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George,I must commend you Thank you for yet another glorious, cogent and extremely informative post! Thank you!Dave
Thanks again for your reply. When we were working on the first gas powered RC boat to go over 100 mph we spent days trying different ideas. If one in 10 worked, I was happy. I think the first step after reading everything I can find (I've studied On the Wire backwards and forwards) would be to build the pump system. I have a selection of high power electric motors from model racing boats to drive the pumps. After that the boiler system would be next followed by a motor.Funny you should mention surface piercing props. My current project is a milling fixture to make propellers. Several of my friends have been bending and breaking propellers at speed trials. I think I can at least mill wax patterns that can be cast in high strength metals. i might be able to mill steel props. We'll see.As you know well there are very few people working with flash steam. Thanks to the internet, they can communicate a little better. Maybe we can advance the state of the art.Lohring Miller
Currently I'm waiting for a copy of Experimental Flash Steam. The engine will be the last part of the build since the pump design will be key. I spent a little time yesterday while snowed in to check the internet for materials. Seamless 316 stainless steel tubing http://www.ebay.com/itm/Coil-Tubing-Welded-ID-194-OD-1-4-50-Ft-L-Wall-028-316-Stainless-Steel/221262739145?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D27%26meid%3D3369944555047739346%26pid%3D100033%26prg%3D1011%26rk%3D4%26rkt%3D4%26sd%3D230982947265%26 (is welded OK?) seems to be readily available in up to 50 fool lengths as does high temperature material like Nitronic 50 http://www.onlinemetals.com/merchant.cfm?pid=10706&step=4&showunits=inches&id=886&top_cat=0 for things like valves. The problem is all the fittings and supporting parts. The best flared connections seem to be the 37 degree style with a sleeve. The flaring tool for these costs at least $100, though. Did you use standard 45 degree flare fittings? Were they available in stainless steel? Did you buy the pump check valves? Where? Are any of the other parts like lubricators available? If not are there some standard designs? I notice that earlier flash steam engines used pump lubrication. Are there any issues with cast iron pistons and cylinders at high temperatures? Has anyone tried different materials? I don't want to reinvent very much if I can help it.The design will be very close to yours since that seems to be the state of the art. I have several fiberglass hulls available as well as all the hardware and boxes of propellers so that won't be a problem either. The only US radio controlled steam 1/16 mile straight a way record was set in 1994 at 9 mph. I would be seriously disappointed if that can't be improved by a factor of 10 using an outrigger hydroplane design.Lohring Miller
WATER AND FUEL PUMPS.Hi George,Thanks very much for all this info, most of it is clear to me but the pump, not so much.Apart from that I have lot more questions about speed control; suitable materials; temperatures; pressure and lubrication.Do you have a drawing from the pump, something that shows the (one way) ball valves; plungers and all?Do I understand it correctly that the pump stroke length is fixed during running the engine?Is there a type of "waste gate" for excess water and /or fuel pumped or is it controlled is any way?How is the engine speed controlled?The steam inlet has a connection for lubrication, how is the oil pump powered and is this pump lubricating other parts too? Any details of this oil pump?About the fuel, is the fuel pre heated so that is there is pressurized gas at the jet holder inlet?What are the best material for pumping water - plungers and cylinders; what is best for the piston and the working cylinder?So enough question for today I think, reason for all this is although I never heard of flash steam engines, I thought of it myself and like to build one. After I started searching the internet I found that there already exists engines like this. Which is good now I can make use knowledge from others.I wonder if there are people here who have idea's about making it fuel efficient.RegardsEdmund