Avengeance

iTrader: (4)

Im putting some numbers together for a build coming up.... before I have someone build me an engine I want to understand completely about all the figures going into the process.

As a reference Im using this website for further calculation with the numbers Im listing below.

Sicks Engine Compression Calculator.

Here are all the figures for the motor Im looking to have built:

Head CC - 72cc
Bore - 4.030
Gasket Bore - 4.030
Stroke - 3.622
Piston - -15cc
Rod - 6.125
Gasket thick. - .040
Piston CH - 1.309

Using the deck clearance calculation of (stroke length/2 + rod length + piston CH) - deck height = deck clearance or (3.622/2 + 6.125 + 1.309) - 9.240 = .005 deck clearance. Im assuming this calculation equals a out of the hole .005, or a +.005 using the linked calculator above.

Factoring all this I come up with 9.02:1 CR.

The only thing that has me thrown off is deck clearance. Using the "sicks calculator" is the .005 out of the hole or in the hole???? If the piston is in the hole .005 I can use a .040 gasket to get my target CR. (approx 8.8:1) If its out of the hole I can use a .051 gasket to get approx the same CR.

THANK YOU in advance.

Sales2@Texas-speed

iTrader: (5)

Assuming your block is 9.24" (iron blocks are often 9.235" BTW), you'd be .005" OUT of the hole. If it's 9.235", then your pistons would be .010" out of the hole. At .005" out it's about 9.03:1, at .010" out it's about 9.12:1 or so.

Avengeance

iTrader: (4)

Awesome.... thank you very much!!!!

Sales2@Texas-speed

iTrader: (5)

Anytime