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I was looking at the SHM website & their Stroker kits, when the Q popped in my head.

given 3.55 bore & 3.54 stroke of a 4.6L, what is the formula to derive the L-displacement ( & CI for that matter)


thanks in advance...
 

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Bore^2 * Stroke * .7854 * <# of cylinders>

or

Bore * Bore * Stroke * .7854 * 8 = cubic inches

Forgot the one for Liters. My book is at home.
 

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Hmm - never heard of doing it either of these two ways -

This is maybe more familiar:

pi*radius^2 (pi-r-squared - to find the area of the cylinder bore, pi = 3.14)*stroke=volume of 1 cylinder*8 (number of cylinders)
 

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displacement = bore x bore x 0.7854 x stroke x number of cylinders

if you want cubic inches, then make sure that the bore and stroke are both in inches.

To convert from cubic inches to L, divide by 61.02.

Example:

3.55" x 3.55" x 0.785 x 3.54" x 8 = 280 cubic inches

280 ci / 61.02 = 4.59L
 

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My turn.

1" = 2.54cm and the mod engine is 9.02cm X 9.0cm

(9.02/2)^2 * pi * 9.0 * 8 = 4600.822cc or 4.6L
 

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TexasDevilDog said:
My turn.

1" = 2.54cm and the mod engine is 9.02cm X 9.0cm

(9.02/2)^2 * pi * 9.0 * 8 = 4600.822cc or 4.6L
Aha! I knew the mod motors were "hard metric", but I didn't know the exact bore and stroke.

Bore = 9.02cm = 90.2mm = 3.5512"

Stroke = 9.0cm = 90mm = 3.5433"

Disp (in cubic inches) = 3.5512"^2 * pi / 4 * 3.5433" * 8 = 280.8, which rounds to 281 cubic inches. I feel better now. ;)
 
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