Compression ratio

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Nov 21, 2019 | 09:00 AM

sbf

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From: Wilson n.c.

Compression ratio

Can anyone tell me what the cr will be if I used a l92 stock bottom end and a set of 243 heads and what size head gasket dont want to go past 11.1

Nov 21, 2019 | 11:03 AM

G Atsma

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From: Central Cal.

With stock .052 head gaskets you're at 10.74. Going to a .045 HG will put you at 10.93, which is as close as you might want to get.

Nov 25, 2019 | 06:07 PM

sbf

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From: Wilson n.c.

Called tsp to buy gaskets today and was told with the stock ls3 gasket .51 my cr would be 11.2 ?

Nov 25, 2019 | 08:45 PM

G Atsma

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From: Central Cal.

Check the compression ratio calculator on Summit's site.
The piston has 3cc reliefs. TSP might have not considered that.
243 heads have 65cc chambers, which is 5 less than the L92's 70cc.
It came out to 10.77. I figured on the gasket at .052 before. I used .051 this time
With a flat top piston it would be 11.15:1. TSP rounded it up

Nov 27, 2019 | 08:55 PM

01CamaroSSTx

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I was under the impression that L92 heads had 68.5cc combustion chambers. Here's is another site to calculate static compression.

https://speedmaster79.com/tools/engi...pression-ratio

Nov 27, 2019 | 09:46 PM

G Atsma

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From: Central Cal.

Quote:

Originally Posted by 01CamaroSSTx

I was under the impression that L92 heads had 68.5cc combustion chambers. Here's is another site to calculate static compression.

https://speedmaster79.com/tools/engi...pression-ratio

Summit's LS specs site lists the L92 (and all other 6.2's) chamber volume at 70cc

Nov 27, 2019 | 11:42 PM

Che70velle

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From: Dawsonville Ga.

Quote:

Originally Posted by G Atsma

Summit's LS specs site lists the L92 (and all other 6.2's) chamber volume at 70cc

They are 68.5 cc chamber. No disrespect to Summit, but their numbers aren’t always legit. I’ve seen a couple different piston sets, where they have listed the cc’s wrong, with my Wiseco set in my 434 being one of them. Thankfully Tony pointed it out to me while we were setting up my compression numbers. I personally check numbers elsewhere.

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Nov 28, 2019 | 04:02 AM

chrisfrost

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From: phx the cactus patch

WallaceRacing.com has probably 300 calculators from engine and 1/4 and 1/8th mile weight changes ……….etc every calculator You can think of and more free. Its pretty cool