Crossover corrosion.

[56pan]

I'll try to post pictures of what I found today on my exh. crossover. My boost press. had gone from 13 psi to 8 psi at WOT and was slowly decreasing. I noticed I was rolling the coal also at WOT. Checked fuel pressure with a gauge taped to the windshield at WOT and it dropped to about 1 psi. From what I understand this is sufficient at WOT. Checked all the ducting from the compressor outlet through the intercooler to the intake and was sure there were no leaks. Finally noticed when I got under the truck with it idling I could feel an exh. leak below the driver's side manifold. Took the crossover off and the pictures tell the story. I had wrapped the crossover with header thermal wrap about 8 yrs. ago when I put the mandrel bent one piece on the truck. I remembered there was a discussion concerning wrapping the crossover on either this forum or one of the others several years ago, but I couldn't find that again. The gist of it was that there was a disagreement about the thermal wrap on the crossover. Most said it was a good idea, but the detractors said it would cause the pipe to corrode. Which the attached pictures reflect and the detractors had a good point. I put on a new 2 piece Diamond Eye crossover today after giving it 3 coats of VHT and then wrapping it with new thermal header insulation. I'm a retired airline mechanic and on the Boeing, Douglas and Airbus ships, the GE, Rolls Royce and Pratt and Whitney large turbofan engines all have thermal blankets on the turbine sections. To maintain efficiency is what I understood, not for cowling protection. I've also seen large Caterpillar diesel generator sets with blankets on the exhaust feeding the turbine of the turbocharger. If it's good enough for those engineers, it's good enough for me. Just my opinion and worth what you're paying for it. At my age, if the crossover corrodes through again, I'll be long gone. Truck is a '93 C2500, mech. inj. pump.