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WESTERNAERO
04-02-2014, 07:21 AM
How far off keel centerline, left and right, is the optimal placement for water pickups on the cav plates. How far forward off the the trailing edge also, if that matters.

Sharp shooter
04-02-2014, 09:17 AM
How far off keel centerline, left and right, is the optimal placement for water pickups on the cav plates. How far forward off the the trailing edge also, if that matters.

Call Mikey at Prime Marine. (909) 484-8329 with all the experience he has rigging ski race boats he would be a solid source.

SnoC653
04-02-2014, 09:52 AM
I asked a similar question and was told that due to airation by the plates, I should consider moving the pickups under the boat out of the prop blast. I'm working on a true flat though. On your cruiser I would think back more would give you more lateral options to stay wet and out of the prop wash.

WESTERNAERO
04-02-2014, 10:03 AM
Yeah, I want to make sure they are getting clean water. I also wonder about the bottom angle, 15 deg, 12.5 deg and flat. Not sure what the GN Raysons and the like are, 7 deg maybe.

ogshotgun
04-02-2014, 10:52 AM
my water pick ups are 7" from center and 1.5" from the trailing edge of the plate with a 20* slash cut on them

ogshotgun
04-02-2014, 10:54 AM
cp performance part number Cavitation Plate Style -10 AN Water Pick-Up
410-301101

comes in many sizes

WESTERNAERO
04-02-2014, 01:53 PM
cp performance part number Cavitation Plate Style -10 AN Water Pick-Up
410-301101

comes in many sizes

I'm doing -16's and I making them now, so no need for CP's number but thanks. 7.0" off center sounds a little too close to center for some reason. Just from looking at other boats, I was thinking around 12.0" off center. But I am curious if there is some standard to this? Something that figures in the diameter of the prop + the angle of the bottom + distance from the prop, sort of thing.

Sharp shooter
04-02-2014, 05:08 PM
I asked a similar question and was told that due to airation by the plates, I should consider moving the pickups under the boat out of the prop blast. I'm working on a true flat though. On your cruiser I would think back more would give you more lateral options to stay wet and out of the prop wash.

Julian rigged the Biesemeyers with a single pick up under the boat (at the blast plate). If that comes loose or fails at speed your boat will likely sink.

I have 2 #12 pick ups separated by 9.5 inches (centered) 9 inches behind the transom. I still use the blast plate pick up, but mine is set up for the oil cooler and v-drive and I check it for tightness every trip.

http://www.v-drivevideo.net/pictures/albums/userpics/GordyMikeKing_Mikey.jpg

Sharp shooter
04-02-2014, 05:12 PM
One of Mikey's rigging jobs.

http://i208.photobucket.com/albums/bb39/Roadroamer1/DSC08708_zps58dfdf86.jpg (http://s208.photobucket.com/user/Roadroamer1/media/DSC08708_zps58dfdf86.jpg.html)

WESTERNAERO
04-02-2014, 05:13 PM
Damn Jerry, I never noticed how many turnbuckles you have on that thing. Looks bitchin anyhow.

SFV2RVR
04-02-2014, 05:29 PM
Here is a pic of mine on my Schiada.

37080

Sharp shooter
04-02-2014, 05:37 PM
Damn Jerry, I never noticed how many turnbuckles you have on that thing. Looks bitchin anyhow.

Thanks!

Sharp shooter
04-02-2014, 05:39 PM
:)

http://i208.photobucket.com/albums/bb39/Roadroamer1/DSC00102_zps1f34c040.jpg (http://s208.photobucket.com/user/Roadroamer1/media/DSC00102_zps1f34c040.jpg.html)

HotWater
04-02-2014, 05:47 PM
Here is a pic of mine on my Schiada.

37080

That look's like a nice garage dolly. Do you have anymore pics of it?

WESTERNAERO
04-02-2014, 06:02 PM
Here is a pic of mine on my Schiada.

