Angled Transom Exhaust Fitting?

[Delancey]

Hi Folks,

I am hoping someone can recommend a source for an angled transom exhaust fitting. I have a reverse transom and need a fitting for 2" ID hose. 15 degrees should do the trick.

Buck Algonquin has them but their smallest size is 2-3/4". I can always get one fabricated but would prefer off the shelf. Any suggestions would be greatly appreciated.

Thanks!

[sanibel sailor]

On my Bristol, the exhaust exits the reverse transom through a fiberglass tube that sticks out a couple of inches. This way the water doesn't drip on the transom itself. Its angled downward slightly. You could probably fabricate a similar thing using a cardboard or pvc tube as a male mold.

[Delancey]

That's an interesting idea. You can get flame retardant filament-wound exhaust tubing made for the purpose which is what I would expect you have on your Bristol. Any chance you could share a photo of your installation that shows how it is mounted? Would be most appreciated.

[sanibel sailor]

Flame retardant is probably overkill considering the wet exhaust at the transom.

Inside picture. Little tube coming in is cooling water overflow. Bronze fixture is a check valve preventing backflow. I have a separate ball valve as well.

[sanibel sailor]

Outside picture. I had always assumed it was aluminum or something until I backed into the dock.

[model 10]

Holy cow. I did not know an exhaust system could be so complex. Check valves and shut off valves? That is way beyond a simple water lift system.

[sanibel sailor]

When water backs up the exhaust into the engine, you will understand...

[model 10]

Originally Posted by sanibel sailor

When water backs up the exhaust into the engine, you will understand...

Why would you have a system that does that? A water lift actually does lift water. You need to upgrade.

[sanibel sailor]

I have a water lift muffler. Water can still be forced past it under certain circumstances.

[Delancey]

Thanks Sanibel for posting the pictures. Could be a solution to my problem. The tubing is pretty cheap, I think like $12 at Defender, which will just leaving me some aesthetic issues to resolve but nothing that can't be worked out.

Cheers

[model 10]

Originally Posted by sanibel sailor

I have a water lift muffler. Water can still be forced past it under certain circumstances.

I can see how it could happen with the way your boat exhaust is plumbed.

[Delancey]

Originally Posted by Guy

I can see how it could happen with the way your boat exhaust is plumbed.

I see few water lift mufflers installed on most boats that can contain an entire exhaust systems worth of water. Mine holds two gallons but will be adding a check valve anyway. Small price to pay.

Apparently you've never been boarded.

[GrahamHO]

Originally Posted by sanibel sailor

I have a water lift muffler. Water can still be forced past it under certain circumstances.

I take a loop of the flexible exhaust hose as high as possible inside the locker the exhaust runs through and down to the transom exit. I made a copper flapper (with a plastic hinge on a short piece of PVC tube) angled 45* on the outside so gravity closes it. Similar to the flappers you see on truck vertical exhausts.

I have found that seacocks, cast fittings and valves create unnecessary back pressure restrictions to the exhaust flow. Especially it's a restriction when some people extend them by sticking a piece of plastic tubing inside the cast fitting. Then a 1,1/2" dia can become 1" dia or less and we can all do the math on the crossectional area reduction. Some forget that the cooling water is also occupying the pipe and its crossectional area along with the gasses.

One thing diesels really need is a free flowing exhaust.

My transom fitting is fabricated from 1,1/2" dia SS thin gauge tubing (18 / 20 g) and a circular flat plate for a flange with a matching transom angle. It's 17 years old with no signs of corrosion.

I've extended it with a short length of exhaust tubing on the outside with the flapper on the end. That is flexible and goes under the boarding platform and won't damage a dinghy.

One reason for the flapper is to prevent damp air blowing through the engine in the unlikely event of water in the water lock evaporating when not in use as now.
That's my way if it helps.

[Captain Bill 3]

Vernay one water trap company makes all kinds of transom thru hulls. Not expensive and a lot less hassle building one.

[SkiprJohn]

I have some extra 12" pieces of fiberglass exhaust tubing which is exterior diameter 2".

If you are interested I can beat any catalog price and send it USPS flat rate.

I used it to design a multiple curved exhaust system. It can be angle cut and then epoxied together.

Send me a private message if you're interested.

kind regards,