Lifters
m (→Solid lifter) |
(Add image, text.) |
||
Line 11: | Line 11: | ||
Flat tappet cam/lifter valve trains were the primary form of valve actuation for domestic engines from the early '50s until about the mid-'80s. They were reasonable durable and reasonably reliable, although there were better designs. Not until the EPA mandated a change in the motor oil formulations did they fall out of favor. | Flat tappet cam/lifter valve trains were the primary form of valve actuation for domestic engines from the early '50s until about the mid-'80s. They were reasonable durable and reasonably reliable, although there were better designs. Not until the EPA mandated a change in the motor oil formulations did they fall out of favor. | ||
+ | |||
+ | ====Flat tappet lifter foot==== | ||
+ | The lifter foot of a flat tappet lifter is not perfectly flat, instead it is slightly convex. This is done to allow the lifter to rotate, and the shape of the lifter combined with the shape of the cam lobe is what causes this rotation. The rotation of the lifter keeps the highly loaded interface between the lifter and cam lubricated and cooled so as to not cause excessive wear during operation. | ||
+ | |||
+ | [[File:Cam lobe angle.jpg]] | ||
====Mushroom flat tappet lifter==== | ====Mushroom flat tappet lifter==== |