Fuel Recommendation

[Gotzy]

Howdy folks,

What fuel would you run with a drag race iron headed 327 with 11.85:1 static and 9.5:1 effective compression ratio. cam specs are intake duration 300 seat, 252 at .050", exhaust 316 seat, 260 at .050"

is a pump gas 99 RON with an octane booster to approximately 105 RON enough or do I need a race gas. No E85 available here in the UK

Thanks in adavnce

[David Redszus]

Howdy folks,

What fuel would you run with a drag race iron headed 327 with 11.85:1 static and 9.5:1 effective compression ratio. cam specs are intake duration 300 seat, 252 at .050", exhaust 316 seat, 260 at .050"

is a pump gas 99 RON with an octane booster to approximately 105 RON enough or do I need a race gas. No E85 available here in the UK

Thanks in adavnce

ALWAYS run race gas; never run pump gas.

The RON number is useless and should be ignored. Run a race gas with a MON of at least 105, but remember that octane is only one
factor in the proper selection of a race fuel.

[rebelrouser]

Lots of engine programs that will predict the dynamic compression and what type of fuel requirements for any engine combination. A few good engine programs are as important as a torque wrench in building any engine combination in my opinion.

[rebelrouser]

Lots of engine programs that will predict the dynamic compression and what type of fuel requirements for any engine combination. A few good engine programs are as important as a torque wrench in building any engine combination in my opinion.

[randy331]

Howdy folks,

What fuel would you run with a drag race iron headed 327 with 11.85:1 static and 9.5:1 effective compression ratio. cam specs are intake duration 300 seat, 252 at .050", exhaust 316 seat, 260 at .050"

is a pump gas 99 RON with an octane booster to approximately 105 RON enough or do I need a race gas. No E85 available here in the UK

Thanks in adavnce

I'd run 100 LL AV. gas.
$4.35 a gallon here. A bargan for that quality of fuel.

Randy

[B Original]

Aviation gas doesn't have the front ends and oxidizers that actual racing fuel does. It will help withstand detonation. but Aviation fuel has different properties than racing fuel. Avgas has altitude burning properties to keep the front ends from Bowling off at altitude. And it impedes performance at 1000 feet above sea level.

If you got 9.5 effective compression ratio I would think closer to 110 octane would be more realistic

Maybe some of the aviation guys or custom fuel blenders will chime and here an elaborate on the differences and I avgas and racing fuel

[randy331]

And it impedes performance at 1000 feet above sea level.

Oh really ?

So they blend a fuel that impeads performance at 1000', right at the altitude a lot of planes take off from ??

That'd be a great place to impead performance !

Randy

[GARY C]

Me and VP fuels wish you couldn't run AV gas but it's hard to convince those that have run it successfully for years. I have one customer that buys VP Vintage for his fuel injected collector cars and AV gas for all his carb cars, some for over a decade now with no issue.

[B Original]

I'll stand by what I say 110 Octane Avgas is not as energetic as 110 VP or any of the other racing fuel competitors

Avas has much less oxidizers then racing fuel ask some of your dirt Racers how important oxidizers are because many tracks at one time was penalizing drivers if they was caught with added oxidizers in their fuel I don't claim to be an expert in it but I've seen enough evidence that I'm a Believer although at my local airport its not hard to get you can drive right up and fill your tank up but the few racer at Cherokee drag strip that buy fuel from the airport just haven't learned. I challenge you if you got a 13 to 1 or better motor try both fuels if you are an average above sea level altitude the exception to the rule is someone that's racing in Denver or a similar place and of course there's a e85, methanol, ethanol, Nitro..... but that's not part of this conversation

[tuffxf]

G,day ,
petrol I'd use avgas, but if it was mine and drag race only put it on methanol!
Cheers

[randy331]

I'll stand by what I say 110 Octane Avgas is not as energetic as 110 VP or any of the other racing fuel competitors

Avas has much less oxidizers then racing fuel ask some of your dirt Racers how important oxidizers are because many tracks at one time was penalizing drivers if they was caught with added oxidizers in their fuel I don't claim to be an expert in it but I've seen enough evidence that I'm a Believer although at my local airport its not hard to get you can drive right up and fill your tank up but the few racer at Cherokee drag strip that buy fuel from the airport just haven't learned. I challenge you if you got a 13 to 1 or better motor try both fuels if you are an average above sea level altitude the exception to the rule is someone that's racing in Denver or a similar place and of course there's a e85, methanol, ethanol, Nitro..... but that's not part of this conversation

The OP engine isn't 13-1, it's 11.85. It's fine on 100LL av gas.

