Engine Water Plumbing

Details:

NB. Without a thermo unit fitted the water should always enter at the lower point of exhaust manifolds and exit out the higher point then enter at front (dog clutch end). Then through the engine and exit from the high end of the heads or inlet manifold (pipe tapping required) then exit into the exhaust pipes.about 50mm down from the manifold flanges.

We don't recommend using taps or other devices to restrict water flow anywhere in the system.
If wishing to raise water temperature in the engine then use a thermostat control unit as you require some sort of relief valve so not to restrict the water passing through the exhaust manifolds which requires the full water flow.

Failing to install a thermo unit will cause the engine block to be cooler therefore less expansion of the cylinder bores reducing clearance between the bores and the normal hot pistons accelerating wear.

Recommend all boat owners to fit a water strainer filter system before the water pump to eliminate the possibility of ingestion of gum nuts,weed or any other rubbish found in the water that could ruin the water pump impeller.

Remember if you cannot run your hand along the outside of the exhaust manifolds while the engine is idling most likely the pump is not operating correctly and then requires investigation.

The yellow and last image here shows the Rolco brand thermostat control unit.

Hoping this information will keep you on the water longer.

Regards Bob (R&M Precision Marine)