Super MD injectors

As for the precups, now thats a different story. I ended up plugging off the hole on top of the head with rubber expanding plugs, then turning the head upside down and filling the injector cavity with penetrating fluid. After a week I took the fluid out and started taping very gently on the nozzle end of the precup to drive it out, then with a drift I had machined to fit into the hole where the injector goes I tapped on the precup back the other way. I got a couple to move a bit so I repeated the penetrating fluid proceedure a few more times and lo and behold I got them all out. The minor damage done to the nozzle end of the precup was repairable with a file. My diesel tech assured me that what little damage there was left would have no detrimental effect on the operation of the precup, and it hasn't. Incidently, you'd be suprized at how rough you can get without seriously damaging the precup. But you got to be patient. The whole operation for both heads took the better part of a month.

Be very carefull to properly orient the precups in the head when you reinstall them. The only reason I had to take mine out was they had been installed 180 degrees out of turn. They had run that way for who knows how long but it forces the nozzle burst downward towards the piston instead of accross the combustion chamber. On one of the engines there was obvious damage to the pistons.

Good luck.