Outer Limits 4x4 Board

Anyone know what the implications/requirements are to run AVGAS in a standard petrol motor (I have 1.6 16V EFI zook)

I know its now illegal to run on the street and if caught I believe fines up to $15,000 are payable. No mechanical changes have to be made to run avgas but to make the most of it the engine needs to be tuned accordingly. This is where a aftermarket computer with two maps helps. 1 or comps with avgas and 1 for the streets running normal ulp. I think the main advantage of avgas is that it has a high octane rating allowing your motor to rev higher without pinging. On a standard motor though this may not be so useful.

why would you want to run avgas in a low compression engine , you will not gain any more horsepower !
Avgas is needed or other high octane fuel where the engine is running high compression 10.5:1 + to stop the engine detonating. the extra power is gained through the higher compression Not the Avgas.
But then theres METHANOL you will make more horse power with that stuff but thats another story!

the lead in it would foul up your exhaust oxygen sensor.

you would also loos power because the burn rate of avgas is alot slower then that of PULP and simply adjusting the timming would not be enough.

when your running 11:1 compression or a 30 PSI plus turbo setup it would be of some use to you. but only if you have a computer that will run with out an oxy sensor

Thanks for the replies guys, was interested because I can get some AVGAS foc. but may need to rethink the benefit...

All thats been stated about Avgas is quite true but Avgas obviously is designed for Areoplane's with piston engine's. Because planes fly at high altitudes where the is less oxygen in the air and lower atmospheric pressure, piston engines need to have higher compression ratio so as to get good combustion. At high altitude a plane engine will run fine with normal automotive petrol. When taking off planes use max power and are usaully close to sea level the high compression ratio engine needs a high octane fuel to prevent detonation. I built up a 12.5:1 high comp Small Block Chev with the intension of running it on Avgas. The more i looked into it, it was recomended not to use Avgas as it was designed to be used for relitively slow reving plane engines and is too slow burning for a fast reving racing engine. I ended up using VP C12 Racing Fuel ( real 108 octane ) which gave excellant results and detonation protection. That my piece to add from my experiance.

Wally

stuee wrote:I know its now illegal to run on the street and if caught I believe fines up to $15,000 are payable..

Isnt it sold in NT as petrol to stop the sniffers?

How could it be illegal?

bogged wrote:

stuee wrote:I know its now illegal to run on the street and if caught I believe fines up to $15,000 are payable..

Isnt it sold in NT as petrol to stop the sniffers?

How could it be illegal?

Contraviens ADRs for the said vehicle.

Dozoor wrote:Contraviens ADRs for the said vehicle.

so how to petrol stations selll it?

We used to mix it 50/50 and ran it in just about everything. We got LOTS of it "cheap" when i was an aircraft refueler in the Army. Didn't hear of any major problems, but we ran it for the cost not the perfomance.

bogged wrote:

Dozoor wrote:Contraviens ADRs for the said vehicle.

so how to petrol stations selll it?

By the litre i think

80 ute said[All thats been stated about Avgas is quite true but Avgas obviously is designed for Areoplane's with piston engine's. Because planes fly at high altitudes where the is less oxygen in the air and lower atmospheric pressure, piston engines need to have higher compression ratio so as to get good combustion. At high altitude a plane engine will run fine with normal automotive petrol. When taking off planes use max power and are usaully close to sea level the high compression ratio engine needs a high octane fuel to prevent detonation. I built up a 12.5:1 high comp Small Block Chev with the intension of running it on Avgas. The more i looked into it, it was recomended not to use Avgas as it was designed to be used for relitively slow reving plane engines and is too slow burning for a fast reving racing engine. I ended up using VP C12 Racing Fuel ( real 108 octane ) which gave excellant results and detonation protection. That my piece to add from my experiance.
]


80 ute did you ever try avgas in your engine? i've used av, bp 100,& the VP fuels on the strip difference between them was nothing avgas was by far the cheapest & easiest to get .the slow burning =slow reving is plain wrong!
one of the slowest burning fuels is methanol which will increase hp partly due to its calorific value(more energy p/litre) partly due to its slow burn rate .
during the combustion cycle in stead of a big bang on the top of the piston like normal fuel & its all over, methanol ignites & continues to burn pushing the piston further through the power stroke, giving you engine more torque hence more horsepower.[/quote]

360 scout: do you still run that small block? where did you buy the racing fuel from? as far as I know, you need a notebook to record any purchase of racing fuel if I am not wrong..

You don't need AVgas to rev. We used to race 2 strokes regularly up to 17000rpm+ using pump premium (Optimax) with out drama, others up to 20,000rpm. The AVgas will probably run more compression though. As already said, planes dont do a lot of revs, but need the quality fuel so they dont drop. The planes also set mixtures based on EGT, which I assume the AVgas helps with also.

revs dont have anything to do with it, its the amount of compression being run as already been stated..

Ah, yes.

robbie,
yeh still have the small block, having choppers on the place to muster cattle & shoot pigs helps they always leave a bit in the bottom of the drum when their finished!!!
buy the way you can't run ANY leaded fuel at ANDRA meets anymore as they do a SG check on your fuel.

so what fuel are people using at ANDRA meets? where to buy without the log book?

fuel at Andra meets,
you can buy high octane unleaded fuels from VP, I think the touring cars use one of them.
or we are going back to methanol don't need a log book up here it's only about $1/ 1.50 a litre (you burn twice as much of it ) & it's legal on the street!!

Dozoor wrote:By the litre i think

smartarse

360 scout wrote:fuel at Andra meets,
you can buy high octane unleaded fuels from VP, I think the touring cars use one of them.
or we are going back to methanol don't need a log book up here it's only about $1/ 1.50 a litre (you burn twice as much of it ) & it's legal on the street!!

Here ya are Robbie
http://www.automatictransmission.com.au/methanol/

Buy from Rodney in bulk!

bogged wrote:

Dozoor wrote:By the litre i think

smartarse

Hehe


Apart from all the whoharr ,

These days its not a noticable difference in performance.


Just for a bit of history , It was a great thing back in the seventys

if i remember was a rule of thumb starting at super , for av or bp100

an increase in main jet size around 10% would get you started when setting up ,
For methenol 60 % increase in mains gets close ,
Probs with meth is insuring the carb and lines could flow an extra 60%
To get it to the jets,
You can,t leave any mineral fuel /oil residue in the lines carb or tank when changing over to meth either , Or you,ll end up with jelly in the carb .

All this is just old shid now , today with efi and det sensors multiple timing curves and stuff
You can get away with low oc and resonable compression

As before you needed high octane to run 10 1/2 plus or you'd just have fragment under the bonnet


Larry

I've run AVGAS in a TB42 before with no real differences in power or economy.

bogged wrote:

stuee wrote:I know its now illegal to run on the street and if caught I believe fines up to $15,000 are payable..

Isnt it sold in NT as petrol to stop the sniffers?

How could it be illegal?

http://www.deh.gov.au/atmosphere/cleane ... ports.html

This covers it a bit. I'm still trying to find something more concise and directly related to this topic. I originally found this out from a Street Machine magazine.

MQ080 wrote:I've run AVGAS in a TB42 before with no real differences in power or economy.

Is it EFI / Carby, does it even have a knock sensor ?

It needs to be tuned to take advantage of the extra octane, and I doubt the standard maps even if it is EFI would be tuned for >92 RON octane.

The only "easy" way for you to have tested it's effectiveness would have been to wind up the ignition timing, but even then it wouldn't have been perfect.