I'm runnin a Mr. Viper lake race motor w/ 2 degree timing and 150 psi of compression. I'm runnin vp c-12, is this to much octane? If it is how bad will it hurt the performance of this thing. Can't quite figure out the clutching but will hopefully find it in the summer when we put it on the timers.
mopar1rules
Active member
i still don't get why you just don't ask don your engine builder on octane requirements. you should be knowing what octane to run, as the builder should ask you at the beginning of the build what octane you want to run. that's usually the first question asked to customers. just pm don and he'll tell you what you need. going off a compression gage reading to dictate octane is incorrect.
Check with Don ,,,, but I think a 50/50 - race / premium will be more than safe.........
Mac
Member
Race Fuel
I agree ask Don what he recommends.
I run 24cc heads on my BB that reads 150 psi on both my compression gauges. This number of course is not a true cranking compression calculation but does begin to make me believe more octane should be required. I run 50/50 100LL and premium for an average 96 octane. Motor seems to pull good and plugs look great. Another question I have is if Don has you running that 2 degree timing key? Vipers already have very advanced timing unless you are spinning very high RPM. Hope your running CPR's at 9300 RPM.
I pulled this info from VP website.
I think both of these fuels would be overkill and expensive and probably more than required. These fuels have to be $10-11 dollars a gallon. 100 LL here at my airport sells for $4.25.
VP-110™
Not your "standard" 110! Highest rated MON of any 110 fuel on the market. Formulated for use in all naturally aspirated engines with CRs up to approximately 12:1-13:1, as well as applications with turbo- or superchargers with boost pressures up to 7-10 psi. Compared to other 110 octane fuels, VP110 burns cleaner and provides greater detonation protection. Good lower cost alternative.
TYPICAL VALUES
• Color: Purple
• Motor Octane 107
• Research Octane: 113
• R+M/2: 110
• Specific Gravity: .720-.735 @ 60° F
C12™
The best all around racing fuel made for power and consistency. Compared to 110 octane fuels, C12 provides significant performance gains in applications above 6500 RPMs in terms of power, torque and detonation protection. Burns cleaner and vaporizes better than fuels with comparable MONs, leading to lower engine operating temperatures—a key benefit particularly in off shore racing under full loads. Recommended for naturally aspirated engines with CRs below 15:1 and turbo- or supercharged applications with boost pressures up to 7-12 psi. One of the winningest fuels in racing history, C12 has fueled champions in IHBA, APBA, OSS, SuperBoat, ULHRA and many other series.
TYPICAL VALUES
• Color: Green
• Motor Octane 108
• Specific Gravity: .717 at 60° F
I agree ask Don what he recommends.
I run 24cc heads on my BB that reads 150 psi on both my compression gauges. This number of course is not a true cranking compression calculation but does begin to make me believe more octane should be required. I run 50/50 100LL and premium for an average 96 octane. Motor seems to pull good and plugs look great. Another question I have is if Don has you running that 2 degree timing key? Vipers already have very advanced timing unless you are spinning very high RPM. Hope your running CPR's at 9300 RPM.
I pulled this info from VP website.
I think both of these fuels would be overkill and expensive and probably more than required. These fuels have to be $10-11 dollars a gallon. 100 LL here at my airport sells for $4.25.
VP-110™
Not your "standard" 110! Highest rated MON of any 110 fuel on the market. Formulated for use in all naturally aspirated engines with CRs up to approximately 12:1-13:1, as well as applications with turbo- or superchargers with boost pressures up to 7-10 psi. Compared to other 110 octane fuels, VP110 burns cleaner and provides greater detonation protection. Good lower cost alternative.
TYPICAL VALUES
• Color: Purple
• Motor Octane 107
• Research Octane: 113
• R+M/2: 110
• Specific Gravity: .720-.735 @ 60° F
C12™
The best all around racing fuel made for power and consistency. Compared to 110 octane fuels, C12 provides significant performance gains in applications above 6500 RPMs in terms of power, torque and detonation protection. Burns cleaner and vaporizes better than fuels with comparable MONs, leading to lower engine operating temperatures—a key benefit particularly in off shore racing under full loads. Recommended for naturally aspirated engines with CRs below 15:1 and turbo- or supercharged applications with boost pressures up to 7-12 psi. One of the winningest fuels in racing history, C12 has fueled champions in IHBA, APBA, OSS, SuperBoat, ULHRA and many other series.
