Bravo 3 exhaust bellows or tube??

[Shaun78]

What should i get. Is the tube OK to have the drive all the way up while in the water(while docked) since it's not connected to the drive? not sure if it will hurt anything thats why I'm asking. Does it give more power?

 

[Don S]

Re: Bravo 3 exhaust bellows or tube??

 

[180shabah]

Re: Bravo 3 exhaust bellows or tube??

Like Don "said", it don't matter. The only real advantage to the tube is ease of installation.

Yes it is OK to raise the drive while in the water while docked, but why would you want to?

 

[Shaun78]

Re: Bravo 3 exhaust bellows or tube??

I dont know i just want to make sure. Where does the hole on exhaust side of the drive go to?

 

[180shabah]

Re: Bravo 3 exhaust bellows or tube??

The exhaust tube is clamped to the exhaust port on the transom shield. The other end is slighty "flared", as the drive is lowered the exhaust port on it just slides into the end of the tube.

 

[Bondo]

Re: Bravo 3 exhaust bellows or tube??

Where does the hole on exhaust side of the drive go to?

Ayuh,......

To the Big Hole in the middle of the Prop...............

 

[45Auto]

Re: Bravo 3 exhaust bellows or tube??

Not sure of your motor, but some of the big blocks specify a tube instead of a bellows. If I remember correctly, with the bellows the motor can cause a vacuum at the prop (I assume from the volume of exhaust gases) at high RPM and hurt your performance.

 

[Shaun78]

Re: Bravo 3 exhaust bellows or tube??

exhaust tube it is then. Easier to install anyways

 

[Don S]

Re: Bravo 3 exhaust bellows or tube??

Not sure of your motor, but some of the big blocks specify a tube instead of a bellows. If I remember correctly, with the bellows the motor can cause a vacuum at the prop (I assume from the volume of exhaust gases) at high RPM and hurt your performance.

Never heard of that before????????

They did have a problem with the big mpi engines having too much back pressure, and the tube relieved some by lettting it out around the inlet of the drive instead of forcing it all thru the prop.

 

[Shaun78]

Re: Bravo 3 exhaust bellows or tube??

Are aftermarket bellows just as good as OEM? They are much cheaper.

 

[Bondo]

Re: Bravo 3 exhaust bellows or tube??

I've never had any problems with Sierra parts......

 

[Shaun78]

Re: Bravo 3 exhaust bellows or tube??

Your sure that no water will back into exhaust having the tube thats not connected to the drive housing. I dont want to cause engine damage

 

[stinger222]

Re: Bravo 3 exhaust bellows or tube??

water would come up through there anyway even with the bellows clamped on there...it comes back up through the prop. The waterline is well below the motor so water should not back into the motor unless you are driving backwards and you suddenly turn off the ign. Exhaust bellows is going to be the quietest, a ***** to install, about 100 rpm hit on the top end.

exh tube easy to install, louder, no perf difference

 

[45Auto]

Re: Bravo 3 exhaust bellows or tube??

Hi Don,

From the Mercruiser Gasoline Installation Manual, 90-863021020, May 2002, page 41:

MAGNUM BRAVO MODEL EXHAUST RECOMMENDATION
Important: To get maximum performance from Magnum Bravo Models, through the transom exhaust is required. It is recommended that the exhaust bellows on the transom assembly be removed. This is necessary to avoid creating a vacuum at the exhaust outlet in the propellor at higher boat speeds. This vacuum could degrade propellor performance on some boats.

Note: If noise regulations do not allow the use of through the transom exhaust, an exhaust pipe kit (Quicksilver P/N 44266A6) must be installed for the through the prop exhaust. This kit also contains an exhaust tube that is used in place of the exhaust bellows.

I would scan it in for you but my fancy printer/copier/scanner decided it won't talk to the computer any more!

 

[Don S]

Re: Bravo 3 exhaust bellows or tube??

You're talking apples and oranges here 45, the question is about using either the tube or the bellows. You are referring to things to be done using the thru transom exhaust (aka Mercruisers Silent Choice exhaust system)
Shaun is referring to only the thru the prop exhaust system.

 

[45Auto]

Re: Bravo 3 exhaust bellows or tube??

Don,

Read the second paragragh (the note). If you have to run through the prop (say you have a Silent Choice or Captains Call switchable exhaust set up) you need to use a tube, not a bellows.

 

[Don S]

Re: Bravo 3 exhaust bellows or tube??

Good grief man, pay attention, He doesn't have that type system, neither Captains Call or Silent choice.
All you are doing is repeating a part from some installation manual that has nothing to do with the question ask or the type exhaust sytem the original poster has.
Both the Captains Call or Silent Choice exhaust sytems are completely different from the standard exhaust system.
You really need to understand what you are talking about, not just repeat what you read from some manual that isn't related to the question.

 

[45Auto]

Re: Bravo 3 exhaust bellows or tube??

The original question was "what should he get?" No mention of what he had already, or what kind of engine.

I said:

Not sure of your motor, but some of the big blocks specify a tube instead of a bellows. If I remember correctly, with the bellows the motor can cause a vacuum at the prop (I assume from the volume of exhaust gases) at high RPM and hurt your performance.

If he's got a big block with that Bravo 3 he needs a tube, per the Merc manual. Doesn't matter what kind of exhaust he's got. If it goes through the prop, he needs a tube.

No need to get bent out of shape because you aren't familiar with everything Don!

 

[Shaun78]

Re: Bravo 3 exhaust bellows or tube??

I am going to get the tube. Aftermarket ones are just as good I am guessing.

 

[Don S]

Re: Bravo 3 exhaust bellows or tube??

I am going to get the tube. Aftermarket ones are just as good I am guessing.

Sure is.