General: Cummins VT 903

I've searched this forum, and a dozen others, and all I seem to find on this engine are complaints, annecdotes, and unrealistic numbers concerning a good buddy's souped up tractor with a 9-0-nothing.

I've expanded my search into the V 903, VTA 903, and V/VT 903M, and not found much more beyond stories of shimming the fuel pump, and how loud they can be.

Any more general info on this engine? I've read that 700 hours is a good interval for setting the valve lash clearance, but that's about all.

Are there still any decent mechanical fuel pump shops around? I'd like to have mine gone through to get the seals and O-rings changed out for neoprene so I don't run into issues with biodiesel. $300 is what I've read for a tear down, and it sounds like money well spent to me, but I don't know where to take it.

Are there any big reasons I shouldn't consider having the springs and shims played with on the pump while its off the truck, other than premature driveline wear? I'm not looking to hoon around at 80mph in my large car, but I've read they do a bit better on the hills with the extra power, and they can do a bit better on fuel if you keep out of it. Should I just go straight for the 600HP setting, or are the intermediate settings that would be advisable?

Thanks in advance for your time to anyone that still knows anything about these engines.

 

The truck only has 17,000 miles on an in frame, so hopefully I shouldn't be too far off from being able to think about turning it up.

Does the standard shop manual cover the overhead settings? I've seen clearances vary from person to person.

Also, would it be unwise to add a secondary fuel filter? I've never felt comfortable with less than 2 filters going into a mechanical pump, and prefer having at least one on the return line. How much do I need to worry about backpressure/low pressure with these large pumps?

 

Oddly enough, this is the only VT 903 I've ever heard of that doesn't smoke. I haven't gotten to take it uphill under a load yet, but haven't seen a puff of it at startup, idle, or running around bobtail.

The injectors were replaced 17k miles ago as well. Think they'll need to be set soon? I read something in a marine engine forum about "rotating the injector bodies 30 degrees". Does that make any sense?

Is the V/VT/VTA 903 sometimes referred to as the 903C? That's the only digital manual I've found outside of austrailia. It covers a few old cummins engines, and has about a hundred pages covering the fuel pump that's used in the VT 903, but no mention of the VT 903 itself, just a "903C" V8.

 

That just makes it seem like a return line filter would be even more worthwhile.

I've read that backpressure on the fuel return line can cause some sort of mayhem in older engines, though.

 

Thanks. They aren't too far from home either. Just got a digital army/air force technical manual for the fuel pump and injectors, and it looks like it isn't too bad to field service. I'd still like to get the machining and seals done right before I get a chance to play with it on my own.