I have a 1983
Volvo MD11D with a OEM
heat exchanger. It is currently
on the hard, getting ready to launch. When I run the
engine the conventional way (raw
water strainer intake hose in a bucket of water), I get little to no
water flow out of the
exhaust. But when I bypass the strainer (raw
water pump intake hose in the bucket), I get plenty of flow. Impeller and
gasket are new, I tightened the "sealing" bolts on the strainer, primed the system by filling the strainer with water, put a dab of silicone grease around strainer
gasket, still no flow. At the end of last year's season, flow when the
boat was in water was fine. Someone suggested I
rebuild the
water pump, but before I open that can of worms, I wanted to check if there was a really basic "physics" reason for the strainer-dependent flow and if I can hope/expect good flow once I'm back in the water, with ocean hydrodynamics in play.