E-85 fuel

[firko]

While discussing having my Cheney-Yamaha dyno'd, the dyno guy asked what fuel I'd be using. After telling him I'd be using 98 octane he suggest I try the new E-85 'bio-fuel' available from some Caltex stations. http://www.caltex.com.au/latestnews/pages/newsitem.aspx?id=13192. He informed me that he'd had a number of air cooled 2t and 4t classic road race bikes on his dyno and that every single bike showed a marked increase in horsepower and torque after a switch to E-85 from 98 octane and even Avgas.

Has anyone on here had any experience with E-85 and if so, can you pass on your opinions? I'd assumed that an 85% ethanol fuel would require some major jetting changes but the dyno guy said that the jetting changes aren't as drastic a change as one would think.

Lozza?

[Doc]

Firko, there is quite a bit online about E-85 in 2strokes. The bottom topic paragraph on this page is of interest  http://www.klemmvintage.com/gasolines.htm

[firko]

Thanks Doc....Harry's opinion is diametrically opposed to my dyno guy, a bloke who's been tuning race bikes almost as long as Harry Klemm. I'll do some more digging around on the WWW and see what I can find out.
I'm not going to do any weird experiments with fuel this close to the Nats but it might be worth experimenting with later on, especially with my dirt track tackle.

[Mike52]

If E85 has 108,878 BTU,s per imperial gallon and Regular has 150,100 BTU,s per imperial gallon then how the hell do you get more hp from E85 when it contains less energy ?

BTU,s are a measurement of energy.

If an engine is tuned to get heaps of hp out of  E85 then surely you could tune that engine to get MORE out of regular fuel.

I,me off to look at a perpetual energy machine tomorrow maybe that will explain how you get more out of less.

http://en.wikipedia.org/wiki/Fuel_efficiency

[micks]

MA will not allow the use of this fuel it`s got 105 to 108 ron so it can`t be use in competion. know off a bloke who was using it in his road race bike (club level PCRA) admitted he was using it then the fun began.have heard that you have to jet up to use it, was told about 40% but the dyno guy would be best bloke to talk too.there is a bloke up newcastle way (big bang engines) that would know a bit about runnig this fuel and he has a dyno to.     

[firko]

how the hell do you get more hp from E85 when it contains less energy ?

No idea, I'm merely quoting what a respected dyno driver told me. I'm a bit dumb when it comes to chemistry and physics, I guess I was at the beach the day they taught those subjects at school. All I've picked up on in the E85 writings that I can understand is that it's 105-108 octane which surely amounts to something?

[Nathan S]

If E85 has 108,878 BTU,s per imperial gallon and Regular has 150,100 BTU,s per imperial gallon then how the hell do you get more hp from E85 when it contains less energy ?

BTU,s are a measurement of energy.

If an engine is tuned to get heaps of hp out of  E85 then surely you could tune that engine to get MORE out of regular fuel.

Significantly better detonation resistance (not just because it's slower burning, a la AvGas), cooler running and being oxygenated is how you can make more power out of it.

If you just pour it in, you will be disappointed.
If you retune to suit (including optimising compression ratio), there are definitely power gains to be made.

I'd treat it like Methanol, though - drain and flush the tank, carb and motor before storage, etc.

[Mike52]

how the hell do you get more hp from E85 when it contains less energy ?

No idea, I'm merely quoting what a respected dyno driver told me. I'm a bit dumb when it comes to chemistry and physics, I guess I was at the beach the day they taught those subjects at school. All I've picked up on in the E85 writings that I can understand is that it's 105-108 octane which surely amounts to something?

That was not an attack on you Firko , that is the way I look at this question.

Yep higher octane rating means that you can raise the compression ratio but as Nathan says you then have to retune the motor to use the new fuel.

And after all that you are still using a fuel that has LESS energy that the fuel you were using.
Why not just tune your motor for a fuel with the most energy per gallon ?

If you are chasing the max hp then surely you would use the fuel with the max energy.

[Lozza]

Your dyno bloke is correct firko. Tune/fuel flow etc is roughly half way between ULP and methanol. Though you don't need to run e85 to get 90% of the benefits of ethanol.

[Montynut]

If E85 has 108,878 BTU,s per imperial gallon and Regular has 150,100 BTU,s per imperial gallon then how the hell do you get more hp from E85 when it contains less energy ?

BTU,s are a measurement of energy.

If an engine is tuned to get heaps of hp out of  E85 then surely you could tune that engine to get MORE out of regular fuel.

I,me off to look at a perpetual energy machine tomorrow maybe that will explain how you get more out of less.

http://en.wikipedia.org/wiki/Fuel_efficiency

Lozza would be able to give  more detail. My understanding is the secret of obtaining more power from fuels that appear to have less energy per unit of volume is the ideal fuel air ratio acceptable to each fuel along with the higher compression ratios achievable.

ULP burns ideally at around 14:1 (14 units of air to 1 unit of fuel) I believe while methanol burns ideally at, again I think, around 8.5:1 therefore you can put 1.65 times as much methanol with the same amount of air. Given that the engine can only flow a set amount of air then that extra fuel means more power even though methanol has a much lower BTU index. The same applies to Ethanol. it has a lower fuel air ratio than ULP so more fuel is burn at a given air flow.

Basically you gain more power by being able to burn more fuel and therefore release more total BTU of energy per engine cycle. Fuel consumption obviously goes up as you get nothing for free. The V8 supercars I believe gained a fair bit of power going to E85 but now require two more fuel stops at Bathurst or am I imagining things?

Interestingly the old leaded 'super' petrol had less BTU than the old 'standard' fuel but generated more power.

Well that is my understanding and the way it was explained to me years ago when I ran an RM125B on fuel. With the 2Ts we always ran the bike at the end of the day on petrol to wash out the alcohol before loading the bikes up. The RMB tank held just enough fuel for a hard 45min moto but bloody hell it went

Remember riding it at a Dubbo mixed meeting with short circuit Saturday and MX Sunday. The thing passed RM250s on the straight . Those mixed meetings were just great why did they ever stop

[VMX247]

He informed me that he'd had a number of air cooled 2t and 4t classic road race bikes on his dyno and that every single bike showed a marked increase in horsepower and torque after a switch to E-85 from 98 octane and even Avgas.

as above posts ~why would you go down in energy and the other things to take into consideration is jetting etc has to be changed......more to this story.....
Just what I picked up today trackside. 
cheers A

[Lozza]

The trick is in the tuning to that fuel. Alcohol fuels cool the crank case which gives a denser intake charge as well as detonation resistance. So you can run way more comp without deto, that makes way more HP.Alcohol fuels don't require 'spot on' jetting

[TT5 Matt]

ok im sold on e85 with its good points explained and could use the extra power and cooling effect the fuel has along with a good jump in comp ratio for my bombed out ts185a dirt tracker so what type of 2 poke oil suits this type of fuel???

[Nathan S]

Castor oil.

[Montynut]

I don't think we can run E85 in VMX or MX for that matter. Can anyone confirm? Rule 18.3.1 which says Methanol or fuels no more than 100RON