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Author Topic:   AV GAS
eric08
Dirt Roller

Total posts: 6
posted March 31, 2003 10:20 AM
ANY INFO APPRECIATED. RUNNING 355 FLAT TOP
4412 CARB STOCK 441 HEADS

rico 08
Dirt Freak

Total posts: 372
posted March 31, 2003 12:18 PM
That's what i plan on running,sometimes it's hard to get they are not allowed to sell it for street use even tho you will be using it for racing off road they will assume otherwise,one trick i've learned is to use someone's tail number and tell them you are getting it for someone working on their plane at home and give them the number you borrowed and you should be ok.Some may say premium unleaded will be enuf but i like the peace of mind av gas gives in case something happens which might send the motor into detonation,also racing fuel seems to keep going up and in my opinion is way overpriced.

Flatlander
Dirt Freak

Total posts: 310
posted March 31, 2003 01:04 PM
I always mixed it half and half with premium fuel the good thing about av gas is it is always the same never had any trouble buying it but I guess diff areas I just took the car and filled it and then filled my containers you had to sign for it

odb93
Dirt Freak

Total posts: 214
posted March 31, 2003 01:40 PM
You guys run any Marvel mystery oil in that airplane fuel.

eric08
Dirt Roller

Total posts: 6
posted March 31, 2003 01:46 PM
that was the plan to add marvel

odb93
Dirt Freak

Total posts: 214
posted March 31, 2003 03:15 PM
Eric,

What percentages do you run. How much oil, gas, and AV fuel?

eric08
Dirt Roller

Total posts: 6
posted March 31, 2003 04:03 PM
I run a 16 gallon cell 3/4 av gas 1/4 premeum
unleaded 8oz.marvel to that.That is what im
going to try since turbo blue is 4.50 gallon.

dirtbuster
Dirt Freak

Total posts: 353
posted March 31, 2003 04:19 PM
If you are running flat tops i assume your compression is around 9:1 or 10:1. If so I would think good 92 pump gas should work for you but if you want to mix why not just mix 1/4 race gas(110 octane or so) and 3/4 premium(92) pump gas. On a 20 gallon tank that would give you around 96 which would be more than you ever need. That way all the fuel you put in your tank is formulated to run on the ground not 20,000 feet in the air, and i am sure it is easier to get ahold of.

eric08
Dirt Roller

Total posts: 6
posted March 31, 2003 04:25 PM
if im not mistaken av gas is 100 octane,
100 low lead.adding 92 premium to that would
be less octane than race fuel and premium and
also buy me a few more tires over the season
since they only last 2-3 nites.just trying to
spend money on other things more important
than throwing money out the window for race
fuel that seems to be on the rise, can't
understand why since its for off road use.

66jj
Dirt Freak

Total posts: 352
posted March 31, 2003 04:35 PM
avgas is junk...

run it one week then run premium and youll see.

youll be changing your jets when you change fuel avgas takes a ton more jet if i can remember correctly, its been 7 years since i was educated on fuels.

avgas is rated at 100 per diff standards than pump gas its the same as premium. call someone who sells ultralights and ask them what to run for fuel. theyll tell you avgas or premium.

rico 08
Dirt Freak

Total posts: 372
posted March 31, 2003 09:05 PM
Alot of aviation motors are at least 10-1 compression and are really high output so they need a really good fuel,also they gripe about fuel prices too so they try to keep the prices down unlike racing fuel,if you have any motor at all i'd run the pump gas,the service station premium is no good for racing,saving a few dollars is not worth a racing engine.

dirtbuster
Dirt Freak

Total posts: 353
posted April 01, 2003 09:13 AM
I beleive 66jj is right the AV gas octane is rated differently than regular auto gas.

i agree that some airplanes have high compression, high output engines but they also are not flying at sea level. As you get higher the air thins out so it effectively decreases your compression because you cant get as much air in the motor.

