130 



from the engine base to provide access 

 to the valve heads which are inside of 

 that member, and which cannot be 

 reached from the outside, as is true of 

 the L or T-cylinder construction. 



The preferred method of carrying the 

 valves when they are placed in the cylin- 

 der head in the Buick 6-cylinder motor, 

 is shown in Fig. lo. The valves are 

 carried in cages which are readily re- 

 moved from the cylinder head by un- 

 screwing the retention nut that keeps 

 the valve cage tightly pressed against 

 the seating at its lower end to ob- 

 tain a gas-tight joint. The valve cages 

 are easy to handle and it is a relatively 

 simple operation to compress the valve 

 spring and remove the pin which makes 

 for easy removal of the valve. When 

 this construction is followed it is 

 possible to grind in the valve by simply 

 removing the cage assemblies from the 

 cylinder. It is not necessary to disturb 

 the cylinder in any way and does not 

 call for disconnection of intake or ex- 

 haust manifolds ; the only things that 

 need be removed are the valve operating 

 tappets, which is work of but a few mo- 

 ments. 



Valve GrhiSng Process 



Much has been said relative to valve 

 grinding, and despite the mass of in- 

 formation given in the trade prints it is 

 rather amusing to watch the average re- 

 pairman or the motorist who prides him- 

 self on maintaining his own car perform- 

 ing this essential operation. The com- 

 mon mistakes are attempting to seat a 

 badly grooved or pitted valve head on 

 an equally bad seat, which is an almost 

 hopeless job, and of using coarse emery 

 and bearing down with all one's weight 

 on the grinding tool with the hope of 

 quickly wearing away the rough sur- 

 faces. The use of improper abrasive ma- 

 terial is a fertile cause of failure to ob- 

 tain a satisfactory seating. Valve grind- 

 ing is not a difficult operation if certain 

 precautions are taken before undertaking 

 the work. The most important of these 

 is to ascertain if the valve head or seat 

 is badly scored or pitted. If such is 

 found to be the cause no ordinary 

 amount of grinding will serve to restore 

 the surfaces, in this event the best thing 

 to do is to remove the valve from its seat- 



Popular Science Monthly 



ing and to smooth down both the valve 

 head and the seat in the cylinder before 

 attempt is made to fit them together by 

 grinding. Another important precaution 

 is to make sure that the valve stem is 

 straight, and that the head is not warped 

 out of shape or loose on the stem when 

 the valve is a two-piece member. 



Valve Grinding Processes 



Alention has been previously made of 

 the importance of truing both valve head 

 and seat before attempt is made to refit 

 the parts by grinding. The appearance 

 of a valve head when pitted or scored 

 is indicated at Fig. ii, A, in order that 

 the motorist or novice repairman can 

 readily identify this defective condition. 

 After smoothing the valve seat the next 

 step is to find some way of turning the 

 valve. Valve heads are usually provided 

 with a screw driver slot passing through 

 the boss at the top of the valve or with 

 two drilled holes to take a forked grind- 

 ing tool. The method of arranging the 

 valve head for the grinding tool and the 

 types of grinding tools commonly used 

 are also shown at Fig. ii, A. A combi- 

 nation grinding tool which may be used 

 when either the two drilled holes or the 

 slotted head form of valve is to be ro- 

 tated is shown at Fig. ii, B. This con- 

 sists of a special form of screw driver 

 having an enarged boss just above the 

 blade, this boss serving to support a U- 

 shaped piece which can be securely held 

 in operative position by the clamp screw 

 or which can be turned out of the way if 

 the screw driver blade is to be used. 



As it is desirable to turn the valve 

 through a portion of a revolution and 

 back again rather than turning it always 

 in the same direction, a number of spe- 

 cial tools has been designed to make this 

 oscillating motion possible without trou- 

 ble. A simple valve grinding tool is 

 shown at Fig. ii, C. This consists of 

 a screw driver blade mounted in a handle 

 in such a way that the end may turn 

 freely in the handle. A pinion is secure- 

 ly fastened to the screw driver blade 

 shank, and is adapted to fit a rack pro- 

 vided with a wood handle and guided 

 by a bent bearing member securely fast- 

 ened to the screw driver handle. As the 

 rack is pushed back and forth the pinion 



