Timing a twin cylinder

[trevParticipant @trev]

Hi could somebody please help with a way to time a twin cylinder horizontal steam engine ,mine is the sir william armstrong twin ,how do you set up the cylinders ? Are they at opposite ends of the stroke? Any help would be appreciated

[trevParticipant @trev]

[Capstan SpeakingParticipant @capstanspeaking95294]

Although 180 degree timing would produce the smoothest torque it can cause starting problems.

Google and read up on "steam engine locomotive quartering"

[JasonBModerator @jasonb]

Well the drawings show the cranks at 90degrees so the easiest way is to set it as two singles. The high point of the eccentric wants to be 90degrees plus about another 7deg in advance of the crank as a basic starting point. If you do that for both cylinder/valve sets then you should get it running.

Also make sure the valve block is central over the ports before you start setting the timing, with the chest cover off rotate the engine by hand and see that you get an equal opening each side of the valve, if not adjust its position on the valve rod until you do

If you are not sure ask again as I have a sketch somewhere that shows relation of crank to eccentric.

Edited By JasonB on 11/04/2015 10:15:48

[Neil WyattModerator @neilwyatt]

Best I saw was a twin-cylinder single-acting with 90-degree cranks.

Neil

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