Thread: Making a model diesel engine?

Originally Posted by jack620

They are most likely glow plug engines. The fuel for those is readily available. It's methanol, castor oil and nitro. The old style "diesel" engines use a different fuel containing ether.

Hi jack620, yea, I didn't think of that, next time I see someone at the park flying I'll stop and have a sticky beak and a gawk and ask a question or two. Plus the good bit, I've even seen radio controlled ones there, never ever owned anything like those things but always been attracted/curious.

Here is a home brew "diesel" mix and discussion using readily available ether, I guess "Start-Ya- Bastard" might be ether based, or "Aerostart".

Mixing Model Diesel Fuel (with pictures) - RC Groups

I only read a few of the posts there, so over to you.

Avagoodnewyear

Cheers.

Log,
thanks for the link.

Peter,
The model I am going to attempt is milled & turned out of a piece of solid 6061 which I happen to have a piece of in the scrap box. Apparently this is about the simplest DIY motor you can build. If I can't make this one there's no hope for me! I'll order a full set of plans ($15) and see how it goes.

building it: Building the ML Midge Diesel

In action: Homemade model diesel engine the M L Midge 0.8cc. - YouTube

Looks like it would be a really good project .

Ron's is a good and interesting site, in the past I've spent quite a reasonable amount of time on there, just find it interesting. I though don't need a new project, plenty of semi-finished ones on the go already .

Hope you press on with it, good luck if you do.

Cheers.

I always wondered about those RC glo plug engines . Are they another type of diesel, as you don't have a electrical ignition source ?

I remember the little .049 cc wen mac and cox engines , you needed a battery to make the plug glow red . But after they started the ignition was by compression only ? The diesel had a little T bar adjustment thing on top of the cylinder head .

Mike

Mike,
from wikipedia:

"Once the fuel has ignited and the engine is running, the electrical connection is no longer needed and can be removed. Each combustion keeps the glow plug filament glowing red hot, allowing it to ignite the next charge, thus sustaining the power cycle."

Originally Posted by jack620

Mike,
from wikipedia:

"Once the fuel has ignited and the engine is running, the electrical connection is no longer needed and can be removed. Each combustion keeps the glow plug filament glowing red hot, allowing it to ignite the next charge, thus sustaining the power cycle."

OK , so in effect, it is still a compression ignition motor - because without the compression there would not be any combustion to keep the filament glowing .

Originally Posted by morrisman

OK , so in effect, it is still a compression ignition motor - because without the compression there would not be any combustion to keep the filament glowing .

No, glo plug engines are not compression ignition engines. The mixture is ignited on the surface of a spiral that glows a bright red color. When starting, you use electric current from a battery to glow the filament in the plug. Once running, the combustion heat keeps the filament glowing.

Compression ignition engines use a fuel with an extremely low low ignition temperature, that ignites solely by the heat generated from the compression. Compression engines need more skill to build, the cylinder needs to be very slightly tapered, making for a tighter fit at the top of the stroke. They will be hard to start, or won't start at all with insufficient compression. Whereas glow plug engines will start and run with a comparatively loose piston fit. Chris