Twin Engines - Do both have Power Steering and Alternator Hooked Up?

[rcmpvet]

I may be in the wrong forum and if so I apologize, however the question does cover three topics; steering, electrical and engines.

My vessel has twin 4.3. 205 HP, V6, 1987. Only the starboard engine has a functioning power steering pump and alternator. The port engine has both items but neither are functioning in that there is no drive belt on that engine, additionally I do not see any connections of these components that would tie in with the starboard engine.

My question is if this is normal? Of course if by some emergency I had to run only the port engine then I would be drawing on batteries and manual steering without any assist. I guess the plus side to this is that I do have spare components.

Nothing I am really concerned about as the vessel does run fine, but as I just acquired it last fall I am spending this winter ensuring everything up up to snuff and that it runs as new.

 

[alldodge]

What you have is normal for many manufactures.

 

[Chris1956]

A single PS unit is common. However, usually both motors have a functioning alternator, as many boats have a dedicated starting battery for each motor.

It sounds like your boat has had some "Southern modifications"

 

[Scott Danforth]

usually in twin applications, one has the PS pump, both have alternators with an isolator. however I have also come across installations where the second motor has a second alternator (house bank) and a few installations where one has the PS pump, and the other has the alternator.

 

[rcmpvet]

It sounds like your boat has had some "Southern modifications"

Hmmm, should I be afraid to ask? I have visions of a cooling system modification make home brew while fishing.:laugh:

 

[bruceb58]

Hard to imagine you don't have a drive belt on the second engine. You at least need a belt for the circulating pump.

 

[alldodge]

Hmmm, should I be afraid to ask? I have visions of a cooling system modification make home brew while fishing.:laugh:

Just noticed you said "it has no belt on the port motor" , is this correct? You have a V-belt motor and it should have one which goes around the crank to water pump to alternator. The ALT doesn't have to be wired, just used to tension the belt

 

[rcmpvet]

That is correct, no belt. That is why I asked, the engine did not overheat otherwise. Now it appears that a belt will have to be installed. I guess I can hope for my son to come down during Spring Break, that way he can ensure that even the alternator is correctly wired and charging the battery.

Many a year since I actually did any mechanical work and since I paid for my son to get his red seal and raised him. He might as well start his payback .

 

[smokeonthewater]

Yep absolutely must have a belt turning the water pump.... Pretty much unimaginable that it wouldn't overheat... Generally the alternator would be hooked up on it as well but no you can't run two power steering pumps and you don't want a belt on the second one.

 

[alldodge]

Got ya, your motor will use one of 2 sizes and it depends on the diameter of the water pump pulley

The 5 1/2 inch diameter pulley uses a 44 inch belt 57-53658Q
The 7 inch diameter pulley uses a 46 inch belt 57-48120Q1 or Sierra 18-15460

As before putting a belt on the ALT is fine (electrically hooked up or not), just don't put one on the power steering pump, running it dry will burn it up

 

[frantically relaxing]

The engine water pump is a vane type pump, which doesn't actually 'pump' water, it just pushes it around.

In a car, it moves water FROM the cooled end of the radiator, thru the engine and back TO the un-cooled end. The system is closed, so the pump is always primed, surrounded by water. It needs no help from a second pump.

But a boat engine is an open system, and must be fed water from the lake via a second positive displacement seawater pump. The engine pump can only move whatever amount of water is forced in by the seawater pump, no more, no less. Ergo- is the engine pump even necessary? Water being forced in by the seawater pump is under pressure and will fill and circulate thru the engine and risers and find its way out back to the lake.

Seems proof of this is borne out by the OP not burning the paint off the risers!

 

[bruceb58]

If you don't have the circulating pump, you will have major hot spots at the back of the engine. Most of the water will just exit the manifolds The gauge may say it's cool but it definitely isn't.

This is the #1 item in the list on a Mercruiser manual to diagnose an overheat:

1. Possible broken or loose drive belt.

 

[smokeonthewater]

Yep the circulation pump is VERY important....
As Bruce said, without it you'll have nice cool exhaust but major heat probs in the engine.

 

[thumpar]

The temp gauge sender is at the thermostat housing not the engine. The raw water comes in at the thermostat house so you have no idea what the rest of the engine is at if you don't have a working circulating pump.

 

[rcmpvet]

Thanks all, I really appreciate the feedback. When the weather improves for spring and I can get inside the boat this will be one of my first projects.

 

[bruceb58]

Seems proof of this is borne out by the OP not burning the paint off the risers!

Which of course the circulating pump has no effect on anyway.

 

[thumpar]

Which of course the circulating pump has no effect on anyway.

Yep. All the water that comes from the impeller goes out the exhaust if it gets circulated in the engine or not.