Testing a Beam Engine?

[MalcParticipant @malc]

Over the past few years (on & off) I have been making the Julius De Waal "Balanced beam engine with cylindrical valve". I have reached the stage where I would like to test run it before dismantling it to make it look "presentable". However, the only air supply I have is a cheapo mini air compressor for pumping up the car tyres. Having tried it the engine tries to work but will not run continuously. I have tried experimenting with the timing of the valve but to no avail. The mini compressor is capable of pressures up to 10 Bar but it's flow rate is only 35 Lts./min. and of course it has no tank. The beam engine has a 30mm dia. cylinder and a stroke of approx. 40mm. so it's not a big capacity. I had considered connecting it to one of my car tyres and using that as an air source, but I have no idea of the pressure / flow required to run it. Is there a simple way of testing this engine without having to resort to a compressor?

[MalcParticipant @malc]

[SillyOldDufferModerator @sillyoldduffer]

The pump produces a small volume of air at high pressure, while the engine needs a large volume of air at much lower pressure. You need some way of converting from one to the other, it's usually done with a tank and a regulator.

A car tyre is one possibility but you can only charge and empty it in bursts. For temporary engine testing I've successfully used a 2 litre lemonade bottle as a reservoir between the pump and a small engine, pinching the rubber output tube between finger and thumb as a crude regulator/throttle. I made a pair of brass nozzles to connect the plastic pipe-work to the bottle.

Not found a cheap, quiet, moderate pressure, high-flow pump for testing engines yet!

Dave

[MalcParticipant @malc]

Your remarks are a real help. I will certainly try introducing some sort of tank into the air supply. You have also made me suspect the size of the inlet pipes to the valve chamber, they are 4mm copper so the inside diameter is only 3mm. Now I know what is required I can have another play! Thanks for the help.

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