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mphatc
02-22-2011, 10:01 PM
I'm about to proceed on a full power steering conversion on my Magnum 27 . . it has twin Volvo drives . . although this is not on my Donzi, I'm posting this here because I believe others might also want to know about doing this.

There is very little information online short of buying a full system from one of the major suppliers . . and I haven't been able to find a flow schematic.
I have been able to find from many folks, that creating one's own system is much less costlier than buying a new one. Looking at parts prices confirms that.

My boat has cable steering w/o any power assist, so I need to build everything . . I have the brackets for the drives, and a tie bar and two Latham rams along with the transom brackets.

who can help . . . ?
How do I size the helm?
What do I select for a helm once I know the size?
The pump, one one engine, is it a standard PS pump as used on a car?
(my application has 2 SBC engines)

Any and all help / information appreciated.

thank you,
Mario L.

Conquistador_del_mar
02-22-2011, 11:04 PM
Mario,
Here you go. You will need a PS pump which is at any automotive store and the hydraulic lines (I have the one here). I am not an expert at rigging these, but this would be a good start with your Volvo drive setup. Bill

http://www.donzi.net/forums/showpost.php?p=566183&postcount=1

mrfixxall
02-22-2011, 11:09 PM
Mario,,for your external steering set up i would talk to George carter,i guess you can save a bunch of money by using a helm from a forklift..as for your p/s pump i would wait until you decide which power your going with..LS or the old fashion SBC take 2 types of power steering pumps.

gcarter
02-22-2011, 11:12 PM
Mario;
First, pick your cylinders. The cylinder displacement determines everything else.
Determine the displacement of one cylinder, which is the inside diameter calculated
for area times the stroke will give the displacement of one side of the piston, then
find the area of the piston rod times the stroke and subtract that volume frome
the total volume of the cylinder. Then add the two volumes together.
That volume then needs to be divided by the number of turns of the helm you want
from lock to lock. The new displacement will be the the displacement per revolution of the helm.
A Char-Lynn helm has a geroter built into the back side of it to act as a volume "regulator".
The length of the geroter gives a specific volume per revolution.
The longer geroter gives more volume per revolution and fewer turns, etc, etc.
Take a look at;
http://www.donzi.net/forums/showthread.php?t=59708 post #12.
Lots of good info there.
A standard GM power steering pump is used. A reservoir may be needed.
The pump output is plumbed to the input port of the helm. There're right and left ports and a
return port that goes back to the reservoir.
Back at the cylinders, the left port will be plumbed to the inner end of the right cylinder and
the outer end of the left cylinder, and vice versa.
There needs to be a relief valve plumbed into the the left and right lines.
Also, there needs to be a low pressure filter in the return line.
There's more, just ask some more questions.

MOP
02-23-2011, 07:07 AM
Question about the hydraulic lines? What ID is needed? I have fair a bit of 3000 & 5000lbs. aircraft S/S braided stuff coiled up in my stash that could use a home, I will have to check the ID to see what it is don't remember off hand.

Phil

HallJ
02-23-2011, 09:43 AM
Question about the hydraulic lines? What ID is needed? I have fair a bit of 3000 & 5000lbs. aircraft S/S braided stuff coiled up in my stash that could use a home, I will have to check the ID to see what it is don't remember off hand.

Phil

3/8 with -6 ends will do the job. 1000 PSI or higher.

Mario, you will want an "open center" Steering unit.

Jeff

gcarter
02-23-2011, 10:18 AM
I want to say that while I have had a good bit of hydraulic design experience many many years ago,
Jeff was really a great, tremendous help when I started playing w/my steering system.
In fact he supplied the Word Document I posted above.

mphatc
02-23-2011, 08:26 PM
WOW!!! Looks like I asked the right group for help here. A bit of reading and some measurements on my cylinders and I'll certaily have some more questions.

