Hi,
I'm a new owner of a Catalina 34 1995 with M35 engine (hull 1292). The main recommendation from the survey was to change the Exhaust riser. It looks like Catalina D offers 2 exhaust risers that can fit my engine and differ only at one end that attaches to the engine flange. Part Z3055 use a normal elbow and a nipple to attach to the flange. Part Z4491 use a street elbow and therefore doesn't need a nipple.
My question is ... can I use either? if yes, what are the pros/cons of each part. If no... how to I check which one fits my engine? (remove the thermal jacket?)
Part #: Z3055
https://www.catalinadirect.com/shop-by-boat/catalina-36/engine/exhaust-system/exhaust-riser-c-30-c-34-c-36-w-m-25xp-or-m-35/
Part #: Z4491
https://www.catalinadirect.com/shop-by-boat/catalina-36/engine/exhaust-system/exhaust-riser-c-30-c-34-c-36-w-m-25xp-or-m-35-street-elbow/
Thanks in advance
Francois
S/V Whitecaps
Hull #1292
I know that riser dimensions are critical on the C-30, lest we get into relocating the muffler base.
I see that at the flange end that the
- nipple'd riser has a 3-1/2" extension
- street-elbow'd one has a 2-1/2" extension
I can't say whether that's critical as far as on the C34 but I'd measure carefully and determine that.
Have you checked with CTY parts for a riser? I know that C-30ers have found a big cost difference by heading to the go-to source for many parts (the original factory.)
Apparently, CTY doesn't supply the thermal wrap, but you can easily get that aftermarket a lot cheaper than from CD. Or (I wonder whether it would fit w/an M35) install the water-cooled riser.
https://c34.org/wiki/index.php?title=C34_Exhaust_with_Water_Cooled_Riser
Francois : I looked at both and what you are going to have to do is remove you existing riser and lay out the measurements. Then see which of the two CD risers measurements best matches your measurements!!
If you get a new hump hose get the 8" as you can always cut it shorter if need be.
Also when I got a new riser, I took it to a welding shop and had them put a bead on the INSIDE of that stake weld - that just gave it more strength.
Make sure that the hose from the Anti-syphon valve to that nipple on the riser is nylon reinforced hose. Catalina used wire reinforced hose which is too stuff and transmits all of the engine vibes to the nipple weld - eventually cracking the weld.
Do as Ken suggested on the insulation as the CD price is :shock: or use the insulation from you old riser. :thumb:
A few thoughts
While the CD insulation is pricey, IIRC they won't sell you the riser without it. I believe they say that on their website, and they told me that on the phone when I did mine 5 or so years ago. It is good product, actually, and has a neat strap arrangement for securing the insulation.
Quote from: Stu Jackson on June 20, 2020, 04:02:11 PM
While the CD insulation is pricey, IIRC they won't sell you the riser without it. I believe they say that on their website, and they told me that on the phone when I did mine 5 or so years ago. It is good product, actually, and has a neat strap arrangement for securing the insulation.
having just purchased a new riser through them, yes this is true. they will not sell it without the insulation. however, the insulation does seem pretty stout over just using heat wrap tape. and it's substantially better then the old wrap i pulled off my old riser. is it worth the price they charge, unknown.
When I replaced a riser a few years ago, CTY was significantly cheaper than CD and they threw in the insulation at no additional charge. I think I had to buy a street elbow to complete the installation but I was able to get a stainless elbow on Amazon. Frankly I was irritated at CD's policy of not selling you the riser without also selling you their expensive insulation kit.
Quote
it's substantially better then the old wrap
Both the OEM woven-type wrap and aluminized blanket type are available along with the stainless "zip ties."
If clearance allowed I'd likely do a thin (non-overlapping) wrap and then the blanket on top.
Thanks everybody, this really helping. For the record, I did call CTY for the Riser and was quoted $285 and a leadtime of 4 weeks (no stock). So, similar pricing than CD for the exception CD request you buy their expensive (but good quality) thermal Jacket. CD has more than 10pcs in stock of both Riser variant.
So, next step is to figure which of the two part fits best, 2 1/2 or 3 1/2 extension (Thanks to KWKolbler as I did not realized the difference).
Regards,
Francois
Ah... nothing easy. I removed the muffler riser today and it looks like I got a 3 pieces nipple'd riser similar to CD part #Z3055 (see picture). But, I do measure the extension closer to 3 inch. So, should I go with Z3055 with 3.5inch extension or Z4491 with 2.5inch extension? Or it really doesn't matter and both will work?
Frasse : You should have looked at how much clearance there is between the boat structure and the riser. That will determine which of the CD risers you should order!!
