Rate My Bottom

[rssfla]

OK OK Settle Down!! No this is not a t-back post.
The boat is a 74 Riviera Tahiti as discussed about a month ago. Well the motor is almost done and the hull is being worked on. I have only driven the boat twice before I Had to break it down. Water in the oil and such! Here is the problem, I spent about an hour or 2 driving the boat, once with the diverter operating and once not. This boat just sticks like glue to the water! Motor turned about 5000 rpm (455 olds, jacuzzi pump) boat ran about 55mph. Never even felt like it wanted to plane off. Stuck I tell ya Stuck!!! Looking down the bottom of the boat, it appears to have pretty good hooks on both sides. What can I do aside from major corrections to the bottom to loosen it up and get a bit more out of her? The motor will be fresh and be about 450hp when done. Mild cam and bored .30 over with forged pistons, port work to the heads, 850 holly and a 200hp shot (prob wont be hooked up).
Do you think the mfg built the hull to stick like this? The boat was very very stable but felt like it really needed to air out. The diverter didn't seem to do anything beside throw a beautiful roster. I will attach a few pics, I don't know how to post other then an attachment ( maybe someone will convert them for the post )
Thanks for the continued help to a jet novice in florida.

[rssfla]

if you look close you can see the hook in the chine

[superdave013]

now is time to fill the hooks.
And yes, some did put them in so the boat would plane at slower speeds or with a few fat boys in the back.
But if you want it to be all you can be fixing the hook is a start in the right direction.

[rssfla]

So to fill in the hooks am i just working on the areas between the chines or including the chines. What do I fill them in with?

[superdave013]

sorry, I'm not the guy to answer that. But I'm sure someone will come along pretty soon with all your info.

[rssfla]

here is another shot of the bottom

[rssfla]

my pump and diverter
is a ride plate a way to go? is there one for jacuzzi pumps?

[rssfla]

forgot the photo

[rssfla]

here is the pump intake.
the impeller looks good, no signs of chips or nicks, i was told it was pretty fresh.
I do have a loader grate and will try both when i'm back in the water.
Any suggestions will be helpful.

[BrendellaJet]

Yes, you need a shoe and a ride plate. That will be easy since you have the ability to move the boat around like in the pics. Both will help with pump loading and airing out the hull. Looks like a 12WJ, but its hard to see the impeller in that pic. Since its practically torn down, finish tearing it apart to get a better look at it.
As far as the bottom goes, you need to run a straight edge on the supposed wetted surface. I think for most boats this size/shape/style, the wetted surface is from the rear outside corners to about a foot infront of the pump(triangle) only concern yourself with that area. The rest of the hull may show some hook, but if its not in the water at WOT, it doesn't really matter as much...Hopefully others with this hull can chim in and tell you what works well on their hulls and you can get advice form them. Generally, depending on the depth of the hook, you would use fiberglass mat to fill in(have fun!).
Im betting that the old motor didn't have enough power to get the hull up out of the water, combine that with questionable pump, and your hull will feel like it is glued to the water.

[rssfla]

I guess I'm still abit confused on the shoe? what excally is a shoe? and does anyone have a pic of one and also a ride plate on a jacuzzi? any photos out there?

[rssfla]

pump from inside

[Ken F]

http://community.webshots.com/user/kenf100
Go to the section on Intake Setback/Blueprinting.
Ken F

[Old Guy]

Nobody wants to find that the bottom of their high performance boat hull has a hook. I've often wondered why it's called hook. Maybe it's because of the effect it has. Your boat stays "hooked" to the water. Kind of like dragging an anchor. A high performance hull cannot have a hook in the bottom.
Some say that as long as the hook is in front of the wetted area, it's not going to be a problem. Of course that assumes that you have enough power to overcome that hook and get it out of the water. Good luck on that one.
If you want to be satisfied that you are going in the right direction and improving performance, get rid of all the hook everywhere. Keep checking and fixing until there is no hook.
A little rocker (the opposite of hook) will work and can be trimmed out without loosing speed. There is no way to trim out hook.
Are you sure that it is dry under the floor of your boat? Mine had over 200# of water in it. It didn't slosh. It was soaked into the wood. Extra weight slows you down.
A shoe and ride plate would be good additions. I'll let somebody else comment on that.

[rssfla]

Someone please show me a picture of a shoe!
Who has a ride plate on their jacuzzi?
Thanks So Far Guys, Please keep the comments coming!

[BrendellaJet]

Originally posted by rssfla
I guess I'm still abit confused on the shoe? what excally is a shoe? and does anyone have a pic of one and also a ride plate on a jacuzzi? any photos out there?
Here you go.
http://www.***boat.com/image_center/data/520/212100_0600-med.JPG
Boat is upside down, but you can compare to your stock intake and see the new shoe and the rideplate.
The shoe comes in several designs. Its primary function is to load the pump. The one in the pic also has a back cut. A shoe with a backcut will load the pump, and also provide transom lift, which will air out your boat, provided you have a solid pump and a motor to get the boat out of the water enough...