Thank you!
Mario

mphatc
02-26-2011, 09:44 AM
I called Latham Marine yesterday and spoke with Tom. What a wealth of knowledge . .in three minutes I learned more from him and he did all the calculations while conversing on the phone. I had the model numbers of the Latham rams as reference.

As I'll set this up as full power steering and run Redline synthetic PS fluid which allows for a higher temperature operation than conventional PS fluid, how should I route my cooler?

As planned my engine oil coolers will run on the water pump inlets, and my engine oil thermostatically controlled. I really desire to have both engines run the same identical cooling circuits, so adding the heat load of the PS cooler to one engine seems wrong? Or is this how it is done on dual engine set ups? this is all new to me . . .

Mario L.

gcarter
02-26-2011, 04:23 PM
Virtually every Merc built has the steering cooler in the circuit. There's no concern.
The engine w/o the cooler will have slightly less heat load.
The engine and oil thermostats will make up for any differences.

In the red
03-02-2011, 08:01 PM
I just did an upgrade to full hydraulic on my 06 28zx. It had the twin latham rams between the drives connected to a merc brazil valve and then a teleflex cable to the helm. Everything from the transom forward is now new. Latham recommended a 114cc helm control for these rams (they don't sell charlyn). I ended up going with a 120cc charlyn, IMCO stainless column. IMCO filter in the pressure line from the pump to the helm, and the IMCO stainless reservoir kit that taps into the cap of the power steering pump. There are lots of drawings in the IMCO catalog available on their site. Ron at IMCO NEvada was very helpful and I'm really impressed with the quality of their stainless parts. They have custom length columns available so you can get the exact reach you need. I went with the 15 degree fixed column turned upside down and it matched the angle on my dash perfect. Mine is about 3 1/4 turns and very easy to turn while running.
http://img691.imageshack.us/img691/2284/p1030700d.jpghttp://img228.imageshack.us/img228/5729/p1030713rt.jpg

In the red
03-02-2011, 08:12 PM
I just did an upgrade to full hydraulic on my 06 28zx. It had the twin latham rams between the drives connected to a merc brazil valve and then a teleflex cable to the helm. Everything from the transom forward is now new. Latham recommended a 114cc helm control for these rams (they don't sell charlyn). I ended up going with a 120cc charlyn, IMCO stainless column. IMCO filter in the pressure line from the pump to the helm, and the IMCO stainless reservoir kit that taps into the cap of the power steering pump. There are lots of drawings in the IMCO catalog available on their site. Ron at IMCO NEvada was very helpful and I'm really impressed with the quality of their stainless parts. They have custom length columns available so you can get the exact reach you need. I went with the 15 degree fixed column turned upside down and it matched the angle on my dash perfect. Mine is about 3 1/4 turns and very easy to turn while running.
http://img691.imageshack.us/img691/2284/p1030700d.jpghttp://img228.imageshack.us/img228/5729/p1030713rt.jpg

gcarter
03-02-2011, 08:17 PM
Hi In The Red, your new system looks really nice. I hope it works well for you.
Just so you know, in the picture you posted is a Char-Lynn helm.
There's almost nothing else used. They are almost usniversally used in industry,
like fork lifts and industrial tractors.
This is nothing against the systems that the major players in this niche business
offer, but for anyone putting a system together themselves, high pressure
filters aren't generally used in similar industrial steering applications, only low
pressure return line filters which are a lot more user friendly.

HallJ
03-03-2011, 12:04 PM
Just an idea.........

maddad
03-03-2011, 01:21 PM
This thread has really helped me to understand what a solid hydraulic setup needs. HallJ, in that series of pics with the old teleflex bezel, how did the splined shaft on the helm become a 3/4 tapered shaft in pics 4-5? Or does the wheel attach to the splined shaft? I'm putting full external hydraulic steering on my old Volvo and want to use the original chrome bezel.

gcarter
03-03-2011, 08:21 PM
This thread has really helped me to
understand what a solid hydraulic setup needs. HallJ, in that
series of pics with the old teleflex bezel, how did the splined
shaft on the helm become a 3/4 tapered shaft in pics 4-5?
Or does the wheel attach to the splined shaft? I'm putting
full external hydraulic steering on my old Volvo and want to
use the original chrome bezel.

