HorizonblueDK
Petty Officer 1st Class
- Joined
- May 27, 2010
- Messages
- 355
Last year I posted few pictures of my homemade exhaust system, which generated a vibration in the boat. I suspected that the length, depth and rigid construction of the pipes, caused the vibration.
This is how it was made, until recently. The tape indicates where I'm about to cut.
A few evenings in the workshop, cutting and welding (but many evenings polishing) and I made this.
As you can see, they are also quite long, but not as deeply submerged as the old ones. You can also see, that they are connected to the pipes going through the transom, with a short rubber hose. Under the hose, there is a zinc anode, to protect from galvanic corrosion. The anode also serves as a "safety line", in case the rubber breaks, so I don't loose a pipe on deep water. The rubber hose can absorb vibrations.
The boat was launched yesterday. And it fulfilled my expectations. The vibration is gone, wonderful. On plane, the noise level is fine, maybe just a little lower than before.
It is not allowed to turn to one side and trim fully up, but I never do that anyway. In the normal position, the outdrive can be turned lock to lock, without touching the pipes.
So the conclusion is that it was time well spent, cutting, welding and polishing.
Well, I don't have any questions, just want to show you how the vibration problem was solved.
This is how it was made, until recently. The tape indicates where I'm about to cut.
A few evenings in the workshop, cutting and welding (but many evenings polishing) and I made this.
As you can see, they are also quite long, but not as deeply submerged as the old ones. You can also see, that they are connected to the pipes going through the transom, with a short rubber hose. Under the hose, there is a zinc anode, to protect from galvanic corrosion. The anode also serves as a "safety line", in case the rubber breaks, so I don't loose a pipe on deep water. The rubber hose can absorb vibrations.
The boat was launched yesterday. And it fulfilled my expectations. The vibration is gone, wonderful. On plane, the noise level is fine, maybe just a little lower than before.
It is not allowed to turn to one side and trim fully up, but I never do that anyway. In the normal position, the outdrive can be turned lock to lock, without touching the pipes.
So the conclusion is that it was time well spent, cutting, welding and polishing.
Well, I don't have any questions, just want to show you how the vibration problem was solved.