1FastBrick

iTrader: (17)

With the pistons out of the hole .006 it should look like this to get 10.6:1

AGearHead4Life

iTrader: (5)

wait a min, Negative deck clearance?

1FastBrick

iTrader: (17)

If you assume L33 spec with a 0 deck and 65cc combustion chamber on the summit one I get a correct value.

1FastBrick

iTrader: (17)

When the piston is up out of the hole, the deck value is negative.

Some of the other calculators have this info listed next to this variable.

1FastBrick

iTrader: (17)

These other two calculators list that info and show a similar number to what the summit one comes up with.

Engine Compression Ratio (CR) Calculator
RSR Static Compression Ratio Calculator

AGearHead4Life

iTrader: (5)

Good catch. I forgot about the heads they used.

AGearHead4Life

iTrader: (5)

Damn! Another good catch! I see that you have put a lot more thought into this. lol thank you for showing me the light.

Here's what I was looking at. I'll try again with a neg deck height.

1FastBrick

iTrader: (17)

The castings vary but I think 65cc is a close enough value.

AGearHead4Life

iTrader: (5)

Its coming up with what you said now. Wow man, I'm glad you caught this. It could have been a headache down the road trying to figure out what was going on with a .5:1 difference in compression then I thought I had. I would have been over 11:1! That would be fine for my Camaro, but not in my Daily driver.

1FastBrick

iTrader: (17)

Should put you right were you want to be with out needing to mill. Maybe just a clean up pass.


I would CC before and after the intake valve change to see were you are at before having any milling done.


Ironically I started this well over a 2 years ago and wanted to do a max effort NA build and see if it could set a record for the fastest stock bore 5.3L. My partner got out of the performance scene. I have now turned it toward a more efficient performance engine build for my DD.