[rssfla]

So I'm understanding that the shoe is the piece inserted inside the opening of the pump. Designed to direct water to the impeller without creating drag while doing so? Is this something available from Rex or similar supplier? Now the ride plate, the one pictured also looks like it attaches to the back of the pump inlet, is this also a common bolt on part available?

[BrendellaJet]

The intake needs to be machined to accept the shoe. Its depth can be adjusted with shims, and there is a balance to be found(dependent on your boat, power, etc)between drag and pump loading. The ride plate bolts to the shoe, and is supported by a cradle that bolts to the bowl.(the bowl needs to be drilled for this)
Typically, for this pump I dont think anyone stocks the parts, maybe they do for the Berk models, not sure. I got mine from Jack. I gave him my pump and had him do a stage3 race prep on it and those parts came with it. You will probably want to yank the intake and ship it to someone capable to do the work, Since your closer to Hi-Tech, Id ship it there, not sure if there are any shops in your neck of the woods capable of this work...

[Oldsquirt]

Originally posted by rssfla
So I'm understanding that the shoe is the piece inserted inside the opening of the pump.
Just to clarify, that is a "loader". The next piece to the left of it, with the curved edge, is the "shoe". Finally, the piece on the far left is the "ride plate"

[BrendellaJet]

Guess I forgot to mention that! MPD also made me a trick stainless loader. Cant buy those in the store. I think it cost $250. You can get the cheapo angle iron ones if you dont plan on going fast...

[OMEGA_BUBBLE_JET]

you have a jacuzzi wj. it is a mixed flow pump and can be made to perform. jacuzzi never made a shoe or rideplate for any pumps that they made. at least not that I am aware of. Good luck with your hole in the water to throw money into;)
Omega

[OMEGA_BUBBLE_JET]

Originally posted by BrendellaJet
Guess I forgot to mention that! MPD also made me a trick stainless loader. Cant buy those in the store. I think it cost $250. You can get the cheapo angle iron ones if you dont plan on going fast...
how does a stainless loader make a boat any faster than a steel one??:confused: I would think design would play a larger factor not material.:p
Omega

[BrendellaJet]

Originally posted by OMEGA_BUBBLE_JET
how does a stainless loader make a boat any faster than a steel one??:confused: I would think design would play a larger factor not material.:p
Omega
The operative words here were trick and cheapo. Im sure the stainless can withstand the pressures exerted on it better than the angle iron.

[rssfla]

I already have a cheapo one made of angle iron. I will try it and the stock one when its done and see if there is a difference.

[ChetCapoli]

Originally posted by rssfla
I already have a cheapo one made of angle iron. I will try it and the stock one when its done and see if there is a difference.
You'd be surprised how that little "cheapo" angle iron deal works alot better than those fancy $250.00 deals...especially stainless...why stainless?? How much more performance did you get over the angle iron deal brendella?? Just curious is all. I would think at 55mph/5000rpm a angle iron loader would fit the bill. A shoe and rideplate is a waste or money in your application rssfla....get a diverter of some sort first.
CHET

[BrendellaJet]

Originally posted by ChetCapoli
You'd be surprised how that little "cheapo" angle iron deal works alot better than those fancy $250.00 deals...especially stainless...why stainless?? How much more performance did you get over the angle iron deal brendella?? Just curious is all. I would think at 55mph/5000rpm a angle iron loader would fit the bill. A shoe and rideplate is a waste or money in your application rssfla....get a diverter of some sort first.
CHET
Chet, have you seen an intake on a 12WJ? Sounds like you have not, bucause if you had you would know that factory piece is very poor in the section the shoe replaces. Since it will come with a provision to do a ride plate, it cant hurt.
As far as my loader goes, I dont know what performance I have seen, because the boat is not ready yet. But its gonna do over a hundred, and pump loading is gonna be an issue. Since the previous angle iron loader I had cracked and pieces started falling off, I wanted something made with a quality metal. Jack insisted on stainless for my application.
As far as your diverter recommendation, I agree with you, but since he already has one, doesn't really make sense for him to buy another..."A shoe and rideplate is a waste of money in your application"
As far as an angle iron loader goes, nobody ever told him it would not work.
Try to pay attention please...

