Thread: 6.5 injection in a 6.2?

Mechanical injection systems and parts should be 100% interchangeable.

The only issues I have run across is short versus long injectors (requires slight bending of injection lines at the injetors) and using later model 6.5 heads, which have a slightly different injector mounting angle (and, again, required a slight bending of the injection lines).

Originally Posted by mblazer

Im lookin into a grad project to upgrade my 1986 Military 6.2L Diesel and i was wondering if an Early Mechanical 6.5L. Turbo Injection Pump would work on my 6.2 since it is also mechanical...Also wondering if the fuel lines would be the same or not
Thank you

Yes it will work, but it will put more fuel in the engine than it needs because a turbocharged engine needs more fuel. You either need to turn the fuel down or put the 6.5's turbo on your 6.2 to add the extra air back into the mix. The injection lines may or may not work if you are swapping those also. Your existing lines should fit the new pump without any issues. Mike

another question..now im no expert but im pretty sure that the turbo wastgate needs a vacuum pump and being bare bones military(no A/C)how would that all hook up?

The vacuum control system requires a PCM which your 1986 vehicle does not have. The PCM is required for electronic injection.

The early 6.5 turbos had a spring-controlled waste gate. Turbo Master makes them or you might build your own. Get a boost gauge and EGT monitor so that you don't melt your engine. Keep it under 1,100 degrees F and 10 PSI boost and you will be okay.

The 6.5 injection lines also have a slightly larger ID to move more fuel, & the 6.5 injectors have a slightly higher pop pressure. Have you tried turning up the fuel (don't go more than 1/8th turn) & advancing (turn the IP top slightly towards the passenger side) the injection? If you add too much fuel without increasing the airflow, you'll just make smoke & waste fuel.