Open Library - открытая библиотека учебной информации

Открытая библиотека для школьников и студентов. Лекции, конспекты и учебные материалы по всем научным направлениям.


Высокие технологии Valve adjusting shim thickness chart
просмотров - 318

Measure the shim thickness with a micrometer

A Install the cam follower tool as shown and squeeze the handles together to depress the cam follower, then hold the follower down with the smaller tool so the shim can be removed

by squeezing the handles of the cam follower tool together, then hold the cam follower down with the smaller tool and remove the larger one. Remove the adjusting shim with a small screwdriver or a pair of tweezers (see illustrations).Note that the wire hook on theend of some cam follower tool handles can be used to clamp both handles together to keep the cam follower depressed while the shim is removed.

8 Measure the thickness of the shim with a micrometer (see illustration). To calculate the correct thickness of a new shim that will place the valve clearance within the specified value, use the following formula:

24.7b Keep pressure on the cam follower 24.7c . . . a pair of tweezers or a magnet  
with the smaller tool and remove the shim  
with a small screwdriver... as shown  

1•20 Maintenance procedures

    New shim thickness mm (in.)  
Shim Thickness Shim Thickness  
2.55 (0.1004) 2.95 (0.116)  
2.60 (0.1024) 3.00 (0.118)  
2.65 (0.1043) 3.05 (0.120)  
2.70 (0.1063) 3.10 (0.122)  
2.75 (0.1083) 3.15 (0.1240)  
2.80 (0.1102) 3.20 (0.1260)  
2.85 (0.1122) 3.25 (0.1280)  
2.90 (0.1142) 3.30 (0.1299)  

N = T+(A-V).

A = Valve clearance measured.

N = Thickness of the new shim.

T = Thickness of the old shim.

V = Desired valve clearance (see this Chapter's Specifications).

9 Select a shim with a thickness as close as possible to the valve clearance calculated. Shims, which are available in 17 sizes in increments of 0.050 mm, range in size from 2.500 mm to 3.300 mm (see illustration). Note:Through careful analysis of the shimsizes needed to bring the out-of-specification valve clearance within specification, it is often possible to simply move a shim that has to come out anyway to another cam follower requiring a shim of that particular size, thereby reducing the number of new shims that must be purchased.

Caution: The engine must not be rotated with any shims missing.

10 Place the special cam follower tool in position (see illustration 22.9a), with the longer jaw of the tool gripping the lower edge of the cast follower boss and the upper, shorter jaw gripping the upper edge of the follower itself, press down the cam follower by squeezing the handles of the cam follower tool together and install the new adjusting shim (note that the wire hook on the end of one cam follower tool handle can be used to clamp the handles together to keep the lifter depressed while the shim is inserted. Measure the clearance with a feeler gauge to make sure that your calculations are correct.