TYPICAL VALUES
• Color: Green
• Motor Octane 108
• Specific Gravity: .717 at 60° F
you have WAY too much octane or corn syrup in that thing. Whammy is right on in his reply, cut the 112 with pumpgas right off the bat. 50/50 blend, do 2 gallons at a time and check piston wash/plug coloring after runs, youll see as soon as you cut the corn syrup, the engine is going to make more power(rev higher) and dry up the pistons. work your way down diluting the c12 with premium pumpgas till you find the edge, thats why I said do it in 2 gallon mixes. the edge will be the elctrode(center of the plug) is going to get all silver across the center and the piston will take on a very dry smoke coloring. if i had to put a octane number on it, i would venture to say youll need around 96-98 octane with good jetting and it will make very good power.
I dont run 112 octane in a pro stock engine. You only want enough octane to keep from having detonation.
The octane makes the sled RICHER without touching the jets!
Did you get the clutching off Jason as well for this engine when you bought it??, he bought all the whole set up, 8bu weights,spring, helix,etc, you should be turning 8700rpm on top with it.
(Mac, its a srx, thanx for the help, good info on the fuel.)
I dont run 112 octane in a pro stock engine. You only want enough octane to keep from having detonation.
The octane makes the sled RICHER without touching the jets!
Did you get the clutching off Jason as well for this engine when you bought it??, he bought all the whole set up, 8bu weights,spring, helix,etc, you should be turning 8700rpm on top with it.
(Mac, its a srx, thanx for the help, good info on the fuel.)
Thanks everyone for the replies, Don I didn't wonna bother you with your resent problems. Yes I did get the clutching but never really tried it, I run 660 and 500 will that set up work for those distances? Also gladly will cut fuel back as it was expensive. I am currently run a Hauck kit w? orange primary, silver sec, his G helix with the new launch weights, is this wrong? it worked great in the grass but with a totally diff. motor, I know this makes better power but I have alot to learn on clutching yet. Thanks again.
YAMMIEGOD3:16
Active member
DUDE, GLAD DON REPLIED BECAUSE SHURE HE IS THE ONE TO ASK, ONE THING I WILL ADD WITH THAT HIGH OCTANE ESPECIALLY IF YA ICE RACE IN THE WINTER THAT SLED WILL BE A BEAR TO GET STARTED. 3:16 (yammie tony)
Yammiegod, it's funny you say that, was wondering what was up with that. well gonna drain the bowls today and put her away til prob. july, but now I know. will definately have to start over on clutching as well as jetting as the carbs are bored as well.
YAMMIEGOD3:16
Active member
YA YOU NEED TO CUT HER BACK SOME. I USE 1 GALLON OF SUNOCO 110 WITH TWO GALLONS OF (midgrade) 89. I AM JUST SCARED OF TODAYS CRAP. WORKS GREAT, AND NO COLD WEATHER STARTING ISSUES. 3:16 (yammie tony)
Thanks for the reply, I will cut it back starting at 1 to 1. On the vp c-12, do ya go by the motor octane of the fuel? which is like 108 or the 112 #? I figure 1 vp to 1 89 will start there. Little by little I will get this thing to haul azz, First thing is to get clutching back in order, right now it is laying down on the top end but ice is all over here, had a 4 wheeler go thru last Sunday as he was cleaning our track.
YAMMIEGOD3:16
Active member
BEING VP, IF THATS 112, MY GUESS YOUR GETTING 112, THATS GOOD FUEL. ALOT OF BIG SLED RUN THAT STUFF. DON,T BE AFRAID TO KNOCK THAT BACK WITH 87. 3:16 (yammie tony)
yamalars
Member
Don sad that fusions engine should peak at 8700 rpm. Are their any mods done
to the pipes/manifolds to hit 8700? Thanks! //Lars
to the pipes/manifolds to hit 8700? Thanks! //Lars