Exhaust type?

[Matt]

Hi Don,
I'm having trouble identifying what type of exhaust sytem I have on my 1978 Catalina 27. Here's my issue, normally water 'batches' out of my discharge at idle (or did until this pipe broke ) so I'm assuming that I have a water lift type muffler. I'm also basing that on the fact that the broken section looks like it's plain old 1 1/4" galvanized pipe.
Looking at the system though there is no "muffler" to speak of, just a 6" section of galvinized pipe that hangs down from the connection where the water from the block enters the exhaust, after the hot section. Am I missing something or is this just how the old owner tried to save a few bucks by using this pipe instead of an acutal muffler?

Thanks,
Matt
C-27
Salem, MA

[Wilseaya P-31]

Matt, Although I new to the A4 and to my own boat, I am an aircraft mechanic and thus have done lots of reading about A4's here and in This Old Boat and the MMI A4 manual.

Here is the skinny as I see it. Starting at your exhaust manifold the standard steel pipe should turn down and in that elbow should be a water hose from the engine cooling to inject water into the hot section of that pipe. The hot section should also be wrapped in with insulation. Connected to the no cooled steel pipe is a section of rubber exhuast hose which is also wire meshed inside for strength. That hose leads to a small tanks about the size of a large coffee can. That is the water lift muffler. From there is is likely all hose all the way to the through hull. That is how my Pearson 31 is and how This old Boat book describes a basic water lift muffler system. Hope this helps.

Brian Muller
S/V Wilseaya P-31

[marthur]

C-27 Exhaust

Your first thought is exactly right. The factory exhaust on the C-27 is just galvanized pipe, connected to flexible exhaust hose about 6" after the water is injected into th exhaust stream.

That is what I had on my '77 C-27 until I added a waterlift muffler. It made the engine much quieter!

On the bright side, Home Deport sells all of the materials necessary to replace the hot portion of your exhaust.

ma

[Don Moyer]

Catalina 27 exhaust

Matt,

I'm not sure how I missed your post, but I'm going to try and attach the Catalina 27 exhaust sketch from the factory to this message. I really like the Catalina 27 design. It is as engine friendly in terms of guarding against water getting back into the engine, as its cousin (theCatalina 30) is unfriendly. Unless your engine noise really bothers you, there's a lot to be said for simply replacing what you have.

Don

[HarryB]

Water Lift Muffler

I need to replace the factory 'standard' exhaust on my 1976 Catlina 27. How much difference in the exhaust noise level would the installation of a water lift muffler make?

[keelcooler]

Harry, The factory fiberglass box is a water trap or water lift type. Should be about the same noise level unless you wish to install an optional inline baffled silencer/ muffler just bellow transom loop prior to discharge fitting.