94 



SCIENCE OF SUCCESSFUL THRESHING 



towards the cylinder. "Case" engines are marked for 

 finding the dead-centers at the factory, and by applying 

 one of the company's trams, as indicated in Fig. 29, they 

 may be readily placed on either dead-center. It may be 

 necessary to scrape off the paint to find the prick-punch 



marks on the frame and on 

 the crank-disc. The tram 

 shown in the illustration 

 measures eight and three-six- 

 teenths inches between the 

 points, which size has been 

 used by the' "Case" company 

 for many years. It will be 

 seen that a "Case" engine 

 may be put on its dead cen- 

 ters by using a pair of dividers set to this distance, but 

 they do not serve the purpose as well as the tram. The 

 following method of finding the dead centers is the one 

 used at the factory, and is generally used on all styles 

 of engines. To put it into use, first take up all lost motion 

 in the connecting-rod brasses, crank-shaft bearing and 

 cross-head shoes. Then turn the engine until the piston 

 lacks an inch or so of completing its stroke. Make a 

 prick-punch mark at any convenient place on the cross- 

 head (see Fig. 30), insert one point of the tram in the 

 mark and with the other point, make a scratch on the 

 engine frame to locate a second prick-punch mark. The 



FIG. 29. TRAM ON DISC. 



