A few years back I replaced my water lift muffler and had a new exhaust riser made by Catalina at the same time. I have noticed since then that my max RPM has dropped from 3,300 to 2,800. I get an oil analysis every year, and the engine is in good shape. It starts quickly and has no smoke.
Last year I took the riser off, and noticed the size of the aperture to the water lift muffler was not much bigger than a quarter. I used a brush to clean it out, but did not get much of an improvement. I have decided to make a new one out of schedule 80 black pipe like JAS and chs1517 have done.
I have a couple of questions:
1. I have a Universal M-35 and would like to use a union like JAS and chs1517’s did. From looking at their pictures I need four nipples. What lengths should I order?
2. I need three elbows and a union. Do the elbows and union need to be a certain schedule or are the standard ones good for all pipe schedules?
3. Mainesail has recommended schedule 80 black pipe. You can also get schedule 160 which is thicker. Would this be a good idea?
4. I want to get pipe made in the USA. I am thinking of ordering from McMaster’s (http://www.mcmaster.com/#standard-metal-pipe-fittings/=wb61m3). Does anyone know if they carry good quality USA made pipe?
Thanks for the help,
Ron St. Onge
C-36 MKII Hull 1384
Ron St. Onge
1995 Catalina 36 MKII Hull 1384
Ron
If I was to build a black iron system I would use schedule 80 seamless pipe. It's a little more.
I'm worried about the extra weight of the schedule 160.
Mcmastercarr is a great source.
I have to ask, have you checked your tack?
What is the build up in your exhaust pipe?
I think I might buy junk home depot pipe for mock up purposes and then order the good stuff from mcmastcarr.
Chuck Lennox
97 MKii Ventura Ca
Island Girl Hull #1611
Chuck,
Checking the tack is a good idea. It is something I have wanted to do for a while.
I tried to clean out the build up last spring, but think maybe the riser itself is too restrictive. My RPM problem showed up right around the time I replaced it. I think am going to build the new riser anyway since it is not all that expensive and looks pretty straight forward.
Thanks for the reply.
Ron St. Onge
C-36 MKII Hull 1384
Ron St. Onge
1995 Catalina 36 MKII Hull 1384
Regarding testing your tachometer, Catalina Direct has an "Engine Instrument Tachometer Calibration" device for less than $20.
Has anyone used this model? I just replaced my tach (from Catalina Direct) and included one of these devices, but have yet to check the actual RPM vs the gauge.
https://www.catalinadirect.com/index.cfm/product/3492/engine-instrument-...
Steven Jones
C36/375IA FaceBook group administrator
C36/375IA Jib Sheet Editor 2012
Seal Beach, CA, USA
C36 #2164 Maléna 2003 Mk-II SRig/FullK, Long Beach, CA
stevenjones21@gmail.com
My C36 #2164 2003 year w/1200 hrs has the original exhaust riser. I understand that as my boat is 15 years old, this riser should be replaced. I expect to order the parts from Catalina Direct.
I spent an hour reading the numerous posts in our website Tech Forum, and did not find the answers to these questions:
1): When I disconnect the old riser from the aqualift muffler, would I expect sea water to come out of the muffler?
2) Is this a job that can be done in a day?
3) Besides the actual riser and insulation, I suppose I should replace the blue exhaust hump hose?
4) How does the stainless steel riser connect to the manifold?
Any additional advice is appreciated.
Thanks in advance.
Steven Jones
C36/375IA FaceBook group administrator
C36/375IA Jib Sheet Editor 2012
Seal Beach, CA, USA
C36 #2164 Maléna 2003 Mk-II SRig/FullK, Long Beach, CA
stevenjones21@gmail.com
Steve -
To your questions:
1): When I disconnect the old riser from the aqualift muffler, would I expect sea water to come out of the muffler? No. You will, however, end up releasing antifreeze when you disconnect the exhaust flange from the manifold. (Hint: make sure you purchase a replacement gasket for the flange to manifold connection).
2) Is this a job that can be done in a day? Yes -- if everything lines up OK and you don't discover other problems (you know how that goes). In order to gain access you will need to remove the bulkhead between the galley and the aft cabin, and the box in the aft cabin that encloses the riser. Also, as indicated above, you will need to drain and refill the antifreeze loop.
3) Besides the actual riser and insulation, I suppose I should replace the blue exhaust hump hose? If you don't have one already (i.e., you have just a straight hose), absolutely. Otherwise, if it appears to be in good shape, don't know if these wear out very much,.but since you're already there...
4) How does the stainless steel riser connect to the manifold? It threads into the exhaust flange, which is bolted onto the aft end of the exhause header with 3 bolts. It can be a total PITA to unscrew the old one from the flange, but careful use of a Sawzall can make this much easier -- see this comment I posted a few years ago and the pictures there: www.catalina36.org/comment/58399#comment-58399
One last thought: You might save some money (and possible make the install easier) by building the riser yourself out of black pipe and/or stainless pipe and fittings (I got the stainless pipe and fittings at Grainger). Here's a link to a post showing the completed project from a few years ago (www.catalina36.org/comment/58716#comment-58716 You can get the injection fitting for about $64 online ( I replaced the old fitting shown in my pictures this summer with this one pictured below), or have one welded. By using pipe and fittings, you have the ability to adjust the alignment somewhat, which can be useful....
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
I have a 25 xpbut it looks about the same I got my new riser from catalina direct and it is nice and the new heat rap is good . No water will come out and is a easy job less than 2 hours. Expect some smell ,it put off my fire detector to burn in heat rap. On mine 3 bolts hold it on
Bill Miller
S/V Lorraine
Pacific Northwest,Sound Sound
Grapeview,Wa
1990 Mk1