diesel commuter bike ideas

[Beowulfs_Ghost]

I'm thinking of a diesel powered, recumbent/feet forward, motorcycle as a high mpg commuter vehicle. I would like to use a Yanmar L100, but I need to be about to cruise at 65mph.


http://www.craigvetter.com/pages/Motorc ... liner.html

To get better performance out of such a small engine, I was wondering how much of a gain I could get out of using fairings like the above article.

Also, has anyone tried ram air on an L100?

Would a combination of good aerodynamics, high greaing and ram air be enough to run an L100 at freeway speeds? Or is that too much to ask from such a small engine?

What about propane injection? Disposable 16oz propane cylinders are fairly cheap and easy to come by.

[addicted]

With the right set up you should be able to reach 65.

As far as propane you can refill those bottles as well. Just be careful you wouldn't want to add to much.

As far as the ram air...I don't see how it could hurt. I've never actually seen one set up though so I'm not all that reliable of a source.

[Diesel Dave]

You are asking a lot from 10Hp.

Aerodynamics will help but you will find that hills will chop a lot off your top speed too; so you should consider dumping some weight.

Ram air (for the intake) will have a small benefit but you will need to up the fueling to take advantage - this leaves the problem of overfueling when you have a tailwind or are in lower gears.

You could save a hp or so by removing the shrouds and blanking or removing the fins from the flywheel and adding some ram air cooling for the cylinder & head. many have considered redirecting the air flow from the flywjheel to charge the cylinder however little pressure is generated (you can block off the flow easily) and so may not provide much benefit.

Propane will only add power if there is some free oxygen available - this will only be the case if you are underfueling unless you add a turbo or supercharger to get some real air pressure going into the intake.

Methanol fumigation should add a little power as this is not just a fuel but adds some oxygen too - this depends on having some available at a reasonable price though. Similarly Veg oil carries a little oxygen too so you can fuel with this and up the injection rate - the only downside is it contains less energy weight for weight so in the end you don't make any gains but loose fuel economy.

If your serious about getting more HP from a diesel then you need a turbo, I have a small one ready for experimenting with but have yet to make a start.

Hope this helps
Dave

[Beowulfs_Ghost]

I wouldn't expect any sort of possitive intake pressure from a ram air set up, but it might over come some of the power lost trying to pump so much air.

How small is a small turbo? I have 2 IHI turbos pulled off late 80's Subarus. Both were working, and both are water cooled. I know they would be to small for a half liter gasoline engine, but I'm not very familiar with diesel turbos, and I'm not finding alot of info on turbo'ing small diesels. The Subarus were the 1.8L ea82 engines, they are set to 7psi, and would start making boost near 3000rpms.


I would be willing to part with one of the turbos if some one wanted to try one out.

[endlos]

im looking to do the same thing, looking for the highest mpg and hitting about 60 mph, im going to go the dirtbike route with the lightest parts i can find, all alum frame, etc etc.

ram air doesnt work unless you have an airbox/plenum to settle the air down so its stable for consumption by the motor. most motors need that anyhow, or run better if they have it.