domes cc

[mud91]

I just bought a banshee with fmf fattys, silencers, cool head, aftermarket carbs, reeds, stock bore and no port or timimg. elevation is 180-400ft. what domes should be in there? also what if I go with +4 timing. Is 93 enough

[ledofthezep]

Should be ok, get your hands on a compression checker & as long as your compression isn't over 160psi, you should be fine.

[NEVER SATISFIED]

i almost bought a 20cc dome and david at noss head asked if i was going to advance my timing, and said if so then i needed to run atleast 50/50 pump race... i am at around 500 above sea.. i decided to go with 19cc and just call it a day and run the race fuel since prices around here are getting within 2 bucks for 93 octane to 115 octane ... i felt it was worth it..

[JArmShee]

its 2.55 for 93 here in NY.

[mud91]

let say the compression is over 160, how determine what octane to run. I hear race gas but what is considered race gas

[NEVER SATISFIED]

well i think its more octane wise and not race gas... race gas is actually leaded fuel which sheeeeeeee's love... a higher octane around 100 and above is what will be needed... and no you cant use octane boost... the reason you run 50 50 is so the 93 can mix with lets say 110 and you get an average of 101. i just run 115 always leaded..i dunno of they make high octane unleaded..

[NEVER SATISFIED]

its 2.55 for 93 here in NY. 

357015[/snapback]

 

DAMN THATS PRETTY GOOD FOR NY... thought its would be around 3 bucks..

[mud91]

So if I'm at 155-160 com. I should run 50/50 mix with 40-1

[NEVER SATISFIED]

ONLY IF YOUR ABOVE 160... SAFE IS 160... 165 UR PUSHIN IT... (SORRY FOR THE CAPS)

[NEVER SATISFIED]

you can run 93 octane but it will run like a snail and pop and just backfire at times.. no bueno

[Ducman]

I just bought a banshee with fmf fattys, silencers,  cool head, aftermarket carbs, reeds,  stock bore and no port or timimg. elevation is 180-400ft.  what domes should be in there? also what if I go with +4 timing.  Is 93 enough

356820[/snapback]

 

If the guy that you bought the banshee from didn't say anything about running race fuel then you most likely have 21cc domes (which is what comes standard with a cool head becasuse it is safe to run on pump fuel) but don't count on it. If you test your compression then you can figure out what domes you have (based on the chart below I stole from NOSS's web site), or take the head off and read the cc# scribed on the dome. Once you know your domesize/compresion then you can get a safe reccomendation for timing advance and octane requirements. For example, if you have 20cc domes and go +5 timing advance on 91 octane pump fuel near sea level you will be taking a huge risk and probably detonate. +5 deg and 21cc domes on 91 octane and you will be fine. You can get a compression tester at any autoparts store for $15 and it will only take 10 minutes to do the test.

 

Sea Level 1000'

18cc 197 - 178

19cc 183 - 167

20cc 169 - 156

21cc 156 - 145

stock 130