MP Jets Diesel Hybrid no ether fuel, cold start

This clip illustrates how readily a no ether fuel can start even on an ABC diesel conversion. Note the ice cube sitting atop the cylinder head. Note the ice and water being blasted away by the prop. The engine was actually cold to the touch. It took only three prime bursts for the engine to catch and keep running. The compression screw had been turned in a full quarter turn for the start. Note that it sounded fully tuned before it sagged slightly whereupon the compression was taken out a bit. This sounded good and final but after the clip ended, the engine sagged some more and the compression had to be backed off some more to a full quarter turn.

Fuel was 20 castor, 80 kerosene and 2 Amsoil. The other mixes with motor oil and MEKP were tried but the engine would not run without prior application of the heat gun. The MEKP was doubled with no result. The motor oil was brought up to 30% with no luck. It appears that the castor and the Amsoil have some sort of magic that allows much easier starts with a no ether fuel.

Prime was with a new mix, 20% castor and 80% ether. Applying drops was difficult because with the volatility of the ether, the prime comes out with a squirt. Note the excess prime bubbling and boiling in the carb's intake throat. Despite this, the engine just blew out the excess and used what it needed. In any event, at one point, the starter just stalled, presumably due to hydraulic lock. Not to worry, for an .06, the Jets has a beam for a conrod and a massive crank.

The starter is custom made from a speed 400 type motor and gearbox. In this case, instead of driving it with the full 12 volts, it was plugged into an auxiliary socket providing 6 volts.

Addendum,

The head contains a counterpiston that is adjusted by the screw. This adjusts the compression ratio. You increase that till the engine fires purely on compression alone. The required compression changes as the engine warms up so as that happens, you have to readjust till it all stabilizes into a nice run."

Category:

Howto & Style

Tags:

• MP
• Jets
• Diesel
• RC
• Airplane

[funkawitz]

two questions. where did you get that needle squirty bottle, and what starter is that?

[hopeso]

@funkawitz The prime bottle is actually a device used by fishermen to inflate worms so that they float on top of the water. I ground off the sharp tip before using it as a prime applicator.

The starter is made from old, electric power parts. The motor and gear box are enclosed in a plastic pipe, plumbing connector, with a switch and end cap added.

[xxxbmxerxxx1]

i feel gay

[hopeso]

@xxxbmxerxxx1 o-k-a-y,,, and,,,

Oh, I get it. Don't be afraid. All of us in the hobby of miniature engines don't discriminate against those who have a chronically, happy and enthusiastic approach to life. Welcome to the club but don't chuckle or laugh when one of us crashes,, m'KAY ?

[TheNoisePolluter]

0:45 is too close.

[rroberts383]

@hopeso i tryed to mix methanol(rc fuel) with diesel. it wont mix. apparently my rc fuel is water based lol.

[Ignantredneck]

these motors suck :P

[seapeddler]

I thought ducted fan motors were safer.

Thanks for the (finger) tip !

[hopeso]

There's no methanol in diesel fuel so the catalytic effect isn't there to initiate combustion. HOWEVER, adding some methanol to a diesel fuel may allow this to work. That's something to try. Thanks for the inspiration.

[hopeso]

Not a problem, your suggestion was valid and that's why I tried it. But no, in fact, the glow plug in a model engine doesn't work by heating the mixture per se. The platinum element, when heated, acts as a catalyst to fire off the methanol based fuel. Other elements, when glowing will do the same but won't continue to glow when the power is stopped. Platinum, due to the catalytic effect with methanol, WILL continue to glow and initiate combustion.