Hey, 66 Submarine! was the life-span of the marine 292 caused by linking the prop directly to the flywheel,without a trans? Water has quite a bit of resistance ,so it may have been harder on the engine trying to get up-to-speed,than it was to run it at a constant high speed. Just a thought. B.T.W... I had the head off of my truck just last August,and the previous owner KNOWS that my 261 has sat more than 10,out of the last 15-years that he and his neighbor owned the truck. i's never been re-built,or tore-down as far as anyone knows. MY point to this matter is that there is virtually no ridge on the cylinder walls,compression tests within 10#/cylinder,and it uses virtually no oil! Odometer reads 98,000 miles,and NO sign of smoke. The way mine runs,it should be good for at least another 50,000 miles. I know my truck hauled some heavy loads of cinder-bloc,as well as a back-hoe towed behind it!! I think as long as you maintain any vehicle,it will respond accordingly. I change the oil every 1,000 miles,since my truck doesn't have an oil filter,(S.C.O. engine.)I use Valvoline ZR 5W50 Racing oil,as well as 4 oz. of ZDD additive per oil change. It's recommended for use in solid-lifter engines,since the gov't. put regulations on zinc in oil,which our 216,235,and 261's were designed to operate with,un-less a passenger car equipped with an automatic-(Hydraulic lifters).
