Wednesday, July 9, 2008

Mechanical Update 2

Warning, read at your own risk!! The contents of the blog entry will put the non-mechanically-interested-reader in a sleep-like haze; but, will arouse goose bumps on the others.

Yesterday, we sea-trialed Tide Hiker for 2.5 hours running her at 1400, 1600, 1800 and 2000 RPM's and also at WOT (wide open throttle) for a short while. The engine ran good maintaining a consistent 180 degrees after getting to cruising speed, no knocking and no air bubbles backflowing into the coolant overflow bottle. Norm found a few hairline cracks in the muffler, continued restricted sea water exhaust along with white smoke (steam) and a couple loose hose clamps. He tightened up the clamps and reported the other items to Hinckley and to American Diesel.

Today he and the mechanic removed the muffler and discovered the baffles inside were all disfigured and forced into the center of the overboard (exit) tube. The mechanic says that is most definitely the main if not the only cause of the restricted flow and the steam. The restriction caused water backup which caused the elbow to increase in temperature. So, the fiberglass muffler is being rebuilt by Hinckley as we take a pause in the action. We might have the new one tomorrow or Friday. The 4" hose from the exhaust elbow to the muffler was delaminated on the inside and will also be replaced.

The mechanic also did a pressure test on the coolant system and it was found to be in working order with the exception of a couple more hose fittings which were tightened on the spot. This is not a 100% guarantee that the head gasket isn't bad or that the block isn't cracked, but is very good news! The mechanic is very confident that we found the problems and "they ain't the engine". Hope I did't just jinx it!

The cause still remains a mystery. We suspect kelp or some other debris was sucked into the intake, held there by positive pressure and then released when the engine shut down. Or, was sucked all the way through and lived it's last minutes being sliced, diced and steamed. (We did travel through several debris fields on our way out there.) Might never find out for sure, but that's what the mechanics think and they say that they have seen it before. The flow at the intake strainer now is perfect.

Tomorrow or Friday Norm and the mechanic will reinstall the new muffler and 4" hose, we'll do another sea trial and go from there. Wish us luck!!

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