LB7 Injector Cups - Thinking out loud...

[More Power]

The LB7 injector cup design was one I wish Isuzu had put more thought into. Why they didn't consider the service problems that could arise is amazing - or maybe they did consider it. When the LLY arrived in the 2004.5 model year, Isuzu obviously had thought it out a little more because the injectors were positioned differently and they had abandoned the cup design.

That was good for the future of the Duramax, but several hundred thousand owners were left with the LB7 injector cup problem... It's thought that replacing a set of injectors presents a possibility for disturbing the cup seals, resulting in combustion pressure finding its way into the cooling system - which can result in water pump seal failure and head gasket replacement (thinking that's the problem).

Thinking out loud... What if the small end of the cup was re-designed? Instead of a smooth-sided end, machine a new cup with shallow self-cutting threads on the small end. The new cup would be installed with Loc-Tite as before, but buzzed in with a power tool in 2-3 full turns. Shallow coarse threads would help lock the cup into the factory aluminum head, possibly making injector replacement a less iffy and risky venture. If it worked, it would be another aftermarket product I'd love to see.

Just an idea....

[DieselDavy]

Wow, MP, that would be huge in the aftermarket. I'm guessing someone like you or Kennedy in conjunction with a machine shop could come up with a process for this similar to installing the tubing in the 6.5 head water jacket passages.
I say, "Go for it!"
Dave

[Kennedy]

There are guys doing them from what I understand, but I've not seen the need personally. We seldom pull up a cup when doing injectors and those that do pull are typically glued together with coked oil due to a rolled body oring so I'd rather have the cup come out because a stuck on cup is a real pain to remove. About the only success I have had is to heat the cup with a torch to try to turn the oil to ash.

[More Power]

As it turns out, there is a company offering cups with threaded ends for the LB7.

http://www.trucktrend.com/how-to/engine/1710-industrial-injection-lb7-duramax-screw-in-injector-cups/

This is what Isuzu should have done from the very beginning when designing the LB7. The only problem I see is that the cup kit is expensive. We'll see what develops.

[DmaxMaverick]

Brilliant, but wow. They sure are proud of them.