Author Topic: Added Stroke  (Read 290 times)

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Online Will-Run

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Added Stroke
« on: December 10, 2017, 07:07:56 AM »
If you put a 4 5/8 crank in an s&s 107" 4 1/4 , what do you wind up with?. And can it be done without a load of
 complications?. Thanks.
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Offline turboprop

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Re: Added Stroke
« Reply #1 on: December 10, 2017, 07:24:51 AM »
Have you tried using one of the many online displacement calculators?

Bigboyz and RB Racing both have very good calculators for just this very purpose. Anyone that provides a displacement will probably have gone to one of these websites and run the numbers. You might as well do it yourself.
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Offline rigidthumper

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Re: Added Stroke
« Reply #2 on: December 10, 2017, 07:47:53 AM »
If you put a 4 5/8 crank in an s&s 107" 4 1/4 , what do you wind up with?. And can it be done without a load of
 complications?. Thanks.
4 5/8" stroke x 4" bore =116" displacement. Piston pin height & cylinder height will need to be matched for the longer stroke- so new slugs & jugs -pricey.

Online Will-Run

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Re: Added Stroke
« Reply #3 on: December 10, 2017, 07:58:40 AM »
 Thank you.
Lean Angle, " Is Life."

Offline Scott P

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Re: Added Stroke
« Reply #4 on: December 11, 2017, 07:41:20 AM »
If you put a 4 5/8 crank in an s&s 107" 4 1/4 , what do you wind up with?. And can it be done without a load of
 complications?. Thanks.
4 5/8" stroke x 4" bore =116" displacement. Piston pin height & cylinder height will need to be matched for the longer stroke- so new slugs & jugs -pricey.

S&S used to manufacture that combination, prior to 124".
That was their largest street engine, and right on, you'll need pistons, and cylinders.

Otto Knowbetter sez, "Even a fish wouldn't get caught if he kept his mouth shut"

Offline BKACHE

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Re: Added Stroke
« Reply #5 on: December 11, 2017, 10:03:56 AM »
PI * R2
Pi = 3.14159
radius squared = 4"
This is the area of the circle.
To get three dimensional multiply by stroke.
Engine size - multiply by # of cyls.