Cooling system schematic

[kawaboy]

Gday to all

I'm in the process of re installing my rebuilt engine.

I would like some advise on how to "wire up" the cooling system.

My thoughts:

Run the strainer, water pump">raw water pump, heat exchanger, transmission cooler, V-drive cooler in series then exit at the exhaust manifold.

The engine fresh water goes to the heat exchanger and back to the engine.

Better ideas, anyone? Or did I get it right?

Cheers

Joe

[kawaboy]

I don't know what caused those typos but it should read:

Run the strainer, raw water pump, heat exchanger, transmission cooler, V-drive cooler in series then exit at the exhaust manifold.

Thanks

[savoir]

Your transmission cooler will probably be in the form of a miniature heat exchanger meaning that it takes both antifreeze and raw water.

[DougR]

Your thinking is correct....
Heat exchanger comes first, then gear cooler or V drive cooler in which ever order makes the plumbing easier, then dump into the exhaust elbow.

Keep the number of elbows and bends as few as possible and of large radius.

Don't forget that the anti- siphon valve needs to go in there on the pressure side of the raw water circuit if the engine is low in the boat.

DougR

[kawaboy]

Thanks DougR.

Good point about the anti-siphon valve.

Regrds

Joe

[jamhass]

Couple of thoughts:

1. Which engine/V-drive? On our Volvo 2003T, the V drive is sea water cooled (only) and plumbed BEFORE the raw water pump -- yes, on the suction side of the pump. Gets the coolest water that way, and yes, that is the factory way. Newer Volvo D240, same V drive plumbing.

2. Do you have a hot water heater heated by the engine? If so, don't forget that branch.

[kawaboy]

I have a 35hp 3 cyl isuzu with velvet drive trans and a walter v-drive.

No hotwater system. Dont need it where we are. 😆

[DougR]

Jamhass is correct that the 2000 series VP engines had the gear box cooler in the suction side of the sea water circuit, but you have to remember that VP has the technical expertise to determine whether this will introduce too much flow resistance and depression to the circuit and possibly cause a problem with the water pump impellor. (The gear cooler loop in the VP ms2 gear is a smooth length of 1/2 inch copper tube about 12" long......very low flow resistance)

If you don't know the maximum depression allowable on the suction side of your sea water pump, or have the ability to measure that depression, you are far better off to place the gear cooler (s) on the pressure side of the circuit. The difference in gear cooling by being placed before or after the heat exchanger will be insignificant, but the sea water pump impellor will be happier if the coolers are on the pressure side of the circuit.

DougR