Exhaust elbow room and cabinetry alterations

Aug 29, 2016
131
Catalina 2004 310 (Hull #250) BC
Hi all - just wondering what other 310 owners have done to address the issue of the exhaust riser burning through the rear bulkhead? Re: design defect had the exhaust elbow hard up against the bulkhead and has been known to cause fires - a clear space around the elbow is the solution. How much clearance space is required - 2-3 inches? Did some of you cut out the bulkhead, and then make a custom box (exhaust sock) that protruded into the aft berth? What materials, specifically heat shielding, did you use to insulate it afterward?
Thanks - BernieIMG_0034.JPGIMG_0034.JPGIMG_4121.JPG
 
Aug 29, 2016
131
Catalina 2004 310 (Hull #250) BC
Yes I have, and it is excellent. However, I am wondering on more details - what heat shielding materials, dimensions that worked well, if any hinges placed on the box etc.
 
Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
bernie, find one of smitty's posts on this C310 forum and pm him. I know he'd be glad to help you.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Hi Bernie,

So here is my blog post that has the details of the engine compartment upgrade I made. Actually a good friend who is an unbelievable carpenter made it for me.

I have been running this with no insulation on the engine compartment or the exhaust elbow for almost 3 years and over 1,000 engine hours.

Please let me know if you have any questions.

It might take me a couple of days to get back to you. Maintenance day on the work boat tomorrow and longer trip on Thursday.

Fair winds,

Jesse
 
  • Like
Likes: BC Bernie

Clydo

.
May 28, 2013
336
Catalina C310 SF Bay/Delta
Hi all - just wondering what other 310 owners have done to address the issue of the exhaust riser burning through the rear bulkhead? Re: design defect had the exhaust elbow hard up against the bulkhead and has been known to cause fires - a clear space around the elbow is the solution. How much clearance space is required - 2-3 inches? Did some of you cut out the bulkhead, and then make a custom box (exhaust sock) that protruded into the aft berth? What materials, specifically heat shielding, did you use to insulate it afterward?
Thanks - BernieView attachment 128295View attachment 128295View attachment 128296

You might check with Catalina factory. They may give you new bulkhead with one or two inch extension sticking
into aft area. Just tell them about possible fire problem.


Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA
 
Feb 16, 2015
36
Hi Bernie

I just install a webasto diesel heater on my boat and used heat shield from a auto shop for a turbo
Around the exhaust where it meats the hull , works great and very cheap
 
Aug 29, 2016
131
Catalina 2004 310 (Hull #250) BC
Thanks for all your responses. My 2004 hull #250 has a heat shielding pad, but obviously is burning through. The issue is that other owners may think that the problem was rectified, way back whenever the problem was identified, by either installing a new heat wrap around the elbow, in conjunction with newer heat shielding, but those earlier fixes may have been only temporary, now that it is 2016.
The real fix is to give spacing of 2-3 inches around the exhaust elbow. Jesse's response was telling in that he has not needed any heat insulation, once the spacing issue was addressed.
Bernie #250
 
Aug 29, 2016
131
Catalina 2004 310 (Hull #250) BC
FYI
Here is my reply from Catalina today:

Yes, later 310’s had an access/separation panel cut and screwed into that aft bulkhead that had a piece of our heavy ½” thick insulation secured to it. So the insulation will be in the place of where the wood bulkhead was. If you have preferred dimensions we will build to that size, if not we have a “typical” size that is around…9” x 13” or “10 x 14” (has 1 inch overlap to secure screws to bulkhead and the cut-out you make is the exact size of the insulation piece we attach to the back side of the teak varnished panel. (specify vertical grain to match is so built) Special cost price on the panel ready to install is $45. Plus shipping. We take Visa & Master card over the phone.


