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compression-ratio

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compression-ratio

Posted: 5/27/09 4:51amMessage 1 of 9
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79 vette. standard block,pistons.if i change heads to 64cc.

what sort of compression ratio will i be at????
1979 Corvette
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compression-ratio

Posted: 5/27/09 7:30amMessage 2 of 9
r
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williamston, NC - USA
Joined: 1/19/2006
Posts: 353
Vette(s): 1969 coupe, 350, m22 trans, ac, black on black,
Other factors involved,,cam,rockers ect,but just as a rule of thumb, Id say about 9.0 to 1,,just a educated guess,,If I were going to do that though, Id step up the cam from stock, also you have to make sure stock intake will mate up to new heads,,good luck, rd
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compression-ratio

Posted: 5/27/09 10:00amMessage 3 of 9
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Duncanville, TX - USA
Joined: 11/8/2003
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Assuming you have 8.5:1 ratio now, you might get around 9:1. The head gasket thickness will play a part, also, as will valve size.

Joel Adams
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compression-ratio

Posted: 5/27/09 11:45amMessage 4 of 9
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Thumbs Upthanks thats what i wanted to know.
how are you doing joel???
1979 Corvette
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compression-ratio

Posted: 5/27/09 6:59pmMessage 5 of 9
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22715
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Who...ME?
I'm doing pretty well, I suppose. Good to see you back on the forum, Jack & Marcia!!

Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

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compression-ratio

Posted: 5/28/09 1:59amMessage 6 of 9
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getting dire over here,if you have a job,you'd better stick with it,as not alot going.
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compression-ratio

Posted: 5/28/09 5:04amMessage 7 of 9
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22715
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Same here...any job is a good job these days...Dead
Sounds like you are getting the Vette ready to go! Good Luck with it, and keep us up to date on how it's coming along.

Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

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compression-ratio

Posted: 9/21/10 9:33amMessage 8 of 9
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New Albany, OH - USA
Joined: 8/17/2010
Posts: 173
Vette(s): 1980 Coupe / Snowcrest White / L48, 350 / Comp Cam / Edelbrock Heads / Cyclone Intake / Holley Carb / Holley Fuel Pump / Patriot Headers / Dual Exhaust / Magnaflow Mufflers / 1964 Coupe / Riverside Red / L76, 327, 365hp
I have an L-48, 350 engine and I just put in a Comp Cam hydraulic roller cam, (210/220 and 112-degrees); a set of aluminum Edelbrock E-Street heads (2.02/1.60; 64-cc); a Holley Street Avenger 770-cfm carb; Patriot tight-tuck headers; 2 1/2-inch aluminum dual exhaust and Magnaflow mufflers.  My CR now measures 9.7:1.  The stock engine was rated at 8.5:1.
Chuck

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compression-ratio

Posted: 9/22/10 10:20amMessage 9 of 9
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Mounds View, MN - USA
Joined: 5/24/2007
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Vette(s): 70 LT1 coupe, 69 350 HP coupe, 69 390HP 427 coupe, 71 LS5 convert, 85 coupe, 93 coupe
79 L48 engines had 8.2:1 ratio with 73 cc heads.  The only thing that affects compression ratio in this example is the volume of the chamber with the valves closed. With dished pistons, your new ratio will be about 9.2:1.  That is enough to support a little more cam, but I wouldn't go wild with long duration:  maybe a 262 advertised degree cam with upper 400 lift.

Larry
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