Compression Ratio Question
02-26-2009, 07:28 AM
#1
Compression Ratio Question Well,
Im looking to build a forged 383 and spray a 200 shot.
Im looking at getting AI 200cc heads but not sure of what compression ratio I want to end up at. Im thinking around 10:1 or so. I want to stay on pump gas.
What should be my piston size and chamber size?
10:1 a decent amount of compression for a 200 shot? Is it to much?
Sorry if these questions are retarded, but Im confused when it comes to compression ratio.
Thanks guys.
Im looking to build a forged 383 and spray a 200 shot.
Im looking at getting AI 200cc heads but not sure of what compression ratio I want to end up at. Im thinking around 10:1 or so. I want to stay on pump gas.
What should be my piston size and chamber size?
10:1 a decent amount of compression for a 200 shot? Is it to much?
Sorry if these questions are retarded, but Im confused when it comes to compression ratio.
Thanks guys.
Last edited by BlackTA96; 02-26-2009 at 07:36 AM.
02-26-2009, 07:37 AM
#2
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the can i rum pump gas question depends more on you dynamic compression ratio than your static compression ration. for instance you can have a 12:1 compression car with a DCR of 9.4 or a DCR of 8.6. You probably would have issues running pump gas on the 9.4 car while the 8.6 would be fine. If you get a DCR calculator you can play around with alot of things to see what combo will work for you. I did and it was pretty fun. Im running SCR 11.3-4 and a DCR of 8.8 with no problems whatsoever on pump gas. even on the street in the summer with the a/c in traffic. Going to spray it 200 in the future as well.
The below was a thread is started with a similar question. Read it over it may help you out.
https://ls1tech.com/forums/lt1-lt4-m...treet-car.html
The below was a thread is started with a similar question. Read it over it may help you out.
https://ls1tech.com/forums/lt1-lt4-m...treet-car.html
02-26-2009, 03:51 PM
#3
10:1 was stock for the iron head 87 octane b-body LT1, the aluminum head LT1 was 10.4 and the LT4 was 10.8 both on 91 octane, all with bad quench.
For an NA or nitrous motor I would set 11.0 as about bare minimum.
Nitrous loves compression, it is NOT like boost where you should lower static compression.
Might talk to the guys at AI about the rotating assembly as they sell the Compstar stuff, including the Compstar Speedpack complete rotating assemblies very good value.
For an NA or nitrous motor I would set 11.0 as about bare minimum.
Nitrous loves compression, it is NOT like boost where you should lower static compression.
Might talk to the guys at AI about the rotating assembly as they sell the Compstar stuff, including the Compstar Speedpack complete rotating assemblies very good value.
02-26-2009, 04:09 PM
#4
Alright...
So I guess i'll shoot for 11.0:1
What the quench on a stock block? What would be a realativly good quench for my build up?
what size piston would i run with the 58cc(that is stock right) chambers to acheive an 11.0:1 ratio?
I'll have to talk to AI about cam specs so I can get my dynamic compression where i want it.
So I guess i'll shoot for 11.0:1
What the quench on a stock block? What would be a realativly good quench for my build up?
what size piston would i run with the 58cc(that is stock right) chambers to acheive an 11.0:1 ratio?
I'll have to talk to AI about cam specs so I can get my dynamic compression where i want it.