Best regards,

Warren Pandy

Catalina-Florida
 
  • Like
Likes: Alansails
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
FYI
Here is my reply from Catalina today:

Yes, later 310’s had an access/separation panel cut and screwed into that aft bulkhead that had a piece of our heavy ½” thick insulation secured to it. So the insulation will be in the place of where the wood bulkhead was. If you have preferred dimensions we will build to that size, if not we have a “typical” size that is around…9” x 13” or “10 x 14” (has 1 inch overlap to secure screws to bulkhead and the cut-out you make is the exact size of the insulation piece we attach to the back side of the teak varnished panel. (specify vertical grain to match is so built) Special cost price on the panel ready to install is $45. Plus shipping. We take Visa & Master card over the phone.


Best regards,

Warren Pandy

Catalina-Florida
Sure sounds like that might be a worthwhile investment/upgrade!
 
Aug 29, 2016
131
Catalina 2004 310 (Hull #250) BC
I had some trepidation that I really didn't want to depend on the heat shielding, and would rather address the issue with more spacing, however I have been reassured by Mr. Pandy of Catalina Yachts:

"...the thick insulation ends up flush with the bulkhead. Why this works is because where the mica & wood was, there is now ½” min of insulation and the wood (new bulkhead or panel) is protected behind it. There are probably over a hundred 310’s out there with it and have been running it for years with no problems, (factory installed and a dozen or two “after-installs”) so we know plenty of folks are keeping an eye on it and no one has had a problem so we really doubt you would be the first with many thousands of hours on this insulator panel."


And so I called and ordered the part...did I say that Gerry Douglas picked up the phone? Awesome!
 
Aug 29, 2016
131
Catalina 2004 310 (Hull #250) BC
I was curious about the longevity of the exhaust riser and elbow - how many engine hours might be a reasonable range before they start going? What can be done? How expensive? Mine is fine right now but who knows for how long?

I did ask Catalina if they actually stocked such items and received this response:

"We do have an exhaust riser available for the 310. I do not have
the elbow or the gasket but yours looks like it can be reused. The cost
of the riser will be $315.00 plus shipping and will include wrapping for the
riser or we could wrap it for you for an additional $35.00. We like to suggest
that if you don’t already have a hump hose, that you get one of those also as
it helps alleviate vibration from the engine to the muffler. The hump hose
is $45.00."

I recently wrapped mine with new heat wrap ($15) and locking wire ($4) - easy peasy to do, so doesn't seem worth paying $35 for that service, but the hump hose suggestion was interesting.
Anyone have any insight on this?
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
I was curious about the longevity of the exhaust riser and elbow - how many engine hours might be a reasonable range before they start going? What can be done? How expensive? Mine is fine right now but who knows for how long?

I did ask Catalina if they actually stocked such items and received this response:

"We do have an exhaust riser available for the 310. I do not have
the elbow or the gasket but yours looks like it can be reused. The cost
of the riser will be $315.00 plus shipping and will include wrapping for the
riser or we could wrap it for you for an additional $35.00. We like to suggest
that if you don’t already have a hump hose, that you get one of those also as
it helps alleviate vibration from the engine to the muffler. The hump hose
is $45.00."

I recently wrapped mine with new heat wrap ($15) and locking wire ($4) - easy peasy to do, so doesn't seem worth paying $35 for that service, but the hump hose suggestion was interesting.
Anyone have any insight on this?
Our factory exhaust elbow went after 450 hours over 10 years. We built a new one our of galvanized pipe from the home store. That lasted 300 hours over 4 years and cost $50. I rebuilt that very soon after we started cruising, we were in Connecticut when I did it. That one has lasted almost 800 hours in the first year.

I have looked at building one from stainless steel pipe fittings from McMaster-Carr. It would cost around $250-300. So I will probably just rebuild it with galvanized again when we get ready to leave St. Thomas to head towards the windwards and on to South America. I might take a second one all built as a spare.

