1LW keeps scoring pistons after inframe and upgrades.

Since inframing 16 months ago i have scored 3 different holes on three occasions. I used cat parts for the overhaul; 8501 injectors, oil pump, oil cooler, water pump, cylinder head. Added pdi nozzle ring turbo with manifold and stage 1 cam. 60,000 miles later #2 piston went down. Blamed it on a bad injector, replaced injector and cylinder pack. 17,000 miles later #3 went down with some scratches on #4. Replaced all 6 cylinders and removed the pittsburgh box. I thought i was overfueling. Well 90,000 later i lost #6. Everytime the piston rings are completely stuck to the piston. Local machinist said combustion heat. Coolant temp never exceeds 210. Egt never exceeds 900. Cam timing is a half tooth to the driver's side. The ecm has not been flashed and injectors were trimmed when installed. Is anyone running a bigger cam without ecm tuning? This truck runs decent but nothing extra ordinary! I have also inspected the piston cooling nozzles and they are good. Thank you for any replies.

 

Thanks superhauler i wondered how your story ended up. The spray pattern on top of the piston seems ok other than some build up from running cold. I 'll look at the turbo. Do you mean yours was getting pretty loose (bearing play)?

 

I understand. I was leaning to re-installing the stock cam to decrease fuel. I run about 30-35 psi manifold pressure when in a full pull. I am usually above 7000ft elevation (san luis valley, CO). Where does the PDI nozzle ring turbo rank as far as air flow? I have been happy with it, but it replaced my 475 stock turbo. Not much to compare it against. I'm also concerned about the cam timing. Do you run a bigger than stock cam?

 

No sir. They were trimmed individually with the four digit code on the injector. I am searching for a way to compare the pdi stage 1 cam with the 1LW stock cam. That would be the only way i am getting more fuel now. I have measured the high and low spots on the lobes to determine the lift for each one, and they seem very close. Granted measuring by hand with calipers is not exactly accurate. Could the stage one cam have some advanced timing built into it, that would cause combustion problems with my timing being advanced a half tooth? Going back to Superhauler's thought on the nozzle ring turbo. What ring are drivers running? Mine came with 13 and 11 vein rings? I have heard the 11 is best for high rpm air flow?