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Rough and Tumble Engineering by James H. Maggard
page 60 of 122 (49%)
You are now ready to proceed with the setting of your valve, and as you
have both dead centers to work from you ought to be able to do it, as
you do not have to depend on your eye to find them, and by the use of
the tram You turn your engine to exactly the same point every time you
wish to get a center.

Now remove the cap on steam chest, bring your engine to a dead center
and give your valve the necessary amount of lead on the steam end. Now,
we have already stated that we could not give you the proper amount of
lead for an engine. It is presumed that the maker of your engine knew
the amount best adapted to this engine, and you can ascertain his idea
of this by first allowing, we will say, about 1/16 of an inch. Now
bring your engine to the other center, and if the lead at the other end
is less than 1/16, then you must conclude that he intended to allow less
than 1/16, but should it show more than this, then it is evident that he
intended more than I/I16 lead; but in either case you must adjust your
valve so as to divide the space, in order to secure the same lead when
on either center. In the absence of any better tool to ascertain if the
lead is the same, make a tapering wooden wedge of soft wood, turn the
engine to a center and force the wedge in the opening made by the valve
hard enough to mark the wood; then turn to the next center, and if the
wedge enters the same distance, you are correct; if not, adjust till it
does, and when you have it set at the proper place you had best mark it
by taking a sharp cold chisel and place it so that it will cut into the
hub of eccentric and in the shaft; then hit it a smart blow with a
hammer. This should be done after you have set the set screws in
eccentric down solid on the shaft. Then, at any time should your
eccentric slip, you have only to bring it back to the chisel mark and
fasten it, and you are ready to go ahead again.

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