AVGAS question

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flat tappet
Posts: 80
Joined: December 20th, 2008, 4:43 pm

AVGAS question

Post by flat tappet »

Does everyone racing a VEE run AVGAS or some other formulation.....thoughts, plus,minus

Thank, Guys!
bobc
Posts: 37
Joined: February 9th, 2008, 10:50 am

Re: AVGAS question

Post by bobc »

There was a long post about a year ago about the differances between gases. Some of the features of avgas are the lack of a lot of additives, some of which attack fuel cells and foam. Another advantage is that it is formulated to sit long periods of time without going bad, a good thing for airplanes that sit idle for a long time. One of the reasons for its high cost is that it is filtered each time it is transfered. Every airport has to drain an amount of fuel each day to check for water. I have been buying these draining at 3/4 the cost of the field price. Last time, because he had so much, I paid $1.00 per gallion.
brian
Posts: 1348
Joined: June 26th, 2006, 12:31 pm

Re: AVGAS question

Post by brian »

I prefer av gas but I have several rural airports that make buying it easy. Only time I run race gas is at the runoffs where it is required. I've proven on the dyno that race gases go flat. The Sunoco I had left over from the runoffs was 3 months old and was down hp. Yes, rejetting and retiming made no difference.
The above post is for reference only and your results may vary. This post is not intended to reflect the views or opinions of SCCA and should not be considered an analysis or opinion of the rules written in the GCR.
Bill Carroll
Posts: 72
Joined: January 21st, 2009, 8:33 pm

Re: AVGAS question

Post by Bill Carroll »

There are both good and bad theory here, but I don't know anyone who ever had a fuel problem with Avgas (100LL), I worked on Aircraft for years and ran it in everything from lawnmowers to Drag cars. I did notice a bit excessive lead buildup if we were running lean. I do know AVGAS is formulted to run on low RPM engines (2400-3200 RPM) but we pulled 10K in drag engines no problems. Running the fuel from the daily fuel checks may give you water once in a while, when I worked at the airport we saw water many days we drainded fuel, especially on above ground tanks or from aircraft (condensation).

I would like to know if our low compression FV engines run on pump 87-89 or 93 unleaded octane are fine?
flat tappet
Posts: 80
Joined: December 20th, 2008, 4:43 pm

Re: AVGAS question

Post by flat tappet »

[quote="Bill Carroll"]There are both good and bad theory here, but I don't know anyone who ever had a fuel problem with Avgas (100LL), I worked on Aircraft for years and ran it in everything from lawnmowers to Drag cars. I did notice a bit excessive lead buildup if we were running lean. I do know AVGAS is formulted to run on low RPM engines (2400-3200 RPM) but we pulled 10K in drag engines no problems. Running the fuel from the daily fuel checks may give you water once in a while, when I worked at the airport we saw water many days we drainded fuel, especially on above ground tanks or from aircraft (condensation).

I would like to know if our low compression FV engines run on pump 87-89 or 93 unleaded octane are fine?[/qu

Good question, Bill. It would be nice to know if 93 octane will run fine.
smsazzy
Posts: 703
Joined: June 24th, 2006, 5:56 pm

Re: AVGAS question

Post by smsazzy »

Bill Carroll wrote:
I would like to know if our low compression FV engines run on pump 87-89 or 93 unleaded octane are fine?
Not only will pump gas run fine, but it will slightly increase your horsepower to to the oxygenators.

However, it will not pass the fuel test for SCCA.

Many people use pump gas in ICSCC which does not test fuel for FV.
Stephen Saslow
FV 09 NWR
supersmile
Posts: 13
Joined: June 25th, 2006, 10:24 pm

Re: AVGAS question

Post by supersmile »

I would like to know if our low compression FV engines run on pump 87-89 or 93 unleaded octane are fine?



