Exhaust Riser needed.

[conor54]

hi Jonathan,

I can't remember the exact costs - all those receipts are quickly torn up and pushed deep into the paper bin to keep them out of sight!

I got the actual water injection peice from ASAP - one of these . The local engineer then welded it onto the pipe sections for less. I gave them the original Perkins elbow as a template for the flange to attach to the engine.

All up with the exhaust hose and the waterlock it wasn't cheap but my engine had had a more expensive reconditioning due to water damage so I wanted to fix the root cause.

Regards,

Conor

 

[Talulah]

How much ... ish?

I seem to remember it was £150.
I sent them the gasket off the old one so the sizing was right and specified how high I wanted it.
The nice thing is the water injection is sprayed through a series of nozzles within the pipe.

 

[jonathanhsm]

Thanks all and Talulah that sounds more like it. I'll give them a call. It looks pretty easy to clean too. Perkins M20/Volvo 2020D notorious for crudding up cast iron exhaust elbow - and mine is probably on the way out.

I've had water in my cylinders about three times now! Once because of blocked anti-siphon valve and latterly water up exhaust.(When I got the boat the exhaust valve on no. 3 cylinder was rusted in- now I know why.)

Fortunately engine seems to have survived and runs and revs well - And water doesn't seem to have got into crankcase - no emulsion in oil, although I'll probably change it to be safe. At some point I suppose I'd better get the head off to check valves etc... but first I'll get the riser sorted and probably put a valve near exhaust outlet as belt and braces because boat sometimes takes a real pounding up the rear end on exposed mooring when wind is coming from the 'wrong' direction. Roll on summer.

Thanks again

 

[bikedaft]

same problem on similarly shaped stern.

put a seacock on exhaust as it left hull, and attach engine key to it when shut

also ran a piece of garden hose from the exhaust water trap/muffler to an easily accessible part of bilge, with a valve on end. open it and drain water trap before leaving boat. (then shut it again)

rubber flaps curl over time

no space for a high rise manifold thingy on ours

watched her on mooring in an f8 (she's since been in more and no water in exhaust) the waves were cresting on the side decks so easily overwhelm swan neck at stern. then when the stern crashes down too...

 

[PuffTheMagicDragon]

Coming back to the flap idea. I recall seeing something like a cage with a captive 'large tennis ball' inside it. This is fitted to the end of the exhaust line and serves as an outlet. When the water rises, as with a wave, the ball would instantly float upwards and temporarily block the exhaust, thereby preventing the ingress of water. It seems to me to be the ideal solution for an exhaust line that points vertically downwards.

 

[jonathanhsm]

exhaust cage

I know - just like one of those old fashioned snorkels that used to choke you when the ping pong ball got stuck. But sounds like a sound idea!