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sab motor with varable pitch prop

11K views 19 replies 10 participants last post by  blt2ski 
#1 ·
Any body have any experience with a saab motor, with a manual control varable pitch prop? My step dad has one on a boat he spent 30 yrs building. it does not have an idle per say, ie prop is ALWAYS turning, idle is when the blades are neither forward or reverse. To go forward or into reverse, you feather/pitch the prop. Kind of a weird way of doing things.

anyway, trying to find easy ways of getting into and out of the slip. With a single lever system, you push forward prop and motor accelerate, move to middle prop quits turning.. this thing it will not seem to coast as the prop is always turning. You can sort of control the speed with the motor at x rpm and feather the prop, but it is not as simple as it sounds any how........

marty
 
#3 ·
THanks lauren

Now that I am spelling "Sabb" correctly...... they do not make the motor in step dads boat any more, have not since 1980! must not have been a big seller, considering how hard it is to handle without more than three on boat, I can see why.

I'll keep digging, trying to see if I can find some info on how to go in and out of a slip easy enough. I'm better off than yesterday any how! Wonder if ralph knows anything about these critters........

Marty
 
#4 ·
Saab are infamous for having marvelous engineering concepts, that fall down short on practical durability and cost.

Everything I've come across about their variable pitch prop systems says the same thing. Great concept, if you can afford to keep it in repair and finctioning over the years. Otherwise it falls into the category of "moving parts located where you can't access them, in a corrosive environment with no spares to be found within a thousand miles".

If you've got it, enjoy it. And if you've got lots of money, call Saab and ask them to sell you a kit of spares if they are still available.
 
#5 ·
Not Saab

Don't confuse Saab with Sabb. The Sabb diesel engine is one of the most simple and dependable diesel ever built. They were used as lifeboat engines as they could be started on the davits and let run for a long time before ever getting dropped in the water. They usually have either hand start or electric and do not suffer the same reversing problems as most feathering prop systems. They usually don't have much power and weigh a lot so can make a great contribution to ballast. If you like the sound of the African Queen then you will like the sound of the Sabb.
 
#6 ·
The Sabb that I have experience with is a very good engine and I have not had issues with trying to coast. You can keep taking pitch off as the boat slows down or you can pitch it for less than the boat speed. This was in a relatively heavy boat so that may have been the reason that we never had any problems. In my mind, the real key is to make sure that the pitch lever is very easily accessible.
 
#7 ·
Yes it is a "Sabb"

The pitch part is not to bad to work with, the rpm lever tho. PITA! move it 2-3 degree's, and the motor goes from 700-1200 or higher rpm!

I have gone out with step sister a few times, think we have it down, or at least a "HOW" to back out etc. Seems to work best if the motor is 800-1000 rpm, slowly engage the blades in reverse, then as she is 90 to the dock or just a bit before to move blades into the forward and away one goes out of the marina, with some upping of rpm or just engaging the prop into a higher pitch mode.

This boat, maybe being a V bottom plywood full keel, about 5500 lbs does not coast real well, not does it turn super sharp, as one can not get the rudder/tiller to go as far as one would like, which also makes backing out a pita along with trying to get the motor/prop etc in a correct mode so it will idle out per say.

Marty
 
#8 ·
I have a rebuilt Sabb 2G (18hp) variable prop in my boat. I seem to have forward down just fine, but reverse seems to be a little elusive (or maybe just plain weak). So far I've settled for walking the boat out of the slip, rather than using the engine. If anyone has any suggestions on how to switch gears properly on an engine that has no transmission...please let me know.
 
#10 ·
As HS says, you need to reverse the prop pitch to go backwards.

At least on my step dads boat, he has a engine throttle, and a pitch control throttle that are in the same control unit. Generally speaking, we put the engine at 1200 or so rpm, then work the pitch to go backwards at the speed we want to go. Seems to work reasonably well, not something I would want on my boat. I can see how rescue style boats a system like this would work really well.

marty
 
#11 ·
I had a 27' Albin Vega with a similar setup - 10HP Volvo Penta with a variable pitch prop. I liked it. Mine had just one lever to control the boat's direction and speed -it was nice. That said, marine mechanics in North America seem to be unfamiliar with these systems and are sometimes reluctant to take them on. I learned how to service it myself and it was no big deal. Most of the parts are generic metric bearings and oil seals available at any good bearing supply house. Then there was the hoodoo about what grease to use in the stuffing box (the stuffing box is really just a couple of oilseals with grease in between to alow the outer control shaft to slide back and forth to adjust the pitch...) - any thic, sticky, waterproof grease seemed to work. The boat had some bad behavior in reverse (what sailboat doesn't?) but I think that was more due to the prop being located above and aft of the rudder than the variable pitch. Its good to note that tug boats and other large vessels use variable pitch propellors a lot. I would go with one again.

As to Sabb, never had one but I used to see them quite a bit as lifeboat engines - possibly a good endorsement.
 
#12 ·
Marty-
Variable props have long been standard on aircraft, so there's reason to think the concept works. I suspect the reason it is shunned on boats, is that putting more moving parts in a corrosive salt water bath and relying on seals...We should all be cringing by now, right? (G)
I'd like an exotic sports car, too. But not the maintenance bill I know it will require. A cheap bulky gearbox, a solid shaft, no bearings, no seals...This is why Detroit products could be fixed with a screwdriver and plier, while German ones required specialized tools.
 
