Catalina 30 A4 exhaust rebuild

[knitchie]

Well, the tiny leak in the hose between the hot section and the water lift muffle has become a stream, in spite of the 5200 slobbered all over. I suspect the muffler is a big part of the problem and that the hot section is due to be replaced too. So, it is probably time for a system rebuild.
Does anyone have any experience or opinions about using the Westerbeke exhaust riser, in place of the hot section, especially in a C30 with limited headroom in the engine room.
Rigspelt mentioned in another thread that the commonly used hot section probably was a cheaper alternative to the riser solution. Any other good reasons to go one way or the other? I don't mind spending a few more bucks, if it makes sense and works in my boat.
I assume the system will be manifold to riser to anti-syphon loop to waterlift muffler.
Thanks,
Ken - Obsession
'78 C30 TRBS
Lake Champlain, VT

[roadnsky]

Ken-
I found the attached PDF in my files (under "Exhaust") and it seems like it might apply to your question.
Hopefully it helps. If not, I'm sure the Catalina owners will chime in soon enough...
-Jerry

[knitchie]

Catalina 30 A4 exhaust rebuild

Thanks, Jerry.
Interesting comparison. I found Don's drawing for the C27 exhaust, as well as Catalina's parts manual of the same. It is surprising to me that there is no muffler and Don commented on the increased noise. So, several more questions...
Is there enough headroom for the C27 style exhaust in a C30 engine compartment?
How much more noisy is the C27 design without a mufffler?
Does the C27 style do anything more than the exhaust riser and could I just run pipe from the riser out the stern?
Still looking for a better solution.
Fair winds,
Ken - Obsession
'78 C30 TRBS
Lake Champlain, VT

[sastanley]

my solution

Ken,
I rebuilt my C-30 exhaust this winter. I used galvanized pipe from the local Lowe's. The pipe itself was the cheapest at about $20 or so. The expensive part was the 'header wrap' which was in the neighborhood of $50, & the (very nice) flange from Moyer. Total was probably $100. I sealed the threads with No.2 Permatex.

I have about 1/2" of clearance between the cabinet assembly & pipe. Now that I think about it, I'll have to check and make sure I haven't burned the cabinet

here are a couple of pics. In these test photos, I was using black pipe (a little cheaper) of different lengths to figure out how high I could make the loop, then I picked up the galvanized sections I wanted.

[knitchie]

Catalina 30 A4 exhaust rebuild

Shawn,
Nice clean solution. What is the hot section plumbed to? That doesn't look like the water lift mufflers that I'm familiar with, but it has a lower profile that probably is superior to the higher cylinder styles.
Can you share your piping dimensions?
Ken

[sastanley]

Those pics were "rough ins" and I had mismatched parts, but I think I can recall most of the shopping list. I have a pic of it completely finished somewhere. (edit - added below)

The shopping list was all 1 1/4" galvanized pipe. I was able to re-use the bronze water mixer,and just cleaned it up on a wheel.
90 deg "street el" to connect to the Moyer flange
2 90 deg female
1 female coupler (to connect to the water mixer)
I think I used 5" pieces for the up & down legs..this was where the different lengths for test fitting came in handy..I wanted to make it as tall as possible in an attempt to delay water ingestion. I tried 6" but it bumped the cabinet I think. The cross piece was 8" I think, but again, its length is dependent on the location of the muffler. In my case the muffler was already roughly positioned based on the new exhaust hose ($$!!) on the other side which I had already replaced. I was careful not to scrape up the stickers or get any goo on them and returned the pipes I didn't use. (You can see a price sticker in the photo above)

The muffler is a plastic "Vetus", as the OEM stainless developed a leak some years ago. I think the P.O. had every intention of repairing the old muffler because I found the old muffler in the bottom of the sail locker, & the Vetus was originally a temporary solution. I think it has been in the boat 20+ years. It appears to be functioning perfectly well, and is the only part of the exhaust I haven't replaced, including the transom thru-hull which I found cracked when replacing the hose.

The first pic below is what was originally there..It didn't give you much of a chance to keep water out if the motor didn't start right away. The old flange was suspect, which is why I took it apart, and just decided to replace everything and add the nice Moyer flange, since the pipe itself was relatively inexpensive.


edit - Sorry to load up your thread with pics of my boat. The 2nd pic is of the exhaust section finished while I still had the cabinet out. Let me tell you it was nice working on her in this configuration, but my wife didn't really like the boat as much with the galley cabinet & counter top missing!

[roadnsky]

The expensive part was the 'header wrap' which was in the neighborhood of $50

Ken (and Shawn)...
The exhaust wrap that Don sells (Product No. - EXHT_01.0_455) is $21 and covered my entire Hot Section just fine. Might save you a little $$?
-Jerry

[sastanley]

Good find Jerry & a nice clean job on the exhaust! I was in a rush (as usual) and stopped at the local auto store. Of course they only sell 1000' rolls, enough to do the headers on a V-8!

I probably have enough wrap to do another exhaust! - I was going to offer to send it to Ken just because I'll probably never use it, but I wouldn't dare throw it away after what I paid for it! So, if you want it Ken, shoot me a message.

