simple question from a simple mind
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Junior User
Joined: Oct 2002
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simple question from a simple mind
I got my 351 windsor rebuilt bored out 30 over i believe, and i put a fresh 2 barrell holly carb on it, and a dynomax exhaust. How much power this motor pushing, and exactly what does the bore do and how does it improve performance? Just curious.
Post Fiend
Joined: Nov 2001
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From: Topsfield, MA
simple question from a simple mind
The bore is the diameter of the cylinder. When you increase the bore you increase the size of the engine. Stroke is the distance up and down. For example, a 460ci big block can be bored and stroked out to 514ci. That means that the bore has been increased, and the stroke has been lengthened. The number 514, 460, 351, 302ci..is a measure of the cylinder's volume. Anytime you increase that volume via bore/stroke, you increase that number. As a rule of thumb, the bigger the bore the more hp and the longer the stroke the more torque. For example, the 302 5.0L has a low end torque shortage. They make kits that lengthen the stroke, which makes the engine go from say 302 into 331ci, it's called a stroker kit. They have a 347 kit but it will not allow the engine to last long. Hope that helps.
Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds
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Check out my Gallery for a look-see.
Justin - One Happy FTE Member
Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds
.Check out my Gallery for a look-see.
Justin - One Happy FTE Member
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Junior User
Joined: Oct 2002
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simple question from a simple mind
That makes sense. So say I have a 351 bored 30 over, as they say, my engine in cubic inches would be? I have no clue? And how much extra hp/Torque would that produce?
Senior User
Joined: Jun 2002
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From: Oklahoma
simple question from a simple mind
Engine displacement is calculated by:
Bore diameter times bore diameter times .78539 times stroke length times number of cylinders.
A .030" over bore 351 would be:
[(4.03 x 4.03)x .78539]x 3.50 x 8 or 357.15cid
Bore diameter times bore diameter times .78539 times stroke length times number of cylinders.
A .030" over bore 351 would be:
[(4.03 x 4.03)x .78539]x 3.50 x 8 or 357.15cid
