What direction of movement of the coolant?

[vasya]

Hi there.

I installed Perkins 3.152 engine in my boat. The engine is from loader.

What is direction of movement of the coolant? From the lower branch pipe of the pump to the thermostat housing or from the thermostat housing to the lower branch pipe of the pump?

I have outboard cooling system, is the tube under the water line. Now time i just testing the engine after installation in boat. When thermostat is opened the tube from the thermostat housing to the outside of boat is hot, the tube from outside connected to the pipe of the pump is warm. I was surprised because I always thought that the cold water has to go in the cylinder head because the cylinder head is the most heated part of the engine.  I ask because I need to correctly put the heat exchanger of the hydraulic gearbox - to the coolant exit from outside of hull.

I'm so sorry for my english. I'm from Russia.

[Chewbacka]

Usually out the top by the thermostat, then back in the bottom of the engine.  But see if anyone disagrees before doing anything.

[nicknorman]

Firstly, don't apologise, your English is so much better than our Russian! But I agree with Chewbacka, and your practical experience bears it out. Out from the thermostat at the top, in through the bottom or lower part of the engine.

[Flyboy]

Your engine cooling is working correctly.  Cold water into the pump & hot out of the thermostat.

[bizzard]

Sounds correct. Also pipe temperatures correct. Top one 'out' hot, lower one 'return'.cooler.

[vasya]

Thanks to all.

I just watched this video since I finished my cooling system.

But here the water is supplied under pressure

video

[Neil Smith]

I think  It should be a remote water pump like a jabsco with a brass body, as the engine pump is not a suction pump but a circulating pump, and you must have a mud box fitted to stop muddy canal water being sucked into your engine, if you already have these please forget the above.

Neil

[Tony Brooks]

lucky that one in the video muss have a waxstat in it, otherwise the pressurised water would have forced the stat tight closed and only a dribble would have got through the vent hole.

[vasya]

7 hours ago, Neil Smith said:

I think  It should be a remote water pump like a jabsco with a brass body, as the engine pump is not a suction pump but a circulating pump, and you must have a mud box fitted to stop muddy canal water being sucked into your engine, if you already have these please forget the above.

Neil

Hi, Neil.

It's not my engine on movie.

I have the outboard tube for cooling. I do not have a sea water circuit.

I need to install the oil cooler of hydraulic gearbox in my cooling system. The oil cooler must be fitted first after exit of cooled antifreeze behind the board from outboard tube. But I'm affraid that the gearbox may can be overheated because the gearbox must be cooled by river water directly. After I do it I try to test the temperature of gearbox by infrared thermometer.

[Tony Brooks]

If by "outboard tube" you mean a keel cooling system then you should be fine as long as the tube area is sufficient. Virtually all UK narrowboats use a similar system and ifr they need an oil cooler connect its as you d ecsribe.

[vasya]

I have the place 0,53 quad meters of heat exchange. The engine power is 49 hp at maximum speed 2500 rev/min, the cruise speed is 1600 rev/min and power is ~28 hp.

[Neil Smith]

That tube does not look like it has enough surface area to cool the engine, and what kind of boat is it?

Neil

[cuthound]

I have seen this arrangement before, but only to increase the capacity of an existing, undersized, keel cooler tank. 

[Tony Brooks]

32 minutes ago, Neil Smith said:

That tube does not look like it has enough surface area to cool the engine, and what kind of boat is it?

Neil

I agree and add that such a large bore pipe will allow some of the hot coolant to pass down the middle of the tube and not be cooled so well. On our keel cooled hire boats we had four tubes about 12mm diameter and about 5 feet long running between cast bronze headers that were either faired themselves or has fairing blocks fore and aft to deflect obstructions. Work on 3 to 4 HP per sq, ft. of cooling surface.

However if it the engine does not overheat  why worry, the  coolant should bee cool enough to cool the gearbox oil.

Edited March 12, 2017 by Tony Brooks
Though of soemthing to add

[vasya]

7 minutes ago, Neil Smith said:

That tube does not look like it has enough surface area to cool the engine, and what kind of boat is it?

Neil

This tube is 3m long and 50 mm diameter.

And i have four tanks on skin inside the hull, two 300x600 mm and two 300x400 mm, but this tanks still not connected to cooling system.

The boat is:

http://canalworld.net/forums/index.php?/topic/67424-skin-tank-design/#comment-1332211

[vasya]

Just now, Tony Brooks said:

I agree and add that such a large bore pipe will allow some of the hot coolant to pass down the middle of the tube and not be cooled so well. On our keel cooled hire boats we had four tubes about 12mm diameter and about 5 feet long running between cast bronze headers that were either faired themselves or has fairing blocks fore and aft to deflect obstructions. Work on 3 to 4 HP per sq, ft. of cooling surface.

However if it the engine does not overheat  why worry, the  coolant should bee cool enough to cool the gearbox oil.

Yesterday I tested my engine cooled only by tube (50 mm X 3 meters) with ~2100 rpm of speed. After 40 mins the temperature of coolant was 72 degrees. But water in river still cold, recently freed from ice.

The boat was tied to the pier. In this case, more power is required than when the boat is moving. The propeller is 560 mm diameter and 420 mm pitch.

[Mikexx]

9 hours ago, vasya said:

Yesterday I tested my engine cooled only by tube (50 mm X 3 meters) with ~2100 rpm of speed. After 40 mins the temperature of coolant was 72 degrees. But water in river still cold, recently freed from ice.

The boat was tied to the pier. In this case, more power is required than when the boat is moving. The propeller is 560 mm diameter and 420 mm pitch.

 

What was the coolant return temperature?

Most engine designs rely upon a minimum 20 DegsC difference between coolant exit and return.