Thread:

Engine Crank Stroke???

Originally Posted by Mach80

I'm trying to determine what stroke crank is in my boat. Does anyone have a way to measure stroke or Cubic inches without removing a head? The engine is installed in the boat but I'm not sure if it is a 509 or a 540.

Thanks.

use something like a pencil. Take out the plug. Rotate to BDC, locate an index point (top of threads) make a mark. Rotate to TDC make another mark and measure. Stroke x bore x 8=CID

Originally Posted by 2002CP19

use something like a pencil. Take out the plug. Rotate to BDC, locate an index point (top of threads) make a mark. Rotate to TDC make another mark and measure. Stroke x bore x 8=CID

....

1/2bore x 1/2 bore x pi x stroke x #cyls

Originally Posted by Flat BROKE 612

....

1/2bore x 1/2 bore x pi x stroke x #cyls

bore X bore X .7854 X Stroke X #cylinders

Originally Posted by 2002CP19

use something like a pencil. Take out the plug. Rotate to BDC, locate an index point (top of threads) make a mark. Rotate to TDC make another mark and measure. Stroke x bore x 8=CID

So, you have a magic pencil that can make the turn and drop straight down the cylinder for this high tech method?
Why did people spend 1500.00 plus for a CID tester when you can do it with a pencil?


stock 454 bore/stroke
4.00(stroke) X 4.250(bore) X 8= 136

I what you checking my engine size at the races

Originally Posted by gn7

So, you have a magic pencil that can make the turn and drop straight down the cylinder for this high tech method?
Why did people spend 1500.00 plus for a CID tester when you can do it with a pencil?


stock 454 bore/stroke
4.00(stroke) X 4.250(bore) X 8= 136

I what you checking my engine size at the races

I didnt say it was high tech. Just a thought...

I've been wrong before.

Originally Posted by 2002CP19

I didnt say it was high tech. Just a thought...

I've been wrong before.

OH, I thought you had personal experience with that method

Originally Posted by Franger

Bob, Wouldn't the correct tool for a mechanic to use in this procedure be a ....... "mechanical" pencil?

I perfer to use a Camodian Magic Wand myself.

Originally Posted by gn7

bore X bore X .7854 X Stroke X #cylinders

Ya but mine has PI!!! MMMMM pie.......

Originally Posted by gn7

OH, I thought you had personal experience with that method


I perfer to use a Camodian Magic Wand myself.

Well I have used that method before, just not to measure.


Looks like the cambodian unit will do the trick...

Originally Posted by Franger

Bob, Wouldn't the correct tool for a mechanic to use in this procedure be a ....... "mechanical" pencil?

only if it's a "union" mechanic.

radius (1/2 bore diameter) squared x 3.1415927 x height(stroke) x 8

or, pi x r2 x stroke x 8

with a p&g meter, if you get really really lucky, somebody might get within 10% of the actual ci with it. POS...

Originally Posted by bp298

only if it's a "union" mechanic.

radius (1/2 bore diameter) squared x 3.1415927 x height(stroke) x 8

or, pi x r2 x stroke x 8

with a p&g meter, if you get really really lucky, somebody might get within 10% of the actual ci with it. POS...

You guys sure do like you PI. MMMMMmmmmmmm pie!

Originally Posted by gn7

You guys sure do like you PI. MMMMMmmmmmmm pie!

Pie is always Good , Bob ,,, Apple , Berry , Peach , Cherry , HAIR , (lol) ....... MMMMMMMMMMM PIE ...