37080

Yeah, but it's a Schiada...:thumbsdown

WESTERNAERO
04-02-2014, 06:33 PM
So I guess people just put the pickups where ever they feel they look good. No reasoning behind it, is that correct?
Looking at Marc's, I'd say those are about 10-12 off center. And even with the pads, so about 1.5 - 2.0 from the end of the plate.
That Prime Schiada looks about the same also.

gn7
04-02-2014, 07:00 PM
So I guess people just put the pickups where ever they feel they look good. No reasoning behind it, is that correct?
Looking at Marc's, I'd say those are about 10-12 off center. And even with the pads, so about 1.5 - 2.0 from the end of the plate.
That Prime Schiada looks about the same also.

Mine are half way between the inner most turn buckles and the next ones out, and even with the turn buckle pads.

WESTERNAERO
04-02-2014, 07:27 PM
Mine are half way between the inner most turn buckles and the next ones out, and even with the turn buckle pads.

So about the same then? So maybe we can say midway between the inner strake and the outer edge of the prop for both sides? I wouldn't think you'd want them directly behind either.

WESTERNAERO
04-02-2014, 07:48 PM
Another thing, the thru hull bulkhead fittings. Above or below the water line? Whats the thinking here? Does having them below make it easier on the pump to prime itself?

SFV2RVR
04-02-2014, 07:50 PM
Another thing, the thru hull bulkhead fittings. Above or below the water line? Whats the thinking here? Does having them below make it easier on the pump to prime itself?

Mine are low because where they come thru the transom they go directly into the sea strainer for a clean connection.

WESTERNAERO
04-02-2014, 08:00 PM
Mine are low because where they come thru the transom they go directly into the sea strainer for a clean connection.

Or does having them below prefill the strainers instead of the pump trying to fill them?

SFV2RVR
04-02-2014, 09:09 PM
Or does having them below prefill the strainers instead of the pump trying to fill them?

The pump still fills them. I thought they actually were mounted lower on the transom, but I was wrong. Here's a inside view.
http://img.tapatalk.com/d/14/04/03/5ehyzene.jpg

78Southwind
04-02-2014, 09:19 PM
So I guess people just put the pickups where ever they feel they look good. No reasoning behind it, is that correct?
Looking at Marc's, I'd say those are about 10-12 off center. And even with the pads, so about 1.5 - 2.0 from the end of the plate.
That Prime Schiada looks about the same also.

My Spectra is about 9" of center. I'll double check tomorrow.

Mitch
04-02-2014, 10:07 PM
Directly inline with sea strainer inlets

http://img.tapatalk.com/d/14/04/03/5y9y7y8e.jpg

http://img.tapatalk.com/d/14/04/03/6ysunyhu.jpg

ptc
04-03-2014, 10:52 AM
Now thats a good looking rear end!..... nice exhaust and extra nice work on all the cav rod/plate hardware - sweet!

http://i208.photobucket.com/albums/bb39/Roadroamer1/DSC08708_zps58dfdf86.jpg

ogshotgun
04-03-2014, 11:26 AM
I'm doing -16's and I making them now, so no need for CP's number but thanks. 7.0" off center sounds a little too close to center for some reason. Just from looking at other boats, I was thinking around 12.0" off center. But I am curious if there is some standard to this? Something that figures in the diameter of the prop + the angle of the bottom + distance from the prop, sort of thing.


i knew you would make your own ... was giving you the part number because i didn't have picture of them .. i looked at several boats yesterday and all of them were different ..

SnoC653
04-03-2014, 07:57 PM
If you're running sea strainers the dual setups posted look great. Finally got the location for moving mine under the boat and off the cav plates. I was told to put it on the blast plate, beside the strut and in front of the prop. This actually makes sense as there should be good flow there and I won't have to worry about the cav plates cracking again. My old plate has a crack across the pickup, through the turnbuckle pad, to the inside split of the plate. I'm thinking at speed the added twist from the pickup drag was just enough to get it to start cracking. Not sure what happens if a plate fails, and I don't want to find out either. So to the blast plate mine goes.

