While prepping a spare engine to replace another troublesome mill, I came across this unusual grind profile on one of the bearing journals...
![](https://lh3.googleusercontent.com/-m4Jd5zXiOYM/ULQRus6cX3I/AAAAAAAAA08/3iV2rbTvMEc/s640/Cam%2520Grinds1.jpg)
![](https://lh4.googleusercontent.com/-RgFfnaXQWOA/ULQRnbQe8lI/AAAAAAAAA0s/9ZFaqiZUUG8/s640/Cam%2520Grinds2.jpg)
![](https://lh3.googleusercontent.com/-EH9WjUV5-Bg/ULQRvh-APwI/AAAAAAAAA1E/BfZ8a8NXP6Q/s640/Cam%2520Grinds3.jpg)
At what "degree" does the cam bearing journal start to melt?
![](https://lh4.googleusercontent.com/-Zqxa0tsz3JQ/ULQRsJIjo6I/AAAAAAAAA00/SLgevUu875k/s640/Cam%2520Grinds4.jpg)
Turns out one of the oil orifices (that little oil-jet orifice in the top of the head, under the cam tower) was plugged with an amber-like material about the size of a small grain of sand. DAMN!
Now for the other grind...
While sifting through my assortment of cams I discovered that one of these is not like the others!
![](https://lh6.googleusercontent.com/--44CjKBTvUk/ULQRx8S6sLI/AAAAAAAAA1M/0dNCRMSGWiw/s640/Cam%2520Grinds5.jpg)
Look at the plateau on top of the lobe! Now I have to scrounge up a dial gauge and figure out how big those bumps are!
![](https://lh3.googleusercontent.com/-hRT03vP0g10/ULQR0jOU7ZI/AAAAAAAAA1U/HKXaJWGJJRk/s640/Cam%2520Grinds6.jpg)