Beta 20

1

10oxometer

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Hi Everybody, In March I had to renew the head, valves and heat exchanger manifold,
they could not be reconditioned due to what looked like bad water damage, my question is if the exaust skin fitting outlet is higher than the engine what stops any water traped in the system when the engine is switched off creeping back and finding its way into the engine, i say this as trhe pistons heads are also pitted the worst one at the back progressivly better going forward. there is an antisyphon vetus arrangement fitted above the engine. it started on the button after recon but now six months later is becoming more difficult.
 
10oxometer said:
Hi Everybody, In March I had to renew the head, valves and heat exchanger manifold,
they could not be reconditioned due to what looked like bad water damage, my question is if the exhaust skin fitting outlet is higher than the engine what stops any water trapped in the system when the engine is switched off creeping back and finding its way into the engine, i say this as the pistons heads are also pitted the worst one at the back progressively better going forward. there is an anti syphon vetus arrangement fitted above the engine. it started on the button after recon but now six months later is becoming more difficult.
Click to expand...

a water lock + exhaust pipe of sufficient dia.+ anti syphon device
see the Vetus catalogue for details
 
10oxometer said:
Hi Everybody, In March I had to renew the head, valves and heat exchanger manifold,
they could not be reconditioned due to what looked like bad water damage, my question is if the exaust skin fitting outlet is higher than the engine what stops any water traped in the system when the engine is switched off creeping back and finding its way into the engine, i say this as trhe pistons heads are also pitted the worst one at the back progressivly better going forward. there is an antisyphon vetus arrangement fitted above the engine. it started on the button after recon but now six months later is becoming more difficult.
Click to expand...

The exhaust from the engine should fall to the water lock at least. Unfortunately a few re engining jobs done in recent years have not ensured this with the result that sometimes the exhaust from the exhast elbow has a slight rise resulting in an amount of water backflowing into the engine every time it stops.

Beta overcome this with the option of a high rise elbow. which assists in preventing the back flow.

It would appear that your engine may be badly installed and insufficient attention may have been given to the exhaust layout so ensuring that it was not possible for this back flow to happen. It sounds like you valves and seats are becoming corroded and starting to leak.
 
daveyw said:
Here's a Nanni pdf. Page 8 might help

http://www.nannidiesel.com/images/stories/manual/N3.21/Notice de conduite N3.21 ENG.pdf
Click to expand...

What I have seen on a few re engined boats is that the hose from the engine to the water lock item 3 rises slightly instead of falling.

Another problem that can show up is when the water lock volume is insufficient to take all the water that could be in the exhaust pipe.

Fitting a high rise bend lifts the engine exhaust anything up to 150 mm
The Beta bend might fit a Nanni if Nanni do not do one.
 
beata 20

Thanks Bilgediver for your reply. looking at all the info i`m not sure the anti syphon is high enough above the waterline ie. 400mm i will check next visit also the volume of the waterlock..it has been installed with the exaust pipe falling all the way to the water lock and rising afterwards to the skin fitting which is encouraging.Many thanks.
 
10oxometer said:
Thanks Bilgediver for your reply. looking at all the info i`m not sure the anti syphon is high enough above the waterline ie. 400mm i will check next visit also the volume of the waterlock..it has been installed with the exaust pipe falling all the way to the water lock and rising afterwards to the skin fitting which is encouraging.Many thanks.
Click to expand...

Definitely check the water lock can take the volume of a full pipe to the transom because it can get quite full at tick over. Not only must the anti syphon be high enough but also must break the vacuum when the engine stops.IE no stuck valve. I prefer the ones with a peeing pipe. You always know when it is clear.

It can either pee into a cockpit drain or a ship side fitting well above the waterline where it can be checked.
 
When I fitted my Beta 25, I fitted a High Rise Exhaust. Fitted after I realised the standard exhaust looked a bit near the waterline so to be safe fitted the High Rise. Bought from Beta on an exchange basis(the engine had not been run). Also fitted a waterlock, muffler & gooseneck - all from Vetus.
 
A water lock collects the water that is in the hose (approx 1 ltr per meter of hose), and a high -lift water injection bend on the exhaust would make it even harder for water to get into the engine. Lots of good diagrams around explaining the system - try Vetus' website
 
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