Will Avgas make my motorbike go faster?

[ToryBoy]

The question is in the title.

Well, will it?

[STC]

Faster? There are far too many variables to determine if your bike will go 'faster' but I can tell you that AVGas is not appropriate for use in most engines used in motorcycles and cars. Even the LL (Low Lead) stuff will leave extremely damaging deposits in critical fine clearance parts that will lead to early wear.

Beyond that, the octane rating may be a little higher than your engine is used to but octane isn't a measure of power its a measure of combustibility. Higher octane fuels combust at higher pressures and temperatures but don't neccessarily contain more energy.

[mono]

It has a higher octane rating (100 as opposed to 98 or 95) so I suppose it should. Your engine timing will have to be adjusted to fully realise any performance gains (and prevent detonation) but that should be it.

However the LL designation (low lead) is a bit of a misnomer as it has much higher lead than forecourt fuels. I am not too sure of the implications of running a high performance engine on such high leaded fuels but would imagine that plugs and ports would foul up more rapidly for a start.

Let us know how you get on!

[AVGASANDY]

Hi ive run a few cars on avgas but never noticed any difference.
Ive got a couple of rally teams buy it for thier cars but there driving old RS Escort 2000.
Iff i was you just upgrade airfilter,cans and rejet if carb.
all the best
avgasandy

[Blacksheep]

How interesting. The oil companies are trying to stamp out Avgas as its no longer economical (i.e. its unprofitable). The airworthiness authorities are approving more and more aero engines to run on Mogas to keep light aviation in the air when supplies of Avgas run out. Now we have people who want to run their motorcycles on it.

When the military still had piston engined aircraft they put dye in the Avgas to identify it. The idea was to stop us knicking it for our motorbikes, or at least to help catch us when we did. I don't recall Avgas doing too much harm to the engines back then. The bikes were usually Beezers and Triumphs though, with the comparatively unsophisticated engines of that era. Something like Redsnail's Junior might not like it.

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Through difficulties to the cinema

[MASI]

o.k fancy answers aside ill tell you it will....BUT.

i ran AVGAS in a kx125 and it was faster of the line and the throttle was definetly mory "snappy"

BUT.......after a short ride ( hard ride) the engine got to hot.....to dry and blew up.....


not worth the hassle......

[Steve513]

Like someone else said, it isn't going to do a thing for you unless you increase the timing properly. Even then you run the risk of fouling plugs, etc. That engine wasn't designed for 100LL. The notio that higher octane fuels simply produce more power is absolutely false. If it does add more power, then you likely had a detonation problem running on lower octane fuels.

[sump oil]

Avgas in itself wont give you any extra power, what it will let you do is run higher compression and or increase your ignition timming without detonation, thus giving more power.

As for negative effects to the engine the main thing to consider is you cat converter, this it will stuff, if you have an O2 sensor in the exhaust you will also coat this in lead, giving your computer the wrong information, but as for the the engine itself you should have no problems what so ever, the increased lead will only help in lubricating your valves etc, (I take it, its a four stroke) but over time and running a lot of it, it may lead to some increased deposits on your pistons, leading to possible hotspots etc, but I would`nt worry to much about it.

When I was working for a certain organisation I managed to acuire enough of this stuff, both avgas and LL, to run almost exclusivley on it for free for about 5 years, and in that time there were no problems what so ever, I even ended up getting the computer and ignition advance curve sorted out on a dyno to make the most of it, I was running better than 10:1 compession at the time. The only problem was when you have to run on the normal old boring stuff that we have to pay for, it use to rattle its head off.

[Ludwig]

Short thread hijack here, can I run my diesel car on avtur?:cool:

[Kanga767]

Diesel engines will run on Avtur, but the lubricity of Avtur is not as good as Diesel, therefore it will wear out the injector pump quicker.

Adding automotive engine oil can solve this problem but leads to a messy exhaust and rear of your car.

Some Diesel engines have injector pumps that have hardened steel pumping elements to take Avtur, I've only seen these in stationary GSE on the airfield since I've worked in Aviation.

In my past life as a diesel mechanic, I never came across them. I can remember repairing lots of diesel cars from the local RAAF base.......

K

[SirPeterHardingsLovechild]

Now I'm interested!

How about 50:50 diesel - avtur mix?

Also, I have vague memories of a lubricity additive that we used to put in the Nimrods

[Hand Shandy]

My diesels` so noisy and sluggish avtur does`nt make bit of difference. i`ve always cut it 50/50 others reckon on a litre of oil per 25 litres , i mean water drain checks must be carried out so i must be doing an ecological favour right.

[Blacksheep]

You're paying for all this Avgas and Avtur now aren't you chaps?

