Thread: CR question?

Tweet

submit

Alright. After much hair pulling and thowing pens across the room a few times.

I have came up with a workable CR of 10.58 with a 76cc head useing the info tech gave me.

Thank You!

Originally Posted by JBoss

Alright. After much hair pulling and thowing pens across the room a few times.

I have came up with a workable CR of 10.58 with a 76cc head useing the info tech gave me.

Thank You!

Excellent!! I came up with the same answer.

Now, you are in a small, elite group of enthusiasts who have the knowledge to figure static compression ratio on any motor without using an online calculator. Congratulations!!!

You have the same static compression ratio I do in my 383. Now you need to learn about Dynamic Compression Ratio (assuming you are not knowledgeable already) so you can choose the proper camshaft so you can run on pump gas.

Originally Posted by rumrumm

You have the same static compression ratio I do in my 383. Now you need to learn about Dynamic Compression Ratio (assuming you are not knowledgeable already) so you can choose the proper camshaft so you can run on pump gas.

OK. I need more enlightenment. Please explain "Dynamic CR"

I will be using a comp cam. 270H

Isnt Google wonderful?

http://www.empirenet.com/pkelley2/DynamicCR.html

Originally Posted by robot

Isnt Google wonderful?

http://www.empirenet.com/pkelley2/DynamicCR.html

Thats the same one I was reading. And YES Google is wonderful.

Originally Posted by JBoss

OK. I need more enlightenment. Please explain "Dynamic CR"

I will be using a comp cam. 270H

Go back to the calculator:
http://www.kb-silvolite.com/calc.php?action=comp
Enter all of your information and then plug in your rod length (5.7 inches) and the intake closing angle for the cam (61 degrees) and this will give you your dynamic compression ratio. It is much more accurate than static compression ratio in determining whether your engine will run on pump gas. As a general rule of thumb, iron headed engines should be 8.0 or less while aluminum headed engines should be 8.5 or less. If you want to read up no DCR, check out this thread:
http://www.chevytalk.org/fusionbb/sh...php?tid/92966/