1967 Donzi 2+3 steering (revised)

[Tom Burke]

Thanks to PaulO and avickers for their very helpful replies. My outdrive is a Volvo 275 (you guys are smart!). Ideally, I would like all steering controls inside the boat, but if safety becomes a concern, I would relent.
What do you think?
Thanks again,
Tom Burke

[PaulO]

Tom,
It is my pleasure to offer any insight on any of the topics I may have some small amount of knowledge on. I will try to accurately explain why the external mounted ram is better than internal:

The pivot points that allow the drive to turn from side to side are among those that wear and even in good condition, allow some slop. When you steer the drive from a lever placed inside, that slop is multiplied by the time it gets to the trailing edge of the drive. If you mount the ram externally, you control the movement of the drive much farther back (where it counts) and the slop in the pivot points is not multiplied. This will result in tighter steering.
PaulO

[AVickers]

Can't help but agree. Also, with outboard steering, you have fewer parts -- each of which will introduce a bit of slop to the overall system.

But, you do have to hang more stuff off the transom and drill through for hydraulic lines. In some people's books, this outboard stuff looks cool -- I love it. In others' books, it's just clutter. And, on an 18' where you use the foot as a step to get in and out of the boat, it's one more thing to get in the way or for some goof to grab (and perhaps break) as they get in the boat from the water.

As for safety, I don't think there's much difference either way -- internal or external. The problem with any purely hydraulic system is that if you loose fluid (or break a fitting or hose), you're screwed! In fact, at high speed, if you loose pressure and the foot's not vertically trimmed properly, it might instantly flop to one side or another and cause all kinds of misery...

As for the mechanical components, for safety's sake, fewer parts is better. An external system has only a very few parts. However, I haven't heard of a Volvo Helmet System coming apart... Sloppy? Definitely! Falling apart? Not!

I looked at both for my boat and chose internal 'cause I didn't want all that stuff hanging off the back of my elegantly simple boat. [I'm a machinist and could have gone either way -- fabricate a bracket to mount to the top of the Volvo drive or fabricate a bracket to mount on the rear of the engine. I chose to work in steel rather than stainless steel and painted the bracket I mounted inside the boat.

As for slop, let's face it... precision steering and boats (especially deep-Vs)? It's almost an oxymoron. Bottom line is that with sideways loading due to prop rotation, the drives preload one way or the other anyway. With my old Teleflex cable system, this preload was about 1/2 of a turn of the wheel --- lots! When I installed the hydraulic system (and replaced bushings and pins), this went to almost nothing -- helm response either way is almost intant. Sure, an external system would have lessened this (and, over time, will wear less), but for the aesthetics of preserving the original "look" of my 18 I figured to stay on the inside and count on a rebuild of the helmet in 2005.

Now, a twin-screw Magnum or Cigarette? Where's my stainless turning stock? It would be external all the way!