Did Ford ever put a merc flathead in their F-5 or F-6 trucks? My buddy just picked up an 8CM out of a heavy duty truck and he was wondering if they came that way or someone transplanted it. This motor has different water pumps on it, they are wider, possibly to fit the heavy frame. The intake has 4 carb studs instead of the usual 3 for the 94-97 carbs. He said the fuel pump is bigger also compared to a stock flatty. He also mentioned it had a truck pan on it. Any info I could pass onto him? Thanks guy's. later plmczy
distributor is in the front. The manifold is stamped 8CM also. He was thinking that they put the merc in there(more horsepower?)and added the heavy truck stuff to use it. Thanks later plmczy
plum...i don't specifics...however, i do know that the merc's have larger water pumps, so the belt should be 5/8ths width, opposed to the 3/8th width that ford used on it's passenger cars...ford did use larger pumps for trucks which makes sense...my guess is that it's a complete merc engine, that someone transplanted ..?? tok
I have one that came out of a big truck too. It's my guess that if you had a big truck in the 50's that needed a motor, you'd opt for the more powerful Merc motor as a replacement. The only way to tell for sure is to measure the piston travel. The water pumps need to be changed to mate up to the truck motor mounts. The 49 Mercs had the wide belts and the 50-53 had the narrow belts but the motor mounts were different.
Very common to upgrade to the bigger engine in trucks. Even fleet type rebuilders put in Merc cranks, etc. Another common swap was to add the 52-3 Ford EAB heads for another small boost. One of my best scores was out of a 51 F5 farm truck. Completly uncracked engine, .030" over, Merc crank and Johnsons. Had the rebuilders tag and the engine looked very low hours. Some have said that the Merc was also available as an option from select mountain state dealers.
Take a look at the rear of the engine on the bell housing (left side) just below the oil pressure sending unit. There should be a couple of letters (numbers) cast in the block. If they have an "M" in the combination, (like 8CM) it's a fairly safe bet that it is a Merc engine. But as Tommy said; the only sure way is to measure the stroke." Ford = 3 3/4", Merc = 4". The Ford company often would put Merc engines in the bigger trucks even though the badges said Ford. Plus someone could have switched the engine from a Ford to a Merc.
[ QUOTE ] The intake has 4 carb studs instead of the usual 3 [/ QUOTE ] Someone else probably knows better than I, but I thought that I read somewhere that those super rare flathead supra chergers were an option on trucks. (?) It may be one of those types of intakes. To repeat what the others have said check the block markings and the stroke. It may be a replacement motor or a super rare super charged super flat super head!
I'd say the 8CM was put in there because bigger Ford trucks I've seen had Lincoln flathead V8s, they have little incommon with the Ford/Merc flatheads. Billy
According to the shop manual for 49-51 w/ 52 supplement: Ford only used the 239 in trucks F1 thru F6's F7 & F8 had 337's (Except for 52 when they went with OHV's) Unless someone has a service bulletin that says differently, it had to be transplanted. Dealers might have done anything for a local client since every accessory on a flathead V8 will swap. The normal merc carburator had a 4 bolt mount. AS mentioned above merc water pumps have a heavier flange where they sit on the motor mount and it is located a little higher on the pump than the ford truck mount. Thus the merc motor would sit a little lower. Fords and mercs used the same block - I've never seen any markings on the blocks to indicate what it was.
Cool, I'll pass the info along to him. He managed to pick this up for $75. I thought he got a pretty good deal on it. later plmczy
[ QUOTE ] Ford only used the 239 in trucks F1 thru F6's F7 & F8 had 337's [/ QUOTE ] I believe the 337's were the "E" series, had the distributor at the back of the engine and NOTHING inerchanged with the 239's. (heads, manifolds, etc.) [ QUOTE ] The normal merc carburator had a 4 bolt mount. Fords and mercs used the same block - I've never seen any markings on the blocks to indicate what it was. [/ QUOTE ] Maybe some of the early Canadian Merc engines are different, some did come with 3 bolt intake manifolds. As far as "markings" go; every flathead engine I have, both Ford and Merc has numbers/letters cast at the rear of the engine. Here is a site showing where the number/letters are located... http://www.agt.net/public/bboogaar/engine.htm
Another reason he thought it might be transplanted, there was a 1" piece of steel between the manifold and the carb that was plumbed with******* to run vaccume port. The carb that is on it is a Carter. Looks to be a 2 barrel. later plmczy
[ QUOTE ] Cool, I'll pass the info along to him. He managed to pick this up for $75. I thought he got a pretty good deal on it. later plmczy [/ QUOTE ] IF it IS a Merc engine and it has a 4" stroke crank (that is still useable) he DID get a good deal! Good Merc 4" cranks all by themselves are worth a couple of hundred bucks!! Hey, Ford don't make them anymore!
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