My flathead's identity crisis?

[wouterftw]

Hi,

Two years ago I bought this '50 Shoebox from a guy in Miami and shipped it to the Netherlands. At the moment I'm tearing apart my flathead to check out what state it is in.

When my car arrived one of the things I noticed was the fact that it had two different heads, one was an 8BA and the other an 8RT. Of course, there's not really a physical difference there, only the model of car it went into.

But now we took the intake off and found this (see attachment). One of the springs is completely different, and I believe the retainer as well. The other retainers look more like the 1951 type (part 6517), right? As we don't have any other material to compare with, I'm turning to you guys! Thanks in advance!

[Mart]

It's as simple as that. Someone has used a later valve assembly (valve, spring, keepers) to replace one valve in your engine.

The odd valve is a 52-53, the rest are 49-51. The later ones are designed to promote valve rotation.

Mart.

[Ross F-1]

Actually the rotator style is '50 -on for trucks, can't say for cars. They have an 0BA part number. If the flywheel is off, look next to the oil pump idler cover for a casting number, the block itself may be 0BA or 1BA. If so, it won't have hardened valve seats (unless they were added).

BTW, lash for rotator style are different, .017 on exhaust.

[1952henry]

Since intake is off, one can look at the "shelf" above the cam in the rear of the block, 'tis where the fuel pump rod passes through. On late blocks, there is a number cast into this "shelf".

[r_reed]

isn't the 8rt head a truck head? might be lower compression head than the 8BA? let's wait for the pro's to confirm or correct that one.

[flatjack9]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by Mart

It's as simple as that. Someone has used a later valve assembly (valve, spring, keepers) to replace one valve in your engine.

The odd valve is a 52-53, the rest are 49-51. The later ones are designed to promote valve rotation.

Mart.

Actually, it is the other way around. The odd valve is the earlier assembly.

[rotorwrench]

The 8BA head was manufactured up to the time the EAB heads came available for the 1952 model year. The 8RT heads were a common replacement for 8BA heads and were manufactured clear up to the mid 50s. I still see NOS 8RT heads now and then. The 1CM head was a replacement for the 8CM Mercury heads after the EAC heads started manufacture. Heads would crack now and then and were replaced more than a person might think.

Rotator valves started into production in the 1950 model year. Both of my 51 Mercs were made in November of 1950 and they have the earlier type valves. The rotators were in full swing in late 1951 and were a common replacement for the earlier non-rotator type valves.

[wouterftw]

Originally Posted by flatjack9

Actually, it is the other way around. The odd valve is the earlier assembly.

That's what I thought. I think my '50 flathead may have been swapped for a '51. Are there any other differences between a '50 and a '51 flathead?

[1952henry]

Originally Posted by Ol' Ron

The 8RT are the lowest Compression heads Ford makes, along with the 8CM

posted 11-26-2010.

[Mart]

Originally Posted by flatjack9

Actually, it is the other way around. The odd valve is the earlier assembly.

Gosh, yes, you're right. I thought the one on the left of the pic was the odd one. I should have looked harder.

I just put a set of French valves into a 59A and they use the later type retainers.

Mart.

[1931 flamingo]

Who knows what's been done to any of these engines over the years??. Or by dealers or someone in a backyard on a Saturday afternoon?? Same goes for the T's and the A's. FWIW
Paul in CT

[wouterftw]

Originally Posted by 1952henry

Since intake is off, one can look at the "shelf" above the cam in the rear of the block, 'tis where the fuel pump rod passes through. On late blocks, there is a number cast into this "shelf".

I checked it out, it says 1BA!