I find that statements like these are made by people who do not know squat about aviation. Normally aspirated aircraft engines only make max power while on the ground under standard atmospheric conditions. Even turbo charged aviation engines have a few minutes cap on making max power and it is generally used only during the take off run on the ground and right about lift off. I think mixing the avgas with auto gas in the practical way to handle this.
My 68 GS400 (93,000 mile un-rebuilt, original motor) loves a 50/50 mixture of LL100 and 93 pump gas. It starts much easier and runs better. I can start it up cold and immediately put it in gear and back out of the garage without it stalling. With straight 93 it will stall 2-3 times before I get it out of the garage.
There is so much 60 year-old horse poop about "octane" and anti-knock additives when it comes to gasoline, it is crazy. Crazy! Here's the deal. Pay no attention to marketers of additives. Try it if you're willing. Just look at the online reviews of http://race-gas.com/ from people who have onboard diagnostics. Know that reformulating your pump fuel is a crapshot, (rolling the dice and hoping it's good) but you don't even know what your pump gasoline has in it to begin with, right? That's actually a big deal, especially if there's ethanol involved. Toluene and xylene are big hitters, but YOU CAN'T PURCHASE those. Hardware store stuff is crap. Next, you might just be slowing yourself down. If you're chasing the best elapsed time at the track and using additives without a clue about the gasoline in your tank to begin with, it could hurt. Last, don't worry about AV fuel. If you can get it, get it. Devon
Aircraft engines don't need top cylinder lubrication? Most are air-cooled and run a hell of a lot hotter then our liquid-cooled automobile engines. As I recall, the maximum operating temperature of my Lycoming O-360 was about 425 degrees F.
So the conclusions of this thread are stay away from from store bought octane boosters. Race gas or Av gas are the most economical and effective way to boost octane. Oh, and RL is not an authority on Aviation
Another statement I like is "avgas is too dry." Yes, avgas is shipped separately by truck to control the lead contamination of other nonleaded fuels and to control moisture content. But, the reason you cannot tolerate any water content in avgas is you often fly at altitudes where the outside temperature is cold enough to freeze any water mixed in with the avgas. When that happens, the engine stops and the propellers stop turning. It is a long way down, especially at night and in bad weather. The other dilly statement I see is "avgas is made for high altitudes." I know it is hard for some to accept, but we run aircraft engines from the ground all the way up to cruising altitudes and all the way back down to the ground.
And, what if your airport is at 7000 ft. elevation? Does the avgas know to compensate for ground level? (I hope my sarcasm comes through, because I'm laying it on pretty heavy)......
That's what its looking like Larry. The only alternative looks to be corn(E-85) if someone wants to run high squeeze on the street, until the aftermarket makes direct injection available for the older engines anyway. Derek
I am going to have to check to see if the original Type Wash (Toluene) is still available. This is what the printers have used for years. I know 1 place I might be able to get it, will have to check.
Found it. www.graphicartssupply.com Look for Varn Type Wash it has the Toluene in it and it is 155$ for 5 gal the stuff aint cheap. VP race gas is 12$ per gal So that show is over on that one. Race gas is still cheaper in the end and it can be found for 7.99$ a gal. 110 You build your car take it to the track, take a 5 gal can with you and fill it up along with your car. Take your truck with your car and get 4 of those 5 gal gas cans from Summit and you are good to go for a while. While you are there you can run it down the track. Except those 350 guys they are too scared to go to the track lol. They are still typing. HA
If you want to mix your own I posted who has the "100% industrial virgin grade" toluene that is probably the most un-cut I would think you can get the stuff as. A quick search through their website and it looks like any Sherwin Williams store is a distributor of their products(CMA products). I'll have to give S/W a call to see what they charge for the stuff locally. Going to ask about the xylene as well to see which one is less. If it is somewhat economical I may consider trying one of those recipes! Derek
Honestly, if you're contemplating any of this mad scientist/chemist stuff, go see if the local airport will just sell you avgas and be done with it. If it won't, go for it. I get the attraction and think its cool, but I sure wouldn't be experimenting with it in any of my engines that I know could benefit from it as they have too much time, tuning, and money into them. Especially when its cheaper and guaranteed good to go to run the real stuff....
Maybe I want the option to increase the octane of the AV gas. An 16:1 compression sbb with a mild no overlap cam would make some serious low RPM power! I don't think you can go wrong with the 100% virgin industrial grade mixing the stuff in gas, what could go wrong? Its either going to work or its not. Derek
I did mention that option in post #49. It all depends on availability, cost and convenience, just weighing the options for now. There is also methanol injection route that can be something to look into as well. The aftermarket needs to catch up and offer flex fuel EFI bolt on kits! Not either or, one or the other that's it, no they need to offer an all pump fuel EFI setup like the OEMs have been doing for what is it like at least 10 years now? With an option to even run on propane or better yet, natural gas would be very cool too! Derek
What you really need is the purple 115/145 avgas. I have heard that it is occasionally produced in limited quantities for events such as the unlimited class Reno air races. This was developed for the heavily supercharged propliners of the late 40's and early '50s. Normal production was phased out in the mid 60's. It was 115 octane at lean mixtures on the ground and at low altitudes, but had an antiknock rating of 145 at full power rich for climb and high-altitude cruising. If you have ever watched the 1955-ish Jimmy Stewart film "STRATEGIC AIR COMMAND ",( Quick review: Kinda sappy, but had the best in-flight film ever) the B-36s were burning 115/145.
I live by the Ravenna arsenal and once in a while I see those BIG 4 engine prop jobs fly by and they seem to like to fly close to the ground, like about a Cessna height not far off ground. Not sure what kind of planes they are but they look bad a**. Derek, 16:1 compression, crap those heads won't hold up to that there are not enough bolts for that. you are just off the hook aren't you lol. When I zoomed in on the Varn Type Wash it looked like there was Xylene added to it, and it has Isopropyl Alcohol too. It has all the ingredients you like. LOL At least you think outside the box.
If it's a four-engine airliner it was almost certainly designed for 115/145 (There are a couple of exceptions). Since this fuel is as a practical matter no longer available, these airliners can no longer use full power. There is an upside and a downside to this - the engines operating at lower power settings last longer, but engine and therefore aircraft performance is reduced. The lack of the intended fuel requires lighter loads to achieve reasonable performance. Detonation in an aircraft engine is an absolute no-no. That's why we shut piston aircraft engines down by cutting the fuel, not the ignition.
