octane?
#1
Junior Member
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Thread Starter
Join Date: Aug 2009
Posts: 6
octane?
I have a sbc 355 with 11.5.1 dome pistions,dart heads,lunati 515 lift cam.that i use to have in my drag car,i use to run 110 octane in it with no problem.my question is what is the lowest octane i can in this?i want to be able to run this in car that is street legal.
#3
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Join Date: Jan 2006
Location: La.
Posts: 2,890
IU think hammertime posted this last yr sometime, since he is a VP dealer.
Zip.
Here is a rough recomendation. I have left out the lead count, the aromatic hydrocarbon content and specific gravity. There is also a difference in burning speed, energy value and cooling effect.
PM me if you want it all.
105 octane, CR under 12.5 to 1
108 octane, CR under 14.0 to 1 (75% of all racing engines)
114 octane, high CR and 8500+ rpm (comp cars)
116 octane, high CR and high RPM (ProStock, comp eliminator)
117 octane, Turbo and blown applications
Dave
Zip.
Here is a rough recomendation. I have left out the lead count, the aromatic hydrocarbon content and specific gravity. There is also a difference in burning speed, energy value and cooling effect.
PM me if you want it all.
105 octane, CR under 12.5 to 1
108 octane, CR under 14.0 to 1 (75% of all racing engines)
114 octane, high CR and 8500+ rpm (comp cars)
116 octane, high CR and high RPM (ProStock, comp eliminator)
117 octane, Turbo and blown applications
Dave
#4
Senior Member
RACING JUNKIE
Join Date: May 2006
Posts: 2,044
Re: octane?
Originally Posted by mmphillips
I have a sbc 355 with 11.5.1 dome pistions,dart heads,lunati 515 lift cam.that i use to have in my drag car,i use to run 110 octane in it with no problem.my question is what is the lowest octane i can in this?i want to be able to run this in car that is street legal.
I believe straight 110 is a bit overkill for a 11.5-1 motor, that's what I run in my 13-1 496.
JMO<Cp
#6
Senior Member
DYNO OPERATOR
Join Date: Jun 2009
Location: Wi
Posts: 522
Re: octane?
Originally Posted by cepx111
Originally Posted by mmphillips
I have a sbc 355 with 11.5.1 dome pistions,dart heads,lunati 515 lift cam.that i use to have in my drag car,i use to run 110 octane in it with no problem.my question is what is the lowest octane i can in this?i want to be able to run this in car that is street legal.
I believe straight 110 is a bit overkill for a 11.5-1 motor, that's what I run in my 13-1 496.
JMO<Cp
#7
Senior Member
SENIOR BUILDER
Join Date: Nov 2008
Location: Phoenix AZ
Posts: 116
I built a 11.5: 355 for my 70 Chevy 4X back in 1988, it was my daily driver for 8 years on nothing but 89 octane and 104 booster with 35* total timing. The same engine is still in the truck today, it's tired and only sees action once a month but on days I need to get two cars out to the track I can still drag the open trailer with it.