I like to show my car and drive it to meetings and any kind of VW related outing. One popular question that I always hear is "what size engine is that?" I say 2110cc. Then the next question seems to be "really, what size pistons and crank makes that combination, dude?" 82 X 90.5. Wouldn’t it be nice to know how to figure out engine displacement? Well there are a couple of ways, and Thanks to Sights like this one and Performance Technology’s website (http://www.racingheads.com), you have a couple of excellent resources for technical info like this.

To determine Bore: Measure the diameter of a piston in millimeters.

To determine Stroke: Turn your crank to Bottom Dead Center. One of your pistons will be at the bottom of its throw. Measure the distance between the top of the piston and the top of the cylinder in millimeters.

Bore x Bore x Stroke x .0031416 (pi) = Displacement in cc’s

Example 90.5 x 90.5 x 69 x .0031416 = 1775 (.4037)

Take displacement in cc and divide by 4 to get the swept volume of 1 cylinder.

Example: 1775 divided by 4 = 443.75 or S= 443.75

To calculate Deck Volume, multiply Bore x Bore x Deck Height in inches x .01996 = Deck Volume or D.

Example: 90.5 x 90.5 x .060 (deck height) x .01996 = 9.81cc deck volume or D= 9.81

H = Head cc volume (for example purposes we will use 50cc for chamber volume)

The formula to figure compression ratio is S+D+H divided by D+H

Example: 443.75(s) + 9.81(d) + 50(h) = 503.56 divided by 9.81(d) + 50(h) = 59.81. 503.56 divided by 59.81 = 8.43 compression ratio.

If the piston has valve notches, cc the notch and add the volume of the notch to the head volume.

* Common engine sizes

* This is actually considered a 1600cc engine by the factory.

Thank you to Fred at Performance Technology for the formulas and the numbers

Visit his website at http://www.racingheads.com

That is it for this month, thank you for reading, and be sure to check in often to catch all the articles and features. See you in the chat room! Adam Wood aka 67 Kafer.