[C320-list] Water lift muffler

[Doug Treff]

On Thu, Sep 26, 2024, at 3:34 PM, Louis Spitz via C320-list wrote:
> Thanks for all your inputs. I would still like to know if anyone 
> actually installed an off the shelf muffler, like the Vetus or other 
> brands, and if so, how they performed.


It's difficult to generalize because over the years there were 3-4 different engine configurations used on the 320 and each one of them could have different issues with the exhaust line routing and muffler capacity requirements.

I have heard of some who tried but in the end there were issues. I can't find the emails using search. But I did find the below information. I hope this is helpful.

Here's what Catalina Direct says about using aftermarket mufflers:
> Don't be tempted to replace your muffler with anything but the original design! Catalina's design is simple, but it is no accident. It has the right geometry and volume to minimize the possibility of water flowing back into the engine when the boat heels. A customer's report illustrates the point:
> 
> During a re-power by a very well respected yard, it was suggested the muffler be replaced with an "upgraded" production built muffler. After all of the money spent for the new engine, the customer felt it was a smart idea.
> 
> Motoring out the first day, the new engine performed beautifully. But after a fine sail, the engine refused to start. Back at the yard, water was discovered in the engine! After much time, confusion, work, and expense (for the yard), the engine was rebuilt and they were back sailing... with the same result!.
> 
> After two engine rebuilds, they finally realized the problem was with the muffler design. Water from the muffler was flowing into the engine through an open exhaust valve when the boat heeled under sail.

--
Doug Treff
doug at treff.us