The Steamboating Forum

Greg- It is baffling the variety of methods and techniques used for the old engines. I looked last night for the info on the rounded edge bearings, but no luck. If I run across it, I will post the source. I guess part of the fun of it is trying to separate fact from fiction. Often the old steam engi...

Greg- As I recall, the from the book, rounding the leading edge of the oil groove on the old engines was quite common, but it also seemed like this was in reference to very large engines, with journals perhaps 12"-18" wide. The idea was to build up a dam of oil and oil pressure such that t...

I read a good steam book on efficiency (can't remember which one), but I did jot down some notes, which are as follows: Can't vouch for their accuracy, but this is what I noted. Steam engine losses: Losses in a steam engine include: a) Rejection loss. b) Thermal loss. c) Mechanical loss. Steam engin...

Mike- I have to agree with you, I have seen too many small steam engines that look like water pumps, they just gush water out of everywhere, expecially the exhaust. From what I have read though, the norm for many/most steam engines is that the valve gear tends to be either poorly designed, or the va...

Jack- That is some good information. I have heard a similar comment about Don Ashton's work applying more to locomotives than to marine engines. I continue to study the subject of valve gear, and I know I have a long way to go before I get a good feel for Stephenson's gear and rod arrangement. It se...

Fred- I guess I don't really follow your arguement very well (my lack of knowledge). I will have to ponder those ideas for a while. Den- I am also confused about changing the cutoff using the links in a marine compound, since it was said that the lp cylinder really did not need a shorter cutoff, but...

John- Thanks, I vaguely remember something about crossed rods and inside admission now. I will go back and review that. Fred- You can't dismiss any restriction in a steam engine, all will limit the power produced. You can have too small a steam supply line, too small of ports and passages, too small...

Greg- I have read the Audel's Guide, and reviewed it recently, and while it provides very good basic information, it Don Ashton seems to have taken the understanding of valve gear to a whole new level, and corrected many misconceptions, some of which can be found in Audel's, such as neglecting the a...

Jack- Interesting information. If I understand you correctly, for a large marine compound engine, the gear could be adusted independently on each cylinder as the engine was running to balance the load between the cylinders? but I guess all the gear had to be connected to a common shaft for reversing...

I know from talking with a Stanley guy that he starts his car with a late cutoff, and then as he gets going, shortens the valve travel via the Stepenson's link to get an earlier cutoff. He says the shorter cutoff at higher speeds is not for efficiency, but due to a minimal sized exhaust port and pip...