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Old 07-16-2006, 12:32 AM
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Default RE: 1/2A Diesel Engines?

I've always had good luck with Mecoa but haven't done business with them in a few years. If you want to try diesel, I agree with Tim to get the RJL head above all else.

If you're curious about how a diesel conversion runs, see this,


The head is my own but I have run the RJL head and performance is the same.

If you can get fuel be cautious though. The small engines really do need fuel with a lot of ether. I stumbled and struggled to get the little stinkers started and running but had a rough time of it till I was told that, like glow and nitro, 1/2As like lots of ether. I mix my own out of necessity. What works best for me is a mix of 40% ether, 40% kerosene, and 20% castor oil. Usually, a cetane booster is also required. This used to be amyl nitrate but it's a heart drug and impossible to get. As substitute for this that's available at your hardware store is MEKP, which is fibreglass hardener. Yes, it's highly corrosive, will take your eye out in an instant. But once mixed at 1 to 2%, you can live with it. And yes, when you handle it, you use extreme caution (safety goggles) but no more caution than when you're mixing resin.

Hardware store kero is acceptable, and the ether can be had in spray cans, called Quickstart used to start full size diesels. The preferred is the John Deere brand because it's guaranteed to be 80% pure ether with the balance "mixed volatiles". I just mix it 40% and it works great. If you have concern with the MEKP, you can get Amsoil cetane booster in 16 ounce jugs from your local dealer. If that doesn't work for you, you can oder from them online and they'll ship from their nearest location to you. I have two jugs and they'll last me a lifetime.

You're going to have to be careful with diesel operation. The parts were meant to run glow at higher rpm. On diesel, the higher (much higher) compression ratio along with slugging a larger prop means high loads on the parts, especially the crank. The Wasp is a good little engine but I did break a crank in the early days of experimenting with diesel. Likely my inexperience at the time was the culprit.

Which prompts me to also advise that when you come to start your little stinker, DO NOT fill the fuel tank. Well, to back track. Run it as glow and get your needle settings. From there, install your head and leave that tank empty. You first want to find the compression setting on the fuel you're running. This means three drops into the intake and hit it with your starter. If no go, tweak in the compression screw a quarter turn and try again. At one point you'll fire off the prime. Only then do you fill the tank and have another go. If you ran out the prime, the CR is close and it'll fire a few times to warm up and then you will get a run. Tweak in the compression first, tweak the needle, go back to the compression screw, back and forth and you'll find that magic sweet spot.

Use only a 1/2A starter, NEVER prime into the exhaust unless you're flipping by hand. If you can start it by hand, you have gorilla arms and I don't want to meet you in a back alley. Another way to say, you won't start it by hand. However, a very safe way to start your Wasp would be to install a spring starter. The Norvel .074 starts without even needing to be primed.

Check out my other videos on the same link, dieselizing the VA .049, the Brodak .049 along with the entire range of Norvels.

Good luck, you're going to have a blast running stinky fuel.