59 AB a Ford or Mercury?

Back in the '50s/early '60s, many flathead powered magazine cars were "said" to use '48 Merc engines, so for many years I believed the '48 Merc was something "special". Many years later, I learned that all '46-'48 Ford/Merc 59 engines were the same, but still wonder why many thought the '48 Merc was best. :confused: :)
 
Most reference to Mercury is likely due to a change in the crankshaft to the late 8CM 4-inch stroke type. This would be the only way to change a 59 series engine to a Mercury type.
 
The best general statement is that Mercury had the larger 239 cubic inch engines from 39-42 - standard Ford's has the smaller 221 cubic inch engines. (Though I believe you could special order the larger 'Merc' engines in some Fords???). From 46 - 48 the 59x series was used (typically 59AB) - and there were no specialized 'Mercury' versions that I know of. (I hate to say 'none' - cause somebody will have a special case to refute me!). In 1949 to 1953 - the Mercury flatheads were the larger 255 cubic inch flatheads - using the same basic block as Ford, but with a different crankshaft, pistons, heads and a few other things.
 
In Fordspeak the "9" in 59 means 239 motor, the other digit is the intro year. Earlier versions were 99A, 19A, 29, etc. This does not actually mean Ford or Merc, as versions were used from the beginning in Ford trucks, Ford industrial motors, etc.
The 9 was also used to identify Mercury car models but the engines were used in various ways from '39 on and the 9 went into the serial number of whatever it was used in.

And...the engine is actually just 59A, the B is from the other end of the part number and represents only a minor change in cylinder head cc's from about 1946.
 
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My 46-48 Is only embossed 59 with no A on the bellhousing does this mean anything out of the ordinary

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I'm confused. What is actually the fact? I was told by an EFV-8 Club authority that the production engines in the 1946-48 production Ford and Merc cars were 239s marked 59. The 59A and 59AB should be Ford's after market replacement engines that were bored to either 221 or 239. Is there a contemporary Ford document confirming what was going on at the time?
The early reference to '48 Merc engines could be related to the "big news" in 1948. The 1949 Mercury was presented in 1948. Who knows?
 
The confusion might be blamed on the Ford advertising, but he engines in the 46-48 ford and Mercury's were the same. Yes some replacement engines were 59 series with 221ci. Another Myth is the hP these engines produced. A well tuned engine in excellent condition produces less than 80 hP without fan and generator. I think what most of youse guys should do is buy a copy of JWL's book "Flathead facts". You might be surprised with what you will learn
 
5 means 1945, the release date and the first bit of postwar civilian market production. 9 says that it is the 239 engine. The A simply designates it as a Ford passenger car part... all parts were thus designated based on first or main intended use, even for parts that were used in many other applications. Here, the very same engine went into mercs, pickups, etc., and the versions for heavy trucks differed only in externals, but the basic unit was A...
I think basic number for the whole lump would have been 59A-6005. Same number, same engine if it went into a Merc or a pickup or whatever, but if you want to quibble the A there makes it a Ford passenger part.
The B in 59AB has a different source entirely...
The cylinder head released with the new engine in '45-6 was 59A-6050. Partway through 1946, that head was replaced in production by a new head with slightly higher compression, 58A-6050B. The B in that position means that it is the second version of that part, and the 59AB was cast right onto it so service could tell what proper replacement part would be. At that time, the first head BECAME 59A-9510A for catalog purposes so proper part could be ordered for early cars, but of course the heads were not so marked because when they were made they were the only head and so did not need the letter. When you see a 59 AB, the B applies only to the head.
Normal 239 blocks were marked with the 59 at the rear for the benefit of service people, a correct marking, but the replacement postwar made block for 221's with small bore also incorrectly had the 59 simply because most of the casting cores were 59 cores with only the cylinder walls cast differently. The were sold under a correct part number, 41A...1944 design 221. They were not listed under the 59 # on the rear because they were not 9 series. These blocks were not used in production since Ford (in the USA) was not building 221 cars any more...their purpose was to fill the vast need for parts for early cars that had been run into the ground during WWII.
 
Ford Motors was slated to introduce the new Bonus Built trucks and Mercury cars in 1948 but due to problems with design and production on the Mercury cars, introduction was delayed on them untill the 1949 model year along with the new style Ford cars. The Bonus Built trucks were ready so their intro was on schedule in early 1948. Ford was actually manufacturing the older 59 series engines at the same time as the 8BA series for that year. I'd bet that was a headache for some of the folks at Ford.

Who would have known then that just a half dozen or more years later they would be manufactureing around 3X that many different engines.
 
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Having problems with the starter rotating the motor (thread:Need someone smarter than me..) allegedly the starter purchased from Dennis Carpenter was the wrong part. They said they do not sell a starter for a 48 Mercury. So what is the facts if both engines are the same?The starter bolted right in, but wouldn't rotate the motor when hot then was locking up.
 
Bruce, you state that the small bore 59 series blocks were the same as the 59 large bore with the only change being a smaller bore diameter. I have a small bore 59 series block with the small ledge above the cam gear cover whereas all of my large bore 59 series blocks do not have this. Were there both styles of blocks for the small bore series? I seem to recall never seeing a 3 1/16 bore 59 stamped block without this earlier feature. Thanks again for sharing your knowledge.
 
The 41A block design was never for mass production since it was a replacement part for the prewar engine blocks (circa 1944). Although Ford didn't make a lot of the automotive type V8 engines during the war, they did make some. I've seen evidence of engine production for the T-16 carriers that were equiped with 239 CID engines. As the war progressed even the war department could see a need for replacement parts, if nothing else, for prewar civilian vehicles to keep up the effort for transportation in agriculture and war industry needs. The 41A design dates to 1944 but the blocks didn't start production till the go ahead from the war department in early 1945 so production started out as a mix between 239 engines and 221 engines. They used the same core box for production of both engines so they all cariried the charictaristic 59 on the back bell. The 41A had sand cores for the prewar 221 wired into the same core box as the 59 type blocks. This created a hybrid mix between the two but they are not the same. The prewar 221 blocks and therefore the post war 221 were same basic or similar design and don't have the near the cylinder wall thickness of the 239 CID blocks.
 
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