Who here uses av gas?

[dmontzsta]

I need to mix 91 pump gas with race gas since I am running a healthy shot of nitrous now. Ras gas (110) is freakin expensive and I am wondering if running a 50/50 mix of av gas and 91 pump would be safe.
I have heard bad things about av gas...
and I have heard great things about av gas...
it is definately alot less than race gas and is even a few cents less than pump gas.

[Jet City]

I need to mix 91 pump gas with race gas since I am running a healthy shot of nitrous now. Ras gas (110) is freakin expensive and I am wondering if running a 50/50 mix of av gas and 91 pump would be safe.
I have heard bad things about av gas...
and I have heard great things about av gas...
it is definately alot less than race gas and is even a few cents less than pump gas.
Do a search on this forum, Lakes Only did a good write-up on avgas. I just located the Trick dealer in my area, after seeing the pricing for this crap I don't mind using the term "dealer". Having a 12:1 CR engine with a pair of double pumpers is like a gambling habbit, I would like to check into avgas too. Can anyone show up to the local airfeild with gas cans or what?

[InKahntrol]

Pop's Barron Sprint flatty has a radical BBC with 12:1 compression and Kinsler mechanical fuel injection, and he's been running straight AV gas for years with no problems. We get it at the 76 station in lake havasu next to Mudshark Brewery and the Movie Theater... it's usually about the same price as pump premium.

[djdtpr]

I have had really good luck with av gas i used to run it straight and add some marvel mistery oil to it cause it is extremely dry.I found that it ran a little leaner than vp or other race fuels.A buddy of mine mixes it with regular gas and has no problems at all.I know in Blythe you can pull into the airport and fuel up your boat and a can they have no problem with it.

[dmontzsta]

I would like to run around 100 octane. What kind of mix of av gas should I mix with pump gas? anyone know...

[djdtpr]

That would depend on how big your tanks are and what pump gas you are running.I have never heard of having to run race gas because of nos before!Who told you that you needed to?I have ran it on my rail and on a street car and never had to change fuels cause of it.The only thing i ever worried about was enough fuel to the fuel solinoids and not robbing the primary fuel system.

[dmontzsta]

The tanks are two 8 gallon = 16 total.
I also bring 3 - 5 gallon cans.

[SHAKEN Not Stirred]

My motor was built for 91, but I run about 1/3rd tank (30 Gal) of 100LL and 2/3rd tank (55 Gal) of 91......
Just to be safe.....
CJG
:clover:

[LakesOnly]

