Exhaust muffler

[chrishelen]

I have wet exhaust system straight through to the transom. The exhaust exit is just above the water line, but when the boat is loaded this goes under the water and silence the exhaust note. But when the boat is unladen the exhaust is above the water and pretty loud.
I want to add a muffler but I am worried about the extra back pressure when the exhaust is under water.
Any advice?

 

[Portofino]

Fit an additional smaller above the WL ( when loaded ) T eed off the main -to mitigate back pressure Issues .

I,d like to say speak to Mario Amati who invented the whole underwater exhaust concept ,often copied -but he is dead .

 

[Tranona]

I have wet exhaust system straight through to the transom. The exhaust exit is just above the water line, but when the boat is loaded this goes under the water and silence the exhaust note. But when the boat is unladen the exhaust is above the water and pretty loud.
I want to add a muffler but I am worried about the extra back pressure when the exhaust is under water.
Any advice?

Don't think the Vetus type muffler adds any backpressure. Give it a try, you can always replace it with a straight bit of pipe if it does not work.

 

[chrishelen]

Don't think the Vetus type muffler adds any backpressure. Give it a try, you can always replace it with a straight bit of pipe if it does not work.

That's exactly what I was looking at.

 

[Bandit]

OP what are the engines & boat?

 

[chrishelen]

Displacement fishing boat. Perkins engine.

 

[Firefly625]

I think Centek water silences are better than vetus if you go that route. Laterstarter1 previously of this parish all round engine guru was a fan on Centek

I have a Mitchell with Perkins Sabre 225 - exhaust noise is fine with one of these fitted;

https://www.asap-supplies.com/exhau...centek-vernalift-inline-grp-waterlock-1500100

 

[oldgit]

Been there done that.
Pair of M135 Perkins.
First five mins after start ....Luverly throbbing rumble telling fibs about your power .
After 5 mins esp on long journies tiresome drone drowning out eveything else for miles.
Depending on the depth of your pockets and power output from the Perkins an internet search will reveal budget alternatives to those rather expensive Halyard et al silencers.
Mine were easy fit,simply remove ( hacksaw or grinder )section of pipe and insert water lock/ or whatever.Double clip those unions with nice stainless clips mine were included in kit.
Kept old pipe "just in case".
Bit doubtful that result would be worth the money/time/ effort involved.
It transformed the enjoyment of all our long distance cruising,best few quid we ever spent on a boat.

Just bought a Princess 35, flooding back came all the long forgotton joys of the unsilenced marine diesel and a quick look down below no room to fit anything in the lazerette to shut the blimming noise up..