WESTERNAERO
04-03-2014, 08:46 PM
What material were your plates made from?

SnoC653
04-03-2014, 09:08 PM
What material were your plates made from?

The plates that were on it were Aluminum that mic'd at .209 (3/16th is what we think it was supposed to be). They had a doubler that was 3" wide of the same material. Just the plate cracked, the doubler is still fine.

WESTERNAERO
04-03-2014, 09:16 PM
The plates that were on it were Aluminum that mic'd at .209 (3/16th is what we think it was supposed to be). They had a doubler that was 3" wide of the same material. Just the plate cracked, the doubler is still fine.

Yeah I assumed they were aluminum, do you know what type and condition they were?

gn7
04-03-2014, 09:58 PM
I have my doubts about material that measures .209. We use a lot of .020 5052 H32 at work.

I never seen a 6061 T6 plate crack back at the turnbuckles.

SnoC653
04-03-2014, 10:21 PM
They were on the boat when I bought it. We believe the boat was a K boat or a PS boat before but nobody remembers the fisherman from the Texas coast that used to race it. The 1" transom rod and the cav setup seemed to be done right back for back in the day. To be honest, I just assumed they were 6061 5 gauge but have since been told they were probably 3/16th. The screws were 3/16 stainless fine thread bevel head with lock nuts.

The crack started at the water pickup and than ran pretty straght along the screws for the turnbuckle pads toward the middle. Towards the outside the crack was jagged and moved in closer to the transom. Over all the crack probably measures 7".

Any quick way to determine what type it is?

WESTERNAERO
04-03-2014, 10:38 PM
Could have been 6061 but in a t3 condition maybe. Sometimes you can have cracks form from the wrong angle of countersink to bolt fit. If the plates were uncoated and there was a lot of white chaulking going one they could have been 7075 or 2024, more so with the 7075. Getting plate oversized is not uncommon there are tolerances that the mills can use up. +.020 tolerance would put you at the .206 for .1875 plate.
A bad c/s with a lot of vibration would for sure over time fatigue and crack the material.

WESTERNAERO
04-03-2014, 10:45 PM
If you think they might have been 7075 pore a little ammonia on the plate, if it turns black there's a lot of zinc and is most likely 7075.

SnoC653
04-04-2014, 07:34 PM
If you think they might have been 7075 pore a little ammonia on the plate, if it turns black there's a lot of zinc and is most likely 7075.

Well they aren't 7075 then. I put ammonia and soaked the area between the turnbuckle pads and no black. The plates were painted black and you can see the doubler was also. Paint is worn off/polished off the doubler. 37267

Here is a picture of the crack itself. You can see where it ran along the pressure line from the turnbuckle pad and then started heading to the front edge. This is the bottom of the plate.
37266

WESTERNAERO
04-04-2014, 07:55 PM
We're they painted or were they anodized. Anodize fades in the sun like I'm seeing there, and it won't let ammonia or a mind acid react with the zinc. I am seeing a white chaulking corrosion in the c/s holes. That crack looks like the plates saw some trauma and hole to hole was the weak link.
It's kinda funny my old hardware on my boat half of was made with 7075. There's a lot of chaulking on some of the parts. Kinda like these old boat builders were just that and racers on the side. Seems like they would just go down to the local material supplier and grab all the rems of aluminum that were available. Because aluminum is aluminum , right?

SnoC653
04-05-2014, 11:21 AM
We're they painted or were they anodized. Anodize fades in the sun like I'm seeing there, and it won't let ammonia or a mind acid react with the zinc. I am seeing a white chaulking corrosion in the c/s holes. That crack looks like the plates saw some trauma and hole to hole was the weak link.
It's kinda funny my old hardware on my boat half of was made with 7075. There's a lot of chaulking on some of the parts. Kinda like these old boat builders were just that and racers on the side. Seems like they would just go down to the local material supplier and grab all the rems of aluminum that were available. Because aluminum is aluminum , right?

