What Are these Hoses Doing ?

[ozmike]

I have removed the compressor for the freezer (fitting new system) and have removed some of the pipework, I have these 2 hoses coming from the motor, the red hose on the left comes from the saltwater intake on the saildrive through a strainer, through the pump (bottom pulley) out the other side and goes into the refrigeration system, comes back via the black hose (one with white zip tie). question, what do I do with these hoses can I just disconnect the black hose, cut red hose and fit where black came off, will these keep the water circulation going or is there any other reason they go around to freezer.

[Albro359]

The raw water probably comes from your intake, through the impeller pump, then through the refrigeration system condenser and then to the heat exchanger on the engine and continues its way through to the exhaust.
OR if that impeller pump is only for the fridge system, it will exit the condenser o'board somewhere (that's pretty unusual)
Why would you want to bypass the pump in either case ??

[ozmike]

Albro359. I don't want to bypass the pump, the photo on the right shows the refrigeration and all its pipework, on the lower right hand side of that photo you can see the 2 hoses I am talking about, when everything is gone I have to do something with these hoses, I just want to make sure I am doing the right thing, by cutting the hose, lower right of left hand photo and putting it on where the black hose (with white zip tie) is coming back into motor.

[Albro359]

Yes, I thought about that after I posted the reply...the reason you've taken the negine driven compressor off is because you're putting in a DC system...therefore you no longer need the condenser.

So if I have this right...the red hose from strainer to pump inlet..leave it as is...the pump outlet hose....leave it on but cut it to the right length to go to the motor, at the connection the return hose from the freezer is currently on....

You should be able to locate and remove the driere and condenser now...
Cheers

[never monday]

the looks like a raw water cooled 3GM Yanmar. The outlet from the impeller should go to the fitting the black hose is going to on the block. What I'm not seeing is the bypass hose for exhaust cooling. Can you post a front on pic that shows more of the engine.

[Albro359]

On My Yanmar, the salt water plumbing is :

Raw water -> fridge condenser -> impeller Pump -> Heat exchanger -> Exhaust manifold

This system was:

Raw water -> impeller Pump -> fridge condenser -> Heat exchanger -> Exhaust manifold

By doing what I suggested they will have :

Raw water -> impeller Pump -> Heat exchanger -> Exhaust manifold

That will work fine...don't you agree ?

[ozmike]

Albro359. yes I am replacing with DC system, much simpler and neater, on our delivery trip down from Airlie beach, the system stopped working.
never monday. have added a couple of photos for you, and motor is a yanmar 27 hp. not sure where the bypass hose is. could you point it out for me.

[Joli]

You can have a dc system with a water cooled condenser. If your new system doesn't require it then secure the old intake and exhasut lines.

[Albro359]

Originally Posted by ozmike

Albro359. yes I am replacing with DC system, much simpler and neater, on our delivery trip down from Airlie beach, the system stopped working.
never monday. have added a couple of photos for you, and motor is a yanmar 27 hp. not sure where the bypass hose is. could you point it out for me.

ooo!...its hard to tell..this a raw water cooled engine by the look of things...mine is FW cooled with a heat exchanger...but still the flow should be :
raw water->pump->engine somewhere-.exhasustmanifold-> exhaust

When you talk about "bypass hose"...what do you mean exactly ??

[cal40john]

I think what Never Monday is talking about is where the water goes when the engine is cold. I think that the long black hose is teed to the short more vertical left black hose on the engine. The thermostat housing is at the top end of the short hose. When the engine is cold, thermostat closed, the water flow is through the short hose bypassing the engine. The chamber in the thermostat housing above the thermostat (towards us in the picture) allows the water to flow through it from the short vertical hose to the hose above it leading to the exhaust manifold and then to the exhaust. When the thermostat is open the short vertical hose is blocked and the flow is into the engine then through the thermostat and out the top half of the thermostat housing to manifold, etc.

John