Need some education of flathead

[akacustomcab]

Pick up a 50's Mercury flathead motor; 3 carb intake, heads and intake both edelbrock; told its rebuilt and bore 60 over; is this the max for it.
Also the manuel fuel pump is block off and was givin a 3 rail port that mounts of fire wall to distribute fuel from a electric fuel pump. Does this sounds right? Motor going into a 50 F-1 with factory 3 speed.
Thanks

[Bassman/NZ]

Bore can be double that or more if the cylinder walls check out with sonic testing. Most triple carb setups use electric pump mounted back near the tank. 3 port rail is probably the most common way to send fuel to the 3 carbs.

[B-O-B]

There is a lot of literature out there on these flat heads. Pick up a few books for you reference library. Try Amazon.com for good prices.

[ford3]

most blocks can be bored to .187 over, that was common, but only if you have a good block, like was posted, have it sono tested, only draw back going that far it cant be bored again

[Mike in AZ]

which carbs??....will probably need pressure regulator and pressure gauge.....Mike

[mikebishop]

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Originally Posted by ford3

most blocks can be bored to .187 over, that was common, but only if you have a good block, like was posted, have it sono tested, only draw back going that far it cant be bored again

The biggest drawback to a massively over-bored block -- greater than 3-5/16-in. -- is that the motor will run hot for sure. For all practical, real-world applications it makes no sense to bore a flathead block any more than the next oversize to clean it up. You can get greater real-world useable poke from a flathead through increased stroke; keep in mind that our much-loved Ford L-head rascals are torque 'farms' that will, off the line, kick the collective ass of OHV motors of equivalent displacement.

Mike

[akacustomcab]

Thanks for the replies; I'm use to 30,60 over bore; havn't had anything more than that. Had a 302 mexican block bore 60 over, ran fine and mantianed high compression.
For carb's haven't really investigated them two are ford and one aftermarket. Will cross that hurdle soon.
Thanks.

[gmc1941]

If your running dual carbs and a pressure gauge a three port would be appropriate. My feeling it's better to have a extra than short on ports.

[1936ford64]

The thinner the cylinder walls the hotter it runs, I have never had a flat head that ran overly cool.

[Pete]

"only draw back going that far it cant be bored again"

"The thinner the cylinder walls the hotter it runs"

Both statements only partially true.
There are and have been many blocks that will go 3 7/16 +.030 safely.
Yes they run hotter but not because of the thinner walls. It is because they are making a whole lot more horsepower. ANY engine that is modified for more hp will run hotter.
The main reason people have trouble cooling flatheads is they don't have the block stripped. Accumulated rust and scale in the water jacket can only be removed by stripping.
Many people forget the radiator also. They figure it worked before hopping up the engine so it should be ok. WRONG. A bigger cubic inch more powerful engine requires more cooling, ie, more rows, more fins, bigger fan, shroud and more engine compartment venting.
A sprint car has very limited radiator frontal area but somehow we made the 315 ci flatheads cool fine in the old days. It is still being done today so it is not a lost art.
It makes me puke when I hear people say a flathead can't be cooled or it can't be bored over 3/8.

[texas webb]

Words of true knowledge!^^^^^^