11.88 Comp. Ratio

[MTChevy]

Is there any possible way i could run 91 octane plus octane booster with this combination?

 

[iwaxmyjimmy]

Yeah back the retard the timing, but I dont trust them octane boosters at all. Luckly we've got a couple places here that have 100 and also 106 octane.

 

[merace19]

Those octane boosters only raise it a point or two. other words start with 87 then you would have only 87.2......
http://www.gnttype.org/techarea/misc/octaneexplained.html

http://www.gnttype.org/techarea/misc/octanebooster.html

 

[58 apache]

doubtfull... unless you run race fuel. if you retard the timing you will loose tons of power. I run 9.78:1 and struggle with pump gas

 

[resurrected_jimmy]

Is there any possible way i could run 91 octane plus octane booster with this combination?

aluminum heads

 

[58 apache]

aluminum heads

what the hell are alum heads gonna do for him? NOTHING. I run alum heads and that dosnt change the fact he wants to run 91 pump gas at 11.88:1. not gonna happen

 

[k20]

yeh with aluminum heads, the max I would try is 10.5-11 and we have 93 around here

 

[pauly383]

http://www.popularhotrodding.com/tech/0606phr_understanding_compression_ratio/

 

[58 apache]

yeh with aluminum heads, the max I would try is 10.5-11 and we have 93 around here

I'm running 9.78:1 alum heads on 93 and will still get some spark knock occasionally


here is a video of my 406

http://www.youtube.com/watch?v=B8j7iRsA7D8

 

[k20]

yeh I say 10.5 b/c a friend of mine build a f*rd stroker with alum heads at 10.5 and his only has spark knock a couple times til we monkeyed w/ the distributor, then it was fine

 

[58 apache]

http://www.popularhotrodding.com/tech/0606phr_understanding_compression_ratio/

good article. and I agree it can be done but how much cash ya got?

 

[pauly383]

Don't need money , I go wheeling with a 305 ...... for now

 

[58 apache]

yeh I say 10.5 b/c a friend of mine build a f*rd stroker with alum heads at 10.5 and his only has spark knock a couple times til we monkeyed w/ the distributor, then it was fine

if you stay at 10:1 or under youll be much happier.. if you retard the timing or the curve with springs etc to avoid knock or detonation you loose power and fuel efficency so whats the point? unless your racin

 

[58 apache]

Don't need money , I go wheeling with a 305 ...... for now

get er done

 

[Hogback Fabrication]

Propane

 

[58 apache]

Propane

never did anything with it does it allow a higher comp ratio? is there an "octane" rating for propane?

 

[DEMON44]

Propane is 110 octane

 

[twoslo4five0]

Propane

im with you..

 

[pauly383]

never did anything with it does it allow a higher comp ratio? is there an "octane" rating for propane?

It does allow a higher compression ratio IIRC .

Natural gas , less mentioned on here , loves compression . I did read about a 13 to 1 smallblock El Camino in one of the go fast rags years ago . Oil stayed cleaner too .

 

[twoslo4five0]

they say after 100k on a propane motor the oil still looks like ti does when you poar it in...i heard its hard on valve seals though...i know formud runs it and has no problem..