Draining exhaust silencers for lifting

[Nick_H]

It's a bit after the event now, as the boat was lifted a couple of weeks back, but I have stickers by the helm, and in the engine room, saying the Halyard exhaust silencers must be drained before lifting the boat.

This wasn't done by PMYS when they lifted it for the purchase survey, and hasn't been done any other time it has been lifted, and i've not noticed any adverse effect.

Should I be draining them, or do they drain just by the seacock being open (I guess not as theres a loop in the outlet pipe). What's the risk if they're not drained? If I drain them, do they self fill again afterwards?

 

[jfm]

I have the same instructions but I ignore.

The "danger" is that if the lift goes wrong and the arse end of the boat is too high, the water in the silencer could defeat the swan neck in the exhaust pipe and get to the valves and generally kill the engine. But to do that you'd have to hang the boat near vertical. It just aint gonna happen. So i ignore this instruction, always have done in 10 years fo having that type of exhaust

If you do empty them, there is no need to refill when the boat is launched. They fill from the spent raw water cooling outlet, automatically

 

[Nick_H]

Thanks for the info, I can now ignore them from a position of knowledge, rather than through apathy and ignorance.

 

[mjf]

I concur jfm advice.

Princess told be the same - if the lift is done correctly with slings in line with saloon door and in line with base of windscreen the angle is fine. No chance of water where its not wanted

 

[Hurricane]

Yep - I had the same advice.

Think about it - the boat probably rolls more at anchor than in a lift or on the hard.
The other reason to drain, I believe, is to protect against frost damage - not an issue with yours.

A good reason for not draining is that the drains are into the bilges - I dont like water in the bilges - I like to keep them dry - you can than tell immediatly if somethings wrong.

 

[volvopaul]

Beware, ive come across this on a sealine boat before.

The boat was lifted and transported to a yard near me to be sold.

It sat in the yard for quite sometime before an offer was made, survey carried out and launched for sea trial, to find 1 seized solid engine, as the water had sat in the cylinders for quite sometime, the engines were TAMD63ps from memory it was a sealine 410, so beware, it may have been caused by the lift out or may have happened on the lorry, perhaps when the lorry braked water ran up exhaust hose into the head.