I'll answer for Jeff. This column is commonly used in industry.
You can get a column like this and have a machine shop
duplicate the shaft, only w/a 3/4" tapered end for your wheel hub.
Or, have the hub machined to fit the straight splined shaft if there's
enough meat in it.

maddad
03-03-2011, 10:12 PM
Thanks George.

HallJ
03-03-2011, 10:36 PM
My apologies guys, The picture with the taper is the cable helm.
You can also buy the extension with the taper or the spline, whichever you prefer. I don't like flashy stuff so just made it fit under the original helm.

I cant wait to see George's boat put together!

Jeff

Greg Guimond
03-03-2011, 10:44 PM
Might be worth a phone call depending on the rams.......


Complete Self Contained outboard steering system... Capilano Helm, Hoses & Fittings, thru hulls, 2 Side Mount Rams. Was on 30' Outboard Cat w/2.4s Mercury Race Engines. Should work on any twin or triple engine setup. (possibly I/O also?) Still in Boat can see work. call for info 732 801 3733.

mphatc
03-04-2011, 09:32 AM
Jeff,

Did you fab the adapter plate to retain the Teleflex helm cover? I want to do the same on both boats, for the same reason, no bling needed . . and it costs less, looks original.

George, I agree on the filter set up, and plan on running a low pressure hydraulic filter before the return to the reservoir, or should it be after the reservoir to the pump inlet? One side is positive pressure, the other is suction , or does it not matter?

Mario

gcarter
03-04-2011, 03:56 PM
Jeff,

Did you fab the adapter plate to retain the Teleflex helm cover? I want to do the same on both boats, for the same reason, no bling needed . . and it costs less, looks original.

George, I agree on the filter set up, and plan on running a low pressure hydraulic filter before the return to the reservoir, or should it be after the reservoir to the pump inlet? One side is positive pressure, the other is suction , or does it not matter?

Mario

Mine will be between the helm and reservoir. Keep in mind that the reservoir is simply an extension of the Saginaw/GM pump/reservoir, if that's what you're using.
Question Mario......You're using something other than a Saginaw/GM pump, aren't you?
If so, what is it?
There's a lot more choices in pumps than there are w/helms.

In the red
03-05-2011, 09:03 PM
Hi In The Red, your new system looks really nice. I hope it works well for you.
Just so you know, in the picture you posted is a Char-Lynn helm.
There's almost nothing else used. They are almost usniversally used in industry,
like fork lifts and industrial tractors.
This is nothing against the systems that the major players in this niche business
offer, but for anyone putting a system together themselves, high pressure
filters aren't generally used in similar industrial steering applications, only low
pressure return line filters which are a lot more user friendly.

Guess I wasn't entirely clear in my previous post. Latham doesnt offer Charlyn, but I bought my Charlyn from IMCO because they had the best price on them. Latham told me theirs is made in France exclusively for them and you pay for it. IMCO also recommends the filter in the pressure side between the pump and Charlyn so thats what I did. I think their theory was if the PS pump takes a dump the trash wont take out the seals in your Charlyn. I had all my lines made to size with fittings by Fluid Systems in Detroit. Jim there was great to work with as they also do a lot of industrial hydraulic work. George, what makes a low pressure filter more user friendly than a high pressure filter?

mphatc
03-06-2011, 06:25 PM
this thread has really been very good and explanatory, and a great bit of info!

Red, thanks for the pics and the lead on IMCO for the lowest priced helms!

George, the cost of the HP filters from IMCO makes following standard procedures a no brainer, The lowest quality item in these systems is the PS pump, and I will be using a Saginaw, simply because my entire accessory belt drive assembly will be March using serpentine style belts with individual tensioners. I did this on the Corsican, and like the fact that my belts last a long time w/o needing tensioning or service over v-belts.

