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Compression rate assistance, please

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Old Sep 15, 2016 | 08:29 AM
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Default Compression rate assistance, please
I have a 6.0L iron block, bored to .030 with a 4" crankshaft and 6.125 rods, the pistons is a -29 cc one (JE). My questions is: what's the CR if I use the mentioned combination with a 243's head with 64cc chamber and if I use a 317's with 72cc chambers? I'm planning to go twin turbo. Also can use a standard stroke crank with the 6.125 rods and flat pistons (Diamobs-3cc's); by using the same heads, what would be the CR and which combination would be better for the TT combo?
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Old Sep 16, 2016 | 09:38 AM
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With the 243s the compression will be roughly 9.1:1 with a standard gasket. If you were to put the combination together with the 317s that would put you around 8.5:1.
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Old Sep 16, 2016 | 11:22 AM
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Originally Posted by Mike Cordero
I have a 6.0L iron block, bored to .030 with a 4" crankshaft and 6.125 rods, the pistons is a -29 cc one (JE). My questions is: what's the CR if I use the mentioned combination with a 243's head with 64cc chamber and if I use a 317's with 72cc chambers? I'm planning to go twin turbo. Also can use a standard stroke crank with the 6.125 rods and flat pistons (Diamobs-3cc's); by using the same heads, what would be the CR and which combination would be better for the TT combo?
Try this:
Compression Ratio Calculator
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Old Sep 17, 2016 | 02:23 PM
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Originally Posted by KCS
I'm only looking for an estimate. I don't know about numbers, just what I wrote at the beginning of the post; no idea of gaskets gross/thickness or other number to calculate. Can you do some numbers??? with the -29cc JEpistons or if I go with the -3cc Diamonds?
Last edited by Mike Cordero; Sep 17, 2016 at 03:16 PM. Reason: add info
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Old Sep 17, 2016 | 03:18 PM
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Originally Posted by Aaron at SDPC
With the 243s the compression will be roughly 9.1:1 with a standard gasket. If you were to put the combination together with the 317s that would put you around 8.5:1.
Think that these numbers are with the -29cc's, what if I ise the -3cc's with the two heads options?
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Old Sep 19, 2016 | 07:49 AM
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Originally Posted by Mike Cordero
Think that these numbers are with the -29cc's, what if I ise the -3cc's with the two heads options?
With a -3cc piston you would be looking at a compression of approx. 11.7:1 with the 243s and approx. 10.7:1 with the 317s.
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Old Mar 16, 2018 | 07:45 AM
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Default What is my compression ratio
looking to find out what ratio i got

block been bored .10
flat top pistons with valve reliefs
317 heads been decked .10
stock crank
630 lift cam
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Old Mar 16, 2018 | 09:03 AM
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Originally Posted by Kele McCarley
looking to find out what ratio i got

block been bored .10
flat top pistons with valve reliefs
317 heads been decked .10
stock crank
630 lift cam
Try this:
Compression Ratio Calculator
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Old Mar 16, 2018 | 11:11 AM
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Default
Originally Posted by KCS
Originally Posted by Mike Cordero
I'm only looking for an estimate. I don't know about numbers, just what I wrote at the beginning of the post; no idea of gaskets gross/thickness or other number to calculate. Can you do some numbers??? with the -29cc JEpistons or if I go with the -3cc Diamonds?
I know this is from 2016, but this is my new favorite post.

"Hai guyz. Wuts mah compression?!?"

"Here's a tool that will allow you to plug in the numbers and figure it out."

"I dunt have all teh numberz to do it mahself! But hey, can u use mah incomplete numberz and do it for meh?"
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Old Mar 16, 2018 | 12:02 PM
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Default Eap
Hi Kele, I use EAP for compression Ratio Calcs.

I do this for ALL LS-1 Tech members who ask.

PROVIDE your specs, you will get an answer ?

Lance
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Old Mar 16, 2018 | 02:15 PM
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Originally Posted by MuhThugga
I know this is from 2016, but this is my new favorite post.
"Hai guyz. Wuts mah compression?!?"
"Here's a tool that will allow you to plug in the numbers and figure it out."
"I dunt have all teh numberz to do it mahself! But hey, can u use mah incomplete numberz and do it for meh?"
Sounds like some of us..... lol
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Old Mar 16, 2018 | 04:12 PM
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From: Conroe, TX
Default
Originally Posted by MuhThugga
I know this is from 2016, but this is my new favorite post.

"Hai guyz. Wuts mah compression?!?"

"Here's a tool that will allow you to plug in the numbers and figure it out."

"I dunt have all teh numberz to do it mahself! But hey, can u use mah incomplete numberz and do it for meh?"
You can lead a horse to water...
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