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I have just rebuilt a 1956 Ford 312 that I will be installng in my 1955 Mercury that had a 292 originally. One of my car club members tells my the 292 distributor won't work with the 312 and neither will the good old "tea pot" carburetor. Another guy with lots of Y-Block experience ) Which I don't have being a mainly Chevy guy) says there won't be a problem. Who's correct and what are the differences I'm facing here?
By the way, the neoprene rear main seal I bought at Car Quest for the 312 had a big warning right in the instructions that said, "Only use a wick style seal for 312's" so that's what I used even though I feel a neoprene one would be better to cure these engines ususal lealing rear main seal problem. Any ideas about this phenomenon?
 

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The distributer and the carb should work on either one.
 

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Discussion Starter #3
Thanks Henry

Much appreciated, Henry. You've saved me time and money. By the way, the Merc is for sale. She's a rust-free 1955 Monterey two door hardtop with Merc-O-Matic. Its got factory visor and skirts and an aftermarket Continental kit. There's exhaust cut-outs behind the front wheels, too, and she sounds great with them open! The car has excellent all red paint with a red and white tuck 'n roll interior. It also has power steering and someone added a dual master cylinder to the brake system for safety sake. This was done right since there's no pulling or grabbing at all!
 

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I checked the Fel-Pro catalog and while they show a rubber two-piece seal for the 292 (along with a rope-type), they only show the rope for the 312. They do show the same rope seal #'s for both engines. My guess is that the seal cavity is a little different for the 312 and the rubber seal may not seat properly in it. BTW, that can be a problem in any case where a rubber seal is substituted for a rope seal.

tom
 

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Discussion Starter #5
Rope seal vs. neoprene seal for 312 motors

Thanks Machine Shop Tom for the info. The rope seal is in there now so I hope the s.o.b. won't leak like the neoprene one did in motor beforehand.
 

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BobWishart said:
Much appreciated, Henry. You've saved me time and money. By the way, the Merc is for sale. She's a rust-free 1955 Monterey two door hardtop with Merc-O-Matic. Its got factory visor and skirts and an aftermarket Continental kit. There's exhaust cut-outs behind the front wheels, too, and she sounds great with them open! The car has excellent all red paint with a red and white tuck 'n roll interior. It also has power steering and someone added a dual master cylinder to the brake system for safety sake. This was done right since there's no pulling or grabbing at all!

Post a picture. I'd like to have a 56. I like the top better.
 

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BobWishart said:
I have just rebuilt a 1956 Ford 312 that I will be installng in my 1955 Mercury that had a 292 originally.

One of my car club members tells my the 292 distributor won't work with the 312 and neither will the good old "tea pot" carburetor.
Here's the problem. FORD used the LOAD-O-MATIC distributor (full vacuum advance-retard/no mechanical advance) with the HOLLEY 4000 carburetor (aka Teapot aka The Towering Inferno). They must be used together. If you go to a 4160 HOLLEY or WCFB (or AFB), you also have to use a 57/ distributor. This is what they are referring to.

Now, as to wanting to shake the MERC, I have but one thing to say;



As for the seal, there is something with the 312 main cap that I cannot seem to remember. I will search it out if anyone needs the information (the HP trick on these things is to use the 312 crank in the 292 block).
 

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nitro_baller4692 said:
i think there is a pin in the 312 main cap for the rope seal and would not be for the rubber.not totaly for sure though.
The pin is removable. Isn't there some other reason?

Surely nobody would install a rubber seal and mash it over the pin..... :rolleyes: :rolleyes:
 

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My Bud and I installed the two piece neoprene rear main seal in 56 T-Bird with 56 312 motor. We did this with the motor installed and the most difficult part of the job was getting the oil lines reconnected. It does not leak!!!!! The rope did not either: it poured!!!! This 312 has the Holly tea pot and the dual diaphragm distributor. Don't know why you could not put a different carb on and still use the old distributor as long as you can get two vacuum ports with near the same vacuum levels as the distributor is designed for or visa-versa.