Flatlander
Dirt Freak

Total posts: 310
posted April 01, 2003 12:04 PM
you will have to jet up as av gas will lean out the reason I ran it was racing fuel in barrels brought to tracks sometimes mean water as far as av gas being junk if you use it right it the way to go for consitant fuel but opinions are diff I agree with me and you agree with you the way it was explained to me the rating on av was about 110 and prem was 92in my book that makes it 101 plenty for a 9 or 10 to 1 motor i did use 6 oz of marvel per 20 gal but know alot who didn't if they mixed it

rico 08
Dirt Freak

Total posts: 372
posted April 01, 2003 01:13 PM
that's another reason i won't run track fuel is most tracks use the 55 gallon barrels and in the summer/sunshine they have to loosen a bung to keep the barrell from balooning,then if they don't tighten them and they get rain on top when the barrell cools down it will suck in the water and foul up everyone that runs it.

eric08
Dirt Roller

Total posts: 6
posted April 01, 2003 01:45 PM
I have seen many motors blow up from racing
fuel, detonation being a factor and also
distributors of race fuel ordering mass quantity to make themselves money by getting
a better buy and it sits around for up to two
years,and their are the ones who add pump gas
to make even more off the racer on a budget.
Av gas has to meet regulations unlike racing
fuel,I have yet to see a motor detonate from
Av gas,so i cannot understand why people have
bad things to say about the stuff, But everyone is entitled to their own opinions
and good and bad experiences.

racer3397
Dirt Roller

Total posts: 18
posted April 01, 2003 03:32 PM
i have run avgas for 2 years and never had a problem, i always add a little 2cycle oil to mine,because avgas is so dry!!!!

eric08
Dirt Roller

Total posts: 6
posted April 01, 2003 03:36 PM
agree 100% it runs dry and almost as clean as
propane.upper cylinder lubrication like marvel or 2cycle is probably a smart thing to
consider.

rico 08
Dirt Freak

Total posts: 372
posted April 01, 2003 03:45 PM
It's not that bad,anything is better than premium,i've seen many engines blown on premium.

Earl Parker II
Dirt Full Roller

Total posts: 39
posted April 01, 2003 06:40 PM
You might want to go to http://www.parkercarburetion.com/information.html and scroll down to the 'Racing gasoline vs. aviation gasoline' link- interesting reading.

------------------
Earl Parker II
www.parkercarburetion.com
704.482.7588

racer2
Dirt Maniac

Total posts: 166
posted April 01, 2003 07:02 PM
ran av gas for 6 years with no problems.
just add oil ,but have run dry before.
and i do run in the front of the pack.

Flatlander
Dirt Freak

Total posts: 310
posted April 01, 2003 08:26 PM
Mr Parker that is a good article But lets remember who wrote it and most of the motors we are talking about are hardly in the price range he quotes I agree if you're a late model or limited with a big motor then yes by all means racing gas is the tool But go to the distibutor and buy not out of a barrel

Earl Parker II
Dirt Full Roller

Total posts: 39
posted April 01, 2003 09:46 PM
Actually, I believe Tim used those figures to illustrate the point that, in general, most racers are better off using fuel designed for racing engines, regardless of the class they're racing in.

------------------
Earl Parker II
www.parkercarburetion.com
704.482.7588

chevy_20
Dirt Full Roller

Total posts: 50
posted April 01, 2003 10:00 PM
I've used av gas for 2 years now. I haven't had a single problem running it. The airport i buy the gas from told me that they test the octane of the gas periodically and the 100 actually was about 115 octane. They told me that it wouldn't hurt my engine to run it as long as i use a top lube like marvels. They also told me to store it in an air tight container because it absorbs moisture more than reg gas.

CAGEMAN
Dirt Full Roller

Total posts: 30
posted April 03, 2003 02:21 AM
I run Avgas, always have always will, I have never added any LUBE to it but I havnt noticed any problems, 54 nights on current motor and she looks good inside.
As for the 20,000 feat thing, airplanes do run on the ground, and also at high altitudes, thats why they adjust the air fuel mixture in the cockpit as they climb. Having to change jets in a race car is an everyday thing, not just because of avgas.
12 to 1 on a two barrel is good for avgas. sure a 10 to 1 motor might run on premium, but the avgas has lead in it and is only a few cents more nowadays.

rico 08
Dirt Freak

Total posts: 372
posted April 03, 2003 05:37 PM
You're absolutely right cageman also a 10-1 motor can run on 91 octane i agree but it leaves no margin for error or it will ruin the engine.

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