There are two problems with wrapping the exhaust elbow in my opinion. First it keeps all the heat at the elbow rather than allowing it to radiate out. This could shorten the life of the elbow. Second and more importantly, it makes inspecting the elbow near impossible. When our factory elbow failed it was wrapped. We could see the signs that it was getting ready to fail (pin hole rust stains at the weld). So when it went the elbow fully seperated at the weld and sprayed hot salt water all over the engine. It made for a lot of work cleaning and repainting the engine so we didn't have rusting issues. When my home made elbow started to go, we just saw some little rust streaks on it. I got new parts and built a new one it a day. We never had a full on failure like we did with the wrapped elbow.

On the hump hose, I wonder why they are recommending that when there is already 18-24 inches of hose between the elbow and the muffler. Vibration has never seemed like an issue there.
 
Aug 29, 2016
131
Catalina 2004 310 (Hull #250) BC
In my diesel mechanics course tonight I showed the instructor pictures of our exhaust riser and elbow - he commented of course that Catalinas make their own and are not made by the engine manufacturer...and he said what Jesse has pointed out: the heat wrap traps, rather than dissipates the heat, therefore contributing to a faster fail rate of the exhaust riser/elbow. He showed me the elbow that is made my Universal/Westerbeke meant to fit the 25 xpb and it is aluminum, which dissipates heat quickly and does not need heat wrapping. It sure looks alot beefier than the Catalina one too.
Sure begs the question why we couldn't modify our engine and use the engine manufacturer's part? I have to modify the bulkhead cabinetry anyway - I wonder if this part is too big to fit and allow enough air space - Anyone ever try?

I am awaiting to receive the modified panel from Catalina, but am still thinking to add more air space rather than depend heavily on heat shielding.

Jesse - it is obvious you have many talents - one does not simply make an exhaust riser and elbow in a day! Is it? Does it not require mastery of the welding arts? I have read your blog and your various versions, is fabrication something most owner's could do on their own?
Cheers,
Bernie
 
Aug 29, 2016
131
Catalina 2004 310 (Hull #250) BC
Thanks Stu. These are photos of my exhaust riser and elbow - welded nipple
1. Original wrap and mesh
2. Viewof unwrapped part

image.jpeg
image.jpeg
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
  • Like
Likes: BC Bernie
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
I'm guessing that the exhaust riser on our C310 (#31, 2000) has been modified at some point. We motored 10 hours straight when we delivered the boat from San Francisco to Santa Cruz, and there's no evidence of overheating or scorching of the bulkhead (total engine hours are >2000). In fact, the hose for the coolant overflow runs behind the riser.
So I'm not sure modifying the bulkhead is worth the trouble? Or maybe I've just been lucky so far?
(Breaker mounted on bulkhead is future project, rewiring the alternator).
IMG_0702.JPG IMG_0703.JPG IMG_0704.JPG IMG_0705.JPG IMG_0706.JPG
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
I'm guessing that the exhaust riser on our C310 (#31, 2000) has been modified at some point. We motored 10 hours straight when we delivered the boat from San Francisco to Santa Cruz, and there's no evidence of overheating or scorching of the bulkhead (total engine hours are >2000). In fact, the hose for the coolant overflow runs behind the riser.
So I'm not sure modifying the bulkhead is worth the trouble? Or maybe I've just been lucky so far?
(Breaker mounted on bulkhead is future project, rewiring the alternator).
View attachment 128920 View attachment 128921 View attachment 128922 View attachment 128923 View attachment 128924
Marchem,

That exhaust riser looks to be very close to the original design. My guess is it has been replaced or you have been very lucky with this one.

You also have been lucky with your bulkhead. A lot of C310s have had burning on the bulkhead.

On you alternator project, I would consider a different stop for the breaker. To get wires to where you have the breaker will require crossing the exhaust riser twice with potential for heat and vibration issues. I mounted my alternator service disconnect down low, on the engine base. It's out of the way and out of heat.

Good luck,

Jesse
 

Attachments