604 



Removing and Applying Valve- Stem 

 Guides by Pressure 



AFTER an autoniol^iic engine has 

 . been in use for a time, the guides or 

 hearings for the valve-stems depreciate 

 to such an extent that tiiere isappreciable 

 looseness between the valve and its bear- 



Popular Science Monthly 



PRESSURE NUT- 

 BUSHING 



VALVE CHAMBER 

 CAP 



-PRESSURE BOLT 



TE.N5I0N BOLT 



VALVE SEAT 



WATER JACKET 



SPACE 

 CLNTERING PLUG 



REMOVABLE VALVE STEM 

 GUIDE 



Pushing the valve-stem guide out of its 

 place by screwing down a pressure bolt 



ing. This not only results in noisy action 

 but also interferes with proper engine 

 operation, because air leaks in on the 

 suction stroke through the inlet valve 

 guides, dilutes the mixture and makes 

 for unsteady engine operation at low 

 speeds. On well designed engines, the 

 valve-stem guides arc removable and 

 new ones can be easily inserted in 

 place of the worn members. 



A simple and effective method of rc- 

 mcning is illustrated at A. The valve- 

 chamber cap carrying the spark-plug 

 is used as a basis for the device. A 

 bushing to replace the spark-plug is 

 screwed into the cap, this being tapped 

 out for as large a bolt as possible. If 

 the spark-plugs are ^-in. standard pijie 

 size, a i^^-in. or 7/16-in. bolt can be used 

 to advantage. The bushing is easily 

 forced out by pressure obtained by 

 screwing down the bolt. This is superior 

 to the ordinary method of driving the 

 bushings out with a drift, because the 

 seating or casting may be damaged by a 

 careless blow of the hanuner. 



The method of applying the new guide 

 is onlliiied at B in the accompanying 

 illustration. A long boll, the size of the 

 valve-stem is used as a tension screw, 

 this passing through a piece of slcel or 



iron bar resting on the valve-cap. Pres- 

 sure applied against the guide by eithci 

 the top or bottom nut will draw the 

 bushing in place in the c\'linder-casting 

 without injuring it. The usual methotl 

 followed of driving the bushing in is apt 

 to result in breaking that member. 

 While a lead or copper hammer is not .so 

 apt to mar the surface as the steel ham- 

 mers are, still there is always danger of 

 breaking the bushings. This is entirely 

 eliminated by the forcing in process. 



Quickly Adjustable Automobile 

 Fan- Belt Fasteners 



ANKW type of automobile fan-belt 

 fastener has just been brought out. 

 It is quickly attached, adjusted or 

 repaired. .The fastener consists of two 

 metal parts, each attached to one end 

 of the belt by means of three small 

 brads. One metal part, the male, has 

 two curved hooks \\ hich are slipped into 

 two corresponding slots cut in the female 

 half to make the belt continuous. 



The fasteners are used with a special 

 fabric belt and may be attached in a 

 few minutes by means of the small brads. 

 If the belt works loose on the pulleys, it 

 may l)e taken off in a few seconds simi)ly 

 by unhooking the fasteners, whereas 

 with a laced leather belt this takes 

 several minutes and is a disagreeable job 

 if one has to lean over a hot engine that 

 has been running for several hours. To 

 adjust the loose belt, the three brads of 

 one of the fasteners must be removed, 

 the fastener itself moved back a sliort 



Any length of belt can be made up and 

 adjusted by the use of the fasteners 



distance on the belt and the brads jmslu'd 

 through the belt at otlu'r points. 



Tlu' fasti'ners are made of c-old rcilKii 

 steel, the hooks being lieat-tri-ated but 

 not made brittle, while the female 

 fastener is left soft. 



