pump gas
03-14-2007, 12:50 PM
#3
2nd Gear Member
Join Date: Jan 2007
Location:
Posts: 213
RE: pump gas
Thats a hard question to answer as itcan varygreatly from combo to combo. For instance an engine that's using iron heads and a cam with a short duration will tolerate less compression than one using aluminum heads and a longer duration cam. To give you a more accurate recommendation I'd need to know more abouttheengine in question.
03-14-2007, 12:56 PM
#4
6th Gear Member
Join Date: May 2004
Location: las vegas, nv
Posts: 9,092
RE: pump gas
agreed. the cam and type of heads used will have a major effect. also, where i live, 91 is the highest you can get from the pump. many states tho have 93 octane at the pump. if you live in one of those states, you could run more compression because of the higher octane fuel available at the pump
03-14-2007, 03:24 PM
#5
6th Gear Member
Join Date: Dec 2006
Location: Citrus County, FL
Posts: 8,007
RE: pump gas
a good general rule is 10:1 for iron heads and 10.5:1 w/ aluminum heads.
obviously having 91 or 93, shorter or longer duration cam, and your total timing all come into play, but all in all the above number hold pretty true.
also keep in mind that most peoples compression is actually lower than they think it is, do to pistons being below deck, valve reliefs, gasket crush thickness, etc.
personally, i have a 12:1 302 with iron heads and a 300 duration (advertisied not @ .050) cam and 93 is no good for me, it will run but will ping like a biatch if i tried to get on it at all. but blended with 110 to achieve somewhere around 100 octane is runs fine.
obviously having 91 or 93, shorter or longer duration cam, and your total timing all come into play, but all in all the above number hold pretty true.
also keep in mind that most peoples compression is actually lower than they think it is, do to pistons being below deck, valve reliefs, gasket crush thickness, etc.
personally, i have a 12:1 302 with iron heads and a 300 duration (advertisied not @ .050) cam and 93 is no good for me, it will run but will ping like a biatch if i tried to get on it at all. but blended with 110 to achieve somewhere around 100 octane is runs fine.
03-15-2007, 11:27 AM
#6
5th Gear Member
Thread Starter
Join Date: Sep 2005
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Posts: 2,486
RE: pump gas
i dont know what they are... what are canfields? the closest thing i could find is "Cast from the finest A356 Virgin Billet" and for the cam... its most likely going to be a custom grind from camshaft innovations. i can get 93 from a pump in my area
03-15-2007, 11:36 AM
#7
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Join Date: Jul 2006
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Posts: 1,897
RE: pump gas
ORIGINAL: luckythirteen13
im running 10:1 on 91 octane. i have aluminum heads tho
a buddy of mine ran 11:1 but it had almost all the timing pulled out. it was a big block tho, so it still made plenty of power
im running 10:1 on 91 octane. i have aluminum heads tho
a buddy of mine ran 11:1 but it had almost all the timing pulled out. it was a big block tho, so it still made plenty of power
Cometics?
03-15-2007, 09:31 PM
#9
6th Gear Member
Join Date: May 2004
Location: las vegas, nv
Posts: 9,092
RE: pump gas
ORIGINAL: LTnone
10:1 and a blower...sounds like head gasket hell to me Cometics?
ORIGINAL: luckythirteen13
im running 10:1 on 91 octane. i have aluminum heads tho
a buddy of mine ran 11:1 but it had almost all the timing pulled out. it was a big block tho, so it still made plenty of power
im running 10:1 on 91 octane. i have aluminum heads tho
a buddy of mine ran 11:1 but it had almost all the timing pulled out. it was a big block tho, so it still made plenty of power
Cometics?