Catalina 30 Muffler

[rkohl44]

detail on positioning new muffler

I got all the gunk off the manifold with sandpaper, so no worries there. Neil, can you post a picture or diagram of how you fit the Centek muffler in your boat? I think I have it figured out, but it is going to straddle the galley drawer space, with the hot side (in) under the drawer and the cool side (out) under the sink side. Is this how yours fit? Did you have to cut down either of the ports into the muffler?

[ndutton]

My Centek is directly below the sink space to port of the engine. I did not need to cut anything for fit.

[ndutton]

Before it fails altogether

Well, that picture gave me the willies. I hadn't made a visual check on the hot pipe for a long time, just grabbed it and gave it a shake once a year. As long as it was still solid I rationalized putting its replacement off a little longer . . . and a little longer and a little longer.

The hot pipe is now 14 year old black iron in salt water and frankly looks like shi-shi. It is still solid but I'm not putting it off any longer. The new 316 stainless sched 80 hot pipe fabrication is complete (first picture), ready to install at the next opportunity. The second and third pictures are of the thread sealant I used. I'll report back after installation and some run time on how it worked out.

[alcodiesel]

Ooooo, stainless. You can't hide money, Neil.

[ndutton]

Ooooo, stainless. You can't hide money, Neil.

Do it right, cry once . . .

[ndutton]

Finished

The new stainless hot pipe is installed and working. The project was not without drama however. Removal of the old pipe uncovered coolant inside the dry exhaust path of the manifold so that initiated a week of pressure testing, manifold and block/head separately and careful inspection. A few emails to selected forum members with symptoms and test results walked me back from the cliff. With rock solid pressure tests we concluded the errant coolant must have come in through the aft manifold mounting stud during disassembly. There was some evidence supporting the conclusion too.

The first picture is the old pipe with old school asbestos heat wrap.

edit: Another slight modification I made was removing the mounting screws from the bottom flange of the Centek waterlift allowing it to move with engine vibration. The attached hoses on a Catalina 30 are supported close enough to their attachment on the waterlift that they keep it in place fine without formal mounting. The pictures don't show it but there is actually space between the waterlift base and the mounting pad on the hull.

[Peter]

Hi Neil,

Very interesting to see this exhaust set-up. Thank you for posting the photos. Good to hear that you did not have to leap over a cliff with that coolant issue.

I am quite curious to hear what your experience is with that exhaust wrap. I tried a similar looking wrap when I re-did my hot section and it stank horribly. The smell was so bad I eventually replaced it with non-coloured wrap and the smell went away.

Best regards,

Peter

[ndutton]

Yeah, it's stinking up the joint right now but we will see if it cooks off after a decent run. On the other hand, as long as things were opened up I also did some repainting in the area including a full prime and repaint of the manifold so both are contributing to the bouquet.