kwb

havasucat - I live in San Clemente, so Oceanside is close. Where is the airport? Is it on the base?

Thanks

Mother

I hate to rain on your parade guys, but it just doesnt work like that!

1) The different chemicals/hc's in a gas mixture yield a certain octane working together, its not always linear. In fact its not usually linear. It all depends on what the fuel 'design' was like. You could add equal amounts of 110+90 and end up with 96 or 106 octane just as easily as 100. I believe this is very much the case when TEL[lead] is involved.

2) 'Octane boosters' probably don't do much unless you are adding huge amounts of them. Most of the 'octane boosters' are just really expensive bottles of xylene, toluene, etc...

3) You have to be really sure that the two different gasolines have mixed well, or you might end up with getting a 'slug' of 91 octane fuel into the motor at the wrong moment!

4) Knock sensors will only really work on the exact enginge the sensor/processor has been designed for. Every motor 'sounds' different. Luckily most modifications will just cause 'false knock' and leave you with retarded timing, missing knock would be much more costly. I suppose you could pay someone to determine what your motor 'sounds' like when it knocks, for enough money...


Sorry guys

--Adam

puder

yes i too have heard that you can't justy mix 2 different grade fuels and expect to get an octane in the middle somewhere. As for octane boosters you need alot of those little bottles. and i have hear dthey are good to keep aroudn in case you NEED gas and can't find any of teh good stuff. In yoru case if they recommend 92 and all you can getis 91 throw in a few bottles of booster (for piece of mind) and you should be fine though.

Mother

If you are interested in gasoline/octane info...

The Gasoline FAQ

--Adam

Turbojack

Mother
Thank for the address on the gas faq.

I knew a lot of that information from reading sometime before but helped refresh memory. Now off to get some mothballs.

HavasuCat

KWB,

If you take the 5 south and exit on the 76 east the airport will be on your left about 1-2 miles from the 5. I went there to get gas once when they were open and it was a hassle because they made me put it in cans first. The guy who ran the place told me to come back at night (I believe after 7:00 pm) when they were closed to get gas. They run a flight school out of there so he did not want the students and instructors to see him filling up a boat, even though it is legal because boats are not subject to road tax as cars are. There is a gate that appears to have a keypad operated lock on it but it does not work. He told me just to push the gate open and pull in and fill up with a credit card. The pumps are right next to the gate. I hope this works for you.

RumRunner

Mixing different types, and octane fuels will not give you a happy medium. Although it will help your octane total, there is no way to say how much without having it tested, it may not even mix at all. Because of the different chemicals in fuels the won't always mix together.

mcollinstn

I had heard before that 100LL avgas was not much more octane than 92 unleaded. I think the deal had something to do with the avgas being rated in a manner that shows a higher reflective number than what we have on our auto gas pumps - something like the Research Octane and Pump Octane being rated differently.

Also, a friend with a Beech Bonanza with a flat-6 motor now can use 89 octane unleaded in it. The motor supplier said that the only difference in the motor in its "110LL" configuration and the "89 unleaded" configuration is the material of the exhaust valves, the valve guides, and the exhaust valve seats. The ignition map and the power output are unchanged, as is the compression ratio, etc..

This leads me to be suspicious of the avgas octane system in relation to car gas and race gas ratings.

Any thoughts??

CigProject

Tell your friend to be careful. He will need to watch his altitude and listen for engine changes. The vapor point of avgas is much higher than auto gas. What this simply means is that as altitude increases, the ability of the gas to not vapor lock in the fuel lines is affected. If the aircraft engine is fuel injected and the pump is in the tank, than all should be well. I hope this helps.

bobby daniels

I agree AV-gas is alot different than 91 street fuel the Union 76 rep told me it is made to burn better at altitude where not much oxygen is avaiable to burn and it says LL but it has twice the lead of the old street fuels ( sunoco 260 ) ect.
But his thought were it should do good in the marine enviroment and is rated at 100 MIN. but could be as high as 108 ??

I know alot of people who run the stuff all the time and it works great for them