Get a spec sheet from Phillips 66 or one of the av gas supliers and compare to race gas and then test it on a dyno back to back against 110 vp on a 11.85-1 ish comp engine. I have done that switch.

You can keep repeating all the av gas myths you want but there are lots of people running it sucsessfully in a wide variety of racing engines.

You really think they put 110 vp fuel in a turbo charged airplane engine to take off from a low altitude airport in the summer?

Randy

[GARY C]

I'll stand by what I say 110 Octane Avgas is not as energetic as 110 VP or any of the other racing fuel competitors

Avas has much less oxidizers then racing fuel ask some of your dirt Racers how important oxidizers are because many tracks at one time was penalizing drivers if they was caught with added oxidizers in their fuel I don't claim to be an expert in it but I've seen enough evidence that I'm a Believer although at my local airport its not hard to get you can drive right up and fill your tank up but the few racer at Cherokee drag strip that buy fuel from the airport just haven't learned. I challenge you if you got a 13 to 1 or better motor try both fuels if you are an average above sea level altitude the exception to the rule is someone that's racing in Denver or a similar place and of course there's a e85, methanol, ethanol, Nitro..... but that's not part of this conversation

You do know VP110 is not oxygenated don't you and is not recommended for most applications over 13.1? Round Track and VP113 is. Not saying there would be 0 power difference or that AV gas would be best for high compression but the OP is under 12.1 and depending on engine combo the same could be said for any brand of fuel or any type under a brand.

I have been a VP fuel distributor since the mid 90's as well as arranging the VP fuel test DV did several years back, not saying AV gas is the best fuel out there but I know many that run it even with nitrous and never experience problems and run no faster with VP or any other brand.

[GARY C]

Personally because I have massive amounts of VP at my disposal, at that compression I would probably find a blend of 1 or 2 gallons race gas to 3 or 4 of 87 octane even though some say you can't do that either but knock detectors and dyno's say otherwise. But thats just me.

[B Original]

Who ever said you cant run avgas successfully. The real myth is what you believe ↓↓MYTH BUSTED↓↓
You can run and tune for avgas but is it optimal? Unless you have a low compression application probably not.

There are many racers and teams that blend there own fuels but the mass just buy the general racing fuel for there application.

Copy and paste from

http://www.whitfieldoil.com/171.287/rac ... oline.html

"Racing Gasoline vs. Aviation Gasoline
Don't Substitute Aviation Gasoline For Racing Gasoline

Don't substitute Aviation Gasoline for Racing Gasoline unless your race engine operates at 10,000 feet altitude, and does not exceed 2,800 RPM.

Many racers see Aviation Gasoline (AvGas) as a way to reduce the cost of their racing operation. This may be true, but if you want the most out of your engine and want to avoid problems. AvGas may not be your first choice. AvGas is a good gasoline for low speed aircraft engines that run at 2,700 to 2,800 RPM at 10,000 feet or higher. This does not mean it is a good gasoline for racing engines operating at 8,000 to 10,000 RPM. AvGas is also illegal to use in anything except aircraft engines. Violations can carry a potential penalty of $25,000.00 per day of violation.

AvGas octane numbers are determined in a different test than motor gasoline octane numbers. Do not be confused by the big numbers from the AvGas test method. They are not comparable to motor gasoline test numbers. The 110 leaded gasoline will test out at about 160 on the AvGas scale.

AvGas is held to tighter requirements than street gasoline, but not nearly as tight as is the entire line of Racing Gasolines. Some racing gasoline blenders us AvGas as a blending component to save money.

AvGas has a lower specific gravity than most racing gasolines. This means that if a racer tries AvGas and has not re-jetted, he can burn a piston because the air-fuel ratio is too lean and/or the engine detonated. To make a good comparison between two gasolines, the air-fuel mixtures must be the same. Even after re-jetting, the racer can experience burned pistons with AvGas if the Motor Octane Number (MON) is lower than what his or her engine needs.

Another potential problem with AvGas is that there are several different octane grades. The 80/87 grade is red in color and can get you in lots of trouble because of its very low octane number. The 100LL is blue and the 100/130 grade is green. Both of these have much lower Motor Octane Numbers (MON) than most racing gasolines and will detonate when the engine octane demand is greater than the octane number of the gasoline.

The bottom line is: Feed that high dollar racing engine a good grade of gasoline so it will deliver the maximum performance. Don't use "low bidder" mentality."

Debate is over, you all can go on and stay in the dark ages without me and modern tech. GOOD LUCK

[GARY C]

That reminds me of when politicians use the term "Life Expectancy" when discussing "Life Span". did they provide any fuel spec comparisons?