59A heads

[fordwife]

I have 2 V8 engines, I believe 1942-48. On one the heads say 59A and the other say 59AB. What's the difference?

[Fred A]

59A can be an engine, while 59AB is only a head. Often when we don't know what we're looking at, the biggest label is assumed to be the whole thing. Flatheads '38 and beyond are often and wrongly called 59AB. Functionally there is a small difference. Good Luck: Fred A

[Fordestes]

I think the difference in the A and AB are designations for right and left heads, least that is what I see a lot of times on the 59 engines at swap meets and pictures etc , I will check the green book. I have a few of both , I may do a side by side comparison, it most likely has to do with valve location in the block, I have a tool to cut the cyl. head valve pockets on the earlier engines in order to use the heads on opposite sides.

[38 coupe]

The 59AB heads have a small reduction in combustion chamber size with a small increase in compression compared to the 59A heads. The 59AB heads have the highest compression of the commonly available 38-48 factory Ford heads.

[V8COOPMAN]

Originally Posted by Fordestes

I think the difference in the A and AB are designations for right and left.

That IS NOT the case! Ford had designated part numbers for heads that were intended for specific placement, either RIGHT, or LEFT. Heads meant for RIGHT side use carried part #6049. Heads meant specifically for LEFT side use carried part #6050. In cases where either head was meant to be interchangeable (LEFT or RIGHT), it fell under the number #6050. DD

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[ford38v8]

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Originally Posted by V8COOPMAN

That IS NOT the case! Ford had designated part numbers for heads that were intended for specific placement, either RIGHT, or LEFT. Heads meant for RIGHT side use carried part #6049. Heads meant specifically for LEFT side use carried part #6050. In cases where either head was meant to be interchangeable (LEFT or RIGHT), it fell under the number #6050. DD

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Cm'on, Coop! Is that all you have to say to Mr Fordestes post? You're getting soft in your old age!

[1942deluxe]

V8 COOPMAN is correct. My 59 AB engine I just took to be rebuilt had the 59A-6050 P/N
stamped on the heads facing the intake manifold. Ford mentioned in some of their sales
literature they were interchangeable and that was a change from prewar II.

[rotorwrench]

The prefix break down in Ford part numbers is as follows
5 = 1945
9 = 239
A = passenger car
The alpha figure B following the prefix on cylinder head was a way to designate an engineering design change on the cylinder head. I've not seen that on any other parts other than the cylinder heads. Initial intro in 1945 was 59A only. The B was added in somewhere in early to mid 1946 for a small design change. 38 Coupe has the change in his post #4.

Bruce Lancaster posted the clearance volume change in this thread.
https://www.fordbarn.com/forum/showt...2800&showall=1

[fordwife]

Thanks Rotorwrench, that's what I was wanting to know.

[Pech33]

Ok, good information to know. So, my 40 convertible has a 59 stamped on the bell. It has “A” heads. Obviously (if 1945 was the change date) someone used the heads off the original motor. Would a “59” have had a cylinder head that had a different casting to increase the compression ratio or is it the same as an “A” head?

[Mart]

Pech, A or 59A?

If A the heads were probably from the original 40 motor and were swapped onto the 59 motor when it was swapped in.

In theory they should have been modified to clear the valves due to a different positioning of the valves between 40 and 59A engines.

The use of the earlier heads was touted as a benefit due to smaller combustion chambers.

Not 100% sure on the above but I had to clearance some A heads for use on a 59A motor.

[rotorwrench]

Ford could have just started up with the 19A block after the war but they decided to make a good bit of engineering changes to the engine design for post war production. The war department allowed for production of the 41A replacement 221 block in 1944 but production for it seemed to exist along with the 59 series blocks in early 1945. Both can have the 59 on the bell even though they are two different designs. The valve angle change that Mart mentioned and the deck port design are the most noticable changes that led to the 59 series. Ford made them for all V8 applications after the war so they only had to make the one block for new V8 automobile production. The 221 block was only for much needed replacements. A lot of cars and trucks in operation during the war were still the old 221 engines and a lot of them were already well worn before the automobile manufacturing shut down in 1942.

The late 59 series heads will fit the older prewar engines but the prewar heads won't fit the post war engines unless they valve relief areas are machined out a bit. This tooling to modify the chambers was available after the war for a time. There is no real advantage using the Big A (81A) heads on a 59 series block since the AB heads have a better chamber size but some folks either like the heads or just don't want to buy another set. Some just want the engine to look like the prewar engine.

[Pech33]

You guys are a wealth of information. My engine runs as smooth as a kitten purrs so I guess the previous rebuilder did it right. It appears that it was bored 60 over. So if they bored it out, they must have machined the heads to use the “A” heads.

[Fred A]

You guys are so polite. Elements of the responses may be dead wrong, but the better explanations save the day. Sometimes we need to already know the answer to sort it out. The broader history lessons are welcome even though they are well beyond the original question, Fred A

[ford38v8]

Originally Posted by Fred A

You guys are so polite. Elements of the responses may be dead wrong, but the better explanations save the day. Sometimes we need to already know the answer to sort it out. The broader history lessons are welcome even though they are well beyond the original question, Fred A

Fred, most of us are mindful that we're here to have fun rather than to carp on each other for misinformation. The occasional responses that go beyond the pale are quickly disposed of by Ryan, and the poster wears a dunce hat for a time. As for the history lessons beyond the questions, that's part of the fun also! The "tool" mentioned earlier in this thread to cut valve pockets is a KRW Flycutter, has nothing to do with right versus left heads, is used on the early heads to accommodate for the wide set valves in later blocks. It was developed for use with new or rebuilt short blocks in order to use original heads.

[V8COOPMAN]

Originally Posted by ford38v8

Fred, most of us are mindful that we're here to have fun rather than to carp on each other for misinformation. The occasional responses that go beyond the pale are quickly disposed of by Ryan, and the poster wears a dunce hat for a time. As for the history lessons beyond the questions, that's part of the fun also! The "tool" mentioned earlier in this thread to cut valve pockets is a KRW Flycutter, has nothing to do with right versus left heads, is used on the early heads to accommodate for the wide set valves in later blocks. It was developed for use with new or rebuilt short blocks in order to use original heads.

Fred .....Alan ("ford38v8") will be one of the first to tell ya that I don't mind (somewhat POLITELY) informing a guy that he's 'full of it', if he is in fact FULL OF IT! I HATE that folks put out bad/incorrect info, or the passing-on of old wives' tales as gospel! DD

[ford38v8]

Originally Posted by V8COOPMAN

Fred .....Alan ("ford38v8") will be one of the first to tell ya that I don't mind (somewhat POLITELY) informing a guy that he's 'full of it', if he is in fact FULL OF IT! I HATE that folks put out bad/incorrect info, or the passing-on of old wives' tales as gospel! DD

Coop, yer full of ..it! See post number 6!

[V8COOPMAN]

Originally Posted by ford38v8

Coop, yer full of ..it! See post number 6!

It has also been said, at times, that Alan don't know good wood from brush! Now, back to our regular programming! DD
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[ford38v8]

Originally Posted by V8COOPMAN

It has also been said, at times, that Alan don't know good wood from brush! Now, back to our regular programming! DD
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You know my wife?