is my boat odd?

[LoudDog]

I have a 96 Regal with a Mercruiser 5.7 and an Alpha 1. It?s raw water cooled. It?s my first boat so I don?t really no much about any other boats.

I was talking to a friend that does seem to know a lot about boats and apparently my boat is odd? The coolant water exits the boat from two ports, one on either side of the out drive. Apparently normally the water comes out the prop and/or a single port in the center?

Looking at some photos at boats running on plane, mine is sure different. Here is a photo of what I have (enlarge the cover photo of the manual and try not to stare at the ladies):

http://www.amazon.com/Clymer-Mercru...=sr_1_5?ie=UTF8&s=books&qid=1253735743&sr=8-5.

Apparently that water shooting out the side of the outdrive is not typical? Or is my friend missing something?

If it's odd, is it a good or bad odd?

Thanks

 

[windsors03cobra]

Re: is my boat odd?

Its normal, they are called idle relief ports. Too much back pressure to push exhaust that far down at idle I believe.

 

[Bondo]

Re: is my boat odd?

Or is my friend missing something?

Ayuh,... Apparently... As noted,.. Those are the Idle Relief ports...

Not saying you've got a Problem,....
But,...
If the motors ever been overheated, or run Dry,...
The Exhaust Shutters might have been Burnt up,+ they can fall down into the exhaust passages, blocking the exit through the Prop...

 

[LoudDog]

Re: is my boat odd?

In that photo on the book that boat is not at idle and there is a lot of water coming out of those? Is that normal?

When running my boat on the hose I just get a trickle of water out of the prop. When I had the risers off I reached back and those flapper valves are in place and fine.

 

[LoudDog]

Re: is my boat odd?

So maybe a dumb question, but is the water that shoots out the sides that has not gone up to the engine? or has it gone through the manifolds?

I'm so confused on what happens to the water after it leaves the manifolds!

 

[Maclin]

Re: is my boat odd?

I would say that the water from the idle relief ports has already been thru the engine. But that front cover photo looks like a lot more water coming from the side of the drive and not the idle relief ports as they are at the bottom of the trans shield under all that.

Are you saying that is what your boat is doing, what that front cover shows?

 

[haulnazz15]

Re: is my boat odd?

Any water that come out of the boat has already been through the engine/manifolds. The idle relief ports are located at the bottom of the exhaust pipe where the water "pools" and drains out of the ports. When not at idle, the exhaust flow is enough that it carries more of the water through the exhaust bellows and out of the prop. The picture on the manual does not show the relief ports, as they are almost under water. You should just get a steady pulsing of the water in rhythm with the engine from the idle relief ports.

I doubt there is anything wrong with your boat, and your friend doesn't know what he's talking about.

 

[LoudDog]

Re: is my boat odd?

Are you saying that is what your boat is doing, what that front cover shows?

Yes.


Another question: with these two ports expelling water, is the left one from the left side of the motor and the right one from the right side of the motor? Or does the exhaust/water get pooled then split again?

 

[Bondo]

Re: is my boat odd?

Or does the exhaust/water get pooled then split again?

Yes....

 

[haulnazz15]

Re: is my boat odd?

The two ports are both coming from the bottom of the y-pipe, so they are not separated by exhaust bank. It just so happens that they designed the two relief ports to exit on either side, even though it is mixed exhaust.

 

[LoudDog]

Re: is my boat odd?

Thanks all!

So it appears my boat is working as intended.

But is this a normal design?

 

[windsors03cobra]

Re: is my boat odd?

Its a normal MerCruiser design, been that way for the better part of 40 years on that drive.