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Hi! Usually I build IC engines, but as I have never built any hot air engines, I thought to give it a try. The lamina flow or thermoacoustic engine is probably the simplest engine to build. This project took only 1 day to build. The most challenging part was to find a perfectly round test tube...

Stefan, I did not give up. I will keep on trying. But I have to rework the whole hot bulb design, as I just loose too much heat to the cylinder head. Maybe some glass ceramic isolation will do the trick, or as with the engines of Find Hansen, a long, very thin walled stainless steel tube. The...

Hi! Now this is so frustrating, I reduced the compression to 6:1, attached a carb and coil with spark plug, and it fired right away and runs perfectly smooth. Although my left flywheel wobbles quite a bit :( Anyway, here it is running on gasoline: https://www.youtube.com/watch?v=7h2mRWFsjmY...

Hi! Today I tried to start it again, but sadly failed again :( I get a nice spray from the injector, engine compression is very good, I also get ignitions, but it just refuses to run. As fuel, I again tried diesel fuel and a light kerosene, the result is quite comparable, the engine won't...

Ripcrow, interesting idea, although maybe a little bit hard to regulate, as the pressure will decrease significantly with decreasing fuel amounts under no load conditions. Jens, currently there is no return pipe. Currently there are no leaks past the O-ring yet, but for further testing I need...

Hi! long time no update, was very busy recently with other work. I have a new injector now which sprays far more reliable than all my previous ones. It's also spring loaded with a fine needle, but 8 mm piston. The piston has an O-ring seal and the spring tension is adjustable. I'll see if there...

Hi! There is some progress, but minor. I managed to get a sort of useable injector, but the spray is still too bad. I had the engine running for a minute or so. but excess soot forced my to stop it quickly. after this short time, the hot bulb built up quite some soot deposits. I tried a lighter...

Hi! It looks like I'm failing again. No matter what I try, I never get a useable spray from any injector. It doesn't matter if they are open injectors, or spring loaded injectors. Either they are just dripping or the spray is very irregular. The frustrating thing: If I close the pressure hose...

Hi! A spring loaded injector is a real challenge. It's quite difficult to machine a needle with little taper that is perfectly round and furthermore drill a tapered hole that holds the needle. All things must be 100 % tight and the injector must make a squeaking sound when pumping fuel through...

Hi! Allright, I've played around with the injection pump the whole day and I think I came up with a version that is worth tying. I removed any springs and made the pump setup vertical, so only gravity will move the ball valves. This pump now creates 100 bars easily and holds them several...

Hi! It turned out that it's not the valve seats that are leaking! I'm using springs to retain the balls in place. I found that the ball valves will leak if the spring pressure is not 100 % dead on. Even if the spring is only distorted by < 0,1 mm, the uneven pressure on the ball will...

Hi! I'm struggling with the injection pump. Always, one ball or both balls are leaking. I tried to produce a good valve seat by giving them a light knock, but it doesn't seem to work. What's the best material to machine the valve seats? my first try was brass, But I feel it's not the best...

Hi! Made some troubleshooting today. Looks like the intake ball valve of my injection pump is leaking a bit, so the whole system has problems working against the compression of the engine causing the injector to just poorly drip. Also, the intake valve is not 100 % tight and causing some...

Hi! Ready for first start attempt: Using a small propane burner I heated my hot bulb to dark red (barely visible). I flipped the engine several times and got lots of white smoke from the exhaust indicating lots of evaporated diesel. In some cases, I also got some very weak combustion, but no...

Hi! I recently mounted the engine onto a wooden board. Furthermore I have finished the Diesel tank which rests just below the cylinder. It has a little acrylic glass level indicator. The pressure line between injection pump and injector is also finished. It's made from 3 mm copper pipe. The...

Hi! Not too much to report over Christmas. But I've managed to finish the roller chain tensioner. It's not spring loaded, but easily adjustable using a screw. best regards, Alex

Michael, my engine will be a hot bulb type engine with preheated hot bulb. Progress: Finished the 1:3 gear with new governor shaft. the governor response is way better now. Things left to do before 1st start attempt: - fuel tank and fuel piping - throttle lever which changes the tension of the...

Hi! Things like that seem to happen when building an engine without any plans ;) anyway I have found a solution for my problem. I've made a second shaft just parallel to the camshaft which will hold the centrifugal governor. It will be gear driven from the camshaft with a 1:3 gear ratio. This...

Hi! Today I ran into a problem. I finished the governor setup and tested everything on my lathe. It does actually work, but due to the low rpm on the camshaft, the governor response is very slow. Probably way too slow to have the engine running nicely. I'll see how I can change this over the...

Hi! The centrifugal governor is now fully assembled. I had to make quite heavy weights, as it runs directly on the camshaft. I want to have the engine running at 400 rpm idle, so the governor needs to work properly at ~200 rpm. Tried it out on my lathe and from 150 rpm onwards it works ok. In...