| Message |
When the valve wear out(sink into head), the valve tip will move higher towards the cap+lifter, causing you to have lesser and lesser lash. When the lash reduce to zero, you'll have a valve that will not close. This valve will be burned during the combustion process as there is no heat transfer from the valve to the head. And at this point, the cylinder should have no compression at all. The driver should notice there is a problem by now. *quote*
"When the valves wore out, they wore way beyond the lash point and the cams began grinding into the caps of the solid lifters"
How is that possible? Take a look at the tomei lifter.
The camlobe will not, in any case, grind into the lifter cap when the lash wear out . The cap (shim) is so much stronger than the valve tip. The tip will wear out first before the cap. I believe the failure is, the tip wear off, causing the cap to hit on the retainer, and break the valve lock. The valve then will just drop into the piston. The failure mode you described is very interesting. I've seen a lot of valvetrain failures on racing engine (IRL,NASCAR etc) and OEM engine on durability testing. I have never encounter a failure like this. Do you have any pictures of the damage? This is by no mean to start a flame. I'm just interested in learning this failure mode. Thanks
|
 |
