What is better. Higher compression more Quench or Lower compression Tighter Quench?
#1
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Ok I picked up a bone stock 2000 ls1 from a Corvette 80k miles. Im building my first LS motor. Carbureted single plane setup with the ws6stores high lift ASA cam 226-236 .600 110, I have a pair of 243 2.5 cnc heads that I want to mill to get the most compression I can. Ws6store says I can run .030" milled 243s safely with factory head gaskets. With that said is it more efficient to run higher compression with the factory .051" head gasket stock pistons .007" for a .044 Quench or less compression with a tighter Quench in the high .030s. or am I over thinking it and splitting hairs?
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Hi ZT, Higher Compression AND TIGHTER Squish is BEST.
I would fit a FelPro HG @ .041", the LS-1 small bore gasket.
This should give you a Piston/Head of .033" Quench.
Your Altitude ?
Lance
I would fit a FelPro HG @ .041", the LS-1 small bore gasket.
This should give you a Piston/Head of .033" Quench.
Your Altitude ?
Lance
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Ok I picked up a bone stock 2000 ls1 from a Corvette 80k miles. Im building my first LS motor. Carbureted single plane setup with the ws6stores high lift ASA cam 226-236 .600 110, I have a pair of 243 2.5 cnc heads that I want to mill to get the most compression I can. Ws6store says I can run .030" milled 243s safely with factory head gaskets. With that said is it more efficient to run higher compression with the factory .051" head gasket stock pistons .007" for a .044 Quench or less compression with a tighter Quench in the high .030s. or am I over thinking it and splitting hairs?
Also your proposed.044" quench with the factory gasket is a room temperature calculation. An all aluminum block "grows" considerably at operating temp and most of that .007" positive deck disappears. This also explains the sloppy timing chain issue that everyone freaks about but actually tightens up at operating temps as the cam moves "north" from thermal expansion
The cheapest route is to use the GM gaskets and mill the heads. The BEST route is to run the .040" gaskets and just a simple .006"-.010" cleanup on the deck of those 243s. You'll have a tight non detonation sensitive 11.0:1 that will clear PTV and work nice with that cam. Great all around selection of parts IMO
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Thank you for the reply guys! I will be pulling the factory 853 heads soon and I'll be able to check piston to deck height to know for sure what it is. What is a safe PTV clearance for these LS motors? When checking PTV do I need a solid lifter vs a hydraulic type like a gen 1 sbc?
I don't mind spending more money on the good head gaskets...what brands/typs do I want to be looking for? Thanks again guys for the help
I don't mind spending more money on the good head gaskets...what brands/typs do I want to be looking for? Thanks again guys for the help
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#8
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My Altitude is 2,750 and 91 octane is the highest I see these days in Idaho. This setup is for a 70 Camaro with a manual transmission and 3:73 gears. It's setup for autocross and a weekend hotrod. I'd love to have as much low/mid range I can get with this combo hence higher compression!
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Couple things to consider here. First. Milling a head usually reduces its flow
Also your proposed.044" quench with the factory gasket is a room temperature calculation. An all aluminum block "grows" considerably at operating temp and most of that .007" positive deck disappears. This also explains the sloppy timing chain issue that everyone freaks about but actually tightens up at operating temps as the cam moves "north" from thermal expansion
The cheapest route is to use the GM gaskets and mill the heads. The BEST route is to run the .040" gaskets and just a simple .006"-.010" cleanup on the deck of those 243s. You'll have a tight non detonation sensitive 11.0:1 that will clear PTV and work nice with that cam. Great all around selection of parts IMO
Also your proposed.044" quench with the factory gasket is a room temperature calculation. An all aluminum block "grows" considerably at operating temp and most of that .007" positive deck disappears. This also explains the sloppy timing chain issue that everyone freaks about but actually tightens up at operating temps as the cam moves "north" from thermal expansion
The cheapest route is to use the GM gaskets and mill the heads. The BEST route is to run the .040" gaskets and just a simple .006"-.010" cleanup on the deck of those 243s. You'll have a tight non detonation sensitive 11.0:1 that will clear PTV and work nice with that cam. Great all around selection of parts IMO
There are many ways to look at it, but like i said before, with a mild combo youd see better gains from the incressed cr vs quench in this area.
If you want to spend the extra time and money and can accurately measure, then doing both will help, but youd want to buy 3 gaskets so you can torque one down to check.
The alternate version is just do both and flycut.
Ive done that before, but only on more "max effort" higher duration cams.
#19