Tartan-30 Exhaust Question

[TomG]

Greetings MMI/A-4 Braintrust,

First of all, thanks to MMI for a superb forum. I've been looking to move from my Catalina 25 to a bigger boat for the last few months and many of the boats in my budget are powered by the Atomic 4. As such, I've been a frequent reader of this forum and have been truly impressed with the camaraderie and knowledge I have witnessed. My humble thanks to you all.

I very recently (as in yesterday) became the owner of a Tartan-30 powered by a rebuilt (2008) MMI Atomic 4. The engine is in great shape, but the currently installed water-lift muffler is shot. As I was removing panels yesterday to get access to the exhaust system, and contemplating a replacement hot section and new water-lift muffler, what I found has truly perplexed me. I was hoping to tap into the vast reservoir of knowledge this forum offers in helping me understand what exactly is going on with this current system.

The Tartan 30 (and 34) have the engine mounted very low just abaft the mast with the exhaust exiting amidships on the port side. There are certainly many positives with this design, but one of the trade-offs is the exhaust system. It's difficult to get enough vertical drop in the hot section without running into the issue of cooling water backing up into the manifold.

That said, the current set-up is puzzling. I have the "usual" water injection point just downstream of the hot section and just prior to the water-lift:


What is puzzling is this arrangement in the top of the exhaust loop:



What I'm wondering is, is this a wise set-up? Is there a method to the madness?

Since I need a new water-lift muffler anyway, I'm thinking about getting the new Moyer Standpipe muffler for Tartans.

Thoughts?

[ArtJ]

If you look in a recent post of mine entitled "needhelpuploadingapicture"

You will see complete pictures of the Tartan 34 Exhaust system.

Regards

Art

[ArtJ]

The way I found my post was by searching for "standpipe'

Then I found my post "needhelpuploadingpicture'


I'm Not sure how to attach a link in these messages- comment appreciated.

[TomG]

Art,

Thanks for the link... I found it. Is this your original standpipe? Any problems?

I'm thinking seriously of going with Moyer's standpipe. It's a lot more expensive than a typical fiberglass water lift muffler, but I'm not really thrilled with my current set up... seems too easy to get water back up the exhaust. It seems like the standpipe makes water intrusion nearly impossible.

[ArtJ]

I recommend going to the original configuration. Everything shown is
original. You can get black iron pipe cut to size at Home Depot inexpensively.
Cover with several wraps of high quality exhaust wrap. I have also
strapped stove pipe to the vertical extension of the exhaust pipe because
of proximity to the plywood plenium, or chimney. Not sure if you have this
plywood box or not. There is also a exhaust for the bilge vent fan which
extends vertically up from the box and thru the deck under the Dodger.
This vents the bilge of fumes and also provides a early sniff of potentially
dangerous gasoline fumes.

Be sure that you use a elbow for the vertical to horizontal connection.
My boat originally had a plugged T there. This worked fine when it was
originally stuffed with asbestos plaster, but created a heat issue when
wrapped. keep a distance from all wood.

[Al Schober]

Hi Tom,
Welcome to the wonderful world of Tartan 30s!
Yes, your photos are curious. Looks like it might be a waterlift, but without the water lift! Looks like you have water injection at two points, assuming both of those upper hoses are water lines. If so, what is shown is very liable to get water back into the cylinders.
I went through this two years ago. see: http://pages.cthome.net/maren/T30Exh.htm Keep in mind that the Moyer riser can was not available at that time. If I was doing the job today, I'd bit the bullet any buy the Moyer riser can - MUCH easier to fit into the available space.

[TomG]

Al,

Thanks for the information and the link to your T-30 exhaust project. I had actually stumbled upon this link a few weeks ago (and bookmarked it!) and was very impressed with your approach and really appreciate the pictures. Something about pictures to describe a project that really makes it easy for me to understand... could be the caveman in me.

My current system has the water lift can, that's why I don't understand the second (and third) injection points. The cooling water port at the top of the loop is cooling the exhaust that has already gone through the water-lift. It's really weird.

Why there are two lines going into the top of the loop is really baffling.

It's great to be a part of the Tartan family! I have really enjoyed my Catalina 25 and she really looks great, but she was just bit small for the family. I am anxious to get my T-30 looking as good and my Atomic 4 purring like a kitten. Thanks for your help!