AvGas is a high octane fuel for our engines, but it is not to be confused (or benchmarked alongside) race gas. Although race gas and AvGas are entirely different animals, AvGas may be run in an internal combustion engine without trouble (assuming the same octane rating). It most likely will not generate as much power. Read on...
I've run over 100 gallons through my jet boat at sustained 5000 rpm without trouble, and I have no intention of changing as it seems to work fine. I know others that have run it for years without trouble. It is a much, much better choice of fuel than what we have available at the pump here in California (91 octane Research+Motor/2). It is a true "100 Motor Octane" rating (which is significantly greater than the R +M/2 method), and the 100LL has 2 grams/gallon lead in it (pump gas has no lead, ERC 110 race gas has 3.33 gr/gal).
You'd better believe the Feds do not want planes falling out of the sky, and so there are strict requirements that must be adhered to when manufacturing AvGas. As a result, there is only a handful of refineries that produce this highly quality-controlled fuel, which is much more highly refined--and made of higher quality materials--than any typical commercial pump gas on the market (unleaded race fuels aside).
Pump gas manufacturers may use most anything they wish to increase octane, be it alcohol, MTBE, whatever. AvGas can use just one octane increasing chemical: Lead. Period.
The "130 Supercharge" octane rating mentioned above ("100/130") is actually a test requirement that AvGas must pass, and that auto pump gas is not required to pass (nor would it pass).
Saying that AvGas "was designed to run at high altitudes" is a bit misleading; specifically, AvGas must have incredible stability (yet another fine attribute) to withstand sudden atmospheric changes, including altitude, temperature, humidity, etc. that come with a sudden change in altitude. It must maintain its volatility over greater extremes and not vapor lock, etc. On the flipside, pump gas in the U.S. is now maufactured for specific regions around the country, for those regions general atmospheric conditons--there are even seasonal blends within each region. This is (in part) making pump gas more expensive.
Indeed, AvGas is blended for an altogether different application. So, its characterstics are different by way if its boiling point/evap point/freezing point/volatility/oxidation stability, etc. Since this is the case, your engine will most likely not perform as well on AvGas as it will on high performance automotive race gas like VP or Sunoco. But if, like me, anti-knock is the primary thing you're after, AvGas can fill the position with a little common sense, and is a much better choice than today's "cat piss" pump gas.
AvGas is manufactured using a lighter cut of the carbon molecule. Mainly because of this, a gallon of AvGas weighs about 5.9 lbs, whereas a gallon of race gas weighs more like 6.2. So yes, you'll have to jet for it...
Also, AvGas was designed to be used in a piston engine that cruises along at a sustained 2000-3000 rpm, so the burn rate is nothing to get excited about.
I telephoned Chevron, an "Aviation Division," and spoke to somebody about purchasing a drum of fuel, and the conversation went something like this:
"And do you sell it by the 55 gallon drum," I continued.
"55 galion drum? Well, no, why would you need that?"
"I wish to use this fuel as an alternative to race gas in my automobile engine," I said.
"We don't recommend you do that," he replied.
"Why not," I asked, "will it harm the engine? How is AvGas a different fuel"?
There is a long, 3-4 second pause on the line. Then he replies, "Well...uhm...actually, it's just that it is our policy here at Chevron to discourage the use of this fuel in an automobile." And then he took my fax number and sent me all kinds of info and data about AvGas. After reviewing what he faxed to me and also reading elsewhere, my speculation is that it is Chevron's official position to discourage the use of this fuel in an auto engine because, 1) federal road taxes are not included in the sale of AvGas (illegal in a street-driven car), and 2) AvGas contains lead (illegal in a street-driven car). Chevron would not want a finger pointed at them if someone wgot busted using the fuel to motor down our public roadways. But hey, we don't do this; we use it at the track and/or on the lake (off-highway use).
So if you're a hard-core drag racer trying to get the most HP out of your engine, you're most likely going to get that with the proper, highly refined race gas for you application. But if you've got yourself a weekend door-slammer that you take to the track for kicks or you're like me and just in need of 100 octane leaded, you may run on AvGas. It may not be the best alternative to pump gas, but it sure as hell blows typical pump gas clear out of the water.
LO

[LakesOnly]

I would like to run around 100 octane. What kind of mix of av gas should I mix with pump gas? anyone know...
AvGas 100LL is 100 motor octane by itself.
LO

[dmontzsta]

Dang, thanks a TON for all the info.
I think I might just go to the airport and fill the boat and 3 cans with pure av gas. Instead of hassling getting 91 pump gas $2.40 per gallon and then 110 octane race gas $5.45 per gallon and doing a 50/50 mix to come up with 100 octane. I can get avgas for around $2.25 per gallon at the airport. I have a holley 750 dp that has a 72 jet in it. The boat has always ran rich, I still have not gotten it right, so I think it is getting plenty of fuel and maybe with the lighter av gas I might be able to dial it in better. I have no problem with going to the airport to fill up the tanks and cans. I have a hunch that av gas might be a good choice for me. What do you think? any downsides?

[texas-19]

How about a ballpark figure on how many jet sizes to go up?I have heard it is hard to read plugs when you go to the lighter fuel,any comments on that,true or not?

[don johnson]

Check out Bob Teague's comments in this months Powerboat magazine tech section. Bob actually comments that Av Gas is an exceptional fuel to run in engines that require the added octane levels.
Bob also comments that AvGas actually runs cooler due to it runs richer then pump gas due to the oxygenated blend that the fed requires. That is contrary to djdplacecrafts comments that AvGas runs leaner.
I personally run straight avgas in my 33' Daytona with twin GT Perf 1050 HP Blower motors with some Marvel mixed in. I have never had any problems. With the price AvGas the same as prmium pump gas it makes sense as my motors running at 11 lbs of boost are on the border of pump gas... Cheap insurance.

[dmontzsta]

Sounds like av gas might be the ticket. It is also less expensive than pump gas. I was thinking how many planes actually have engine troubles due to their gas? My only concern now is jetting. I have a holley 750 dp that has been jetted to 82 I think...I will have to look, I know it is jetted up higher than it comes from holley.

