Loud Exhaust...

[NetDoc]

I finally have all the kinks worked out of my 3.0 l engine. I put in a marine circulation pump, remade the bracket for as well as rebuilt the raw fuel pump and even replaced/torqued the loose bolts on the flywheel. The engine and outdrive are running smooth and quietly. Still, the exhaust is louder than I like. Are there any options, or do I have to live with it?

 

[Bondo]

Re: Loud Exhaust...

I finally have all the kinks worked out of my 3.0 l engine. I put in a marine circulation pump, remade the bracket for as well as rebuilt the raw fuel pump and even replaced/torqued the loose bolts on the flywheel. The engine and outdrive are running smooth and quietly. Still, the exhaust is louder than I like. Are there any options, or do I have to live with it?

Ayuh,... Is the exhaust, in tact, through to the prop,..??

Where ya gettin' the noise from,..??

 

[NetDoc]

Re: Loud Exhaust...

The exhaust consists of the manifold, a riser and a silicone down tube where it goes through the transom via a rubber flap just at the waterline, but not through the outdrive. Everything is tight up to the flapper. It's the noise coming out the back that's bothersome. I wonder what it would take to make it go through the outdrive.

 

[04fxdwgi]

Re: Loud Exhaust...

The exhaust consists of the manifold, a riser and a silicone down tube where it goes through the transom via a rubber flap just at the waterline, but not through the outdrive. It's the noise coming out the back that's bothersome. I wonder what it would take to make it go through the outdrive.

Never mind... I see it's a Volvo. Can't comment on them.

 

[NetDoc]

Re: Loud Exhaust...

The outdrive is an VolvoPenta AQ200... I wonder if a parts manual exists. Don S has supplied me with the service manual, but it doesn't have part numbers. mind you, this is circa 1968. Where would I look for an aftermarket muffler? I'm not sure I have the room for one.

 

[04fxdwgi]

Re: Loud Exhaust...

The outdrive is an VolvoPenta AQ200... I wonder if a parts manual exists. Don S has supplied me with the service manual, but it doesn't have part numbers. mind you, this is circa 1968. Where would I look for an aftermarket muffler? I'm not sure I have the room for one.

Is it a 3" exhaust?

 

[NetDoc]

Re: Loud Exhaust...

Is it a 3" exhaust?

I am not sure, but that sounds about right.

 

[NetDoc]

Re: Loud Exhaust...

OK, I measured the outpipe and it is 3". I tried to measure the pipe coming off of the riser, and it's at MOST 3.5". The silicone is in the way and since I am heading out diving in a few, I don't want to pull it off.

There is a fitting on the outdrive for an exhaust. The corresponding hole through the transom has not been drilled. You can see where it's supposed to go through the aluminum, but the wood is solid.

 

[04fxdwgi]

Re: Loud Exhaust...

OK, I measured the outpipe and it is 3". I tried to measure the pipe coming off of the riser, and it's at MOST 3.5". The silicone is in the way and since I am heading out diving in a few, I don't want to pull it off.

There is a fitting on the outdrive for an exhaust. The corresponding hole through the transom has not been drilled. You can see where it's supposed to go through the aluminum, but the wood is solid.

I would just throw on one of those aftermarket mufflers. These are examples of what is out there. There are many more and a few a bunch cheaper. Let your fingers do the walking thru Google
http://www.google.com/#hl=en&sugexp=les%3B&gs_nf=1&gs_mss=marine%20exhaust%20mu&cp=22&gs_id=1v&xhr=t&q=marine+exhaust+mufflers&pf=p&sclient=psy-ab&oq=marine+exhaust+muffler&gs_l=&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.&fp=718c92b1a1c30f3d&biw=1152&bih=663

They make em to go inside the hose,
http://www.keitheickert.com/p-12628-full-time-inline-silencers-3quot.aspx

or replace the thru transom fitting.
http://www.keitheickert.com/p-12600-3-next-generation-silencer-system-trumpet-tip-replacement.aspx

 

[NetDoc]

Re: Loud Exhaust...

Today a friend gave me a 4" muffler... but there's just no room. I think I have to go with a vernalift top in/out style. At $250 and then more for the stuff to make it work, I want to be SURE it will fit.

 

[Don S]

Re: Loud Exhaust...

I would bet that if you were to put a vernalift muffler on it, it won't idle, and will loose all kinds of top end power. Way too much exhaust back pressure with that system for that engine.

 

[NetDoc]

Re: Loud Exhaust...

What would you suggest?

I would bet that if you were to put a vernalift muffler on it, it won't idle, and will loose all kinds of top end power. Way too much exhaust back pressure with that system for that engine.

 

[Don S]

Re: Loud Exhaust...

Live with it. You have a big boat for a 4 cylinder. It's a mix of Volvo, Merc and/or OMC If you could run the exhaust through the drive as it would normally be, it would be a lot quieter. It's just too "Custom" to find an easy fix.

What you need to find is an exhaust pipe to go from the engine to the bottom of the transom shield. Chances of that is probably below 0.