Exhaust extension

The transom exhaust pipe exits about 2 " out from transom. I want to extend it so the diesel exhaust smoke doesn't blacken transom.Part of the problem is the dinghy attached to transom via weaver davits. The smoke bellows up/around leaving the transom darkened. Question is : To what limit can I the exhaust pipe without restriction of exhaust and water flow? Ideas? Thanks David

I think you are going to find that the exhaust gasses are sucked back toward the transom when underway and no minor extension of the tailpipe is going to completely solve your issue.

I have seen extensions up to about 6 inches. Some use a 45 at the end to get the flow out from the back of the boat. I have seen that on a Mainship and the owner said it worked.

There is a boat next to me at the yard that has a 2 foot extension. I noticed it right away. Not advocating it but apparently it works for him.

Salisbury made a rubber type elbow that routed the exhaust into the water. I believe it was called the Salisbury Hydo-vac silencer. It worked as a muffler and put the stinky exhaust into the water. There were a few holes in it just above the water line probably to let the engine idle and reduce the chance of a hydro-lock. I installed one many years ago it worked great. I have since seen some home made ones by clamping a rubber elbow to the exhaust tube to put the exhaust into the water. I hope those home made ones remembered to drill a few holes above the water line.

Here's Hobo's extension. The bell end of a piece of PVC, about 2'. total.

Larry M said:

Here's Hobo's extension. The bell end of a piece of PVC, about 2'. total.

Click to expand...

We have the same set up. It extends almost to the end of the swim platform.


Mike Metts
KK 42-165
Virginia Beach, VA

Sent from my iPad using Trawler Forum

Larry M said:

Here's Hobo's extension. The bell end of a piece of PVC, about 2'. total.

Click to expand...

thanks .photo answered question ..no problem with "back pressure" adding 12 " extension..thanks to all.

An extension like that will not affect backpressure

The boat I was referring to in the earlier post.