I figured it was paint because it didn't cover the edges in the middle. I also sanded an area down and rechecked with the ammonia, no color change. There was definitely a lot of flex going on where they cracked, the doubler has metal transfer from rubbing and a small crack forming as well. The new plates will be 6061 T6 if that is what is prefered these days. I even considered going to stainless since the pedal will have some type of assist on it for racing.

gn7
04-05-2014, 08:09 PM
I figured it was paint because it didn't cover the edges in the middle. .

That's because who ever made the plate tried to use a single plate and found out they couldn't get the boat to handle for shit and cut the plate in half.

Sharp shooter
04-06-2014, 08:36 PM
We believe the boat was a K boat or a PS boat before but nobody remembers the fisherman from the Texas coast that used to race it.

This may or may not help, but I've never seen a Biesemeyer K boat with 8 turnbuckles. I've never even seen an NRKA Biesemeyer with 8 turnbuckles. :D

I think the boat was backed into something or rear ended causing the plate to break.

ogshotgun
04-06-2014, 10:24 PM
Well they aren't 7075 then. I put ammonia and soaked the area between the turnbuckle pads and no black. The plates were painted black and you can see the doubler was also. Paint is worn off/polished off the doubler. 37267

Here is a picture of the crack itself. You can see where it ran along the pressure line from the turnbuckle pad and then started heading to the front edge. This is the bottom of the plate.
37266

i have seen this exact issue on a boat before in the exact spot...it was damaged from a floor jack lifting the back of the boat up to service the rudder... no need to re invent the wheel .. its metal its old worn out .. replace it.. if the tire on your car gets a slice do you replace the tire or re invent the wheel ???

also that looks like type III hard anodizing also ... fades bad in the sun will lose the color but not the coating and its i believe aout 2-3 thousands thick

SnoC653
04-07-2014, 05:09 PM
This may or may not help, but I've never seen a Biesemeyer K boat with 8 turnbuckles. I've never even seen an NRKA Biesemeyer with 8 turnbuckles. :D


I think the boat was backed into something or rear ended causing the plate to break.

Don't worry, If I run the boat in the NRKA I'll add turnbuckles between each pair, that should make my boat two turnbuckles faster than your boat and that much harder to get off the trailer and into a race.


i have seen this exact issue on a boat before in the exact spot...it was damaged from a floor jack lifting the back of the boat up to service the rudder... no need to re invent the wheel .. its metal its old worn out .. replace it.. if the tire on your car gets a slice do you replace the tire or re invent the wheel ???

also that looks like type III hard anodizing also ... fades bad in the sun will lose the color but not the coating and its i believe aout 2-3 thousands thick

Guaranteed that isn't a result of jacking the boat. The miniature fissures show repeated stres, as well as the crack traveling over time. What you can't see is that there is also transference from the plate vibrating against the doubler. That doesn't happen with a one time event.

As for Anno or paint, hard to say, but the bottom shows no wear wich leads me to believe it has been re-painted or whatever it is.

ogshotgun
04-07-2014, 09:28 PM
Don't worry, If I run the boat in the NRKA I'll add turnbuckles between each pair, that should make my boat two turnbuckles faster than your boat and that much harder to get off the trailer and into a race.



Guaranteed that isn't a result of jacking the boat. The miniature fissures show repeated stres, as well as the crack traveling over time. What you can't see is that there is also transference from the plate vibrating against the doubler. That doesn't happen with a one time event.

As for Anno or paint, hard to say, but the bottom shows no wear wich leads me to believe it has been re-painted or whatever it is.

if you take the metal and hit it with a wire wheel .. if its anodized there will be a strange smell .. thats how i know for sure

WESTERNAERO
04-07-2014, 09:42 PM
That's anodized

WESTERNAERO
04-09-2014, 01:25 PM
Hey Sno, I'm not sure if you know this, I thought this would be kinda common knowledge but, make sure when you order your new material the grain direction is going with the short length of the plates. Or linear with the boat maybe is a better way to say it.