Other AVGAS LL100 info for the poorride community (unable to buy C12)

[OCD Solutions]

Some good info here that has been covered in many threads already before but never in such a comprehensive format.

Spode:
Re: 100ll Avgas Ok to run?
Real info on Race Gas/Av Gas...

My experience comes from 7 years as the western states representative for 76 Race Fuel, Unocals 40 hours Advanced Products course, Working personally with Tim Wusz (senior performance products Rep for Unocal, Tim was responsible for Unocals race fuel development for 30+ years). I have also met and discussed fuels/motors with just about every engine builder in every facet of racing in the western United States. I also conducted Educational Seminars at the Fred L. Hartley Institute in Brea in which we would invite Engine Builders for a tour of Unocals testing facilities and do live octane tests on any gasoline they would choose to bring to the seminar. Included in the training we would demonstrate live tests how Distillation curve, Reid Vapor Pressure, Specific Gravity, Octane Rating, F;ashpoint, etc are conducted and the importance of these numbers. Some of you will remember me from contingency with my 76 Racing Gasoline hospitality trailer in the 1990's.

Through the 50's, 60's, 70's and 80's Av gas was the base product used for most racing "gasoline". VP, f&L, Turbo Blue, and Trick all used AV gas as the base product. They would buy a tanker (8000 gallons of Av Gas) than add other hydrocarbons/TetraEthylLead (TEL) to the base, drive around the block stopping and accelerating the truck/trailer until they felt the product was mixed well. Obviously this was not science, but it worked for most racers only because most racers use a higher rated octane than they actually need.

In the mid to late 1990's VP graduated to buying there own base product and do there blending of products in a much better fashion. Turbo Blue and Trick have since been bought Sunoco and are blended by Sonoco. Trick was purchased by Phillips 66 and has continued to be blended by Phillips 66.

The only two companies I am aware of who "cracked" there own base product is Sunoco and 76. And as we all know, 76 race fuel is no longer available, leaving only one true manufacturer of Racing Gasoline....Sunoco.

AV Gas has a MOR (motor octane rating) of 96, R+M/2 rating of 100, and ROM (Research Octane Rating) of 106.

AV Gas is lighter than racing gasoline thus more fuel/larger jetting is required. Jetted correctly you should not experience a lean burn at WOT.

I would not use AV Gas as a cleaner. The amount of TEL (2 grams/gallon) and other hydrocarbons makes it extremely carcinogenic. Same goes for all other racing gasolines.

Shelf life is NOT better. The reason pump gas won't last as long is because street gas has extremely lightend hydrocarbons to help your car start and idle. Racing Gasoline does not have these light end hydrocarbons needed for idle and starting, hence the reason race motors start and idle poorly.

Av Gas is NOT designed for low RPM motors. AV Gas is designed to not detonate/preignite causing detination. This would be the same design as race fuel. If you compare the "distillation curve" of AV Gas to Race Gas, you will find they are almost identical. The "distillation curve" controls the speed of burn across the combustion chamber.

You will only "spit" gas out the exhaust pipes if you run to rich or include a supercharger/turbocharger on your engine and "overdrive" the blower. Example would be the bitchin flames you see at the starting line of a drag race on normally aspirated engines and the long flames you see on all "blown" engines.

The LEAD (TEL) added to AV Gas is to increase the octane rating only. All heads these days have harden valve seats. There is no need for lubrication of the valve seats. All engines have come with harden seats since the late 60's.

AV Gas is not formulated for High Altitude. and will have very little, if not any performance differences vs racing gasoline. On the other hand, commercial grade fuels (87, 89, 92) will definitely enhance your performance due to the commercial fuel being oxygenated. The Oxygen enhancers added to commercial fuel is only for California Smog laws.

Advancing timing on your motor will definitely help with AV Gas and Race Gas due to its slow burn characteristics. On the other hand, be careful if your running commercial grade gasoline, more timing can cause detonation/preignition quit quickly.

AV Gas does not go BAD faster. It is extremely consistent. The MOR is only 96, whereas Sunoco Purple or VP C12 is 104. A rating of 96 is good for up to 10:1 on Steel heads and 12:1 on Aluminum heads with water cooling. Air cooled motors run much hotter.

Buying a higher octane for a $20-50K motor is the cheapest insurance available.

Remember this...OCTANE is a measure of a fuels ability to resist detonation/preignition. The higher the Octane number, the slower the fuel burns. Technically speaking 87 Octane fuel will develop more power than 118 Octane fuel. With this said, you should see gains in throttle response and HP by mixing commercial fuel and AV Gas/Race Gas. You now have some light end Hydrocarbons for throttle response and heavy hydrocarbons/TEL for detonation resistance.

Bottom line... use the most consistent fuel you can find and create horsepower by moving as much air as possible though the combustion chamber.

I have no reason to be bias here as I have moved on to much greener pastures. See you on the race course.

Good Luck,
Steve Poole

 

[NVJAY775]

That was a good read for me. Especially from someone with that much knowledge. Thanks for posting it up!

