Alcohol KZ?

Kitten Tooth wrote:

So any idea on what type of carbs to use? Or is it just like a manifold type setup? or do i use the infamous way effing expensive RS34s?

Convert the throttle grip to a spray bottle lever and squeeze... :huh:

Good question, though. I would assume any carb would work with the possible exception of the CV carbs as the alcohol mixture might be bad for the diaphrams?

Otherwise I'm sure there are injectors you could use if you switched to mechanical or electronic fuel injection.

DoubleDub wrote:

Lorcan - you don't happen to have a high-res version of that photo I can use for wallpaper, do you? :blink:

Sorry I don't. That bike will be making a return though

PLUMMEN wrote:

your mileage will be about half with alcohal since it burns so much more is the main problem i see.
another issue might be where to fill up when away from home,unless you can come up with some injectors that will hold up to e85

Correction: It will be about a third of gas. Only synthetic oils most be used, specificaly poliester oils only and all seals must be changed.

This raises a question that maybe Lorcan or someone else with an in-depth understanding of racing fuels can answer. Since alcohol produces about 40% less energy per gram than gasoline why is it used in super-duper race engines instead of gasoline? To the uninformed (me) that would seem counter intuitive (even though I know it works great). Ed

not that I am one of those with in depth knowledge, but I will guess it's because the engines run cooler...

I think it's related to compression. More compression provides more power.

Gasoline can't run at the higher compression that alcohol can without predetonation.

Power doesn't necessarily mean efficiency.

650ed wrote:

This raises a question that maybe Lorcan or someone else with an in-depth understanding of racing fuels can answer. Since alcohol produces about 40% less energy per gram than gasoline why is it used in super-duper race engines instead of gasoline? To the uninformed (me) that would seem counter intuitive (even though I know it works great). Ed

Gram for gram yes it makes less power. But you put at least twice as much in, so you can end up with 10-15% more power than with gasoline.

Add to that it's greater latent heat which gives an intercooling effect and it's ability to run more boost and/or compression without detonation and you have a great race fuel.

This chart should help.

DoubleDub wrote:

Gasoline can't run at the higher compression that alcohol can without predetonation

You're confusing two different terms here.

Pre-ignition is the flame kicking off before the spark ignites it. This can be caused by hot spots in the combustion chamber.

This can lead to...

Detonation which is an uncontrolled burn, rather than a controlled burn.

Both can exist independently but are not the same thing.

Yep, sounds like what I was doing - thanks!

yea, a buddy of my dad's built his son a drag bike with a Briggs and stratton engine that was tuned to be ridiculously powerful. It ran on alcohol and he made the head with a drillpress.. on the head, there were no fins to distribute heat. His son one the race and then engine was BELOW the normal running temp if it would have been stock. Sounds kinda cool to me:)

ill try andget the pics he has of the bike he built. I guess them little 10HP horizontal shafts can be monsters:D

Lorcan wrote:

650ed wrote:

This raises a question that maybe Lorcan or someone else with an in-depth understanding of racing fuels can answer. Since alcohol produces about 40% less energy per gram than gasoline why is it used in super-duper race engines instead of gasoline? To the uninformed (me) that would seem counter intuitive (even though I know it works great). Ed

Gram for gram yes it makes less power. But you put at least twice as much in, so you can end up with 10-15% more power than with gasoline.

Add to that it's greater latent heat which gives an intercooling effect and it's ability to run more boost and/or compression without detonation and you have a great race fuel.

This chart should help.

Thanks for the explanation! I didn't know the air/fuel ratio for alcohol engines was so much different than gasoline. It makes sense now. Ed