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Building Tips and technical articles. => 1/2 A building. => Topic started by: Bruce Shipp on December 09, 2022, 08:10:06 AM
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OK, getting ready to run some reed valve engines for the first time in many years. I’m going to get my fuel from Brodak. They offer both 25% and 35% nitro.
Suggestions?
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OK, getting ready to run some reed valve engines for the first time in many years. I’m going to get my fuel from Brodak. They offer both 25% and 35% nitro.
Suggestions?
If you are looking for peak performance, 25% should do the job for you. If you just want to run them, use whatever stunt fuel that you have. Lower nitro is easier on glow plugs and they should still run fine and needle normally. That's pretty much what I do. Oil content should be at least 18% with some castor for the piston/rod ball joint.
Type at you later,
Dan McEntee
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Thanks, Dan. I figured some good 1/2A fuel would make life easier. 35% seemed high. I figured 25% would do.
A quart will last me a loooonnnnggggg time.
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Bruce,
The 25% is fine for general sport flying on the reedies. If you eventually get to tweaking the reedies to make a Venom or Killer Bee clone, then a step up to 35% is good. I know a lot of guys use the same fuel as they do for their larger engines, but I've never been satisfied with the runs you get on 5% and 10% nitro. The lowest nitro content that Cox sold was 10% in their blue can Glow Power fuel. But I didn't care much for that in planes. More for the Cox cars and boats. I preferred the Cox Flight Power fuel as a minimum, which had 15% nitro, but usually bought the Cox Race Power fuel if I could get it which had 30% nitro. All Cox fuels had 20% oil, 18% being castor and 2% being synthetic Dow Lube (Klotz). The Brodak fuel is 22% oil, half castor and half synthetic. That's more than fine for the reedies. I once read that you can go as low as 5% castor in something that Paul Gibeault wrote somewhere. But I'll stick to a minimum of 10% castor with the rest synthetic.
But, luckily for me, I have a local speed shop that I can buy nitro and methanol from, so I can just mix up what I want. One day I'm gonna mix up a pint of 60% race fuel for the fun of it. No one does racing around here, but I have a Cox magnesium race pan and the fiberglass top for it, and a left-hand crank for a TD, so I might as well give it a go once in my life.
Mark
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Mark, don't wait to try it. It works terrific and if it wasn't for the cost, I'd be using it all the time. I was using 60% and even higher nitro on 1/2A's. It starts great and needles great. It takes a bit of adjusting of head gaskets. With the cost of stock plugs today, it isn't cost effective to run the darn things on high nitro.
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I THINK MOST PEOPLE THINK YOU NEED A LOT OF CASTOR...THE ONLY REASON IT WAS A LOT WHEN THE ENGINES FIRST CAME OUT THE ONLY OIL AVAILABLE WAS CASTOR...