We wouldn't want to be encouraging anything illegal on this forum... :hmm:

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Through difficulties to the cinema

[SirPeterHardingsLovechild]

If it pleases yer Honour...

Nowadays we're not allowed to burn our waste fuel, so therefore I would be saving 'er majesty's taxpayer some money. You should be paying me to take it away.

As long as I took it from the waste fuel compound/trolley

[chuks]

I have an engineer friend who runs a couple of diesel Mercedes-Benz automobiles on Jet A with no probs.

The Merc uses a separate lube oil supply to the injection pump, I am told, so that it tolerates Jet A in place of diesel.

Otherwise, for a VW diesel, say, one should add 1 quart of oil per 200 litres of Jet A, according to something I read somewhere. That keeps the pump from wearing out.

I know in Nigeria we often run our diesel vehicles on Jet A when we cannot get diesel fuel. So far, so good!

[andyb79]

apparantly adding a quart of hydraulic fluid to 50? gallons of avgas does the job, but the lead will still destroy your cat so its only for older cars!

[Kanga767]

Some injector pumps do have their own oil lube supply, but it does not lubricate the actual pumping element(s). The pumping element(s) rely soly on the fuel for lubrication.

Diesel injection systems run up to 4500 PSI, and the working parts are machined to tolerances similar to Jet engine fuel system components.

But if you can't get diesel, you're not gonna to too much harm in the short term.

Just don't put avgas in your diesel car :p


K

[epic]

I've raced a couple of motocross bikes on Avgas and must say I felt the difference only on the high performance motors.
I raced a Honda XR400 with a HRC kit (high comp piston etc) and noticed the difference big time....
Longevity of the engine did not seem to be a problem, although I was told that Avgas was 'drier'. I added a small amount of 2 stroke oil in with the fuel. In hindsight I think that was crap!!
I never fouled a plug, never changed the rings, never broke anything and that engine ran hard on the rev limiter for 3 hour races in the dust and the mud!!!!
That XR would keep up with the 250cc 2 stoke motocrossers in a straight line most of the time....

I have also had a lot of experience 'borrowing' unused Avtur and puting it to good use in my Landcruisers . I first used it in a BJ42 series with a 4cyl diesel and it stuffed the engine I think. The problem is that the Avtur can 'wash' the oil off the cylinder walls and can over a long period of time wear out the piston rings. If the engine has any wear whatsover the Avtur seems to get into the engine oil. You MUST change your oil more regularly. As for destroying fuel pumps, I think that a rotary type fuel injector pump will handle Avtur OK. So I'm told. Remember that Avtur is for use in gas turbine engines only. I now use it sparingly mixed with diesel and I do say sparingly. I now own a HJ80 series non turbo. My friend runs it straight with 2 stroke mixed on his turbo landcruiser. I think he is a tight ass and will ultimately pay the price!!!!
:ok:

[xelophab]

Well I have run my car on AVGAS and it did seem to have a bit more oomf. It did, however, run very hot. Solution :- one quart of upper cylinder lube in you petrol tank to one tank of fuel or thereabouts and it seemed ok.

I had to use avgas as there was no other fuel available...for 500km or more, for months at a time. So I just drove slowly and the temps stayed down.

[boeingbus2002]

What about these new high performance fuels?
Shell Optimax and BPs Ultimax? They have a higher octane too, but usually high octane fuels are for High performance Turbo cars, yet these fuels claim they are for all Unleaded vehicles.
Any long term damage from this?

[bobster]

My Turbo Astra loves Optimax and all the other similar types but goes a bit dead on low octane unleaded, have been told standard cars on optimax are just wasting money is this a fair statement?

[ShyTorque]

Modern fuel injected engines have knock sensors (actually Piezo-electric devices) in the cylinder head. These devices "listen" to the internal noise and retard the ignition if knocking through detonation (i.e. pinking) is detected.

The standard setting for the ignition timing advance might result in pinking if low octane fuel is used (depending on the ECU mapping / programme). Using a better quality fuel does make a difference in this case, advanced ignition generally provides more power and better response.

My 6 cylinder BMW and my Honda 750 both seem to prefer Shell Optimax or the new BP Ultimate. The difference is most obvious when changing back to boring old unleaded 95.

Many UK amateur racers use a mix of super unleaded and AVGAS, BTW. As far as I recall, present day AVGAS is something like the equivalent of 109 octane in motoring terms.

It contains a LOT of lead by motoring standards, as someone has already said, despite the suffix "LL". It's Low Lead only in terms of what it USED to contain.

To answer the original question, it might make your bike go faster if you can advance the ignition timing, skim the head, or both. It will actually be the mods that make the better performance, the higher octane fuel just allows you to mod the engine without it suffering from pinking.