GP> So; an in-line single acting motor with poppet valves. (and
GP> lower barrel ports?)
I believe that "piston" or "spool" valves offer more sophisticated
timing changes while running, than poppet or cam operated valves;
and would opt for double-acting cylinders for space, weight & cost
reasons. (Ever try changing a cam at 300 RPM? :) )
AC>I have had a lot to do with steam turbines but I never did
AC>see a steam engine with in-line cylinders. I *suppose* that
AC>a conventional two cylinder steam loco would have total
AC>cylinder volume of roughly 3000 cubic ins.
Besides the usual steam loco setup (two in-line), various
compound locos used 3 or 4 in-line (though not always). Also,
the gear/shaft driven Shay locos used a steam motor with three
vertical cylinders mounted on the right side of the boiler.
(Steam cars usualy were 2 cyl.)
AC>so as a first approximation you have in mind a 6 or 8 cylinder
AC>steam engine. Has there ever been such a thing? [I cannot see why
AC>not]. And if not, why not??
Well, think for a minute about building it...
AC>Apart from the fact that for a given HP, engine costs of mfr
AC>and maintenance increase with the number of cylinders used.
Right! :)
AC>Maybe, that kind of engine was used on the large steam
AC>lorries that once operated.
Why? One cyl. has dead centers; two needs nothing further.
Reggie Arford
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 X SLMR 2.1a X URA Redneck if you do your most shopping at a truckstop.
--- Maximus 3.01
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