[djdtpr]

Check out Bob Teague's comments in this months Powerboat magazine tech section. Bob actually comments that Av Gas is an exceptional fuel to run in engines that require the added octane levels.
Bob also comments that AvGas actually runs cooler due to it runs richer then pump gas due to the oxygenated blend that the fed requires. That is contrary to djdplacecrafts comments that AvGas runs leaner.
Well i cant argue with his knowledge.I can tell what my expeirience with it have been.I did switch fuels this year since the new motor 461 bbc 11 1/2-1 static comp and a big bore 6-71 making 14 lbs of boost.I just didnt know if the av gas would handle it,but it ran well at 13-1 in a 505 na.I just dont see how a lighter fuel is a richer fuel,he must know something we dont.

[GofastRacer]

I been running AV gas for 20+ years either straight or mixed(depending on compression) in my lake boat with no problems whatsoever, but I did learn(the hard way) that even though it has lead it's still very dry and will shorten the life of valve guides big time, but if you use 4oz of Marvel for every 10 gals everything is well lubricated. And if you run injectors it keeps the shafts lubricated so you don't have to squirt them with WD all the time!...As far as jetting goes just read the plugs and go accordingly, no biggie!...

[dmontzsta]

I been running AV gas for 20+ years either straight or mixed(depending on compression) in my lake boat with no problems whatsoever, but I did learn(the hard way) that even though it has lead it's still very dry and will shorten the life of valve guides big time, but if you use 4oz of Marvel for every 10 gals everything is well lubricated. And if you run injectors it keeps the shafts lubricated so you don't have to squirt them with WD all the time!...As far as jetting goes just read the plugs and go accordingly, no biggie!...
So you recommend running 4oz to every 10 gallons? where do you get this marvel stuff? and how much is it for 4oz?
Thanks for the input.

[xDRAG ONx]

I use av gas becuz Bob Teague did tell me it runs cooler and i think makes the boat run better and faster!

[dc96819]

I use 100%

[djdtpr]

So you recommend running 4oz to every 10 gallons? where do you get this marvel stuff? and how much is it for 4oz?
Thanks for the input.
At any parts store and some hard ware stores.If you run a rotary style fuel pump you definatly need it but i used all the time even when i didnt have a rotary pump.Why thy change in fuel if you dont mind me asking?

[GofastRacer]

Marvel has been around forever and lubricates just about anything!..Here's an interesting article about Marvel and Av Gas!..
Marvel! (http://www.pipercubforum.com/marvel.htm)

[dmontzsta]

At any parts store and some hard ware stores.If you run a rotary style fuel pump you definatly need it but i used all the time even when i didnt have a rotary pump.Why thy change in fuel if you dont mind me asking?
Will it work ok with the summit/aeromotive electronic fuel pump I just bought?
I am going to be running a 150 shot of NOS and dont want to take any chances with this motor, I am playing it as safe as possible. Until I build the right motor for it hopefully this winter.

[dmontzsta]

Marvel has been around forever and lubricates just about anything!..Here's an interesting article about Marvel and Av Gas!..
Marvel! (http://www.pipercubforum.com/marvel.htm)
I just found it at my auto parts store, thanks.
I have heard of it before but thought it was one of those gimmicky oil treatments.

[GofastRacer]

Will it work ok with the summit/aeromotive electronic fuel pump I just bought?
I am going to be running a 150 shot of NOS and dont want to take any chances with this motor, I am playing it as safe as possible. Until I build the right motor for it hopefully this winter.
Yes it will work with that pump or any other one, it's also the shit for air tools too!..

