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?