#14 ·
WS,

He built a Bill garden modern day sea bird yawl. One of Rudders "LAST" plans before that rag went kaput! Not sure how many others, if at all were built. HERE is a link to some pics a couple or three years ago when we got in on a trailer, the fall before launching. Gives you an idea of the shape etc.

The design itself has some issues as to how well it turns etc too. It would have been nice of the motor was a bit stronger. Not sure if the tack reads true. Seems to be about half of what it really is turning in my mind. The claim is to run at 1500 or so rpm for best speed performance etc But seems to like about 2000-2200 on the tack, along with get some reasonable speed out of the boat. Not sure of the speed, as a knotmeter is not installed.

It is what it is, when he dies, family will probably sell it, like all things, for as much as they can get. Not sure it will be a lot considering many variables about it.

Marty
 
#16 ·
Home built wood boats can be very hard to sell, but both Garden and the Seabirds have a following. I have the plans for the original, expanded (Seagoer), and an early plywood version. I alway wanted to build my own cruiser. I have built a few dingies and a kayak, but really didn't want to spend the timebuilding bigger. I respect him for doing it.
I like it, but yes she will be hard to sell. You can tell a lot of work and love went into the build. I have respect for anyone who can complete a project like that. I wonder what percent of boats like that never get completed? I would think the majority, as it has to be a multi year project. Plans change and life can get in the way! Props to the completion of the project. Have any interior shots?
 
#15 ·
Home built wood boats can be very hard to sell, but both Garden and the Seabirds have a following. I have the plans for the original, expanded (Seagoer), and an early plywood version. I alway wanted to build my own cruiser. I have built a few dingies and a kayak, but really didn't want to spend the timebuilding bigger. I respect him for doing it.
 
#17 ·
I do not have too many shots that I can show as this one is. It took some 30 yrs from start to finish. as one says, life gets in the way. 6 yrs doing nothing while his wife/my mom fought a battle with cancer, a few yrs of trying to get ones feet back on the ground. One of my sisters and her husband helping for abit, more time off, another helped get it finished as he approaches age 90! as said, wonder how many never get finished.

Nor is it my style of boat. If I inherited it, it would be gone yesterday per say, or a major redo of the trans would be in order. Motor works ok for its size etc. I would go with a neutral style trans, 3 blade prop vs the varible 2 blade to get a bit more bite. Re rig the rigging a bit, along with put wheel steering in, as you do not get a full enough rudder movement side to side with the way the tiller was mounted and designed.

Hull size, from what I can see, about the same as my 28' Jeanneau, you will not get this to move real fast. I've only sailed on it once, we only put up the main and jib. Major case of lee helm! The mizzen might have helped a bit. It's a funky design needless to say. Think I have a pg for the plans some where.

marty
 
#18 ·
I do not have too many shots that I can show as this one is. It took some 30 yrs from start to finish. as one says, life gets in the way. 6 yrs doing nothing while his wife/my mom fought a battle with cancer, a few yrs of trying to get ones feet back on the ground. One of my sisters and her husband helping for abit, more time off, another helped get it finished as he approaches age 90! as said, wonder how many never get finished.

Nor is it my style of boat. If I inherited it, it would be gone yesterday per say, or a major redo of the trans would be in order. Motor works ok for its size etc. I would go with a neutral style trans, 3 blade prop vs the varible 2 blade to get a bit more bite. Re rig the rigging a bit, along with put wheel steering in, as you do not get a full enough rudder movement side to side with the way the tiller was mounted and designed.

Hull size, from what I can see, about the same as my 28' Jeanneau, you will not get this to move real fast. I've only sailed on it once, we only put up the main and jib. Major case of lee helm! The mizzen might have helped a bit. It's a funky design needless to say. Think I have a pg for the plans some where.

marty
Yea, I understand, it is not a boat I would like to own, but I enjoy all kinds of boats, especially ones like this that obviously have a lot of hard work and soul put into it. I think funky designs are cool if other people build and use them. I love the sharpies but would never want to own one.
 
#19 ·
Hi Marty, I've just seen your post and joined so that I could shed some light for you, hopefully! The SABB diesel is a very reliable but pretty agricultural piece of equipment. Having said that I would not swap mine (18HP with the VPP).
The origin of the VPP was for Norwegian fishing boats which went out empty and came home full - hence requiring a different pitch on the prop. The key to ease of use is to set the idle speed as low as possible, preferably around 400 rpm (with prop engaged) as this makes the transition from forward to astern quite simple. If you try to move the Pitch lever with more than about 700 rpm you will find it quite challenging! The Instruction Manual tells you that there is to be at least 15 degrees of free play in the governor (throttle) before you get any response. You can set this quite easily. There is a domed not at the rear of the engine which contains a threaded bolt which increases pressure on the governor. You'll need an Allen Key to screw this in and/or out.
Hope this helps.
P.S. You don't have to be Amish to enjoy the SABB but it would help!!
 
#20 ·
gaffer,

I'll send info to sister that spends most of the time using the boat. But alas, not sure if good or bad, the boat was pulled last fall, and has not gone back in, so it maybe next spring summer before trying to figure out the how to truly make this thing work. But will keep th einfo at hand.

Along with a welcome to the craziness here! Just watch out for some feller named CD, he as some ugly under bit dog........if you see him, run the other way, and call 911!

Marty
 
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