Compression Ratio with pump gas??

Old 04-26-2009, 07:07 PM
  #1  
whitey70ss
Senior Member
MASTER BUILDER
Thread Starter
 
Join Date: Apr 2009
Posts: 175
Default Compression Ratio with pump gas??

What is the max comp. ratio if I still wanna run pump gas??
whitey70ss is offline  
Old 04-26-2009, 08:48 PM
  #2  
Tod74
Senior Member
RACING JUNKIE
 
Join Date: Sep 2007
Posts: 4,137
Default

I have ran 11 to 1 with premium gas with no issues. Most will tell you that's too much and maybe it is...but I got away with it.
Tod74 is offline  
Old 04-27-2009, 10:24 AM
  #3  
ARUSSELL
Senior Member
MASTER BUILDER
 
Join Date: Mar 2008
Posts: 192
Default

I am the same as TOD running 11.0 to 1, but 10.5 is a safe number to shoot for.
ARUSSELL is offline  
Old 04-27-2009, 10:49 AM
  #4  
mep
Junior Member
JOURNEYMAN
 
Join Date: Jan 2005
Posts: 27
Default compression ratio-pump gas

I have a 355 sbc with 10.5 flat tops. It previously detonated when I ran some old steel 64cc turbo Chevy heads, #340292. We replaced them with a set of 68cc AFR alum heads with 180 runners and the detonation went away. I don't know if it was more from the larger chambers or the alum head material, but I suspect it was more from the aluminum since it dissipates heat better. It's may be easier and cheaper to swap heads than pistons. JMO Mep
mep is offline  
Old 04-27-2009, 01:28 PM
  #5  
Tod74
Senior Member
RACING JUNKIE
 
Join Date: Sep 2007
Posts: 4,137
Default

let me rephrase...mine was 11 to 1 on paper, I never measured anything and did the math. It was a flat top piston 406 with 5.7 rods and it had a small hyd cam .507 lift dur @ .050 was about 244 I think. It had a set of the original sportsman cast iron heads with 64 cc chambers( advertised I didn't measure them)
Tod74 is offline  
Old 04-27-2009, 02:46 PM
  #6  
whitey70ss
Senior Member
MASTER BUILDER
Thread Starter
 
Join Date: Apr 2009
Posts: 175
Default

is there any way to measure comp. ratio with the engine in the car???
whitey70ss is offline  
Old 04-27-2009, 03:27 PM
  #7  
Tod74
Senior Member
RACING JUNKIE
 
Join Date: Sep 2007
Posts: 4,137
Default

Originally Posted by whitey70ss
is there any way to measure comp. ratio with the engine in the car???
NO
Tod74 is offline  
Old 04-27-2009, 06:00 PM
  #8  
suicidebomb
Senior Member
RACING JUNKIE
 
Join Date: Jul 2007
Location: Independence, Missouri
Posts: 1,181
Default

Oh, Boy :!: :lol:
suicidebomb is offline  
Old 04-27-2009, 07:36 PM
  #9  
MEMRACING62
Senior Member
RACING JUNKIE
 
Join Date: Sep 2007
Location: orland pk il
Posts: 2,399
Default

are we going to use that magical compression guage again!! :lol: :lol:
MEMRACING62 is offline  
Old 04-27-2009, 08:28 PM
  #10  
Tod74
Senior Member
RACING JUNKIE
 
Join Date: Sep 2007
Posts: 4,137
Default

Originally Posted by MEMRACING62
are we going to use that magical compression guage again!! :lol: :lol:
I almost went there but decided against it...lol
Tod74 is offline  

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -