Cavitation plate

[Carnivalride]

Ya! because I told him It was a 11 1/2 x 14 and he said that should be good but when I got home it was a 11 1/2 x 15 so I just thought i would have it turn to a 14, what do you think, I defiantly want it to burn a little more on takeoff right so should I cut it down a 1/4 or maybe a 1/2 and leave at the 15. And yes I'm going to bow it out a 1/4 to 3/8 and try it.

From my experience and what Harold Kindsvater says cutting 1/4" total off the diameter would bring the flash rpm up roughly 800rpm and your top end rpm up by about 400 so you might keep that in mind.

 

[MikeV-Drive]

Thanks Guy's, with all the advice I think I going to just change the few things on the plat like JJ said, try the prop the way it is with the other changes and then if need be cut the prop down a 1/4 and try it again. thanks!

 

[beaverfab]

You need to know what gears are in your v drive, and you need a down PEDAL not just a handle. Please get a down pedal you have way to much HP for just a handle. Then check how much your plate moves, please. Then we can help. thanks j.j.

 

[73 Sanger Flat]

JJ is correct . There is no way I could drive my boat with just a handle and not a pedal .
 
Listen to what JJ tells you and it will help . He has helped me adjust my plates on my boat .. 

 

[MikeV-Drive]

I took JJ advice Monday and ordered the pedal it will be here today I will install it tonight & tomorrow change the plates a little on the out side from the measurements JJ has gave me. Then Sunday try it out at the river, & Stuart has been kind enough to loan me a prop if need be after that.

 

[73 Sanger Flat]

Good Luck / get some RPM numbers if you can on the prop burn and also max RPM you get ..

 

[Wakemaker]

Since we're on the subject of cavitation plates, I have a question.  Two days after I got my V-Drive I was cruising across the lake at a high rate of speed, at least I thought so, and ripped the left side of my plate almost completely off my boat.  When I had the new plates made, I added 2" to the plates because it seemed like the thing to do at the time I guess.  The turnbuckles are still in the original place and angle that they were in, but I'm wondering now how this affects my boat.  I've done a lot of tweaking to get it to where it feels comfortable and it seems to work good.  I was hopping " can't spell porpoising" at first till I added a little more down to the plates, and I smoothed that out really nice.  I just wonder if I was to take of an inch or two how that would affect the speed, handling, etc.  BTW these are fixed plates.

 

[Wakemaker]

Since we're on the subject of cavitation plates, I have a question.  Two days after I got my V-Drive I was cruising across the lake at a high rate of speed, at least I thought so, and ripped the left side of my plate almost completely off my boat.  When I had the new plates made, I added 2" to the plates because it seemed like the thing to do at the time I guess.  The turnbuckles are still in the original place and angle that they were in, but I'm wondering now how this affects my boat.  I've done a lot of tweaking to get it to where it feels comfortable and it seems to work good.  I was hopping " can't spell porpoising" at first till I added a little more down to the plates, and I smoothed that out really nice.  I just wonder if I was to take of an inch or two how that would affect the speed, handling, etc.  BTW these are fixed plates.

You know if nobody wants to add there input that is alright.  I'll just have to figure it out my damn self. :smile15:

 

[TintMan]

Since we're on the subject of cavitation plates, I have a question.  Two days after I got my V-Drive I was cruising across the lake at a high rate of speed, at least I thought so, and ripped the left side of my plate almost completely off my boat.  When I had the new plates made, I added 2" to the plates because it seemed like the thing to do at the time I guess.  The turnbuckles are still in the original place and angle that they were in, but I'm wondering now how this affects my boat.  I've done a lot of tweaking to get it to where it feels comfortable and it seems to work good.  I was hopping " can't spell porpoising" at first till I added a little more down to the plates, and I smoothed that out really nice.  I just wonder if I was to take of an inch or two how that would affect the speed, handling, etc.  BTW these are fixed plates.

You know if nobody wants to add there input that is alright.  I'll just have to figure it out my damn self. :smile15:

well-i don't know that much about it-but when i bought the new aggressor pump...it is 1.5" longer or so than the berkley so to bolt my ride plate up and mount the yoke to the bowl i needed an extra inch on my rideplate. Well i called and talked to "the ones that know" and was told that most jet ride plates NEED to be 18" and no longer. Why? who the hell knows!  :smile16: There...glad i could help!  :grin: :grin: :grin:

 

[duanehydro]

:smile26: Sorry, dude, not a whole lot of old school true flat guys here.....I suggest contacting JJ Beaver if you are seriously attempting something.

 

[TintMan]

:smile26: Sorry, dude, not a whole lot of old school true flat guys here.....I suggest contacting JJ Beaver if you are seriously attempting something.

Oh ...thought he was talkin bout a jet...i'm no help! :smile14:

 

[Carnivalride]

Since we're on the subject of cavitation plates, I have a question.  Two days after I got my V-Drive I was cruising across the lake at a high rate of speed, at least I thought so, and ripped the left side of my plate almost completely off my boat.  When I had the new plates made, I added 2" to the plates because it seemed like the thing to do at the time I guess.  The turnbuckles are still in the original place and angle that they were in, but I'm wondering now how this affects my boat.  I've done a lot of tweaking to get it to where it feels comfortable and it seems to work good.  I was hopping " can't spell porpoising" at first till I added a little more down to the plates, and I smoothed that out really nice.  I just wonder if I was to take of an inch or two how that would affect the speed, handling, etc.  BTW these are fixed plates.

If longer plates help and they are set up level or "down" in comparison with the back of the hull the boat is riding on them. "If" that is the case shortening the plates will require more "down" to keep the boat riding where it is.

What prop do you have and haw far back is it from the strut? IMO a couple of nickels makes more difference than lowering the plates. Try about 3 nickels in the coupler between the output shaft of the v-drive and propshaft and see what that does for you. Make sure you don't go more than 3/4" away from the strut and less is better on that measurement.

Your next issue is fixed plates it's really hard to make a fixed plate boat run well from off idle to top end.

Good luck

 

[Carnivalride]

You know if nobody wants to add there input that is alright.  I'll just have to figure it out my damn self. :smile15:

Ain't that how it usually goes anyway?!?!?!

 

[MikeV-Drive]

Since we're on the subject of cavitation plates, I have a question.  Two days after I got my V-Drive I was cruising across the lake at a high rate of speed, at least I thought so, and ripped the left side of my plate almost completely off my boat.  When I had the new plates made, I added 2" to the plates because it seemed like the thing to do at the time I guess.  The turnbuckles are still in the original place and angle that they were in, but I'm wondering now how this affects my boat.  I've done a lot of tweaking to get it to where it feels comfortable and it seems to work good.  I was hopping " can't spell porpoising" at first till I added a little more down to the plates, and I smoothed that out really nice.  I just wonder if I was to take of an inch or two how that would affect the speed, handling, etc.  BTW these are fixed plates.

You know if nobody wants to add there input that is alright.  I'll just have to figure it out my damn self. :smile15:

I cant help you I don't know that much myself!! and I own one. LOL!

 

[73 Sanger Flat]

Since we're on the subject of cavitation plates, I have a question.  Two days after I got my V-Drive I was cruising across the lake at a high rate of speed, at least I thought so, and ripped the left side of my plate almost completely off my boat.  When I had the new plates made, I added 2" to the plates because it seemed like the thing to do at the time I guess.  The turnbuckles are still in the original place and angle that they were in, but I'm wondering now how this affects my boat.  I've done a lot of tweaking to get it to where it feels comfortable and it seems to work good.  I was hopping " can't spell porpoising" at first till I added a little more down to the plates, and I smoothed that out really nice.  I just wonder if I was to take of an inch or two how that would affect the speed, handling, etc.  BTW these are fixed plates.

If longer plates help and they are set up level or "down" in comparison with the back of the hull the boat is riding on them. "If" that is the case shortening the plates will require more "down" to keep the boat riding where it is.

What prop do you have and haw far back is it from the strut? IMO a couple of nickels makes more difference than lowering the plates. Try about 3 nickels in the coupler between the output shaft of the v-drive and propshaft and see what that does for you. Make sure you don't go more than 3/4" away from the strut and less is better on that measurement.

Your next issue is fixed plates it's really hard to make a fixed plate boat run well from off idle to top end.

Good luck

Hey Loren : Adding  the nickles  that give more tail lift correct  ?  Pushing the prop back look like it would push the back up more .. or do I have this back ward .. I added one nickle to mine in hope to help from dragging the tail so much ..

Clayton : I would talk to JJ and see what he says about cutting off an inch , I would think I would leave it like you have it now and it is not bouncing  on you anymore .  unless you start bending the plates or braking parts .
Those turn buckles on back get expensive to buy . I just bought enough to make four complete spares and they were just about a 100.00 per complete rod with the eyelevelers ,clevis pins.  base plates and turnbuckles.. So if you start breaking stuff , you need to change back to like it was ..

