Post by: fabbo on August 05, 2012, 02:14:53 PM
does any one out there in twostroke world know anything as to what avgas does to an engine. Is it safe what is the best ratio of fuel to avgas does it work better with synthetic oil or not. What about its effect on plugs. Any info would be helpful
Post by: riffraff on August 05, 2012, 02:55:42 PM
Post by: coblefutch on August 05, 2012, 09:31:51 PM
Post by: TotalNZ on August 06, 2012, 07:57:45 AM
The high octane rating is all good but apparently it falls short in a few other areas.
Post by: Blop on August 06, 2012, 10:29:38 AM
Colours youre piston with lead, aah the lubrication
Post by: 2T Institute on August 06, 2012, 12:26:12 PM
Be aware though that avgas is exactly that, formulated for use at altitude.
The high octane rating is all good but apparently it falls short in a few other areas.
Exactly.Avgas is made to stop planes falling out of the sky, not to make HP. You make more HP with unleaded fuels when you set up for them. avgas and ULP require different set ups which is why I can never understand the 'half pregnant' 50/50 mixes.
Post by: riffraff on August 06, 2012, 03:00:55 PM
Be aware though that avgas is exactly that, formulated for use at altitude.
The high octane rating is all good but apparently it falls short in a few other areas.
Avgas is formulated to prevent vapor lock at altitude and to provide lubrication for the engine, it works just fine at low altitudes. I ride at 5000 ft, a lot of planes fly below that.
Post by: factoryX on August 06, 2012, 03:29:49 PM
Post by: 2T Institute on August 06, 2012, 11:04:20 PM
Post by: 2STROKEREVOLUTION on August 07, 2012, 05:59:21 AM
Post by: TotalNZ on August 07, 2012, 06:38:01 AM
Yes thats right, and to prevent vapor lock at altitude the volatility of avgas is lower than ideal for performance applications.Be aware though that avgas is exactly that, formulated for use at altitude.
The high octane rating is all good but apparently it falls short in a few other areas.
Avgas is formulated to prevent vapor lock at altitude and to provide lubrication for the engine, it works just fine at low altitudes. I ride at 5000 ft, a lot of planes fly below that.
Post by: riffraff on August 07, 2012, 06:50:05 AM
Yes thats right, and to prevent vapor lock at altitude the volatility of avgas is lower than ideal for performance applications.Be aware though that avgas is exactly that, formulated for use at altitude.
The high octane rating is all good but apparently it falls short in a few other areas.
Avgas is formulated to prevent vapor lock at altitude and to provide lubrication for the engine, it works just fine at low altitudes. I ride at 5000 ft, a lot of planes fly below that.
that's true about any high octane fuel, the higher the octane the slower the burn rate, Not to mention I don't run it for performance, I run it because it's free
Funny topic. A lot of private pilots convert their light aircraft to run on pump fuel because it is much cheaper. Avgas was created because of the inconsistent quality of pump fuel. Now, pump fuel is right up there (if you get the right brands). If it is higher octane, then you can make more power with higher compression. Unless you change your compression ratio to suit it, you won't see any gains. Well, maybe slight gains as lead contains more energy than alcohol.
Not that many planes can run pump gas, only low compression engines designed for 80/87 octane fuel and none of them can use fuel with ethanol in it.
Post by: TotalNZ on August 07, 2012, 09:16:18 AM
Yep free's good, i'd prob run it if it was free too. Do you get 98pulp where you are, i've been using that seems to work pretty well.Yes thats right, and to prevent vapor lock at altitude the volatility of avgas is lower than ideal for performance applications.Be aware though that avgas is exactly that, formulated for use at altitude.
The high octane rating is all good but apparently it falls short in a few other areas.
Avgas is formulated to prevent vapor lock at altitude and to provide lubrication for the engine, it works just fine at low altitudes. I ride at 5000 ft, a lot of planes fly below that.
that's true about any high octane fuel, the higher the octane the slower the burn rate, Not to mention I don't run it for performance, I run it because it's freeFunny topic. A lot of private pilots convert their light aircraft to run on pump fuel because it is much cheaper. Avgas was created because of the inconsistent quality of pump fuel. Now, pump fuel is right up there (if you get the right brands). If it is higher octane, then you can make more power with higher compression. Unless you change your compression ratio to suit it, you won't see any gains. Well, maybe slight gains as lead contains more energy than alcohol.
Not that many planes can run pump gas, only low compression engines designed for 80/87 octane fuel and none of them can use fuel with ethanol in it.
Post by: TotalNZ on August 07, 2012, 09:19:15 AM
From my understanding people run the 50/50 mixes to get the higher volatility of pulp and the higher octane of av.Be aware though that avgas is exactly that, formulated for use at altitude.
The high octane rating is all good but apparently it falls short in a few other areas.
Exactly.Avgas is made to stop planes falling out of the sky, not to make HP. You make more HP with unleaded fuels when you set up for them. avgas and ULP require different set ups which is why I can never understand the 'half pregnant' 50/50 mixes.
What do you think of BP's 98unleaded? seems to work pretty well for me, just ran a tank through with my reset squish and all the readings are good.
Post by: TMKIWI on August 07, 2012, 09:47:07 AM
Since changeing to avgas and richening to suit the bike runs great.
I have thought of having the head modified to suit pump gas but with the price difference between the 2 types I havn't bothered.
From what I have read TM changed the shape of the head on later models ( 09 < ?) to run better on pump.
Post by: 2T Institute on August 08, 2012, 12:34:48 AM
From my understanding people run the 50/50 mixes to get the higher volatility of pulp and the higher octane of av.Be aware though that avgas is exactly that, formulated for use at altitude.
The high octane rating is all good but apparently it falls short in a few other areas.
Exactly.Avgas is made to stop planes falling out of the sky, not to make HP. You make more HP with unleaded fuels when you set up for them. avgas and ULP require different set ups which is why I can never understand the 'half pregnant' 50/50 mixes.
What do you think of BP's 98unleaded? seems to work pretty well for me, just ran a tank through with my reset squish and all the readings are good.
Some quick maths 98+100/2=99 so no net gain there. The fuels require different set ups and with a 50/50 mix you can run either ideal set up for avgas or unleaded.
Tuning for the fuel is the trick. BP is pretty good used it for many years, though we have a better ULP now.
Post by: HCE on August 08, 2012, 04:18:48 AM
Best thing to do is try it and see.