Originally Posted by FlyWright
Great to hear, Harry! I didn't even know you were rebuilding the beast. Was the rebuild job brought on by sitting idle for 6 years without being pickled?
After cooler core failed and started leaking small amount of saltwater which made it way into #6 cylinder. We first noticed that with the IR thermometer along the valve cover the last cylinder was 10 deg hotter than the rest. So we had Cummins pull the top end off and check it out.
Turns out the after cooler has a zinc in the top and one in the bottom. They removed the top zinc and used that connection to supply raw water for the stabilizers. Sure enough ten years later the top of the core failed. Now it has two zincs again and we've reworked the stabilizer raw water intake.
At purchase time, we knew we were doing a top end job within 2 years of buying the boat. We had budgeted for it, so this didn't hurt the wallet as much as it could have.