What causes popping! and WHY

[AH64ID]

These are pretty simple motors, about the simplest I have ever worked on..Now the tuning of the CR's... that's not simple!

[rancherman]

You guys make these simple little B series way to complicated. Throw in timing for the old 855 cummins where you mechanicaly set injector timing and depending what series 855 it was and what it had for a cam ect you get into inner base circle and outer base circle timing settings. Then you have to shim the cam follower housings on the side of the block to get the base timing and get the cam followers shimmed correctly or the injector timing is not going to come in anywhere close.

I've never worked on a 855, but I thought they were kinda the same as my 903's... There is a provision for setting injector timing, with offset cam gear keys.. but it was always 'in relation' to the cam.. (cam timing must change in order to set injection timing) Lately, I've been setting the injectors using the torque wrench method.. just to see if it saves any time versus the dial indicator method.. It is, because I can set the valves and injector at the same time/per cylinder.. I go about 45* after tdc to set all three... five actually when you include the valve cross heads.. Simple design... just need 4 foot breaker bars to work on the thing!