Exhaust Question

[SailingWebGuy]

Hello!

Could you guys help me identify this piece of my exhaust? I need a name for it...I have no idea what to refer to it as when I look for a new one.

I ask because I have almost all the pieces in my shop to duplicate the old one except for that one piece.

Thanks!

[SailingWebGuy]

Trying again.

[donradclife]

That is a one-way or check valve.

[otisgudlyfe]

I'd say it's a swing check valve. I lets exhaust gas flow out and keeps unwanted fluids from flowing back into the engine.

[Faster]

Ditto......

[SailingWebGuy]

Thanks for all the replies!

I've been digging around for info on them. Apparently they were only used on the very early model Catalina 30's. They increased back pressure and were eventually eliminated.

I'm trying to figure out if I should also do away with it. I'll post any interesting info that I might find.

[deniseO30]

My guess is the swing check valve would stick closed (or open) in very short order. C-30s the engine (I think) in the lowest part of the boat and the only right way to get really good access is to remove the galley cabinets. Sounds difficult but the guys that have C30s in my YC do it quite often when working on theirs.



Don't know what engine you have but here's some stuff from Catalina direct
Catalina Direct: Exhaust Riser Universal Diesel Equipped C-30

[Faster]

The use of the check valve there is a nifty idea and theoretically should minimize the risk of a flooded exhaust (from cranking too long without firing, eg) getting into the engine.. but I suspect, as Denise suggested, that it became a trouble spot more often than it prevented a problem.

I'd venture to say that most systems will not have one in place and as long as you follow good practice you could eliminate it now.

[SailingWebGuy]

A little info I found on this. It should be removed but the exhaust exit through hull needs to have a flap to keep out following seas.

[tommays]

Powerboats have gone back and forth on many different forms of swing check valves in rubber and metal

They always wear out with no real way to tell and they have found a correct install with things at the correct height above the waterline solves most issues