Thread: 350 chev marine question

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hi I have a question on water flow on a 350 chev motor.
As its in aboat and drives off timing gear end. Water enters via timing end and exit fly wheel end. The timing end being lower water fill motor then exits.As temp sender is at timing end next to thermostat location if used as no thermostat used its an edelbrock manifold alloy type.My question relates to sender for temp being at same end water enters so would like to know water paths etc or if anyone has same motor in there boat.Any info or sites that will help ?thanks

I'm really confused. Ok, so you have a 350 marine engine, who converted it? Mercruiser? Volvo? Is it straight inboard, jet drive, inboard outboard, etc? What is the application (what style boat)?

I work in the service dept of a marina, so maybe I can help, but I need more info and am not sure what you are asking.

Originally posted by nitrox1971
hi I have a question on water flow on a 350 chev motor.
As its in aboat and drives off timing gear end. Water enters via timing end and exit fly wheel end. The timing end being lower water fill motor then exits.As temp sender is at timing end next to thermostat location if used as no thermostat used its an edelbrock manifold alloy type.My question relates to sender for temp being at same end water enters so would like to know water paths etc or if anyone has same motor in there boat.Any info or sites that will help ?thanks

i think you want to know where to put the temp. sender in the block. i like to get a reading off of the heads, so i put it in the head when i can. if not away from the rad. as posible. if you run a thermostat it don't make as much dif.

Motor is in a flightcraft phantom ski boat.inboard
dog clutch set up so direct drive to prop.
motor has been in boat from new 1982 model boat look to be a standard car motor with few mods to marinize it.
Its cooled with river water preheated via ext manifolds no thermostat
heated water enters heads at front of motor and exits heads at rear fly wheel end.motor sits on about 19deg angle flywheel being high end. I think water flows this way as to fill motor let air escape as water pumped in (water pump belt driven piped to heat exchanger then to motor then exits motor and is feed in to exhast pipes back to river.Im not sure on whats inside motor and would like to find out how water flows what paths etc. As sender is mounted in manifold above entry point in heads is sender reading temp of pre heated water and other end of motor alot hotter.?From temp gauge motor runs cool 70 deg c .
hope this helps .
Thanks for replys

70* C is about right for a raw water cooled motor. If you get much hotter, the water will boil without any antifreeze and once it boils, it stops cooling.

Conventional marine engines like Mercruiser, etc. use the reverse of your setup, as I understand it. Usually, the water is sucked out of the source (river in your case) by a raw water pump into the engine. Then a circulating pump, that looks and mounts just like your standard Chevy water pump, circulates that water throughout the engine, before it is expelled out the exhaust system.

Sounds like in this straight inboard application of yours, they bring the water into the exhaust manifolds first, then that heated water is fed into the engine, then overboard. I guess this would work, but what controls the temperature of the water? You are at the mercy of the exhaust manifolds to do this, and I don't understand why they did it this way.

When I lived in California there were a lot of companies doing unorthodox things when building ski boats, so I guess some company figured this is a good way to do it for whatever reason.

If they are still in business, I would get in touch with the manufacturer. Or, you may have something someone has modified for some reason. Sorry I couldn't help, but this system is something I have never seen in my 20 years in the marine business.