Avgas

[Matt G]

Hi guys,
Does anyone run an Avgas mix with their regular fuel?
I spoke to a performance shop yesterday who mentioned that I should give some Avgas blue a go. He recommended about 10L into a tank. His comments were that it would help with slight run-on when hot, hot starting due to vaporisation, it smells awesome, and it will burn much cleaner which is clearly visible via the colour of your exhausts, and he repeated a few times that "the old girls love it". (Referencing cars - not our darling wives.....).
Any tips on trying it, or mix ratios, and/or places to buy it?
Cheers

[bootlegger]

I get my avgas from the airport but its illegal to be sold over the counter unless you have a racing licence or fly a plane.
The fine is $1000 per cylinder if the coppers work it out (they have noses too). Having said all the ive run it straight in my vette and it makes a world of difference.  Higheroctane and lead are your friend.

[Matt G]

Thanks bootlegger. Solid information. I was wondering why there were a fair few readers and no replies.  At $1000 per cylinder, it might explain the hesitancy to comment.... Trying it could be an expensive experience.  That being said, I might check into the race licence, or speak to a couple of buddies that have plane.
Thanks again.
Cheers

[MADVET]

Many years ago I use to run a hi compression bigblock on avgas and would drive to my local airport and have the car filled up directly from the tanker. The guy would hook up one earth cable to my car and drop the other on the ground. This has long been banned and they won't even fill up drums for you either. You can however still purchase it from a Shell depot, it is labelled as "Racing fuel 100". As pointed out by bootlegger you need to produce your racing licence as well as sign some paperwork stating that it's not being used on a public street.
The problem is that this fuel contains lead, even the one marked as low lead so its illegal for street use.
Nowadays since the advent of unleaded high octane pump fuels such as 98 or 100 it really isn't worth the extra cost and trouble.
If need be you can always tip a bottle of octane boost in to unleaded 98 and this would easily handle any of your hi compression or hi boost needs.
The hot ticket nowadays however is to run E85 with dyno shops verifying significant gains running this fuel especially in turbo or superchargrd applications. The only problem with running this fuel is that you need to have a fuel system that can handle a higher volume of fuel as well as the corrosive effect of the fuel.

[Matt G]

Hmmm, sounds like I should try the octane boost additive first. I'm not sure about the E85, although I've got a fuel rod and a Barry Grant carbi fitted,  so it might be okay - per your recommendations - however I'll have to look into fitting a supercharger to make it work better.  Sounds like a plan.... add a supercharger so that I can run E85. I love it.  I've had my eye on a particular pro-charger unit for a couple of years.  Now I just have to convince my wife....

[bfit]

I remember when benzene  was available on pump at the servo I think it was BP in  Figtree  where we would fill up
 
but the problem with av gas and the like, if your going to get serious about it
you need to work out just how you want your engine to run.
what your going to do with it
Road  track or both.

lean is a problem with Av-gas,
  ignition has to be reduced if your going to run on the lean end of the scale
and valving etc can take an hammering
So what is need is a compromise  between  mid range to rich
the carby will been re jetting  and tuning and  the ignition system will need to be set up  correctly
to get the correct advantage curve in the  distributor.
and one has to drive  to suit the  conditions. no  flooring it and hanging on, it wont work.

 its is not so straight  forward  swapping fuels

I dont see a  real problem to run 10.5/1 or even 11/1 compression ratio on 98  and stile run  22 to 24 degs static advance and  36 degrees total advance.
unless your chasing a few extra HP 98 will do the job
  just don't  give it a big boot full under 3000 RPM in most engines and you wont  lean out and get  pre ignition( Pinging )

  There's so many other influences to consider as well, out side what I have briefly  mentioned
Bfit
 

[Matt G]

Thanks Bfit. A wealth of knowledge as usual. Thank you.  Maybe I should find a good dyno guy and get what I've got running to its best before I try adding some boosters or new fuel.  I can't remember the octane ratings that I used in the USA?  My engine runs smoother now than it every did in the states, however I'm definitely running rich on 98 and my current (unchanged) carbi settings, so I'm now thinking that they must run higher octane which would lean it closer to even based on the above?

[gtc]

Maybe I should find a good dyno guy and get what I've got running to its best before I try adding some boosters or new fuel. 

Reckon that's your best move at this stage. A good tune-up ought to make a big difference.

Club advertiser Ross Carulli at Ace Carburettors & EFI Services, Blacktown, has sorted out a number of members' carbies.

[rosco]

I was running 91 in the states but on a RON its a 95 out here, most of the states thats all you can get, some places do hold the 93 but that,s with ethanol which is 98 out here.
I have been reading the thread and to be honest Matt to even think of Av Gas these days is a dream, why would you ever think of it unless you are running for pink slips and want the total out of the car it was something we did in the 80s same as we mixed Benzine in with the fuel, I think I even have my old beakers and fuel weights if you want to try it.But be prepared re graph dizz cooler plugs ext ext.
Have it set correctly on a good tune its really not that hard if you have all your specs of you compression and cam spec,s but if its out of your hands send it to Easy 10,s at St Marys he will get it going like a scolded cat.

Ross

[rosco]

if you are looking for the extra now and then just get a 150 shot nitro,s system.

Ross

[mention1]

Aircraft have to be weighed periodically, I think its like every 3 years. The engineers have to take all the avgas out to get what's called an Empty Aircraft Weight. The wheels are rolled onto 3 electronically connected scales.
Anyway the point is that the fuel that is removed cannot be ever used in an aircraft again legally, so it normally sits in a 44 gal drum. There are at least a dozen aircraft maintenance facilities at Bankstown/ Camden.
 Just sayin'

[bootlegger]

I used to buy some of that waste fuel from bankstown yearz ago. I think it was less than half the price. He wont sell anything now. Bankstown is really regulated now.