Twin engine Power Steering/Priority Valve?
 

Hello fellow boaters, I have a twin engine Mercruiser boat that has a single Saginaw control valve (old style non hi performance stock system). I simply want to have power steering available from both engines rather than just the one as it is configured currently. I have searched high and low for what was called a "priority Valve Kit" , this was a merc accessory part that now is N.L.A and appears to be tough to find. the valve allowed two power steering pumps to be hooked to it and would shuttle to allow fluid flow and return from one or the other pump as needed allowing constant power steering pressure with either or both motors running.
my question: has anyone found a different Priority valve that works in the same manner or has anyone been able to retrofit a different system in place of the tough o find O.E.M Merc Valve system. I realize this is not a hi -performance application and there are many makers of full pressure systems (Latham, Imco, etc) but their valve systems don't work in the same manner to retrofit that I have found so far?
any info would be greatly appreciated.

Thanks Cmizgo

Re: Twin engine Power Steering/Priority Valve?
 

You can get them from Warlock Performance Marine or Imco. It's not a big deal to plum in. It is simply just a one way valve put in line with the hi-press off each pump just before they T together. You can make your own up with a pair of one way valves and a T fitting.

Re: Twin engine Power Steering/Priority Valve?
 

and welcome to OSO! Now go buy a membership so you can see pictures and enter all the other sections.

Re: Twin engine Power Steering/Priority Valve?
 

Fountain use them on their twin engine boats. Doubt it is a Merc item.

Re: Twin engine Power Steering/Priority Valve?
 

A "priority" valve is different than what most use today for full hydraulic twin pump systems. The one-way check valves into a T works well with full hydraulic because it also doubles the amount of oil to the helm, which helps at the idle. A true priority valve connects the pump with the highest output, or only output if one is shut off, to the helm or in your case the shuttle valve. This would be better in your case because of the smaller orifices that a single valve block would have. I haven't tried a twin pump with check valves into a single control valve. It may work fine, with higher normal running pressures because of the restriction, but I'm not sure.

Good Luck!

Re: Twin engine Power Steering/Priority Valve?
 

Thanks for the Info!!, Falcon I believe a true "Priority Valve" is what I will end up having to search out, I believe any more pressure and fluid volume than one pump can put out would overload the single control valve configuration hence the benefit of the valve to allow only flow and return from one master pump while the slave pump bypasses and flows back to return without restriction,I will spend some time looking at one way valves etc but I think the multiple pump pressure issue will be the problem there when both pumps are running?

Thanks Cmizgo

Re: Twin engine Power Steering/Priority Valve?
 

Do you realize you also need to add a separate "common" reservoir? Maybe someone else could chime in here if the system would still work well with the check valves. The disadvantage would be increased system operating pressure at high pump speeds and the extra heat. It still may work ok.

as purely a limp home back up. looking at my nova the pump is in the middle of boat on port engine. nothing stopping me from running a longish belt from the crank pulley of starboard engine to it. of course, this wouldn't work with serpentine set-ups. oops! didn't realize i was linked to 7 year old thread.