flathead differences Nope. Karl

02-11-2015, 07:07 PM	#8
Karl Wolf Senior Member Join Date: May 2010 Location: Mill Valley,Ca. Posts: 1,509	Re: Ford / Mercury Flathead differences [QUOTE=Karl Wolf;1032125]Nope. Not on the block, that is. Cylinder heads on the Ford, 8BA... Merc had 8CM, and a few others- guess I don't know all of them... The heads will exchange, you can't count on them being original. Karl

02-13-2015, 01:52 PM	#9
Fredb_ Senior Member Join Date: May 2013 Location: Coos Bay, OR Posts: 641	Re: Ford / Mercury Flathead differences I bought 11 flatheads for $1000. Two were mercury blocks with the 4" stroke crank. One of the Merc blocks was busted badly behind the water pumps (probably froze). The other appears to be in good stock condition, never bored or machined. It's been a learning experience parting them out with different oil pans, timing covers, intake and exhaust manifolds, etc. I've enjoyed the greasy task and so far tripled my cash investment. I wanted to know how the experienced hot rodders use the Merc parts on their Ford blocks. thanks for the feedback guys, it is appreciated as always.