Comp. ratio consufion..
#1
Comp. ratio consufion..
From what I've read to date, the LQ9 6-liter has a stock compression of 10.0:1 with it's 71cc heads, now obviously if I were to find an LQ9 and swap on a set of 64cc LS6 heads I'm looking at a bump in compression, my question is exactly how much compression would I be looking at?
As a side note, I noticed the book I've read is telling me the LQ4 and LQ9, although both 6-liters, are infact different in displacement (364cu. in vs. 377cu. in), can anyone tell me where this comes from? All the info I can find tells me they both have 99mm cranks to I'm guessing it's the bore (duh), anybody know the numbers?
Thanks
As a side note, I noticed the book I've read is telling me the LQ4 and LQ9, although both 6-liters, are infact different in displacement (364cu. in vs. 377cu. in), can anyone tell me where this comes from? All the info I can find tells me they both have 99mm cranks to I'm guessing it's the bore (duh), anybody know the numbers?
Thanks
#2
The blocks are the same, they have the same displacement, but some how the LQ9 gets more compression which explain the higher displacement number. I'm not quite sure where the compression comes from because they both have basically the same heads, crank, pistons, and rods.
The LQ9 possibly has a slightly different crank and heavier, stronger, slightly different shaped rods. It has the same pistons but they're coated with some crap to do somthing
I found this link a while ago on another post... very helpful
http://www.automotiverebuilder.com/ar/eb040538.htm
The LQ9 possibly has a slightly different crank and heavier, stronger, slightly different shaped rods. It has the same pistons but they're coated with some crap to do somthing
I found this link a while ago on another post... very helpful
http://www.automotiverebuilder.com/ar/eb040538.htm
Last edited by Chevy_Truck_Man; 10-13-2005 at 12:38 AM.
#4
Originally Posted by JZ'sTA
Acturally if the WS6 you have in the sig is a 5.7 motor then a LQ9 head will be closer to 9.3:1
A 64 cc head and .040 gasket and take you up to 11:1
Check out my sig.
A 64 cc head and .040 gasket and take you up to 11:1
Check out my sig.
#5
Originally Posted by VTC_WS6
From what I've read to date, the LQ9 6-liter has a stock compression of 10.0:1 with it's 71cc heads, now obviously if I were to find an LQ9 and swap on a set of 64cc LS6 heads I'm looking at a bump in compression, my question is exactly how much compression would I be looking at?
As a side note, I noticed the book I've read is telling me the LQ4 and LQ9, although both 6-liters, are infact different in displacement (364cu. in vs. 377cu. in), can anyone tell me where this comes from? All the info I can find tells me they both have 99mm cranks to I'm guessing it's the bore (duh), anybody know the numbers?
Thanks
As a side note, I noticed the book I've read is telling me the LQ4 and LQ9, although both 6-liters, are infact different in displacement (364cu. in vs. 377cu. in), can anyone tell me where this comes from? All the info I can find tells me they both have 99mm cranks to I'm guessing it's the bore (duh), anybody know the numbers?
Thanks
#6
Originally Posted by Chevy_Truck_Man
The blocks are the same, they have the same displacement, but some how the LQ9 gets more compression which explain the higher displacement number. I'm not quite sure where the compression comes from because they both have basically the same heads, crank, pistons, and rods.
The LQ9 possibly has a slightly different crank and heavier, stronger, slightly different shaped rods. It has the same pistons but they're coated with some crap to do somthing
I found this link a while ago on another post... very helpful
http://www.automotiverebuilder.com/ar/eb040538.htm
The LQ9 possibly has a slightly different crank and heavier, stronger, slightly different shaped rods. It has the same pistons but they're coated with some crap to do somthing
I found this link a while ago on another post... very helpful
http://www.automotiverebuilder.com/ar/eb040538.htm
and i get the same CR as jhong.
Last edited by jrp; 10-15-2005 at 01:23 AM.
#7
Originally Posted by JZ'sTA
Acturally if the WS6 you have in the sig is a 5.7 motor then a LQ9 head will be closer to 9.3:1
A 64 cc head and .040 gasket and take you up to 11:1
Check out my sig.
A 64 cc head and .040 gasket and take you up to 11:1
Check out my sig.