How to cool BravoIII with thru-hull water pick-up

Lazy Daze said:
Yes, sorry, I wasn't as clear as I should've been - simply leave the drive side open. Thanks for the corrections. I agree it's a good idea to do the block-off thing at the transom.
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We knew you wouldnt do such a thing Dennis.
 
thank you so very much; following thread in case, i have cooling problems.
have transom ass. on boat and motor back in. starting to line engine to day
went with 2.2 drive allso

again sorry for seeming dense about by-pass and for your patients setting me straight.
 
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Sorry I meant bronze not brass.

I got all my stuff in bronze
1-1/4" check valve
1-1/4" 90 to head towards the sea water pump with no bends
1-1/4" 1-piece clam shell strainer thru-hull
1-1/2" hole saw...lol
Tube of 5200
1/2" plug for hose
$100 so far

This is not a salt boat and it is trailered 100% of the time it is not being used.
 
garryowen said:
thank you so very much; following thread in case, i have cooling problems.
have transom ass. on boat and motor back in. starting to line engine to day
went with 2.2 drive allso

again sorry for seeming dense about by-pass and for your patients setting me straight.
Click to expand...
No Problem, Were talking about parts we really dont see.
Henry pointed out the thru hull to me a while back. Then I over research everything. Whats very good about his setup is... Much easier to install using a T fitting.. No need to worry about kelp, plastic bags, etc wrapping around the lower unit blocking waterflow to the engine.
Very cool your putting your boat back together.:thumbsup: Your getting more benefits then just the stronger drive.
I wonder how much added TQ to the prop you get going from a 1.47:1 GR to a 2.20:1 ratio :smt017
The Duoprop is suppose to be good for anther 3 MPH increase at cruise speeds. Ive heard nothing but good things about getting our props cupped. Merc sells cupped props also.
 
shore said:
Sorry I meant bronze not brass.

I got all my stuff in bronze
1-1/4" check valve
1-1/4" 90 to head towards the sea water pump with no bends
1-1/4" 1-piece clam shell strainer thru-hull
1-1/2" hole saw...lol
Tube of 5200
1/2" plug for hose
$100 so far

This is not a salt boat and it is trailered 100% of the time it is not being used.
Click to expand...
YIKES!.... No hose clamps :wow::lol:
I wonder how many GPM of water a 1 1/2" hole lets in.
Funny how we worry about such things when we already have a 16"x7" hole in our transom.

1/2" plug for hose????
The water intake barb looks similar to a thermostat housing. Egg shaped with 2 bolts on each end.
The Merc Bravo block off kit has a flat plate which attaches with two bolts. The instructions also gave warnings of hose clamp positions. Guess its easy to accidentally unlock the lube reservoir line.
Henrys way is using a T. Splices into the engine sea water intake hose. No need for the Merc kit with his setup.
 
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Tail Chaser 661 said:
YIKES!.... No hose clamps :wow::lol:
I wonder how many GPM of water a 1 1/2" hole lets in.
Funny how we worry about such things when we already have a 16"x7" hole in our transom.

1/2" plug for hose????
The water intake barb looks similar to a thermostat housing. Egg shaped with 2 bolts on each end.
The Merc Bravo block off kit has a flat plate which attaches with two bolts. The instructions also gave warnings of hose clamp positions. Guess its easy to accidentally unlock the lube reservoir line.
Henrys way is using a T. Splices into the engine sea water intake hose. No need for the Merc kit with his setup.
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LOL, it is actually a 1.75" hole saw bit.A 1.5" would not pass the thru-hull fitting.

I'm going to let the pump suck from the thru-hull and block off the hose.We get some shallow water down here and the impellers pay the price.I'm about to trim off my outside water line and plug it from inside.


Other than making sure my thru-hull got drilled in the correct spot this is rather simple.My stringer AC pick-up and trailer bunk all came into play...the props are nowhere near.I could imagine a twin would be a whole lot of fun finding a spot.

Yes, I got some more SS clamps.
 
The plug is a 1/2" inner diameter.It's a thick longer PVC cap.It fits wicked tight in the water line and then a clamp.You'll cut the hose before that guy comes out.
 
Shore,

I think that is a real bad plan. If anything ever happens to that plug there is no recovery, the boat will sink. If you want to block off the inlet, do it the right way. Equally, if you don't want to take the drive off, add a tee and another valve.

