Water flow and overheating issues
 

Not my boat but my buddy Hollowpoint's (Wayne).

We put the new 454 (460) in on the starboard side last summer. We've finally gotten it going (some electrical gremlins) but now we have an issue with water flow and overheating.

454 with B&M 250, Stainless Marine exhaust, thermostat housing (no t-stat), and water crossover. On the hose without the engine running, water will start to come out of the starboard exhaust, but not the port. Firing it up (to get the pump running) water flow is strong out of the starboard side, but there is nothing coming from the port side exhaust. Interestingly enough, if you prime the port exhaust manifold, it will work (or at least it seems so).

We are at a loss as to why it flows well out of the starboard side but not the port. We thought that maybe it had to do with the water flow from the hose bib, but today Wayne took her out for the first run of the year and pretty much cooked the port manifold. The water temp was running about 190 degrees before it was shutdown.

Any ideas? If the water pump were hooked up backwards, would you get something like this? Anyone have a diagram for how the water hoses should be routed? My thinking is that something is not right between the water pump and the crossover inlet.

Any advice?

No one????

Very strange for sure. Sounds like either an obstruction in the Tstat housing or in the exhaust.

Hook the garden hose directly to each manifold and see how the flow compares. Then work backwards from there to check flow.

Definitely not at the manifolds. Hooking the garden hose to the inlet of the manifold produces good water.

Maybe something is clogged in the thermostat housing.

On my pump, the bottom port is the inlet, top is out. Water goes to the oil coolers first, then to the cross over.
Does the cross over have the bypass ? Sounds like you may not have enough volume of water to fill the system. Could be the pump for sure or like others said, a restriction at the thermostat housing or the oil cooler. Let us know what you find.
BC

We're going to pull it all apart and go through it.