Re: Latest Project
Posted by: (---.nap.wideopenwest.com)
Date: January 3, 2014 03:57PM
Thank you for the compliment, it has been a very fun project.
The new crankshaft is 1018 cold drawn low carbon and not case hardened. The eccentrics are 330 bronze. The originals are hardened steel and the valve rods are steel. Steel on steel is not an ideal arrangement. I have a steam powered tugboat as well, it has steel eccentrics and bronze lower ends on the rods, this has held up very well. It is reversed in this case, but it should do just fine. The Loco engine has no means in which to adjust the advance of the timing as everything is keyed. I used an old eccentric as a guide for the broach. Take notice of the key placement, they are different from one side of the engine to the other. Getting the old eccentrics off and re-using them was simply not an option - on this engine anyway.
The cylinders were in good shape - for steam anyways. A few thousadths over and the rings looked good and still had ample tension, so none of that was reworked. Even the valve faces were in good shape. The piston and valve rods were changed out with stainless steel. Someone had changed one of the connecting rods many moons ago and the balls were different one side of the engine to the other. Instead of trying to find or make the correct parts, it was decided to just go with sealed ball bearings. I plan on driving this quite a bit, so it needs to be somewhat reliable.
The whole engine was dismantled, sandblasted and painted, then re-assembled. The sprocket on the crank is original and #60 size chain which is 3/4" pitch if I remember correctly. I don't think this engine was used much really, the story was it was stored in an attic of a barn for 90 years. Of course, the water pump and arm was gone. I think that was probably the beginning of the end for these little steamers in their original service-life, someone would allow them to freeze up in the wintertime and either the pump broke or if the pump was full of ice, the arm broke as soon as the engine began to rotate.
Here are some pics of the engine. There is still some small bit to do like the connecting rod retainers. The crankpins were annealed and there is now two 10-32 screw holes in each so the bolts can wire tied.
20131215_172102 (Medium).jpg (107kB)
20131215_172137 (Medium).jpg (97kB)