Eliminator Scorpion running flat and wet

[502 JET]

I worked with a guy years ago on this same hull with the same problem. The only way that we could make it run was by dropping the shoe below the keel and it had to be a flat shoe (no taper or backcut). The center pod of the boat has a bad design and without changing it this was the only way it would work. It would tend to spray water back up over the bow and would not turn at all. I did not like doing this but it was what had to be done. Be very careful. With the shoe this deep, the boat can be very dangerous if shut down to quick or looses power. I don't advise it!
I search the archives here and found some info that dropping the shoe may help so I made a shim and lowered the shoe .030" below the keel last night. It was 1/8" above the keel before. I'm gonna run the boat today and see if it changes anything. Starting off slowly of course. Thanks for the advice.

[502 JET]

That boat was made wider with less sponson in the front unlike a daytona which does not enable it to take a good set. It does exactly what your describing. A good wave will come right over that nose from what i understand if your not careful. Not sure about the bottom. Is that a flat keel or round? If it's a flat one you need to put that shoe level with keel to start. my .02
rondane
I have rolled a few wakes over the nose, not going fast but crossing wakes too slow with the bow down.
The center of the keel is slightly rounded and flat on the sides of it. I'll try and snap some pics of the bottom today. I dropped the shoe and will test it today.

[502 JET]

Thanks JR this is the first positive thing I've seen or heard about this hull. This looks like my boat I just gotta get mine to take set like that.
My boat had the name "Diamond JIM" on it at one time in its life. It was on the side of the cockpit next to the driver.
http://www.r-dmarine.com/files/Download/jrmod.jpg

[thatguy]

Rodane, where is your boat?

[JR131]

yea i wish we still had ours that boat was alot of fun like
i said just give him a call and he will help in any way he can
have fun
jr

[DUCKY]

You definitely can't argue with the performance numbers on the boats above. But there is one thing I notice about both of those pics. The nose is up, but both boats are still dragging the tail in a sense, because the rear most corners are still touching the surface of the water. Basically what is happening in both pics is the boat is setup to fly the nose, and you are relying on the corners of the sponsons to hold in enough air to keep the tail up. With the research I have done of these hulls, I have found two major problems that hold true from the Scorpion, to the Banshee, and beyond. In an outboard application, the hull does not have sufficient surface area to carry the weight of a motor hanging 6-10" behind the boat. In a jet application, since the weight is much more evenly distributed, the surface area isn't the problem, it's just the lack of natural tail lift (which is generally overcome with power) compounded by the fact the the tunnels not only have no compression in them, their corners actually open up and cause the tunnel to get looser towards the rear of the boat.
In 502's case, I make the following suggestions. First off, if the boat has tunnel tabs (many did), they need to come down quite a bit. Now I know that many of you jet guys are going to have a field day with that comment, but what needs to be remembered is that tunnel tabs are not ride plates. Their function is to control the amount of air being dumped from the tunnel. If you do have tabs, you may also consider attaching some aluminum angle to the sides of the tabs to create "dams" to prevent some of the air from releasing too early. After you have gotten some compression in the tunnels, then it's time to get the nose up some, which you should be able to accomplish with ride plate and shoe changes. I think the flat shoe at keel depth will be the place to start. Do you have a wedge in the pump now? Where is your ride plate set?
Regardless of what you do (short of extensive bottom mods) the boat is going to run flatter than most, especially at low speed. That has been the demise of many of these hulls. But flat isn't the problem, it's the low and wet part. Look at a Mirage or STV outboard...They run at about a 2-3 degree angle of attack, with virtually no hull in the water.
PS, to Rondane, these hulls are much narrower than a Daytona, especially up front.

[Sleeper CP]

Thanks JR this is the first positive thing I've seen or heard about this hull. This looks like my boat I just gotta get mine to take set like that.
My boat had the name "Diamond JIM" on it at one time in its life. It was on the side of the cockpit next to the driver.
http://www.r-dmarine.com/files/Download/jrmod.jpg
Is that Ron Signi in the lane next to you in his old '"Blue Bomber" CP Gullwing.
Sleeper CP

[502 JET]

I don't have tunnel tabs. So for now those options are out.
I'm not running a wedge and need to get an angle gauge to measure the ride plate. The ride plate is angling up, I don't know how many degrees.
The bottom mods are not out of the question if that's what it needs I'll do it.
What about a wider ride plate? Would this help pull the transom up on top of the water?

[JR131]

yes it is Ron
the reason you can run so much nose lift is because it has so much
positive down force on the deck but we also changed the keel quite a bit from the standard bottom to get it out of the water like that
jr

[Squirtin Thunder]

Down wedge will lower your thrust line and in turn lift the whole boat some. If you have a 4* intake and no + or - wedge and a droop you are @ 3* up this also helps creat bow lift. But if you want transom lift a 3* down wedge is the place to start, and the cheepest.