Steering ram capacity for a VP DPH drive?

[Whitelighter]

OK, so got an option to get hold of some Raymarine kit at half sensible prices - now they are talking to me. Plotter and radar etc is easy, but while I have had an auto-pilot before it has been attached to a boat with mechanical steering. The new one has hydraulic steering so will use a hydraulic pump.
(cheaper /forums/images/graemlins/cool.gif). The thing is RM list three pumps for differing sized rams. I assume since the boat is fairly light on stern drives then I will probably need the type 1 drive, but I cant find anyhting on the VP web site that actually tells me the capacity of the steering rams.

The RM webby says the type one drive is suitable for boats up to 9000kg (mine is around 6000kg), but with a ram capacity of 80cc's to 230cc and a peak flow rate of 1000cc/min . Does this sound ok for a DPH drive on a light boat or should I find out for sure. Is each DPH standard or do they change boat to boat?

 

[spannerman]

With the DPH drive there is no steering cylinder inside the boat as on the older type drives which worked on the steering arm coming in from the drive.
On your system you have a dual hydraulic system, first there is a 'low' pressure side which is the steering pump at the helm, this only operates a servo shuttle valve down behind the engine at the top of the transom.
The shuttle valve then directs the oil in the 'high' pressure side from the engine driven pump to the left or right steering cylinder mounted on the drive itself.
The autopilot pump will be plumbed into this low pressure system, Raymarine should be able to tell you which size of pump is adequate for your boat, it doesn't have to supply a given volume to drive a cylinder as in the older systems, it just needs to operate the servo valve.
And all the D4/D6 drives steering systems are standard.

 

[Whitelighter]

Thanks, will try Raymarine but they usually gt all clammy and start telling you to refer to the engine manufacturer when asking about techy bits.

 

[SolentPhill]

Jez

When you find out can you post it, my new boat has arrived and it has D4's on it and my guy who is fitting the Raymarine has a similar problem although he is planning on getting the guy who fits the hydraulics down to look, he is unsure where the rudder sensor or something goes and is seeking further advice so any help you can shed would be good.

My guy is down in 9 days if you have not found out I will tell you what he said he has fitted loads of them

 

[spannerman]

The rudder sensor is a big job, the sensor can be fitted anywhere there is space but it is operated by a morse cable kit from Volvo which is a pig to fit.
You have to lift the boat as the cable connects to the S/B steering cylinder which gives it a push/pull motion which operates the rudder sensor.
The hard part is installing the cable, you need to do the following,
1-remove exhaust bend and down pipe
2-remove aircleaner box
3-remove the top bolt on vertical brace under the turbo and swing it out of the way
4-remove the rubber elbow which goes from the aircleaner around the back of the engine block
5-now you can get the correct angle on the flexible rubber tube from the top of
the transom to slide the morse cable through, next to gear shift cable.
6-mount the cable kit as per instructions and check it slides freely by hand
7- now refit all the bits you took off!

 

[SolentPhill]

Thanks SM

Not what I wanted to hear glad im not doing it. If its got to come out Im not sure it will be done, only went in on Thursday so not sure want to take her out just for that.

I take it there is no other way

 

[Whitelighter]

Confirmed with Raydirect.co.uk (who are outstanding by the way and well worth a call or a visit if you want Raymarine kit) that for boats of our size with DPH legs (D4/D6) then the type 1 hydraulic pump is the one to have.

 

[SolentPhill]

have you got the rudder sensor part on already?

 

[wakeup]

Jez is it one pump per leg as a matter of interest or per steering whell system?

 

[Whitelighter]

My boat is in build, so it is a case of installing the gear before the deck goes on, which should make it a bit easier - I hope!!!

Wakeup, as I understand it, the DPH steering system does not have inboard rams. Instead there is a low pressure and high pressure hydraulic system. The low pressure system is connected to the wheel which is used to turn an actuator which then drives the high pressure system connected to the legs (or in my case leg). The pump for the pilot plumbs into the low pressure side of things.

 

[Graham3]

hi
Tried for 6 hours to fit the cable between the transponder and the leg. removed all the euipmremt, still couldn't get the pipe straight enough. Do you have the part number for the autopilot cable as perhaps they sold me the wrong one