I don't believe unleaded pump gas will pass SCCA tech, and there is some concern about the ethanol in it breaking down fuel cells. If it does indeed destroy your fuel cell prematurely you didn't save any money by using cheap gas.
Rob Zatz
flat tappet
Posts: 80
Joined: December 20th, 2008, 4:43 pm

Re: AVGAS question

Post by flat tappet »

Thanks Rob for the info.
Bill Carroll
Posts: 72
Joined: January 21st, 2009, 8:33 pm

Re: AVGAS question

Post by Bill Carroll »

IS there any concern without lead, I don't think a 1964 valve has stellite face or seats which was a big concern many years ago when pump gas went to unleaded? I'm not running SCCA yet so I'll cross that bridge soon. I got a message that pump gas will have some crud buildup around the valves.

I'll check about Fuel cells and alcohol, I don't know if the drag and dirt car fuel cells are different for alcohol.
smsazzy
Posts: 703
Joined: June 24th, 2006, 5:56 pm

Re: AVGAS question

Post by smsazzy »

Speak to your fuel cell manufacturer. The manufacturers I spoke with at the PRI show last year said that the new cells made today should be able to handle pump gas with low amounts of ethanol in them provided you drain them and don't store the gas in them for long periods. You need a completely different fuel cell to handle alcohol fuel though. Although they do make cells that handle both.

I do not think our valves are a concern regarding lead, but one of the engine builders would be better to answer that.

If you're running SCCA though, the point is moot, as you will be DQ'd for failing the fuel test.
Stephen Saslow
FV 09 NWR
spdunlap
Posts: 13
Joined: August 18th, 2008, 11:05 pm

Re: AVGAS question

Post by spdunlap »

AV gas in an air coled engine? Why not? Av gas has an oxygenator that pump gas doesn't have. In effect it's a bigger carb/manifold system. You have to jet up
a bit but it's a go deal. I ran it for years and never had a problem. There is not enough of the "tones" keytones,acteones etc. to hurt your cell.
SR Racing
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Joined: June 24th, 2006, 1:58 pm

Re: AVGAS question

Post by SR Racing »

Street premium is more than enough octane for an FV engine and it will produce slightly more HP than AVGAS when both are tuned (jetted) correctly. (It will however fail the SCCA fuel tests)

Fuel Safe and Aircraft Rubber say that street (10%E) gas is fine in their cells. They actually told me that even E85 does not appear to be a problem, but they will not recommend it.

In the 70's when LL came out and later no-lead, VW immediately said that this was a non issue with their ACVW 1 engines.

BTW, AVGAS (100LL) while called "low lead" actually contains 4 times the lead that the street fuels had when they contained lead. You will get some lead deposits when using it. But with usually less than 50 hours on an engine between rebuilds it not a big issue.
cendiv37
Posts: 386
Joined: June 25th, 2006, 7:29 pm

Re: AVGAS question

Post by cendiv37 »

As Jim says, 100LL AV gas contains quite a bit of lead. It does not contain any oxygenators. If AV gas contained any oxygenators, it would not pass SCCA's leaded race fuel tests. It passes these tests quite easily and is commonly used in Vees where fuel is tested. It is my fuel of choice except where forced to use something else. My engine builder generally prefers it to most track fuels because it is consistent and causes less build-ups of all kinds in the ports, and combustion chambers.

It may not produce the most power, but it is good enough to win lots of races. It does seem to be easy on fuel cells as well and it stores much better than most race fuels or today's street fuels (which no longer contain preservatives as they once did).
Bruce
cendiv37
hardingfv32-1
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Joined: December 1st, 2006, 8:01 pm

Re: AVGAS question

Post by hardingfv32-1 »

Will NO lead AV gas, when available, pass the SCCA fuel test? I always thought the lead played a role in the dielectric part of the test.

