Compression and pump gas.
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Member
Joined: Dec 2000
Posts: 121
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From: Crawfordsville, IN
Car: 1991 Galant VR4
Engine: 2.0L 4G63 Turbo
Transmission: 5sp transaxle/transfer case
Compression and pump gas.
Whats the highest compression you can achieve of 92 octane pump gas?
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1986 Camaro
Carbureted 305
700R4
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1986 Camaro
Carbureted 305
700R4
TGO Supporter
Joined: Jan 2001
Posts: 957
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From: Mesa, AZ
I'm assuming you mean whats the highest compression you can run in an engine on pump gas. Usually you would want around 9.0:1 to 9.5:1. I think the later is about as high as you would want to go for a daily driver on pump gas or just on pump gas in general. After that you will run into problems.
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350 TPI
Flowmaster Cat-Back exhaust
Performance Chip (am trying to find out which one)
Modified MAF
Smog equipment removed
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350 TPI
Flowmaster Cat-Back exhaust
Performance Chip (am trying to find out which one)
Modified MAF
Smog equipment removed
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Joined: Dec 2000
Posts: 221
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From: South of GR, MI USA
Car: 1971 Corvette
Engine: 6.0 LS1 L92 heads sheet metal etc.
Transmission: M21 4-speed
Axle/Gears: 3.36
My 406 is 10.25:1 and i have had no problems. I run the crap out of it too. I think 10.25 is about the max you can go on a non-new car motor. the Lt4s were 10.8:1 but they have much better combustion chambers and can get away with more compression.
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88 S10
Dropped 3/4
Dart equipped 406
12.20 @ 115.25 mph
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88 S10
Dropped 3/4
Dart equipped 406
12.20 @ 115.25 mph
Supreme Member
Joined: Jul 1999
Posts: 18,457
Likes: 16
From: Loveland, OH, US
Car: 4
Engine: 6
Transmission: 5
It depends on alot of things...
For a carbed car with cast-iron heads, 10¼ or 10½:1 is about as high as you can go. With aluminum heads, maybe 11:1 if it's set up right. The more cam you run, the higher your static CR can be.
I have had a 400 at 10.4:1 for the last 135,000 miles. Right now it has a Comp XR282HR, before that it had a XE274H and before that a 282 solid, it has always worked OK. The other cams are a little better than the 282S was but even it wasn't bad.
What are you thinking about doing?
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"So many Mustangs, so little time..."
ICON Motorsports
For a carbed car with cast-iron heads, 10¼ or 10½:1 is about as high as you can go. With aluminum heads, maybe 11:1 if it's set up right. The more cam you run, the higher your static CR can be.
I have had a 400 at 10.4:1 for the last 135,000 miles. Right now it has a Comp XR282HR, before that it had a XE274H and before that a 282 solid, it has always worked OK. The other cams are a little better than the 282S was but even it wasn't bad.
What are you thinking about doing?
------------------
"So many Mustangs, so little time..."
ICON Motorsports
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