Engine size (cubic inches)

[Kahuna]

I have available to me a very nice, uncracked (with old Mag test tag), 1936 Ford LB Block. I also have a good Mercury crank.
I'd like to know from the wizards here, just how big an engine can I put together?
Can the block be bored to 3 3/16? Or Bigger? (assume sonic test)
What road blocks are presented? IE- what rods will/will not fit? I have the rods from the Merc crank, but I can also acquire 21A rods without too much difficulty.
Will the rods (whatever ones used) clear if the crank is offset ground to 4.125?
I have zero experience with the 32-36 engines

Any thoughts appreciated
Jim

[Lawrie]

Jim, from my experience the 36 LB blocks I have used don't like much over .060,
Lawrie

[jimTN]

It has been written up. See if you can get a copy7 of Tex Smith's "The complete Ford flathead v8 engine manual. There is a detailed article in there written by Vic Thompson and Rex Gardner about great race 21 stud with 4" crank and all the other mods needed to make it a first class dependable and powerful engine. There are good pics and a required parts list in the write up.

[Init1]

I wouldn't waste time or money on a real early flathead. The later ones are better all around.
Just my two cents.

[34billct]

Be happy with 85 Guys are always trying squeeze the last hp out of these old blocks

[Brian]

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I wouldn't waste time or money on a real early flathead. The later ones are better all around.

Whereas....I would....the later flatheads, whilst more cubes, are, in my opinion, no where near as good as the prewar blocks

To answer the original poster; sure, as mentioned, it can be done. However, in my experience, one of the best features of a 36 LB block with a 3 3/4 stroke, is its ability to rev. Chucking a longer stroke crank innit is gonna take away that ability. Those blocks have thin walls, taking then out to .060" is risky. If you want to bore a 21 stud, use a 37 block, more meat in the walls. I'm in the process of doing this right now. Head gaskets could be a problem....

[rotorwrench]

The one in the Tex Smith book was a 1937 21-stud so they would at least have a 21 stud for their 1935 coupe to run the GAR. They bored it for 3 3/16" sleeves and put a 4 inch crank in it. I think they had to cut down the crank a bit to get it to fit in the crank case properly.

I don't know if I'd try all that stuff in an old LB engine. It seems the main sizes would make a larger crank shaft a difficult situation.

[Lawrie]

Scat make a 4 in crank for these early engines
Lawrie

[Kahuna]

Thanks Guys.
Not sure what I'll do and didn't remember that a 37 block was used in that Great Race engine.
Jim