Improving the Raw Water Circuit

This is our raw water coolant pump with its new Speedseal cover. Given the somewhat inaccessible location of the impeller pump I thought it best to replace the OEM seal with a SpeedSeal. Now you really can replace a impeller while blindfolded! We replace our impellers every year... they aren't cheap but a smoked engine or exhaust hose is worse.

Note the leftover paint on the rubber hoses and the impeller housing - this definitively is not powder paint! Replacing the rubber hoses on your engine is much like replacing impellers. While an impeller presumably has a shorter life than the hoses in and around your engine, it is best to replace parts that haven't broken yet than to have them go when you really need them. Some of the rubber interconnections on engines have very proprietary shapes that should encourage folks to stock up ahead of time - or be stuck in port with a big mess.

Replacing the Raw Water Strainer

Here is a picture of our raw water strainer for the engine. It is a pretty beefy Groco unit that we expect to last a long time. The unit that Prout Catamarans installed, a cheap plastic see-through thingie, exploded when a truck ran over the freshwater hose plumbed in while we were testing the engine. Naturally, we have been a bit more vigilant about the incompressibility of water before plumbing a freshwater line into our system again. This year we tested our engine using a freshwater hookup - but no impeller. We still posted a lookout to ensure that the water supply would not be blocked.

Behind the strainer you can see the three lines that feed each hydraulic motor held in place while we effect repairs. The thicker lines are color coded and carry the hydraulic fluid from the pumps to the motors. The third line siphons off some fluid for cooling and returns it to the main reservoir.

Replacing Inadequate Valves

Our OEM thru-hull for the engine consisted of a regular gate valve(!!!) that you can see in the right image. Even boat show attendees spotted this no-no. What made the choice so curious was that other thru-hull in the boat are of better quality. Why would Prout Catamarans use a cheap gate valve for the engine, yet more expensive ones elsewhere? Mysteries abound.

We replaced the gate valve to the right with the ball wall you can see in the left picture. The hose that connects this thru-hull to the strainer has also been replaced with a wire-reinforced version. The hose that runs from the strainer to the hydraulic oil heat exchanger and from there to the engine will suffer a similar fate. If our hose replacement scheme seems paranoid, it is because of the overall quality of hose used on board.