When using a closed cooling system like Innovation Marine uses on many of their engines, are the water jackets in the exhaust system part of the closed cooling system or does the raw sea water run through it? Does the raw sea water simply run through the raw water pump through the heat exchanger and then dump overboard?

Thanks

The raw water goes through the sea strainer... the raw water pump... the oil coolers.... the heat exchanger.. then through the exhaust headers at which point it exits the boat. The only part that is cooled by the heat exchanger is the engine block, and heads..... When the coolant exits the thermostat housing it returns to the heat exchanger and back to the circulating pump.The circulating pump is generally mounted where a water pump is on an automotive application.

I owned the Innovation DPX 600's. I agree with the above statements, and would like to add that you should treat the headers carefully by flushing and draining to prevent water in the cylinders. I caught mine just in time.... I think next time out the motors would have hydraulicked. The headers were four years old and occasionally I did not flush them.

There are closed cooling systems available that circulate through the exhaust manifolds. The raw water is discharged through the tailpipe or riser. The system you described would be a "Partial Closed Cooling System".

Here's a couple diagrams of these types of systems to give you an idea of how these work. If you need a quote on a system just give us a call.

gotta just about double the size of the heat exchanger if you close in the exhausts...

I've got MarinePower EFI Big Blocks and they are standard with the full closed colling system. THe raw water (sea water) from the heat exchanger is dumped to the exhaust at the riser (elbow). THere is a stainless steel gasket that seals off the manifold/coolant from the riser/elbo area.

In my situation we had to use 6" spacer blocks and we set system up so the spacers are also cooled by coolant from the heat exchanger instead of raw water.

I installed a FULL system on my engine and the engine temp. dropped 10 to 15 deg. and the heat exchanger is normal size you just need a system designed to handle it all.

Suggestion: add header drains so you do not have to flush headers. All salt water will drain from the bottom of the headers when the engine is turned off.

Skaterboy,
Got any pics of a setup like that? Where do they drain and how is it automatic?

Viper 31,

Sorry "no pictures" at this time the boat is all covered, but if you are familiar with the 525EFI engine there is a common rail just below the header that runs the whole length. By simply removing the plug from the lowest end of the common rail and connecting a hose to it. Then install a exit stainless steel fitting on the side of the boat (above water level but below the headers) and connect the hose. The excess flow of water will flow while the engine is running and then when you shut the engine down , all the water left in the headers will automatically just drain out.