Even put it all back together again - to get those measurements!!
A thought
Ron's right. You are the ONLY person in the entire universe who has those parts and YOUR boat right in front of you. We simply do not. Good luck.
Quote from: Frasse Pelle on June 30, 2020, 08:22:48 PM
Ah... nothing easy. I removed the muffler riser today and it looks like I got a 3 pieces nipple'd riser similar to CD part #Z3055 (see picture). But, I do measure the extension closer to 3 inch. So, should I go with Z3055 with 3.5inch extension or Z4491 with 2.5inch extension? Or it really doesn't matter and both will work?
please post or send me a message re which riser you get and why, as I have a 97. also, did you have to replace the exhaust flange? and how long for various things. think I'll have to have mine done, as I can do basic stuff but this seems over my head. thanks.
A number of years ago I had to replace my rise. CD required/requested that I send the old one to them so they could correctly match the unit as well as get all the angles correct. If they didn't do that with you, maybe ask them about doing that to insure you get exactly what you need.
Regards,
Ed
Guys : At one time when Catalina made replacement risers, they wanted your old one to match!!
Randy just be a where that Catalina makes C34s that are similar NOT exact !
A few thoughts
Francois
Make sure on the measurements you're looking at apples and apples. The CD site shows on the drawings where the measurements are taken from/to.
K
Thanks Ron. You would think there would be more consistency within models. Oh well, so far, so good on mine. I do smell maybe a little faint smell when I open up the engine but have not yet poked around to get a better look. Maybe in a few days after I finish the more pressing issues. So far, just did the racor primary filer R-15S and the transmission fluid change and ran the motor for about an hour total.
Quote from: captran on July 07, 2020, 07:15:01 AM
Quote from: Frasse Pelle on June 30, 2020, 08:22:48 PM
Ah... nothing easy. I removed the muffler riser today and it looks like I got a 3 pieces nipple'd riser similar to CD part #Z3055 (see picture). But, I do measure the extension closer to 3 inch. So, should I go with Z3055 with 3.5inch extension or Z4491 with 2.5inch extension? Or it really doesn't matter and both will work?
please post or send me a message re which riser you get and why, as I have a 97. also, did you have to replace the exhaust flange? and how long for various things. think I'll have to have mine done, as I can do basic stuff but this seems over my head. thanks.
Hi Mark (Captran), I got the Z4491 with 2.5inch extension. Did the installation this morning without issues. I did change the flane as well.
Now moving my attention to the heat exchanger re-install. Always something.
Francois : When you reinstall the HX just make sure that there isn't so much insolation that it presses against the exhaust riser.
A thought
Quote from: Frasse Pelle on June 19, 2020, 05:15:26 PM
recommendation from the survey was to change the Exhaust riser
Francois, :thumb: thank you for starting this thread. Did the person performing the survey actually remove the exhaust riser insulation? I'm curious how they came to the conclusion you needed to replace it. I'm impressed that they made the recommendation which seemed correct based on your pictures. I think I wil do the same...we have similar vintage boats.
Anyone, I assume that the number one problem with these exhaust risers resulting in having to replace them is corrosion failure. Does anyone know why this is? Is there a galvanic corrosion issue designed into the system? Is that why we would replace with electropolished S/S?
Quote from: skyward on December 31, 2020, 07:50:42 AM>>>>>>>>>>>>>>>>>>>>>>
Anyone, I assume that the number one problem with these exhaust risers resulting in having to replace them is corrosion failure. Does anyone know why this is? Is there a galvanic corrosion issue designed into the system? Is that why we would replace with electropolished S/S?
Jeff,
I've removed my exhaust riser three times and replaced it twice in the 22 years I've owned our boat. I've written two tech notes about it, the last one being this one in the February 2016 Mainsheet magazine: https://c34.org/muffler-exhaust-riser-replacement-2015/
That tech note includes references to my earlier tech note and to Ron Hill's many contributions on the topic.
The answer is that the mixing of the exhaust gases and the seawater (raw water) that has passed through the heat exchanger is a CORROSIVE mix. As in chemically corrosive.
You can use any material for the riser, and over the years there have been many choices skippers have used: from galvanized to ss.
Here's a link to a much older static 'site post: https://www.c34.org/faq-pages/faq-exhaust-pipe.html
Your boat, your choice. :D
Hi Jeff,
This was reported by both the Engine Surveyor and the Marine Surveyor. Neither removed the insulation but they did find corrosion near the muffler. They might have pulled a bit the insulation at that end. But, both made it clear that this was a must do before using the engine for extended hours. so.. I essentially changed the Exhaust Riser, the heat exchanger and many cracked hoses. They engine has run smooth since.