z.zuperboat

My thought is alot of time spent on something thats going to have some really bad slip numbers. The arneson drive is a great drive. Ment to surface . The drive is going to be to high to have bravo type props get enough water to be effective . The diameter of the bravo type props are around 15 inches on the large side, including the hub. Put those props on that drive with 800hp at the surface and watch the blades come off. My boat with a 4 blade at 15.5 in diameter will not even plain off, running a speedmaster at 2 below the bottom. High x needs big diameter, and for a 30 superboat that diameter is a min of 17.

Rik

Not so. You are looking at what you have to do with your drive and a Speedmaster propeller, not an Arneson nor a Bravo propeller.

What you are not looking is the fact that the Arneson is adjustable. Unlike a Bravo or your speedmaster I can bury the down to get on plane whereas you cannot with your drive or a Bravo. Also without a Speedmaster propeller the boat will get on plane much faster.

As for surfacing, you are 2" below the bottom of the boat. I will be even.. That is not going to have an effect as if you could run yours higher and still get on plane you would. You are compromising between the two I am not.

Rik

There is a skeg. Look in the photo again. I took a quick pic and used a 2X4 to hold the drive up with rather than going through the work to put a trim cylinder on and then take it all back apart.

z.zuperboat

Ok you got me on the plane off thing. Now with the drive even with the bottom I still dont think your going to have enough blade area to be effective. The other arnesons have very thin hubs using larger props and effectively using alot more blade of the prop.
I think Arneson should use Superbabie for testing. If it works like you think im sure Gary would more than happy to buckup.
I did notice the skeg. Whats the square block on the top for ? The up and down ram . Also looks like the steering ram locations will be in the way of water flow. I would have put them higher maybe on the side of that top plate. By me they would get covered with weed and it would never plane off.

Rik

The standard Arneson has a Standard Speedmaster propeller. A standard Merc SSM#6 or Hering was always used, nothing special.

Your running a speedmaster propeller yourself. Just look at how much thicker (in this day and age of thinning the blades down 1/16") your speed master propeller is in regards to the Bravo propeller. That leaves a lot of speed on the table. Also you are fighting the bow lift of the cleaver design, vs the cup and rake and camber of the Bravo design.

I think what you are missing is that they are surfacing a Bravo propeller already on a lot of boats (the ones that can at some point get on plane that is) and they still work. You have to overcome the Arneson point and look at a propeller is what a propeller is. Same as it is with a Speedmaster propeller. Everyone thinks the propeller knows what is spinning it.

Superbabi

Rik, sorry I did not see the skeg this morning when I posted. That really is a slick looking drive !!!! How much power can she handle ? Did you do any trial runs ??

Rik

Same power rating as the standard #7M. The #7MB drive is the same just a different housing and such to accomodate a Bravo propeller.

Should be testing mid next week.

FX10

Personally I see a few flaws such as Mike said. Steering rams should be located at least 6" higher, on top of cavitation plate. Is there one? Steering rams will cause water turbulance, raising slip #'s. Any clean wayer hitting those rams will distroy the slip #'s
This is just my opinion. RIK possibly tested the unit. And had excellent results. But this is my opinion. Everyone is entitled to one.

Rik

Already tested the steering years ago. It is not in the water nor is it an issue. I did a video filming of them on a race boat and in 30 + minutes the steering cylinders never got wet nor did they interfere with the water flow to the propellers.

Believe me I studied this for months before I did it. The steering is the same as it is on the standard #7M drive units and I get less than 5% slippage with the #7M' so I see no reason why it would be an issue now. Remember, the drive is out of the water and the steering cylinders are attached above the water line. You have to visualize how an Arneson works. Other than the rudder, there is nothing in the water.

I was far more concerned with things greater than this. All I have changed from the standard #7M (which has been working great for the past 3-4 years) is the design requirements to accept the Bravo style propellers. I put more time in looking at the propeller hubs than anything else. The fronts of the propellers are different based upon manufacturers and had I only seen one brand of propeller I would have designed a major screw up. Luckily, I had the opportunity to design around their obstacles before I made this drive. Unlike others, I have not copied others nor Mercury. So I had to go about things in a different manner.

As Mike stated, propellers are a major thing that even he has had to learn to adjust to. A cleaver propeller is a cleaver propeller. They have a different “lock up” speed than a conventional bravo style propeller. In order to over come this, the diameter has to increase to make a compromise between getting on plane or not. What has a positive effect on one end has a negative effect on the other. There are many many other attributes to the clever and I have lived with the positive and the negative for the past 20 years. I have just adapted a different propeller with different characteristics and hope for the same positive effects that this design brings to its other applications. I have many more conventional design propellers on larger commercial boats and they all get on plane fast, maneuver extremely well and perform on top end very good also.

Hoping for the same here.

My customers are looking for a less expensive, more readily available, more manufacturers to choose from and more positive handling characteristics for a smaller sized boats. I have not, but anything is possible, looked at this for a larger twin engine boats, but these would work in those applications as well.

FX10

RIK
Do you have any pictures of this drive mounted on a hull ?