Water Pickup

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Originally Posted by SFV2RVR

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

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

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Originally Posted by WESTERNAERO

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

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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

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Originally Posted by WESTERNAERO

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.

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

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

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/b...ps58dfdf86.jpg

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Originally Posted by WESTERNAERO

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.

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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 ..

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.

What material were your plates made from?

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Originally Posted by WESTERNAERO

What material were your plates made from?

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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.

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Originally Posted by SnoC653

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.

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

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.

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?

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.

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.

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Originally Posted by WESTERNAERO

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.

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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. Attachment 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.
Attachment 37266

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?

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Originally Posted by WESTERNAERO

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?

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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.

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Originally Posted by SnoC653

I figured it was paint because it didn't cover the edges in the middle. .

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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.

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Originally Posted by SnoC653

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.

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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.

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Originally Posted by SnoC653

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. Attachment 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.
Attachment 37266

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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