 

[Carnivalride]

Since we're on the subject of cavitation plates, I have a question.  Two days after I got my V-Drive I was cruising across the lake at a high rate of speed, at least I thought so, and ripped the left side of my plate almost completely off my boat.  When I had the new plates made, I added 2" to the plates because it seemed like the thing to do at the time I guess.  The turnbuckles are still in the original place and angle that they were in, but I'm wondering now how this affects my boat.  I've done a lot of tweaking to get it to where it feels comfortable and it seems to work good.  I was hopping " can't spell porpoising" at first till I added a little more down to the plates, and I smoothed that out really nice.  I just wonder if I was to take of an inch or two how that would affect the speed, handling, etc.  BTW these are fixed plates.

If longer plates help and they are set up level or "down" in comparison with the back of the hull the boat is riding on them. "If" that is the case shortening the plates will require more "down" to keep the boat riding where it is.

What prop do you have and haw far back is it from the strut? IMO a couple of nickels makes more difference than lowering the plates. Try about 3 nickels in the coupler between the output shaft of the v-drive and propshaft and see what that does for you. Make sure you don't go more than 3/4" away from the strut and less is better on that measurement.

Your next issue is fixed plates it's really hard to make a fixed plate boat run well from off idle to top end.

Good luck

Hey Loren : Adding  the nickles  that give more tail lift correct  ?  Pushing the prop back look like it would push the back up more .. or do I have this back ward .. I added one nickle to mine in hope to help from dragging the tail so much ..

Clayton : I would talk to JJ and see what he says about cutting off an inch , I would think I would leave it like you have it now and it is not bouncing  on you anymore .  unless you start bending the plates or braking parts .
Those turn buckles on back get expensive to buy . I just bought enough to make four complete spares and they were just about a 100.00 per complete rod with the eyelevelers ,clevis pins.  base plates and turnbuckles.. So if you start breaking stuff , you need to change back to like it was ..

By adding nickels or spacing the prop back it will try and lift the transom and that will usually lower the nose. What it does by lifting the back is usually "rolls" the boat over a little and that should help dry up your chines.

As power is added to the boat they go faster, the addditional speed causes the tail to lift which in turn the nose tends to roll over so to keep them from "belly sliding or plowing the prop is moved farther forward to keep the boat at the proper attack angle. So what happens from here is guys buy an ex-race boat set up for 700hp or more and they drop in a 450-500hp pump gas big block and the boat porpoises and/or drags the tail at the new slower max speed. So to fix that you have to either rebalance the boat for the lower power or put power back in it.

Now some boats that have hook or are just under powered will actually run faster flying the nose and dragging the tail. LOL

Use your GPS and see what happens but a nickel or two might make your boat "set" better on the ride pad and pick up a little. Or if the chines are a little long they may drag (be wet) even at your best GPS speeds. You get more hydrodynamic lift the faster you go so boats that were tuned for 8 second and quicker passes will be different than ones that were tuned for 10.0s with the least amount of power.

JMO sorry if that rambled.

 

[73 Sanger Flat]

I need to get my engine back in and dialed in and then start the balancing part . I know I need to get mine balanced out better.. So I may be taking the one nickle out of mine if I get enough power this time to push the nose over more and pick the tail up a little also .  .. The prop was right up against the strut barrel ( maybe 1/8 inch ) when i got the boat , it had a Blown BBC in it ..  , I think I was on the right track for balancing last time , so will start over with the new power plant this spring and if I am plowing to much , I will take the nickle back out and try that .. ..Thanks Loren for the info

Sorry Clayton for hijacking your  thread.. ..

 

[Carnivalride]

Your welcome Billy.  I sure hope your new motor works out well for you.  Feel free to fire question through Pm or email I'm hit and miss on checking the site.  :smile26:

 

[73 Sanger Flat]

Will do . I also need to start checking how much prop burn I have . I think it way to much . I need to learn how to use my memory tach so i can get more data on each run . That would be helpfull to see exactly what it does . My tach will record 4 runs each for  20 seconds . Jim showed my how to do it , but when i am making a pass , I forget something and nothing gets recorded .. I need to put a note on the tach to remind the dumbass how to record a run  !!!
Thanks again Lorenn for the tips ..

 

[Disturbed]

I must say that this has been a very good thread.  I'm learning alot.  :smile16:  Hopefully I'll get to take my Kurtis to the water again in the next couple weeks and get a better idea if I'm even getting any "burn".  I'm running a 11 3/4 x 15 and it man handles the boat to some extent.  I need to figure out my recall tach and use it.  :smile28:  I'm too busy trying to drive the thing to look at the tach very close. lol.