[Jordy]

Originally posted by BrendellaJet
Try to pay attention please...
Chet thinks paying attention will cost him money so he won't do it. :D :D :D

[rssfla]

Originally posted by BrendellaJet
Here you go.
http://www.***boat.com/image_center/data/520/212100_0600-med.JPG
Boat is upside down, but you can compare to your stock intake and see the new shoe and the rideplate.
The shoe comes in several designs. Its primary function is to load the pump. The one in the pic also has a back cut. A shoe with a backcut will load the pump, and also provide transom lift, which will air out your boat, provided you have a solid pump and a motor to get the boat out of the water enough...
I'd like to see a over head photo if you have one looking into the pump to see how the stuff is configured. Is this a Jacuzzi pump?

[BrendellaJet]

You looking for a pic from inside of the boat? I ve got em at home, I can post tonight if you want. Yes, this is a jacuzzi pump, 12WJ.
here are some other pics of the intake...maybe they will help.
http://www.***boat.com/image_center/data/520/212100_0598-med.JPG
http://www.***boat.com/image_center/data/520/212WJ_Loader_finished3-med.jpg
http://www.***boat.com/image_center/data/500/212WJ_intake_shoe_rear-med.jpg

[rssfla]

thanks for the photos, very interesting!
mine looks similar however seems mor rounded at the ass end of it, your appears to be flat where the shoe attaches. Is this correct? is that original or was it altered for the shoe?

[rssfla]

i may be wrong here is a photo.

[rssfla]

oops wrong photo, that is a mike shake, reason the motor came out of the boat. Here is the right photo.

[BrendellaJet]

Originally posted by rssfla
thanks for the photos, very interesting!
mine looks similar however seems mor rounded at the ass end of it, your appears to be flat where the shoe attaches. Is this correct? is that original or was it altered for the shoe?
Im not sure I understand what you are referring to. Mine has been modified. Below the shoe you can see where the two humps were ground flat-max set back option. What exactly are you referring to? I do know that Jack worked on a WJ shortly after working on mine and told me that he came across another one where the intake looked a little different. I think he was referring to the slope of the intake though, could possible result in the "rounded" aspect you are referring to...

[MarKist]

Originally posted by jordanpaulk
Chet thinks paying attention will cost him money so he won't do it. :D :D :D
:D :D :D

[rssfla]

The area where your shoe bolts down to on my pump is rounded / humped up, convex.
Before doing anymore removing of parts and major work, I'd like to try as many more simple, bolt on type mods. I'd like to have the boat in the water ASAP and enjoy it for 1/2 the season if I can. I don't think this hull will ever be very fast, seems to me to be very heavy layup, no stringers all glass.

[rssfla]

I also have to know, when you guy do your bottom work, it appears that you cover over the mounting screws. Is this commom practice? what are they covered with, duraglass or similar? I'll be doing my bottom work this week trying to unhook the bottom and reduce my wetted surface. Maybe pich up a few MPH.

[BrendellaJet]

Originally posted by rssfla
The area where your shoe bolts down to on my pump is rounded / humped up, convex.
Before doing anymore removing of parts and major work, I'd like to try as many more simple, bolt on type mods. I'd like to have the boat in the water ASAP and enjoy it for 1/2 the season if I can. I don't think this hull will ever be very fast, seems to me to be very heavy layup, no stringers all glass.
Gotcha, with a ride plate that part of the boat is not touching much water at speed.
When I set the intake I was told to countersink the bolts. They are covered up with the same stuff I set the intake with, Sea Goin Poxy Putty.

[bp]

why are the fins hacked off like that? is that the way it was when you got it? don't quite understand why someone would do that... just curious.

[BrendellaJet]

BP, which pic are you referring to?

[bp]

the pics of the intake. the fins come half way back to the shoe, then are cut down to the keel, rather than the fins extending to where the shoe attaches. it would seem that the fins should taper down to the front edge of the shoe.
are all jacuzzi intakes like that? if not, what was the reason for cutting them like this? again, just curious. i've not seen fins shaped like that before.

[BrendellaJet]

I think they are all like this???
I hear that this is worth 10mph.

[rssfla]

what? 10mph be serious now ...... don't make me get the saw out to later find out you were joking!
Mine are longer. I always thought size did matter.

[bp]

Originally posted by BrendellaJet
I think they are all like this???
I hear that this is worth 10mph.
when we did my bottom (same guy that did yours), after consultation jb cut my fins down so they're not as deep as original. also, they were thinned a bit, and cleaned up a lot. the fins taper toward the rear, but taper down about 2", to the point where the edge of the shoe is. in other words, there is an intake channel up to the biting edge of the shoe.
i've just never seen fins cut so that the sides of the channel end 4 or so inches in front of the biting edge. this may make no difference at all. just curious if the original fin cut down to the intake was original jacuzzi, or if someone else had cut them before.

[OMEGA_BUBBLE_JET]

I think someone did some hacking on that intake. I think my intake (jacuzzi yj) is more symmetrical and extends further back having the same slope on the back sides of the fins as the front side. they are freaking huge too. it is nice when pulling a skier. ass end doesn't wander all over the place.
Omega