Flathead Displacement
Freshman User
Joined: Dec 2001
Posts: 36
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Flathead Displacement
You didn't give quite enough info to calculate it (bore and stroke of that engine), so I'll walk you through it.
displacement=(# of cylinders) * stroke * bore
so, in your case, displacement=# cylinders*stroke*(orig bore+(2)(.040). The (2) is because the .040 was bored on "both" sides of the cylinder.
Hope this helps...
Now I can tell my Mom that I really did learn something useful in college!!
displacement=(# of cylinders) * stroke * bore
so, in your case, displacement=# cylinders*stroke*(orig bore+(2)(.040). The (2) is because the .040 was bored on "both" sides of the cylinder.
Hope this helps...
Now I can tell my Mom that I really did learn something useful in college!!
Junior User
Joined: Sep 1999
Posts: 83
Likes: 0
From: Alaska
Flathead Displacement
To find the displacement of the engine you need to calculate the volume of the cylinders. BoreXStroke doesn't quite get you there.
The bore is the diameter of the cylinder. You use that number to find the cross-sectional area of the cylinder using the formula
(Bore/2)^2*PI. This number is then multiplied by the Stroke and # of cylinders to give you the total displacement. The 239 flathead (at least the 50 through 51) had a bore of 3.1875" and a stroke of 3.75"
so - (3.1875/2)^2*PI*3.75*8 = 239.39CI
If you add 0.040" to the bore and plug it into the formula above, you get a total displacement of 245.44CI
The bore is the diameter of the cylinder. You use that number to find the cross-sectional area of the cylinder using the formula
(Bore/2)^2*PI. This number is then multiplied by the Stroke and # of cylinders to give you the total displacement. The 239 flathead (at least the 50 through 51) had a bore of 3.1875" and a stroke of 3.75"
so - (3.1875/2)^2*PI*3.75*8 = 239.39CI
If you add 0.040" to the bore and plug it into the formula above, you get a total displacement of 245.44CI