Trees
 

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312 rear seal

312 yblock has larger mainbearings than 272 292 also rearseal aria is largerdiametr so seals will not work from the 292. the roap seals ar long enough to use on eather, but it seems material used in rope seals poor and dont last. use the ruber split lip seal. the ones listed on the web site for the 312 would be great. as far as useing a 312 crank in a 292 much machineing tohave it work, plus 312 cranks very rare. if you go to later holley carb(57 and up )you must use the 57 and up disributor which is far supperior to the vacume only type. cliff
 

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cliff tate said:
...if you go to later holley carb(57 and up )you must use the 57 and up disributor which is far supperior to the vacume only type. cliff
The 4000 HOLLEY has a valve that controls the balance of manifold/ported vacuum signal to the distributor (HOLLEY also made the distributor). Like this gentlemen says, if going to a later carb. design, you have to go to the later distributor (well, one doesn't have to, but it makes life one hell of a lot easier).
 

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Pity the crank's in, an old 1950's machine shop trick for Y blocks, Grey Holdens (6 cyl 1948/63) and Zephyrs (6 cyl english Ford) is to turn a shallow reverse thread or Archimedes' screw between the rear main and seal.
Not a lot of room but it worked by winding the oil away from the seal - like a grain auger.
 

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312 vs 292 motor

what your buddy is referring to when he says you can't interchange the distributors is this: In Y block fords some engines had a 12 tooth drive on the cam and others had a 14 tooth. Therefore you can't interchange the distributors unless you also change the distributor drive gear to match whichever cam drive you have. Now....I'm not sure about the 12 and 14 tooth, may have been some other numbers, but I do know for certain Y blocks had two different cams and distributors. Count the teeth.
 

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trees said:
My Bud and I installed the two piece neoprene rear main seal in 56 T-Bird with 56 312 motor. We did this with the motor installed and the most difficult part of the job was getting the oil lines reconnected. It does not leak!!!!! The rope did not either: it poured!!!! This 312 has the Holly tea pot and the dual diaphragm distributor. Don't know why you could not put a different carb on and still use the old distributor as long as you can get two vacuum ports with near the same vacuum levels as the distributor is designed for or visa-versa.

Trees
there is a spark control valve in the Load o matic carbs, it works special, but it alters a ported vac source, going to a str8 ported vac signal, would advance too much, too fast. the load o matic actully matches advance to engine load ( there is a venturi in the SCV, that when air is forced passed it, creates vacume, but if the engine gets loaded up more, the air speed changes and alters the vac signal, and inturn altering timing.
 

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37 plymouth coupe said:
what your buddy is referring to when he says you can't interchange the distributors is this: In Y block fords some engines had a 12 tooth drive on the cam and others had a 14 tooth. Therefore you can't interchange the distributors unless you also change the distributor drive gear to match whichever cam drive you have. Now....I'm not sure about the 12 and 14 tooth, may have been some other numbers, but I do know for certain Y blocks had two different cams and distributors. Count the teeth.
I think you will find this applies to the first year 239 as there were actually two differently designed engines (different foundries). The MERC 256 was also of this earlier design.
 

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matt167 said:
there is a spark control valve in the Load o matic carbs, it works special, but it alters a ported vac source, going to a str8 ported vac signal, would advance too much, too fast. the load o matic actully matches advance to engine load ( there is a venturi in the SCV, that when air is forced passed it, creates vacume, but if the engine gets loaded up more, the air speed changes and alters the vac signal, and inturn altering timing.

how did you know it was a 312, 272 292 312 all look the same, unless you furchased the neoprene seal recently it was not for a312. lots of 56 57 birds with 292s as 312s so hard to find and easy todiskyse the smaller 72 92
 

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cliff tate said:
how did you know it was a 312, 272 292 312 all look the same, unless you furchased the neoprene seal recently it was not for a312. lots of 56 57 birds with 292s as 312s so hard to find and easy todiskyse the smaller 72 92
still all pre '57 V8's have the load o matic, using the SCV and a load o matic distributor. Loadomatic was introduced in 1949
 
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