Opinions of surface drives
10-07-2002, 10:10 PM
#31
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OOOPPPPPSSS , Sorry Steve . 
Didn't mean that thing about who's behind the wheel ...... Your post wasn't there when I was typing ...... Can you forgive me ??
Didn't mean that thing about who's behind the wheel ...... Your post wasn't there when I was typing ...... Can you forgive me ??
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10-08-2002, 08:51 AM
#33
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Mine are the KAAMA's that Boot mentioned earlier, and so far these things are great. (nothing but big and beefy inside them). Handling at higher speed seems to be fine, just a little less reactive on the cat. Bit it feels very safe.
At the slower speeds (docking, on to the trailer, in-and-out of boats etc) I've been using the Fwd/Rev method versus steering. It has such a wide arc (mine at least), just seems easier the other way. And that works just fine.
One comment though. With the twins, if you loose an engine for some reason its more like guiding in the Space Shuttle. It don't steer with just one.
Bob
At the slower speeds (docking, on to the trailer, in-and-out of boats etc) I've been using the Fwd/Rev method versus steering. It has such a wide arc (mine at least), just seems easier the other way. And that works just fine.
One comment though. With the twins, if you loose an engine for some reason its more like guiding in the Space Shuttle. It don't steer with just one.
Bob
10-08-2002, 12:44 PM
#34
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Kaamacat, You are right there !!!
IF you loose 1 motor , The other won't steer for **** !!! In other words if you are using only the right motor , It won't make a right turn . IT will go left fine but not right . Even with it turned hard to the right . When I go into a lagoon or marina I leave them both running and use the left engine to make right turns and the right motor to make left turns ! Either one will go straight but only turns one way . Now on my old V bottom , 40' formula with Kaamas , you couldn't tell them from bravos at the dock .......
IF you loose 1 motor , The other won't steer for **** !!! In other words if you are using only the right motor , It won't make a right turn . IT will go left fine but not right . Even with it turned hard to the right . When I go into a lagoon or marina I leave them both running and use the left engine to make right turns and the right motor to make left turns ! Either one will go straight but only turns one way . Now on my old V bottom , 40' formula with Kaamas , you couldn't tell them from bravos at the dock .......
Last edited by boot; 10-08-2002 at 12:54 PM.
10-08-2002, 01:51 PM
#35
www.weismann.net
Gold Member
My father did the Kaama and I worked with him on our WSD drive and now the WMD drive.
All three drives were built for specific reasons. Every drive can do atleast one thing right.
The Kaama has a gearset added to it to bring the propshaft closer to parallel to the running surface as well as ratio.
As for surface drives like the Arneson they are not very good around the dock for the reasons they are good at high speeds(if you can keep them straight on a twin)
Having a 6 deg transom will not allow you to trim to level because the prop comes out of the water so you need to add rocker to assist the bow to come up, Buzzi used anti dive planes.
With the advent of stepped hulls it makes trimmability a problem in a Vee bottom.
On cats the natural down angle helps keep the bow stay down at high speeds. But you can do that with a normal drive too. That makes the acceleration a little slower.
I hope this helps a little. There is no "perfect" drive. On the WMD project we did 7 different studies.
As for racing, bring it on. We don't race ourselves and claim to be the best we like competition.
pat W
All three drives were built for specific reasons. Every drive can do atleast one thing right.
The Kaama has a gearset added to it to bring the propshaft closer to parallel to the running surface as well as ratio.
As for surface drives like the Arneson they are not very good around the dock for the reasons they are good at high speeds(if you can keep them straight on a twin)
Having a 6 deg transom will not allow you to trim to level because the prop comes out of the water so you need to add rocker to assist the bow to come up, Buzzi used anti dive planes.
With the advent of stepped hulls it makes trimmability a problem in a Vee bottom.
On cats the natural down angle helps keep the bow stay down at high speeds. But you can do that with a normal drive too. That makes the acceleration a little slower.
I hope this helps a little. There is no "perfect" drive. On the WMD project we did 7 different studies.
As for racing, bring it on. We don't race ourselves and claim to be the best we like competition.
pat W
10-08-2002, 04:50 PM
#36
I was under the impression that a stepped bottom boat performs better with surface drives than a non-stepped bottom boat? Look at Fountain’s success with the Arneson’s!
As for rocker, don’t the stepped bottom boats remove the need for it? I thought I read that in a Poker Runs America article a while back.
No surface drive can have positive trim, whether it’s a Bravo, SSM, Arneson or even Weismann as when the propeller is at the surface, you cannot trim it any higher correct?
What is a 6-degree transom?
As for rocker, don’t the stepped bottom boats remove the need for it? I thought I read that in a Poker Runs America article a while back.
No surface drive can have positive trim, whether it’s a Bravo, SSM, Arneson or even Weismann as when the propeller is at the surface, you cannot trim it any higher correct?
What is a 6-degree transom?
10-08-2002, 04:59 PM
#37
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[QUOTE]Originally posted by shifter
[B]
As for surface drives like the Arneson they are not very good around the dock for the reasons they are good at high speeds(if you can keep them straight on a twin)
shifter: what other weaknesses do you think Arneson drives have?
[B]
As for surface drives like the Arneson they are not very good around the dock for the reasons they are good at high speeds(if you can keep them straight on a twin)
shifter: what other weaknesses do you think Arneson drives have?
10-08-2002, 05:24 PM
#38
www.weismann.net
Gold Member
Transoms always have angle, that is how they get the boat out of the mold. The "standard" transom is 13 degrees. I have seen everything from 0 to 16 deg.
Our drives are not like arnesons, they are more like a stern drive meets a surface drive except the WMD it goes under surface also.
Depending on prop placement from the transom and cg, the leverage is greatly effected on the boat. Propeller bite is proportional to trimability on any boat. If you run 1/3 the blade area in the water the acceleration and control of the boat goes down and the speed comes up, less drag. If you burry the drives and get maximum bite you get good acceleration and control and a bad top speed.
The angle of the bottom acts like a trim tab . If you run negative angle of attack to the running surface the force is lift and drag. Saw tooth bottoms run on points insted of surfaces. less drag less trimability. You can still have rocker with a Step bottom. This is good for another thread.
I am not a naval archetect, I can hardly spell it. I can ask some friends for some more tecnical answers on the hull.
All for now.
pat W
Our drives are not like arnesons, they are more like a stern drive meets a surface drive except the WMD it goes under surface also.
Depending on prop placement from the transom and cg, the leverage is greatly effected on the boat. Propeller bite is proportional to trimability on any boat. If you run 1/3 the blade area in the water the acceleration and control of the boat goes down and the speed comes up, less drag. If you burry the drives and get maximum bite you get good acceleration and control and a bad top speed.
The angle of the bottom acts like a trim tab . If you run negative angle of attack to the running surface the force is lift and drag. Saw tooth bottoms run on points insted of surfaces. less drag less trimability. You can still have rocker with a Step bottom. This is good for another thread.
I am not a naval archetect, I can hardly spell it. I can ask some friends for some more tecnical answers on the hull.
All for now.
pat W
10-08-2002, 05:29 PM
#39
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Originally posted by Two K's
Know what would be cool. A twin arneson/single engine setup.How about it Howard?
Know what would be cool. A twin arneson/single engine setup.How about it Howard?
10-08-2002, 05:56 PM
#40
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Hey guys, Some of the reason you don't see many arneson drives compared to Mercury outdrives are the engine drive packaging. When you go for a different drive than Mercury the manufactuer are on there own. Most of these guys don't like to do any more R&D than they are already doing. In other words if it aint broke don't fix it! that does not mean that the Arneson drive is not a great drive.