Brian
DanRemmers
Posts: 293
Joined: June 24th, 2006, 7:21 pm

Re: AVGAS question

Post by DanRemmers »

What fuel does Formula First use?
dd46637
Posts: 135
Joined: December 24th, 2006, 9:38 pm

Re: AVGAS question

Post by dd46637 »

Most FST racers use AVGAS as well.
SR Racing
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Joined: June 24th, 2006, 1:58 pm

Re: AVGAS question

Post by SR Racing »

hardingfv32-1 wrote:Will NO lead AV gas, when available, pass the SCCA fuel test? I always thought the lead played a role in the dielectric part of the test.
Brian
I think to be sure you would have to run the SCCA test on it.
SR Racing
Posts: 1205
Joined: June 24th, 2006, 1:58 pm

Re: AVGAS question

Post by SR Racing »

dd46637 wrote:Most FST racers use AVGAS as well.
Yep. But our local GenAv port will no longer sell it. So we will be using track gas. The engine requirements for the 1600 engine re: fuel and octane are the same as for FV1200. So we will just jet it for whatever we have to use.
vreihen
Posts: 577
Joined: August 5th, 2006, 9:39 pm

Re: AVGAS question

Post by vreihen »

SR Racing wrote:But our local GenAv port will no longer sell it.
Our local airport will not sell it out of their fuel truck to anyone not in a plane. They have two self-service pumps on the field though, which have credit card swipers and are 100% unattended. As long as you leave your car in the parking lot and hoof across the tarmac carrying your gas cans, the airport staff is fine with letting anyone buy AVGAS. I believe that the big concern is the highway taxes if you put it in a street vehicle, which is why they don't want cars near the pumps.

If you have never used a self-service fuel pump at an airport, find a pilot or fellow racer who knows how it works and bring them along on your first trip. In all seriousness, you might not even know what the fuel pump looks like yet alone how to operate it, because it's nothing like what you'd find at your corner gas station. Well, unless your corner gas station has 100' hoses on reels, ground straps, and a pump that prompts for a tail number before turning on..... :lol:
Matt King
Posts: 304
Joined: December 23rd, 2008, 1:44 pm

Re: AVGAS question

Post by Matt King »

I guess airport policies vary widely. At my local GA airport, the fuel guy helped me carry my jugs through the lobby, filled them up, and helped me carry them back to the truck!
smsazzy
Posts: 703
Joined: June 24th, 2006, 5:56 pm

Re: AVGAS question

Post by smsazzy »

I use race gas from the track for all the reason's listed above. I don't use more than 10 Gallons in a race weekend typically. So saving a couple bucks per gallon is not a huge savings, especially since I live at least 25 miles from the closest place I could buy it, and all the hassle's the last few posts point out.

Plus, it supports the racing industry, and I assume the tracks I buy it from.

Now if you want to discuss the price of entry fees with me.......then you'll get me fired up about saving some money. :-)
Stephen Saslow
FV 09 NWR
72jeff
Posts: 87
Joined: October 1st, 2006, 8:49 pm

Re: AVGAS question

Post by 72jeff »

vreihen,

are you going to orange county airport or randall?
vreihen
Posts: 577
Joined: August 5th, 2006, 9:39 pm

Re: AVGAS question

Post by vreihen »

72jeff wrote:are you going to orange county airport or randall?
Check your PM's.

Funny that you mention one of those airports in the context of racing, because it used to be an SCCA and NASCAR circuit back in the 1950's. Ironically, I've been told that the current operations office building was originally built by the SCCA as our tech shed back in the day.....
jmattox
Posts: 131
Joined: September 24th, 2006, 9:40 pm

Re: AVGAS question

Post by jmattox »

Matt, that GA airport was just glad you didn't have a number of mason jars full of "stuff," for medicinal purposes only.

John (used to live in backwoods GA) fv42
vreihen
Posts: 577
Joined: August 5th, 2006, 9:39 pm

Re: AVGAS question

Post by vreihen »

jmattox wrote:Matt, that GA airport was just glad you didn't have a number of mason jars full of "stuff," for medicinal purposes only.

John (used to live in backwoods GA) fv42
I believe that he meant GA as in General Aviation, not the state that was home to the Dukes of Hazzard..... :lol:
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