Assuming the outdrive is not connected (impeller would fail within a few
seconds) and assuming adequate lubrication and assuming raw-water cooling
and assuming the boat had been in the water and therefore the block was full
of water and assuming the belt to the water pump was disconnected ... the
water would soon boil off ... after that ... or assuming no cooling water
.... exhaust is water cooled so manifold/risers could warp, water hoses could
melt, head could warp, depending on the engine lubricant (some of that
synthetic stuff is pretty good) pistons may or may not seize ... .

Wild guess ... 3 minutes tops ... please post your findings :-)


"IDT 512" wrote in message
om...
how long can i run the engine safely without cooling water? engine is a
Merc 3.0L.