Steering problem after Arneson convertion
 

Just finished a conversion from Bravo one XR to Arneson ASD7M and new power.
Old engine was a HP500EFI (2004 mod). New engine is a custom made 565cid 950HP. I changed to the helm that was in the Arneson kit but kept the pump, cooler and reservoir. Steering wheel gets hard (preassure on "P" hose 100-200PSI)when picking up speed. Oil gets warm. I use Dexron III ATF oil. If we go in neutral and increase the rpm the steering gets better at once (600-700 PSI). We also have adjusted the pressure on the pump (spring on the pressure valve) a bit. Seems to be fine a bit longer
but same problem. When cold just after start, the pressure is almost 1500 PSI when we turn the wheel. The wheel only have about 1,75 turns from side to side. Arneson say it should be 3,8 turns side to side....?
Arneson say that a Mercruiser power steering pump should work fine. I have a big boat (31 feet, 6500 pound) for a single engine installation. In the US I believe you have dual engine application most of the time and then you may have two active power steering pumps. Could the Mercrusier pump be the week link in my case? (It is almost not used, less than 100 hours).

Anybody have a clue what can be the solution?

Seems odd the system turns with less wheel. I would first double check all port connections. Oil should flow against water in flow cooler. The oil will get warm it is always flowing to helm and back. It should get hot though. heat makes me think there is a restriction in a line some where. Did you make lines or where they premade? I would check in the fittings to make sure the inner hose din'd get cut and kinked during assembly.

Just a few thoughts in an attempt to help.

How important is it that the oil flow is against the wather flow in the cooler?

Found it works better that way. I doubt that is the whole problem. But it may be part of it. The 1.75 turns compared to 3.50 implied throws a big curve . Maybe its the wrong helm? Mistakes happen.

the merc pumps are pretty dependable if never run dry. Most boats only use one pump. With two pumps a priority valve gets used.

One summer later: Problem solved! The kit from Arneson had the steering cylinder premounted on the port side. After rebuild and putting the cylinder on the starbord side, steering works fine. It can be explained like this: The prop makes a force that pushes the drive against the starbord side. The nature of a cylinder gives that you need about twice the force to compress than to extract the cylinder. This is because of the smaller surface for the oil to push on. Agree? When the cylinder was on the wrong side, the force produced by the prop was bigger than the steering pump/system could deliver. We put pressure gauges on both side of the cylinder and on the P hose from pump. The pressure on the week side of the cylinder (from prop) exceeded the pressure on the P hose. The sad thing is that I used all summer to figuring this out......:angry-smiley-038:the complete steering system have been apart many times and most of the components have been replaced (including new power steering pump, helm unit, cooler, hoses and bigger reservoir). Testing after every change and red steering oil on my hands... :eek:

This is the before after pictures (inkl. before and after rebuild to starbord side):

Glad ya figured it out.Future rerf,Heres some more info on what I went thru.

http://www.offshoreonly.com/forums/g...ring-bled.html


Why did ya do the conversion?

The original trimmed HP500 with compressor (theoretical 700HP) died on me... replacing the engine I wanted more power. I now have a custom made 565cid "safely" tuned to about 950HP (91 oct, pump gas). With that power the Bravo had to go. I was told that Arneson was a good and easy choice for that power......I have just started testing/dialing in but it seems that I have about 35% slip.... :eek:

Who makes that boat? Doug

I can not believe they did not tell you what side to put cylinder on. I guess with a dual engine set up there is a cylinder on each side, so maybe they did not think of this problem with just 1 drive. Did changing fix the amount of turns, lock to lock?

Hydrolift in Europe, Norway:
http://www.hydrolift.com