[ndutton]

Where do those two lines at the top of the loop come from?

[swallace11]

T30 Exhaust

My T30, hull 384, 1975, has this same configuration, but had an injection elbow rather than the "T" fitting downstream. Yours may have been changed at some point. The nozzle in the injection elbow had corroded and expanded to restrict the exhaust. My waterlift muffler, in fresh water, not salt, seemed fine. My fix was to replace everthing and use the Moyer injection elbow instead of a piping T. This has two advantages: much easier to connect short piece of exhaust hose and the 60deg water entry nozzle with elbow "lip" at hose connection assures that there will be no backsplash into manifold. Did this repair last year. Performance seems better and my two lower spark plugs no longer fail prematurely. I was indeed concerned about the column of water in the riser backflowing into waterlift muffler and surging up into manifold when engine stops, but don't believe this to be a problem in the original design. Someone at Tartan came up with this simplfied exhaust configuration and determined that it would work. It did for about 25years.

[TomG]

Neil,

What I expected to see when I pulled the panel off to get to the exhaust plumbing (the top of the loop is hidden in a chase in the T-30s) was a vented loop at the top of the cooling water hose and the exhaust hose. What I found was the picture you see. One line up comes from the manifold and the other line returns to the water injection point at the hot section. Given the way it looks, I wonder if any cooling water is entering the injection point at the hot section. Like I say, I'm fairly mystified by this set up.

swallace,

Thanks for the information and it's very interesting that your T-30 has the same setup. I too, tend to leave well enough alone when it comes to the original design of things, but his just doesn't look right. I had already ordered the improved injection coupling from Moyer to go between the hot section and the muffler, but I am seriously thinking about going to the standpipe since I need to replace the water-lift muffler anyway. What's another $300?!

[tartansailboat]

Tartan 30 Exhaust Question

I have T30, hull no. 127. The original copper standpipe was leaking and replaced 5 years ago with a Volvo water lift muffler. Very poor installation, mechanic would have made a fine butcher. Two years ago, I replaced that water lift muffler with Moyer's stainless steel unit, much smaller, better installation. No problems, runs great. I have only one water line from the manifold running up into the head area with a anti siphon valve also from Moyer. It seems like the injection point is does not have enough vertical drop to prevent water from getting back into the cylinders but it works just fine. Never had a problem, even cranking for prolonged periods, I know that sounds wrong but there it is. Stick with Moyer, you cant go wrong.

[ndutton]

I think it's Tartan's or someone else's idea of an antisiphon. Looks weird but if it's working, who's to say?

[swallace11]

T30 Exhaust

Your exhaust riser and antisiphon hose top fitting is different than mine and was probably rebuilt when your exhuast was judging by the ordinary plumbing fittings that were used. Mine, in freshwater with less corrosion, I believe to be original and seemed to be a custom combination "L" and "T" fitting. I believe both yours and mine to be a support strut of the exhaust not an injection elbow as apparent. cooling water goes up to top for anti-siphon and then is injected on return at exhuast elbow above muffler. I know this because I didn't have the hose at lower injection elbow clamped tight and a generous flow of cooling water sprays out. Hope this helps.

[TomG]

Neil,

I'm not sure that is working... the #4 valve is sticking and I suspect the current exhaust system is culpable.

To all who responded, thank you for your advice and wisdom. I ordered the standpipe from Moyer on Friday. I'll post pictures as the project unfolds.

[TomG]

Made it to the new (old) boat yesterday, a truly wonderful late November day here in Maryland with temps in the mid 60s!

I ordered the new standpipe exhaust from Moyer last Friday and it arrived Monday. A quick plug to the fine folks at Moyer for such great service!

Yesterday involved removing the old hot section and measuring for the new hot section and mounting for the new standpipe. I thought I would share what I discovered with the old water-lift exhaust. These pictures are not for the squeamish:




This picture is the results of cutting the riser section from the muffler to the top of the loop.




This is a cross-section of the same riser hose.






This is the old muffler.





This is the water injection point. As you can see, it is partially blocked and corroded. I think this is from just two seasons of use.


As the pictures show, I had a real mess with the old exhaust system. The Atomic 4 had been replaced in 2008 and for the life of me, I can't figure out why the exhaust system wasn't updated then... in for a penny, in for a pound, I always say.