RACE GAS OR 50/50 MIX?

[330 R killer]

HEY GUYS WHAT SHOULD I RUN PURE VP 110 OR 50/50 MIX MY COMP IS 157 AT 1100 ABOVE SEA LEVEL AND 176 WHEN I GO TO GLAMIS..FULL RACE PORT, COOL HEAD, 19CC DOMES, V FORCE 3 REEDS, INTAKE SPACERS, AND PRO DESIGN INTAKE, 36MM CARBS 300MAIN JETS, K N FILTER WITH OPEN AIRBOX 3+ ON TIMING.

[Bansh-eman]

150-160 I run 50/50 at 170 up I run race gas. I know of guys that run pump out to 170 but IMO I think it's stupid to chance it to save a few bucks

[locogato11283]

i would run straight race fuel. why take the chance to save very little money?

 

you should try bumping your timing up to +4.

[330 R killer]

OK VP 110 IT IS THEN.. THANKS GUYS

[deckheight]

Assuming your not running some huge bore or something and have ported, but otherwise unmolested, OEM cylinders... And using a compression ratio figuring 19cc domes rather than a gauge reading...

Your totally safe with 100 octane fuel. In fact, your not anywhere near the edge... IMHO

[330 R killer]

NO I AM USING A GAUGE 157 0N THE GAUGE AT MY HOUSE AND 175 AT GLAMIS

[98_shee]

If you run straight race fuel i would bump the timing up to 6.

[deckheight]

What I was saying: If your running an otherwise normal 350 with typical whatever type cylinder porting, typical whatever brand tuned exhaust, etc. and 19cc head domes... and the rider dosn't weigh 400 or 500 pounds... and your not towing your broke down buddies bike with him sitting on the back of yours... or other wise doing something stupid... Then 100 octane is plenty good even a couple hundred feet above sea level at Glamis. In fact your motor will probably run noticably stonger w/19cc domes on 100 than it will on 110 since you will, in all probability, see noticably higher combuston chamber pressures on the 100. Drop a set of 17cc domes in there if you want to run 110... You'll spit less unburnt fuel out the exhaust port that way as well as get a fairly large hosepower increase to go along with it.

Check it out yourself. Take a can of 110 and a can of 92, see how it runs on straight 110. Then drain the tank and blend your 110 and 92 to get the 100 and see how that works??? Report back with your findings... :biggrin: :cool:

[330 R killer]

OK I WILL DO THAT, I WAS GOING TO PUT IN 18CC DOMES AFTER THIS TRIP IF I DO THAT CAN I MIX OR DO U HAVE TO RUN PURE 110??? AND WHAT IS BETTER VP 110 OR C12

[deckheight]

I am not familiar with VP 110. I am familiar C-12 though. It is an excellent fuel that is very stable at high rpm + it has a lot of lead...

Just because the gas can says 110 or whatever... Doesn't mean it is 110 octane gasoline! C-12 for example is only 109 when compared to what you buy out of the pump.

Like I said 110 fuel=17cc domes, 100 fuel=19cc domes. This should put you far enough away from the deto zone to be safe. There is no free ride with horsepower though! Compressions ratios w/17cc domes are going to be a lot harder on your engine than what you will see with 100 octane type compressions, plus higher compressions are much less forgiving to "mistakes". Personally, I consider 100 octane compressions a really good recreation type set-up.

Some of the guys I ride with run 18cc domes with 100 octane 50/50 blended fuel without problems. I run an OEM head with the equivalent of 18.25cc domes on straught 100LL avgas, no problem. I am also very carefull with jetting, timing, fuel quality, engine temps, etc. Some of those other guys I wonder about sometimes... Probably just a matter of time for a couple of them???

Try this link http://www.dmperf.com/fuel_brands_and_octane_ratings.htm Probably more than you ever wanted to know about gasoline :geek:

[330 R killer]

I am not familiar with VP 110. I am familiar C-12 though. It is an excellent fuel that is very stable at high rpm + it has a lot of lead...

Just because the gas can says 110 or whatever... Doesn't mean it is 110 octane gasoline! C-12 for example is only 109 when compared to what you buy out of the pump.

Like I said 110 fuel=17cc domes, 100 fuel=19cc domes. This should put you far enough away from the deto zone to be safe. There is no free ride with horsepower though! Compressions ratios w/17cc domes are going to be a lot harder on your engine than what you will see with 100 octane type compressions, plus higher compressions are much less forgiving to "mistakes". Personally, I consider 100 octane compressions a really good recreation type set-up.

Some of the guys I ride with run 18cc domes with 100 octane 50/50 blended fuel without problems. I run an OEM head with the equivalent of 18.25cc domes on straught 100LL avgas, no problem. I am also very carefull with jetting, timing, fuel quality, engine temps, etc. Some of those other guys I wonder about sometimes... Probably just a matter of time for a couple of them???

Try this link http://www.dmperf.com/fuel_brands_and_octane_ratings.htm Probably more than you ever wanted to know about gasoline :geek:

THANKS FOR THE INFO IT HELP ME OUT ALOT

[deckheight]

No problem. It's kind of nice having someone actually respond to my posts... I feel like a Leper around here sometimes... LOL!

[330 R killer]

No problem. It's kind of nice having someone actually respond to my posts... I feel like a Leper around here sometimes... LOL!

LOL OK GOING TO GLAMIS WED I HAVE A FULL TANT OF VP 110 GOING TO SEE HOW IT RUNS, THEN GOING TO DRAIN IT AND MIX 50 50 TO SEE WHAT RUNS BETTER.

[deckheight]

Let us know what happens? I built a decent 110 motor for a guy who also had a stocker for his kid. Anyway, he comes back with the stocker running like crap. Acts like it's sucking trans fluid or the CDI is stuck on full retard or something??? tried everything and just could not figure the thing out... The guy finally tells me he ran out of 91 last time out and filled it with 110, figured it would run better...

You won't see anything this dramatic because of your 19cc domes, pretty sure it will be noticable though. Make sure you are accurate when blending fuel. If in dought put an x-tra splash of 110 in there!