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7.3 Combustion chamber and injector reports after 50,000 miles on a high cholesterol diet

Well, with a total mileage of about 170,000 miles on my motor and the last 50,000 on oil, I had the unfortunate experience of the #8 piston splitting on me. It didn't melt, it didn't seize, rings didn't even break. The piston simply broke in half, most likely from my performance mods.  Well, this gave me an opportunity to tear down and inspect the top end of my 7.3l PSD.  I sent a pair of injectors (including #8) into Swamps Diesel Performance, a well known PSD injector specialist who did a complimentary injector inspection for me. And here is what Jonathan had to say:

Jason, We got your injectors in a day or three ago, and I just finished inspecting them. They are in perfect condition. First we measure the travel of the poppet valve, which controls the entry and exit of the high pressure oil into and out of the injectors. Wear here indicates valve seat wear, either from high mileage or dirty engine oil. Travel on a brand new injector is .0105", yours were .011".0115". Typical wear is .010" per 80k miles, so you're well below the average here.  The engine oil in the injectors was very, very clean, and not because you just changed the oil--it is a tight engine and has had good air filtration its whole life. Using WVO cannot effect anything in this part of the injectors. Inside in the fuel area, there was heavy varnish buildup on all the parts, which is usually a sign that the truck has sat and not been run for extended periods of time--like umpteen months in Iraq?  The discoloration on the varnished parts was darker than normal, but a light lapping on 800 grit emery cloth on a surface plate quickly removed all traces, and  the metal underneath showed no signs of pitting, rust or corrosion what so ever. Nor was there any rust on the outside of the lower half of the injector body between the lower two O-rings, which is what indicates the engine has had fuel in it with a high moisture content for long periods of time. The plunger and barrel, which is the first part to go in an injector that gets water, gasoline or abrasive particles in the fuel were in better than average condition for the mileage on the engine.  The fuel plates sealed perfectly, and the  nozzles sprayed normally and sealed perfectly as well. Nozzle pop pressure was 2250 on both of them, which is spec.  The only thing that was the least bit unusual was that there was some very heavy carbon buildup on the nozzles--it was thicker than normal, and by far the hardest I have ever seen. I took some pictures, but assembled the injectors before checking to see how well they came out--too dark, but I'll include  a few, before and after cleaning.

So as you can tell the injectors were in excellent shape. I was gone for about 9 months to Kuwait, and the truck did sit for some time. And the hard carbon buildup was from my early attempts at running on oil with a cold motor. That is what happens, you quickly build up deposits.

Injector, Engine and cylinder temp is far more important than the temperature of the oil itself. There is no injector pump on a PSD to fail so the chances of a single catastrophic failure on a PSD is very unlikely. However deposits from poorly burned oil due to running on a cold motor will gradually buildup over time and eventually cause the motor to start wearing exponentially and essentially wear itself out very, very prematurely.

While the heads were off, I took some measurements of the cylinder wall for taper (an issue to be aware of on any forced induction motor), and out of round as well as taking some pictures. The measurements were all within spec, and the pistons were so clean that I could still read the factory engraving on the top of the pistons!! See for yourself!!

Ok, still not convinced, here is the Blackstone Oil report analysis after the fact.

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