My plan is to fabricate some very strong Volvo upper steering ram connections, Maddad, will you need one? Anyone else? These will likley be CNC pieces and more can be produced if there is a demand.

Tie bars . . I will have an upper tie bar, but am also considering a lower tie bar . . the latter more of a security piece . . . this one off the rear most point of the drives. Other than drag every time one takes off and they are submerged, does any see an issue with this thought?

Mario L.

gcarter
03-06-2011, 08:32 PM
Mario, back to the return, low pressure filter, I forgot to mention....
helm, to the return line filter, cooler, then the reservoir.

HallJ
03-07-2011, 10:21 AM
Jeff,

Did you fab the adapter plate to retain the Teleflex helm cover? I want to do the same on both boats, for the same reason, no bling needed . . and it costs less, looks original.

George, I agree on the filter set up, and plan on running a low pressure hydraulic filter before the return to the reservoir, or should it be after the reservoir to the pump inlet? One side is positive pressure, the other is suction , or does it not matter?

Mario


Mario,

That is correct. I made the adapter plate. Here are some pics of a system I made for a friends XK19. It used a KRC stock car pump with an external reservoir. Do you need a return filter? First gen RX7's have an integrated oil cooler/oil filter housing you could adapt for your boat. It makes for nice packaging otherwise I've got a separate return filter and housing if you would like.

Jeff

In the red
03-07-2011, 02:39 PM
What is the advantage of having the reservoir between the cooler and the pump vs the style that feeds into the pump cap? They both just add additional fluid to the system correct?

gcarter
03-07-2011, 03:18 PM
What is the advantage of having the reservoir between the cooler and the pump vs the style that feeds into the pump cap? They both just add additional fluid to the system correct?

All systems that I've seen run from the reservoir to the Saginaw pump cap.

maddad
03-08-2011, 04:05 PM
Mario, I've got a Latham bracket for my Volvo outdrive. Poodle had a run made after getting enough buyers together. Since nobody's posting about their older Volvo hydraulic setups, there could be a few out there available. Came with plate, spacers and bolts.

HallJ
03-28-2011, 05:32 PM
Read up!

http://www.pirate4x4.com/tech/billavista/PR-Hydro_Steering/index2.html

Jeff

gcarter
03-28-2011, 09:19 PM
Excellent piece Jeff!
And the good news is a boat system is a lot simpler than an off road vehicle.

Ralph Savarese
02-27-2012, 07:20 PM
[ QUOTE=$originalposter]{$pagetext}[/QUOTE]

I am doing this same set up with the original helm what length colmumn fron char-lynn did you use?
Thanks Ralph

mphatc
02-27-2012, 08:37 PM
Ralph,

I'll take some pics tomorrow of the Charlyn helm and adapter plate I made for the Magnum 27. It uses the same Teleflex helm as the older Donzi's and I retained that piece to keep the original look and steering wheel.
A simple mod to the adapter column from Imco allowed me to retain the steering wheel adapater.

I am an IMCO dealer, so post me directly, I'll save you some monies! Also a dealer for several other marine supply houses . .

Mario L.

Ralph Savarese
02-27-2012, 09:19 PM
Mario,
I don't plan on buying anything from IMCO I found a place called midwest hydraulics they were great very informative he rebulds the Charl-lynn helms and led me to an Italian equivalant for $299 and a taperd shaft column for $59 he said they are absolutley interchangeable. How could you go wrong great guy to talk to.
Ralph

Ralph Savarese
03-08-2012, 10:38 PM
[ QUOTE=$originalposter]{$pagetext}[/QUOTE]

Hall J, Were you able to get the Part# for that steering column with the tapered shaft?
Thanks Ralph
rsav65@verizon.net

HallJ
03-09-2012, 12:38 PM
Ralph,

My apologies. I look at the boat every day but can't remember to check.
I've set a reminder this time.

Jeff