Henry
 
So what you're saying is a threaded plug with a SS hose clamp will somehow work its way out of a hose with no pressure on it?
 
I don't know. I do know the approach you want to take does not comply with anything the manufacturer has recommended. Maybe you know more about boats then they do. I don't know that either. I do know what the outcome will be if you are wrong.

Here's the thing. You asked for our advice. I gave you my opinion. I think the potential for horrible disaster outweighs any monetary savings your approach will bring you. But at the end of the day my opinion does not matter, its your boat, your money, and the safety of your family, so its your decision. Just don't ask me to validate it.

Henry
 
It's how you said it.

"if something happens to that plug then the boat sinks!"

What?...if merc doesn't say it then it's wrong.....That's laughable when you consider this whole mess is because of THEIR engineering.

By no means am I implying throw that merc book away or poking fun at your opinion.Advice and opinions are what make solutions.

I'm just saying there is always one in a group that cringes when it is done differently.

I should put up a pic of a swimdeck we just made for mine.1.5" Starboard people said would never be strong enough to hold steady.You would have had a heart attack....I got a pic with 8 people on it and it didn't move.Can't be scared to try stuff ya know.
 
shore said:
LOL, it is actually a 1.75" hole saw bit.A 1.5" would not pass the thru-hull fitting.

I'm going to let the pump suck from the thru-hull and block off the hose.We get some shallow water down here and the impellers pay the price.I'm about to trim off my outside water line and plug it from inside.


Other than making sure my thru-hull got drilled in the correct spot this is rather simple.My stringer AC pick-up and trailer bunk all came into play...the props are nowhere near.I could imagine a twin would be a whole lot of fun finding a spot.

Yes, I got some more SS clamps.
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Installation calls for a spot with non aerated water also.
Tough being so anal about things. Stringers,Trl bunks, Lifting strakes. That only leaves a 6" area off the centerline on my boat. Then will a thru hull be to close or hit the oil pan in that area. :smt017:smt021 :lol:
Henry,
I like your canvas setup on your Sig pic.
Sometimes my ride is colder and wetter then I like.
 
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I'm a bit curious as to how much disturbance my AC intake is going to cause.It has a similar but smaller grated scoop.I might have to change that one out to a normal thru-hull fitting.
 
Shore, I would recommend trying to find another location (the port side?) before nixing the grate for the AC. Maybe it would be easier to move the AC and put your cooling thru-hull in the current AC hole?

What's the location of the AC compared to where you were first planning to put the cooling?


PS: Could you fill out your signature? It makes it much easier to help if we can visualize what boat/engine where talking about without having to scroll back through the previous posts.
 
Henry Boyd said:
Shore,

I think that is a real bad plan. If anything ever happens to that plug there is no recovery, the boat will sink. If you want to block off the inlet, do it the right way. Equally, if you don't want to take the drive off, add a tee and another valve.

Henry
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+1 on this - the block off plates cost $23 - if you cant justify that take off the waterneck and use it as a pattern to make your own out of 1/4 inck stock - again, this is done inside the boat, no need to take the drive off so why not do it right? - one of the reasons i did this mod was the security of having seacocks in case of hose, clamp, or some other failure below the waterline.
 
You guys don't get it...just getting the water hose off on mine is a feat of magic.The power steering rack is all over it.

It's not anything like just unbolting the neck and bolting a block-off plate.
 
Lazy Daze said:
Shore, I would recommend trying to find another location (the port side?) before nixing the grate for the AC. Maybe it would be easier to move the AC and put your cooling thru-hull in the current AC hole?

What's the location of the AC compared to where you were first planning to put the cooling?


PS: Could you fill out your signature? It makes it much easier to help if we can visualize what boat/engine where talking about without having to scroll back through the previous posts.
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The AC grate does nothing for the AC.I don't have a on-board Gen.The grate serves no purpose.

As far as moving the AC to the port side...well that would be rather involved.The water line is over there and it is long enough for a LC2 pump as it is.My AC is in the fore cabin.

My water pick-up is about 4" to the side and 3' behind the AC pick-up.Not mention it is a shallow grate.
 
shore said:
You guys don't get it...just getting the water hose off on mine is a feat of magic.The power steering rack is all over it.

It's not anything like just unbolting the neck and bolting a block-off plate.
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:lol::lol::lol: Frigen boats :lol::lol:
The steering ram should come off very easy.
 
What can you expect this mod to cost at the dealer?
 
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