[cookieman]

I run av-gas in my boat and have for 2 years now. I do what most of the others here on the boards and put 2oz. of marvel oil in 5 gals of fuel. I normally run the driver tank with av-gas and the passenger tank with 93octane. I have a tank switch in the back which will let me blend or pull from the av-gas side if needed. I usually just let it mix and I run all season without changing anything but the oil. Now as far as oil goes I am a firm believer of Mobil one 15-50. Best oil in my opinion for these boats. I also have taken the spoken advice from these boards and run a wix filter. I know that I watch the boards and take some the suggestion and advice that others have used to make their boats work. Anyways just my 2 cents worth and maybe someone can use it. Bill "cookieman"

[Kindsvater Flat]

Buy a barrel tight ass!! :mix:
http://www.schoutenranch.com/mike/vp.JPG

[dmontzsta]

Buy a barrel tight ass!! :mix:
http://www.schoutenranch.com/mike/vp.JPG
Damn, how much do they get you for a barrel?
http://dmontzmax.maximaclubca.com/SigsAndAvatars/Smilies/spin.gif

[Kindsvater Flat]

Depends. Start asking around for an inside deal down there and you can get a good price. I saved over a buck and a half by buying the barrel.

[dmontzsta]

Depends. Start asking around for an inside deal down there and you can get a good price. I saved over a buck and a half by buying the barrel.
Down the road from my office is the SC Fuels building. Is there stuff pretty good? I dont know, I might just run av gas, it is a hell of alot cheaper. SC Fuels wants $5.75 per gallon for 100 octane and $6.45 for 110 octane.

[Kindsvater Flat]

Thats more than 2.50/ gal higher than what I paid.

[dmontzsta]

Thats more than 2.50/ gal higher than what I paid.
shit, now I might be able to swing that...and it would help to keep that drum at the house, I could make it last longer by mixing it with 91 octane to make 100. How big is that barrell? It is kind of scary to have in your garage...it is like a bomb.

[Kindsvater Flat]

Its a 55 gal drum. Just don't store it in the sun.

[dmontzsta]

hmmm...so right around $200? that might be doable.

[Nucking futs]

Hey D, did you get the floor fixed in your boat yet?I would address that as soon as posiable.You remember what happened to the CP at c3b?That is exactly whats goin to happen to your boat(especially they way it hops)if you dont get that fixed soon.Don't want to scare you but now you will be putting more H.P with the silly gas and if that bottom keeps flexing it going to give, in a big way. Tim

[dmontzsta]

Hey D, did you get the floor fixed in your boat yet?I would address that as soon as posiable.You remember what happened to the CP at c3b?That is exactly whats goin to happen to your boat(especially they way it hops)if you dont get that fixed soon.Don't want to scare you but now you will be putting more H.P with the silly gas and if that bottom keeps flexing it going to give, in a big way. Tim
I will shoot you a PM.

[powerplay230]

Is Av gas the same thing as Aviation gas? hopefully not diesel even though my boat runs like a diesel truck..Have a friend (only one) who's dad told me the Av gas used to be 140 octane and cheap

[HP350SC]

Dmonszta- didn't catch what your c/r or boost pressure was? No need to run avgas unless you're pushing the limits of 91 pump. I am running straight avgas which is 100 low lead in a 502 with 8 3/4 static and 9 lbs. boost. Lakes only is absolutely correct in his statements. I also run a little Marvel just to be safe.

[dmontzsta]

Dmonszta- didn't catch what your c/r or boost pressure was? No need to run avgas unless you're pushing the limits of 91 pump. I am running straight avgas which is 100 low lead in a 502 with 8 3/4 static and 9 lbs. boost. Lakes only is absolutely correct in his statements. I also run a little Marvel just to be safe.
Compression is around 9:1 and the boost is coming from a 150shot.

[HP350SC]

I would think pump premium would be fine. Do you limit your timing when nitrous is in?

[Hotcrusader76]

Its a 55 gal drum. Just don't store it in the sun.
Why not? :D :D
http://www.pomperaug.com/socstud/stumuseum/web/mushcloud.jpg

[Sleek-Jet]

Is Av gas the same thing as Aviation gas? hopefully not diesel even though my boat runs like a diesel truck..Have a friend (only one) who's dad told me the Av gas used to be 140 octane and cheap
Aviation Gas (or AvGas) is also known as 100LL (blue). Not to many years ago there was also 100/130 (Green) aviation gas, and way back in WWII there was 160 octane (also Red). Both of those went the way of the dodo when the military and airlines quite running recip equipment. (100/130 hung on till the mid 80's) leaving 100LL to fill the needs of high compresion and turbo/super charged aviation engines.
80 octane aviation gas has just recently gone out of production, so any mention of avgas means 100LL.

[powerplay230]

THANKS.... and I'm not roasting marsmallows with Crusader if that's what he uses for fuel. :p