head gasket thickness/ comp ratio
Thread Starter
Cruising
Joined: Jun 2011
Posts: 14
Likes: 0
From: Terrace B.C.
head gasket thickness/ comp ratio
does any body know what head gasket thickness relates to compression.
i have a small block with a doomed piston i was running a double camel hump small chamber head. very high compression (too high) i want to use a special head gasket that is 51 thou thick and a stock 76 vette head ( which has a larger chamber) this is all in an attempt to bring the comp ratio down so i dont have to run 120 octane fuel on the street? thanks for any info...Terry
i have a small block with a doomed piston i was running a double camel hump small chamber head. very high compression (too high) i want to use a special head gasket that is 51 thou thick and a stock 76 vette head ( which has a larger chamber) this is all in an attempt to bring the comp ratio down so i dont have to run 120 octane fuel on the street? thanks for any info...Terry
Pro
Joined: Feb 2012
Posts: 577
Likes: 6
does any body know what head gasket thickness relates to compression.
i have a small block with a doomed piston i was running a double camel hump small chamber head. very high compression (too high) i want to use a special head gasket that is 51 thou thick and a stock 76 vette head ( which has a larger chamber) this is all in an attempt to bring the comp ratio down so i dont have to run 120 octane fuel on the street? thanks for any info...Terry
i have a small block with a doomed piston i was running a double camel hump small chamber head. very high compression (too high) i want to use a special head gasket that is 51 thou thick and a stock 76 vette head ( which has a larger chamber) this is all in an attempt to bring the comp ratio down so i dont have to run 120 octane fuel on the street? thanks for any info...Terry
Terry, my best advice is for you to play around with a compression ratio calculator. Just enter all the information you know and use the gasket thickness as your variable and play with the numbers to see if you find a static compression ration you like.
http://www.csgnetwork.com/compcalc.html
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Stock piston to deck height is .025. with a .051 gasket this gets you .076 quench. Way more prone to detonation and will not solve your issues. Best off using a 75 CC head and a .015 shim gasket. You won't get as much compression drop but the .040 quench is much more resistant to detonation. How big of doom do you have?
PS. check piston top to deck height before making a decision and figure your dome volume. The calculator will help you figure this out.
PS. check piston top to deck height before making a decision and figure your dome volume. The calculator will help you figure this out.
Last edited by 63mako; Mar 7, 2012 at 08:02 PM.
Instructor
Joined: Jan 2012
Posts: 156
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From: Mount Sinai New York
i just built a 355 that's got a 12:1 comp. ratio,besides my pistons, my block was decked to up the compression. Full race timing with cam2 is upwards of 32 degrees @ about 4000 rpm. I can run the engine on the street with 93 octane (maybe a can of octane boost) if I back off the timing a bit.
Thread Starter
Cruising
Joined: Jun 2011
Posts: 14
Likes: 0
From: Terrace B.C.
Stock piston to deck height is .025. with a .051 gasket this gets you .076 quench. Way more prone to detonation and will not solve your issues. Best off using a 75 CC head and a .015 shim gasket. You won't get as much compression drop but the .040 quench is much more resistant to detonation. How big of doom do you have?
PS. check piston top to deck height before making a decision and figure your dome volume. The calculator will help you figure this out.
PS. check piston top to deck height before making a decision and figure your dome volume. The calculator will help you figure this out.
Race Director
Joined: Jan 2000
Posts: 13,015
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From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
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You're no where near 15.0 compression unless that is a really huge motor!
JIM
JIM
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Brett Foote015, 53, c3, comp, compressed, compression, corvette, corvetteforum, gasket, head, headgasket, high, ratio, thickness, zr1