One other problem Ken probably experiences also, is the exhaust runs between the hull & the ice box on a C-30. When I replaced the hose I used some of the wrap on the new exhaust hose where it goes behind the ice box to help keep the heat away from my frosty beverages.

[roadnsky]

When I replaced the hose I used some of the wrap on the new exhaust hose where it goes behind the ice box to help keep the heat away from my frosty beverages.

Ahhhh yes! The cold ones...
Then maybe worth every penny?!

Why is it when we're fixing our boats we're always in a hurry to "get 'er done!"?
Don't we realize as soon as we're finished with that project another one will just take it's place?

[degreeoff]

um permatex? Do I need that? I just did my system and tightened the hell out of them or is that not enough??? Also I used black pipe as the galvanized and fuel make bad gases so I am told? I am going to install tomorrow!!

Josh

[ndutton]

Regarding black pipe vs. galvanized - -

I worked for several of the Southern California sailboat manufacturers in the 70's and we NEVER used galvanized pipe nor were any of our manufactured hot sections galvanized. I'm not smart enough to offer any chemical or metallurgical reasons, but if experience says anything . . . well, I think your choice of black iron is correct.

Neil

[roadnsky]

um permatex? Do I need that? I just did my system and tightened the hell out of them or is that not enough??? Also I used black pipe as the galvanized and fuel make bad gases so I am told? I am going to install tomorrow!!

Josh-
If you got the joint connections good and tight then you're ok. Permatex is just to insure no leaking which a good wrap will also help with.
As far as BLACK vs GALVANIZED; they're both fine. If you're already built with black. Go ahead and install.
-Jerry

[roadnsky]

Black vs Galvanized

I worked for several of the Southern California sailboat manufacturers in the 70's and we NEVER used galvanized pipe nor were any of our manufactured hot sections galvanized. I'm not smart enough to offer any chemical or metallurgical reasons, but if experience says anything . . . well, I think your choice of black iron is correct.

This from Don in a previous post...

"It's OK to use galvanized pipe to reconstruct a hot section. Most of the boat builders in the mid to late seventies used black iron pipe, which is (to my understanding) the same as galvanized pipe without the galvanizing. In replacing the hot section between the back of the manifold and the inlet to the water lift muffler, most people use 1-1/4" pipe nipples and elbows. You can use brass or stainless instead of black iron or galvanized pipe if you wish, but at significantly higher cost of course."

[respite]

Catalina 30 A4 exhaust rebuild

This is a great threat,

I’m in the process of rebuilding my exhaust system on my 78 A4 power Catalina 30.

I’m having difficulties removing the 30+ year old hose we left it in and re-route the new hose. It took me 3 days but we were able to lay the new hose around the icebox and connected it to the muffler. We added 5 more bends to the hose, in addition there is a 2 foot section of the hose below the water line.

1. What kind of problem should I expect with this new exhaust hose layout? If the back pressure is within spec (1.5psi or less) will the system work OK? Any comment and suggesting are welcome.

2. Does any one knows the correct orientation of the muffler? My Muffler looks like the MMI Muffler, top in/Out. The muffler was oriented Outlet facing port, Inlet facing starboard, similar to the muffler on the picture in this threat. Shouldn’t the Muffler be oriented bow to stern?

3. My hot section is heavy, should I be worry about vibration breaking the pipes from the manifold, since I plan to install a hose hump? Is the blue hump hose needed?

Randol,
Respite 78 MK1, Miami, FL

[sastanley]

Randol,

You are right that the hose replacement was a pain. I ended up cutting an access hole behind the stove to manipulate the hose along the hull & it was still hard & wedged behind the ice box. I was able to pretty much duplicate the old routing, with the exception noted below..

Maybe a few pics if you could get them would help. Where in the exhaust is the 2 foot section below the waterline? Where are the "5 new bends"? I would think the engine should eventually be able to batch out the water, unless there is some real tricky stuff going on with the new hose.

When I acquired the boat, my hose hump was connected with a 1 1/4" bronze flapper (which leaked) in the sail locker, about up as high as it would go. I think this keeps the water out in most cases, unless you like to keep the rail buried for extended periods. (The 2nd line of defense should be the "water lock" style muffler.) I removed my one-way 'flapper' since it was broken anyway, and replaced it with a properly sized (1.5" diameter to match the hose) 45 deg fiberglass elbow I found on the Internet.

If your boat still has a plastic thru-hull at the transom, check it carefully..mine was cracked on the inside of the flange from stretch as the transom is not quite flat.

2. My muffler is different (plastic Vetus) so I can't help you with orientation, however, mine is facing about 40 degs left of the bow (roughly 10:00)

3. how heavy is heavy? There have been some other discussions on this board about weight and complexity of the hot section. The MMI flange is much more stout than the flimsy thin one I removed..unless the manifold threads for the bolts are failing, it should be OK. I think I probably at least doubled the weight of my hot section with the new pipes. A guess on weight may be 6 -7 pounds.