Winterising the engine intake / exhaust

[FlyingDutchman]

Now that the season is coming to the end, the question arises what to do over the winter with the engine's air intake and exhaust.
The engine is a 4 cylinder which means that there are always some valves open.
Would it be good to close the intake, the exhaust or both?
The collective wisdom of this forum is, as always, highly appreciated!

 

[Topcat47]

I remove the air filter and the Fexible Exhaust, then stuff an oily rag up each orifice........

 

[Stemar]

If it's practicable to do so, I reckon the best thing to do is neither, but run the engine until fully warm once a month.

If it isn't lift the decompressor and squirt some WD40 (several seconds worth) into the intake while turning the engine over on the starter. On most boats you should close the cooling water inlet first.

Then I'd close the inlet using a very obvious method, preferably one that won't do any harm when I forget I did it next spring! I'd be a bit leery of disturbing the exhaust unless the pipe's newish or due for replacement, on the "if ain't broke, don't fix it" basis. Older rubber pipe doesn't always like being taken off the manifold.

No doubt someone'll be along in a minute to explain why I'm talking bollox.

 

[BobnLesley]

I go for Stemar's WD40 Spray Technique; I then seal the air intake with duct-tape and stuff the exhaust outlet with an oily rag. I also drain off any the water that's sat in the exhaust water-lock.

These tasks may or may not do the engine any good; but they make me feel better, so they can't be all bad. /forums/images/graemlins/wink.gif

 

[FlyingDutchman]

Some reactions:
I can't run the engine when the boat is out of the water.
The engine does not have decompressors.
I cant empty the water from the exhaust water lock.

This means that if I close the exhaust (easy to do with duct tape on the outside) and close off the intake (oily rag) I close up the moisture and water in the system whereas when I leave everything open it can at least ventilate. Or maybe the best solution is to only close the exhaust?

 

[Twister_Ken]

"I cant empty the water from the exhaust water lock."

Can you siphon most of it out using a small flexible pipe stuck up the exhaust outlet?

Or could you blow much of it out by running the engine for a few secs with the cooling water inlet closed?

 

[Refueler]

[ QUOTE ]
Some reactions:
I can't run the engine when the boat is out of the water.
The engine does not have decompressors.
I cant empty the water from the exhaust water lock.

This means that if I close the exhaust (easy to do with duct tape on the outside) and close off the intake (oily rag) I close up the moisture and water in the system whereas when I leave everything open it can at least ventilate. Or maybe the best solution is to only close the exhaust?

[/ QUOTE ]

My solution, even though engine sits in extreme cold winters is to not close of intake and exhaust.

As to running engine out of water, I close the water intake sea-cock and unscrew top and remove filter. Into the now open barrel I direct a garden hose ... this is turned off until engine has started. Flow is adjusted so that only enough is supplied and not overflowing the sea-cock barrel.
This then washes out all salt-water and crud. Once it's been run for a short period - I then remove hose and pour suitable diluted concentrate anti-freeze into water intake to have it pumped through system - this then sorts your water lock / exhaust pipes as well as engine itself.
Once can - I use 5 litres on my Perkins 4-107 and straight exhaust - is empty - I stop engine and put filter / cap back on seacock, leaving it closed so antifreeze doesn't siphon back.

If you are an environmentalist as we all are - the exhaust can be directed via a hose into a drum to avoid anti-freeze being pumped over yard.

Works a treat. Admittedly my engine is raw water cooled - but still aplies to indirect - as seawater cooling for heat exchanger has to be cleared out.

 

[lw395]

If ashore for more than a month, I would disconnect the flexible exhaust pipe, and turn the engine over decompressed to oil the bores. Also flush out the salt water system and drain it. Not worried about the exhaust as it's plastic and rubber, so just want to keep the damp out of the engine.
I would not run the engine with the boat ashore unless I had great confidence in the cradle. The vibration will remove wedges etc. Also if the prop rotates at all (due to gearbox drag?), the cutless bearing is un-lubricated and may be damaged.
If afloat, just run the engine once a fortnight.
It's worth getting rid of any bilge water under the engine, giving everything a good clean, drop of oil or whatever on fasteners, jubilee clips etc.

 

[Refueler]

Mines a bilge keeler so no problem.

The shaft does drag and rotate with engine running - but it's so slow it's not worth worrying about.

My system was passed to me by an old hand mechanic in a yard and works a treat for me.

Oh - bilges etc. get siphoned with a Pela machine. But like all boats she collects water via condensation etc. over winter - so I still end up with a block of ice under the engine in the bilge. No good trying to put heat under there - as it's open to cockpit bilges.

 

[FlyingDutchman]

Thanks for all your comments!
Emptying the exhaust water lock is not an option: the hose is a 2" thick rubber hose that has been connected to the engine since 1994, so I won't attempt to take it off. Also syphoning the water out via the exhaust will be difficult as the hose has a loop inside the boat (gooseneck?). I did winterise the cooling system by pooring coolant in the fresh water filter when running the engine, so that is ok. The engine is fresh water cooled (ie has a separate cooling circuit for the engine itself).
I don't dare to start the engine as I am afraid for the vibrations it would cause to the wedges under the hull (and I think the yard forbids this as they are responsible for the laying up).

 

[milfordman]

I have a 20 year old Perkins 4-108.

Every time I visit the boat through the winter I turn the engine over on the starter with the stop control pulled out so that the engine can not start. I run the engine for 10- 15 seconds until the oil presure gauge registers some pressure to confirm that oil is being pumped arround.

I use this proceedure every time I start the engine after it has been left for more than a couple of days.

I have a painted mark on the crank pulley, which I observe prior to starting. After the engine has stopped I check to see that it has stopped at a different position.

If not then I spin the engine again until the mark is at a different position. This ensures that the same inlet and exhaust valves are not left open all the time.

I do try to visit the boat every few weeks through the winter, but this is the only precation I take, other than changing the oil and filter in October and oil alone mid season.

All the best.

 

[cliffordpope]

Couldn't you run it ashore for just 2 seconds to blast any water out of the pipe?

 

[willie4646]

I pull about a gallon of 25% anti freeze through the raw water system, this helps to stop corrosion and of course stops the sysem from freezing, the air filter is enough to stop moisture entering the engine.
Willie