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Cavitation plate mock up

namba860

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Drain plug was already there and off center. The plates are in the same location on both sides
 

Smooth Mvr

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Drain plug was already there and off center. The plates are in the same location on both sides
Are the plates stationary? I guess I haven't seen a gap like that except on squirters with a ride plate under the bowl. She is beautiful to say the least. love the deep blue! As you see on my Schiada it is hinged without the gap.
 

namba860

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Are the plates stationary? I guess I haven't seen a gap like that except on squirters with a ride plate under the bowl. She is beautiful to say the least. love the deep blue! As you see on my Schiada it is hinged without the gap.
Are you talking about the gap in the middle between the plates? These plates are not stationary. I didn’t want to do a hinge like a trim tab I wanted it to move more like a real cavitation plate not a trim tab. The 24 Spectras didn’t have a recessed bottom for cavitation plates they used Bennett trim tabs. In my opinion a Vdrive boat is not a Vdrive boat if it doesn’t have cavitation plates!
 

78Southwind

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Yeah, my Spectra 20 doesn't have a gap either. I always read that you shouldn't have a gap. When Lang built these for Greg he didn't recess them but instead added a block to the transom. They work great. Nice, Spectra. Who did the gelcoat?

Spectra Ass.JPG


Spectra Ass1.JPG


Spectra Ass2.JPG


Spectra Ass3.JPG
 
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sintax

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Just curious why you didnt cut them into the bottom? I'd also look into the plates not coming together, i've heard of handling issues, but cant recall the specifics.
 

Smooth Mvr

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Are you talking about the gap in the middle between the plates? These plates are not stationary. I didn’t want to do a hinge like a trim tab I wanted it to move more like a real cavitation plate not a trim tab. The 24 Spectras didn’t have a recessed bottom for cavitation plates they used Bennett trim tabs. In my opinion a Vdrive boat is not a Vdrive boat if it doesn’t have cavitation plates!
My OG cavitation plates aren't recessed either and are original 1970 equipment, IMO a true cavitation plate needs to be able to put down force on the water to bury the nose to stop porpoiseing and to turn more efficiently. Sure things have changed and upgraded since new technology has come into the picture but still don't see how those plates can change pitch to exert down force. They look like they just make the keel longer. I will continue to watch the progress of your post cuz I am very intrigued on how that's supposed to work without a hinge Where is the actuator hole?
 

78Southwind

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Here's our old Hallett. We never had big power in it and it did fine with the gap. I never touched the plates.

Hallett_Transom.jpg


Hallett_Nautical_2010.jpg
 

namba860

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My OG cavitation plates aren't recessed either and are original 1970 equipment, IMO a true cavitation plate needs to be able to put down force on the water to bury the nose to stop porpoiseing and to turn more efficiently. Sure things have changed and upgraded since new technology has come into the picture but still don't see how those plates can change pitch to exert down force. They look like they just make the keel longer. I will continue to watch the progress of your post cuz I am very intrigued on how that's supposed to work without a hinge Where is the actuator hole?
This is just a mock up stage before I send them out and have them polished. I still need to install all the turn buckles the control rod the actuator arm etc. Remember these are not trim tabs they are cavitation plates there’s a big difference. How many flat bottoms have you seen that have a hinged plate? Probably none. The point is to create a concave in the bottom of the plate verse a trim tab that just goes up and down on a hinge. I guess you will understand when I’m done
 

namba860

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Can we spectator's get more pics of your beauty, interested in the prop and rudder, from the angles shown ww can't see the bits and pieces. Thx
I haven’t installed the rudder yet once I get it in I will send more pics
 

SpectraPat

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This is just a mock up stage before I send them out and have them polished. I still need to install all the turn buckles the control rod the actuator arm etc. Remember these are not trim tabs they are cavitation plates there’s a big difference. How many flat bottoms have you seen that have a hinged plate? Probably none. The point is to create a concave in the bottom of the plate verse a trim tab that just goes up and down on a hinge. I guess you will understand when I’m done
Do you know if they did any bottom work on the hull when they re-gelled the boat? (Like remove the hook at the back). Looks great! Keep the photos coming!
 

DRYHEAT

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So what’s up with this @namba860 is there another thread somewhere or did you just get busy with work and stuff. I like these kind of threads.😎
 

RiverDave

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It looks to me like you will need to have longer blocks to hold the control rod. The angle from that rod to where the pads are looks pretty steep?
 

namba860

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It looks to me like you will need to have longer blocks to hold the control rod. The angle from that rod to where the pads are looks pretty steep?
I’m running 1 3/4 long control rod ends.
 

Backlash

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I like the colors of the boat and am looking forward to following your project. I may have missed it, but what year is it? That drain plug being off center would bug the sheeit out of me. I couldn't have left it alone. 😁 Did you guys do any bottom work to the hull, or was it blue printed by the previous owner?
 

namba860

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I like the colors of the boat and am looking forward to following your project. I may have missed it, but what year is it? That drain plug being off center would bug the sheeit out of me. I couldn't have left it alone. 😁 Did you guys do any bottom work to the hull, or was it blue printed by the previous owner?
The boat is a1974 I have put a straight edge on the bottom and there is no hook in it. Yah not sure why the plug is off center kinda bothers me but I have a budget to stick to and that isn’t really a priority.
 

Jay Dub

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looks really nice Shane. That boat will be beautiful when you are all done.
 

RiverDave

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Looks like it’s coming together nicely! I am still wondering if you might end up with too much travel with those extended control rods..

I suppose if ya do it would be easy to limit the travel on pull rod.. just make the foot pedal more sensitive (which is fine as some of those things you gotta push the pedal from straight up to flat anyways)
 

Dkahnjob

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Nice looking boat.
Split cav plates with the space was very common on Campbell cruisers and they always worked well.
 

RiverDave

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How did you account for the transom angle with the “L” that you mounted the plates too?
The “L” is 90 degrees right? So the plates would be pushing like 7 degrees down from the get go? Or did you somehow machine one side of the L to take account for that?
 

namba860

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I made a full length shim that went behind the mounting bracket where they are bolted down it makes the plate level with the bottom
 

Water Romper

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These look nice!! Would cavitation plates be a plus for "any" power boat? Are there some types of hulls & power plants that would NOT ba a good fit for these?
 
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