How can I make a gas engine run on WVO?

[confused]

I have been wonderin' how I can run a gasoline engine on wvo for a LOOOONNNGG time now. 1. It could save money. 2. It wouldn't make nasty smelling exhaust. 3. I was thinking about putting a 13 inch 50 lb flywheel on it to give it more torque. But, my only problem is, 'ow am I supposed to convert it to run on wvo?!

[confused]

I had several ideas that wouldn't work, but if someone could tell me 'ow to run a weedeater engine on wvo, that would be 'elpful. I know that hot-bulb engines are 2 stroke, and that the weedeater engine is 2 stroke, but what changes in the engine do I 'ave to make?

Originally Posted by confused

I have been wonderin' how I can run a gasoline engine on wvo ?!

NOT!...

You need a Diesel engine to convert to wvo!

Regards
Richard

[confused]

wat?! how come I can't make it run on wvo? what's keeping it from? If it has a cylinder, a crankshaft, a sparkplug, and all that other diddlecrap, then why not? I could start it on gas, then when it's hot, I could put in the wvo, then I could mix the wvo with alittle gas. Or I could fiddle with it, so when the fuel enters, it vaporizes, then when the piston turns once more, it ignites.

[robherc]

Sorry, I have to ask:

What's "WVO"?

[confused]

waste vegatable oil

[confused]

the stuff resturaunts throw out. they pay you to haul it away. It is the stuff they fry food in.

[robherc]

Hmmmm...I really don't see that burning FAST enough in a gasoline engine....it's a SLOOOOWW burning fuel. I'd guess that's why Richard told you you'd have to use a diesel engine; they're made to run at lower RPM speeds where they can actually burn the veg. oil. Also, with a gasoline engine, the "octane" level of the WVO could be too low, and cause a dieseling (compression combustion) reaction in the motor, which is one of the fastest ways to destroy a gasoline engine. In a diesel engine, this reaction is planned for & intentional, so it doesn't cause problems.

[confused]

I was planning on putting a 50 lb flywheel on it to give it a lower rpm. I guess that wasn't a good idea to run it on wvo.

[mydauphin]

You need higher compression.. And WVO is not best, better to convert to Biodiesel. You could get small engine with supercharger to help compression then run on a 50/50 mix gas with biodiesel. But honestly easier to go 90/10 regular biodiesel/diesel in a low tech mechanical diesel like Detroit Diesel. Let me know your results. I ran Ford Powerstroke on Biodiesel and wvo, had problem with fuel consistency. Went back to regular Diesel after cost of Bio went up. But truck actually ran best with 50/50 than any combination

Originally Posted by mydauphin

You could get small engine with supercharger to help compression then run on a 50/50 mix gas with biodiesel.

We should not recommend such unreliable, dangerous, and ephemeral adventures to a very keen 13 year old boy experimenting with engines hat easily can be blown in parts!
Not only my 0,02 €. I would take that for serious.
Regards
Richard

[robherc]

Very good point Richard, I hadn't recognized his name yet.

@confused:
Don't take Richard's comment as a slight, but DO listen to him on this one. With proper adult supervision and assistance, you should be able to convert a diesel motor for your purposes, but leave adults to risk their lives trying to convert gasoline engines, they VERY WELL may blow up and kill you if something, ANYTHING goes wrong.

[marshmat]

The weed whacker is probably a spark ignition 2-stroke with compression ratio of 7 to 9, using a carburetor for fuel delivery. If so, it will be designed to run on a fuel with specific gravity of approx. 0.71 to 0.77, heating value of 40 to 50 MJ/kg, certain requirements for boiling point, vapour pressure, etc. That is to say, gasoline or equivalent. If you feed it veggie oil, it will run very poorly or die.

No amount of mechanical tweaking that I would consider safe or smart will make a weed whacker run on veggie oil. As a general rule, converting an engine to run on a lighter fuel is usually possible, but converting it to run on a heavier fuel is extremely difficult.

If you could find a supercharger to fit your weed whacker, add heated fuel injection, and tweak a few internals, you could maybe get it to run. But more likely, you'd blow the head off or run a rod through the block. If you want to run WVO, what you need is a small, simple diesel. An old mechanical one, ideally, but you can use a more recent electronic one if you know how to reprogram ECUs.

Torque and power are determined by the design of the engine. A flywheel will let you play with time constants- ie, it would make it take longer to respond to a change in throttle or load- but will not increase torque or power, nor will it let you get the same power at lower RPM.

As Richard and Rob point out, safety is key. I should note that the experimental engine test cells in the campus lab are surrounded by 10 inches of reinforced concrete block wall, and the double wire-reinforced viewing windows are mounted in beefy steel frames, for exactly the reason Rob gives above.

[confused]

wow! so it might blow up, or shoot a rod! dang! I guess I need to think of safety...

[confused]

Tommorows my birthday. today, the steam engine came in the mail!