ROl MBLE ENGINEEK 8 1 



mechanical accuracy. And when we remember also that 



is another one of the things for which no uniform 



can be adopted, owing to the ; rcumstances 



h go to make an engine so different under different 



coml; ry difficult to give you the light 



on this part of your duty which we would wish to. 



however, hope to make it so clear to you that by the aid 



of the engine before you, you can readily understand the 



conditions and principles which control the valve in the 



r engine which you may have under your man- 



c power and economy of an engine depends largely 

 on the accurate operation of its valve. It is therefore, 

 necessary that you know how to reset it, should it become 

 necessary to do so. 



An authority says, "Bring your engine to a dead center 



and then adjust your valve to the proper lead." This is 



all right as far as it goes, but how are you to find the 



: center? I know that it is a common custom in the 



to bring the engine to a center by the use of the eye. 



You may have a good eye, but it is not good enough to 



depend on for the accurate setting of a valve. 



HOW TO FIND THE DEAD CENTER 



First, provide yourself with a "tram." This you can 

 do by taking a % inch iron rod, about 18 inches long. 