 

[Half flip95]

91 / AV100
50 / 50 mix

 

[OCD Solutions]

AV Gas has a MOR (motor octane rating) of 96, R+M/2 rating of 100, and ROM (Research Octane Rating) of 106.

I stumbled across that post in a forum thread while looking for the actual MOR rating of AVGAS. Most guys think it is a true 100 Octane and are not aware that aviation uses a different rating system. I was going to make the argument that AV is great for boosting the rating of regular gas (87 octane) but, less effective when mixing with Premium (91) but at a MOR of 96 Octane, it's still good to boost you a couple octane points ove rpremium pump gas.

I used to get it free by the 55 gallon drum and ran it in my sleds and watercraft. It worked out good for me because I could keep large quantities of regular on my property for the majority of my equipment and then just mix in a little AV for the few toys that required the higher octane.

I wasn't running anything with really high compression anyways and was mixing 4:1 with regular for my Superjet and snowmobiles.

 

[naticen]

Isn't R+M/2 the same way pump gas is rated? It says that right on some pumps. Also if you do the math, it equals 101. Unless I am missing something it sounds better than 100 octane

 

[OCD Solutions]

I think you are correct and google agrees. MattE did a good writeup a couple years ago that blew away all that I had previously thought I knew about octane ratings and the value of AVGAS. I seem to have a few of the details mixed up in my head so I may have to go back and dig it up and get myself square again.

 

[TheBuzzard]

i dont agree with some of that and some is just wrong. there wasnt unleaded gas back in the late 60s and valve seats werent hardened yet either. lead in the gas is the cusion for the valve face slamming on the seat. thats why you need hardened seats using unleaded gas. my 69 firebird was designed to run on ethyl 104 octane and thats what came out of the pumps in 69. in the very early 80s, i used to buy AV gas at the airport. the red was 110 and the blue 100. you cant get red anymore. i used to crank the distributor until my 400 pinged and then back the timing off a hair. no way in hell are you getting more power out of lower octane gas. running AV gas, i could get 4th gear scratch and lucky to spin the wheels in 3rd with pump gas. dumping a little bit of AV gas in garbage gas does basically nothing but waste good AV gas.

 

[Philip Clemmons]

I dont agree with all of it either, but its mostly correct and a great read.
Adding octane can actually cause a power loss.

Race fuel does not necessarily burn slower either......it's harder to ignite.
Octane is not the magic ingredient......the combination is. Matching the octane to the needs of the engine is where it's at.

 

[Half flip95]

dumping a little bit of AV gas in garbage gas does basically nothing but waste good AV gas.

50/50 mix no good for raising octane rating?

 

[speedysprocket]

And isn't it the increase in ethanol in pump gas that has caused a decrease in shelf life for it?...

 

[Draggingto]

Where do you even get this stuff from, I used to hear old rednecks talk about it all the time and just laugh. I can get and usually have race gas all the time for my cars and stuff. Sunoco or VP. Wouldnt even know where to look for AVgas. Is it cheaper than dedicated race gas or something?

 

[N3vrSat1sfied]

local airport for small private planes by me will sell it to the public.

 

[Draggingto]

How much is it a gallon usually? I just like to know what im getting and i trust VP, sunoco, torco ect. If i can trust to run it in my car then its good enough for my ski and the thing is I WOULD NOT run AVgas in my cars.

 

[SUPERJET-113]

I have Avgas at the pump just a 1/4 mile away, but they want like $6 a gal. for it. A few more miles away Sunoco 110 at the pump for $7.50-$8 a gallon. I love the Sunoco 110.

Like said, matching your engine parameters to your fuel is where its at. When I used to race all the noobs with their stock ski engines thought race fuel would make them go faster, when actually they could make more power with pump 87-91...haha Talk about wasting $$$.

 

[OCD Solutions]

I gave away 7 55 gallon drums of 100LL when I sold my property and moved to the US. I got it free from a bulk plant that handled all the fueling stations at all the remote landing strips in our area. Not too many planes use AV anymore but they still had to stock it. They rotate it out on a schedule to keep it fresh so it was nothing to get 4-5 partial barrels a season and every once in awhile, a full one still sealed.

 

[Quinc]

we have a parts house here that sells 110 leaded for 12.99$ a gallon and 100 unleaded for 13.99 at the pump... :-/

 

[Draggingto]

Wow, thats expensive. I can usually get 110 for around $6.50-7.50 a gallon. I run VP C16 in one of the cars and that stuff is expensive at $85 for a 5 gallon pail.

 

[TheBuzzard]

if you aint in california then you dont know what its like to get gouged on about everything you buy including fuel. i think its $85 for a 5 gallon can of sonoco 110. luckily i get my AV gas for about 5$ a gallon. 91 at the pump is a couple cents away from $4 right now. i wont buy and mix $4 a gallon gas when i can run straight $5 AV gas. detonation and heat build up isnt really a factor if you just blip the throttle. holding it wide open for extended racing periods is a totally different situation and requires top fuels.

 

[simofx-1]

new zealand = US $8.50 1gallon of 89

 

[kevbo]

50/50 mix no good for raising octane rating?

The TEL in avgas will raise octane faster at lower mix ratios.