Cubes

M

Mike Mayer

Senior Member
I was checking an old mercury flathead and I found it is has a .030 over bore . My Math skills are such that I can't figure out the cubes .
 
All flatheads did not start with the same stock bore, so .030 over what? What block do you have? Even further, what crank do you have? That's important also.

Mac VanPelt's site is a great one to bookmark and refer back to a LOT.

Displacement chart:
http://www.vanpeltsales.com/FH_web/flathead_specifications.htm

There were varios bores in the different flatheads across the range of years from 1932-1953 and different for Ford and Mercury. And a "Mercury" engine could really be a Ford engine that someone bolted on Mercury heads.

And in 1949, merc motors went to 4 inch stroke, rather than 3 3/4 stroke. That also effects cubic inch displacement.

so, measure the bore size, and the throw of the piston, and repost and we can help you out.
 
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Editing my wrong answer. I said 274.

It's actually 260 cubic inches like estout 81 said below.

Formula: Pi (3.1416) times r² (radius is 1/2 the actual bore size) times stroke times 8 cylinders.

So 3.1416 times (half the bore diameter squared) 2.5881 times 4 times 8 = 260.185 cu. in.
 
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Ooops! You're right! Sorry about that. I was going up to the .125 bore. Staring at that chart a little too much.

Formula: Pi (3.1416) times r² (radius is 1/2 the actual bore size) times stroke times 8 cylinders.

So 3.1416 times (half the bore diameter squared) 2.5881 times 4 times 8 = 260.185 cu. in.

Good catch estout81!
 
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