merc use both engines for power steering?

[roger4]

I heard of a priority valve or other method to enable you to use both mercruiser engines in a twin, to supply power to the power steering rack. Now, if I lose my starboard engine, no power steering as power steering pump that is powering the steering rack is on the port engine. The starboard engine has a PS pump, why not configure it so either can work, like a Y switch or valve? There is talk of a merc priority valve which will do this but so far I have not been able to find a place that sells it. I have twin 496 MPI engines, 2005. There are some thread that say both at same time is a problem, heat, too much pressure, that makes sense. But a selector switch/valve would seem to be a way to do it.

 

[Don S]

Re: merc use both engines for power steering?

why not configure it so either can work, like a Y switch or valve?

Money! They cost a lot of money.

Most people would get the boat home using brute force and then change the pump over. Fact is, power steering pumps seldom fail. It's usually something else. When that something else fails, the priority valve and the new pump are close behind if the valve is switched.

 

[roger4]

Re: merc use both engines for power steering?

thanks all for the reply. The entire purpose is to be able to steer the boat rather than struggle as I did recently when the starboard engine (not connected to power stering rack) failed when I was out on the water.
I think the valve to manually switch would be a great thing, so if the normal port engine wont run, you can at least get back and steer with the starboard engine.

 

[roger4]

Re: merc use both engines for power steering?

Raising the drive and shutting engine down? If one engine fails, it is off. The non-power steering connected engine is running but boat is too hard to steer. If drive is raised, it is an IO drive, will that make it easier to turn the steering wheel. I can easily test that as soon as my engine is working again.

 

[gadget73]

Re: merc use both engines for power steering?

Keep in mind that you can't raise one drive independant of the other if you've got one of those tie bars between the drives. They don't have that much flex to them.

I've experienced this more than once. Our problem child engine was long the starboard steering motor. I thought about setting up a valve system, but I could never come up with a way that I was completely sure would solve more problems than it would create. Power steering pumps can run upwards of a thousand PSI at full load, and I just didn't trust any commonly available plumbing stuff to handle that sort of pressure. Basically I just learned to deal with the really stiff wheel. I eventually replaced the starboard motor, so hopefully it won't be much of an issue anymore.

 

[Bondo]

Re: merc use both engines for power steering?

Ayuh,......

Without doing some reengineering with some Hyd. valving,....
You could plumb the slave/ unused P/S pump back to the Rack,+ join the hoses with a Union,... leaving it as an open loop...

In the event of a Dead motor,...
You'd have to swap the lines on the Rack,+ put the Union on the Dead lines...

 

[roger4]

Re: merc use both engines for power steering?

That sounds like a good plan. The dead engine is just a very short term situation - get me back to dock, so the ablity to with a few tools switch lines with a union or similar connect/disconnect sounds like the way to go. I agree a more complex fancy solution will no doubt result in creating more undependability and problems then it may solve for the day when one engine wont run. I will look at the hoses and see what can be done to create an easy way to disconnect the one engine and connect the other engine's power steering pumps to get me back to dock. Trying to steer with no power steering can get you near the marina, but forget about docking without hitting other boats. By the way, my IO drives can be independantly raised and lowered, and there are two separate switches on the throttle arms for that.

 

[Bondo]

Re: merc use both engines for power steering?

Ayuh,... I forgot to mention,... Brakeline tubing is the same thread pitch, sealing faces...

 

[roger4]

Re: merc use both engines for power steering?

I am not sure how a tie bar can help. My steering wheel is very hard to turn when the power steering engine is off. The tie bar would connect the engines for turning - but they are connected anyway by the linkage and power steering rack. Maybe I have to take a look and see to understand. Under my helm steering wheel is a cable which is pulled/pushed when you turn the steering wheel. That connects to both i/o drives.

Btw - Doral 2005 elegante
twin 496 MPI engines
bravo III drives