Lister Petter ac2w head removal

[St.monans]

Hi all
New to the yachting world and this site.
I have recently purchased a 1968 Halcyon 23 it has a petter ac2w engine.
I dont know the last time this engine was serviced so i am taking that it is probably over due a major service. 1 of the things i don't know is if the engine can remain in the boat while i change the head gasket and service her or do i have to remove it. ?
If i remove it is there a chance that i wont be able to realign the gearbox to the propshaft.
The gearbox was replaced about 2 years ago with a brand new unit (since then it has done around 6 hours )
So if i can get away with out eginge removal that would be a big help.
Thanks

 

[TQA]

Why on earth replace the head gasket ? It is NOT a service item.

Oil and filter, check the valve clearances and replace the raw water impeller.

 

[stelican]

Hi all
New to the yachting world and this site.
I have recently purchased a 1968 Halcyon 23 it has a petter ac2w engine.
I dont know the last time this engine was serviced so i am taking that it is probably over due a major service. 1 of the things i don't know is if the engine can remain in the boat while i change the head gasket and service her or do i have to remove it. ?
If i remove it is there a chance that i wont be able to realign the gearbox to the propshaft.
The gearbox was replaced about 2 years ago with a brand new unit (since then it has done around 6 hours )
So if i can get away with out eginge removal that would be a big help.
Thanks

 

[mtb]

Another why do it!
If you want a nightmare go for it
Do not use gaskets from that fIrm in Yorkshire I used theirs and both failed, the gasket material was cheap and failed.
I found the gaskets from Uxbridge boat center were OK
If I were you I'd coat the whole gasket with sealant not just around the water galleries.
Remember to check the bump clearance with soft solder to adjust this you will need to take the barrels off to add or subtract shims
It's a straight forward job while the engines in the boat providing there is enough clearance to lift the heads off
You can reface the heads using wet and dry with diesel as a lubricant on either a surface plate or sheet of plate glass.
Change the core plugs while the heads are off also the anodes again Uxbridge boat center ( nout to do with me )
Do not allow any water to run down any where near the fly wheel there is a vary fine clearance around the casing and if water, especially seawater gets in there it will sieze and then you will struggle as it's an engine out and flywheel bolts off to try and get the flywheel off.
Check the injectors using a jam jar for safety again while it's in bits
Cheers
Mick

 

[St.monans]

Hi Mick
Thanks for that valuable info. I have had to cut out the starboard berth due to wet/dry rot. It looks like i may have just enough clearance.
i have got a hold of a manual so going to go for it.
The head gaskets have as far as i know never been changed.
Am i doing the right thing by changing them or is

 

[drydog]

Hi Mick
Thanks for that valuable info. I have had to cut out the starboard berth due to wet/dry rot. It looks like i may have just enough clearance.
i have got a hold of a manual so going to go for it.
The head gaskets have as far as i know never been changed.
Am i doing the right thing by changing them or is

Unless your engine has a problem with compression or other related head gasket issues, why replace it.
As has been said, it's not a service item to be replaced at certain intervals.

What does come to mind though is:
a lot of people for some reason, mistake the tappet cover for the cylinder head. If this (usually cork or rubber based) gasket is what you are talking about, then yes by all means change it when the cover is off and you are adjusting/checking the tappets.

 

[mtb]

Leave well alone mate if for example you do take the heads off after rebuilding it to the point of checking the head to piston bump clearance if the barrels need to come off you risk breaking rings re fitting the barrels. The head studs on these are prone to stripping threads the manifolds are difficult to get off
I would check the exhaust manifold is clear do an oil change check tappets new oil .anodes oil filter diesel filter and make the engine work hard which is in my opinion the best way to keep things in good order
I have one of these engines sat in my shed which was meant for a project I waited so long to get parts I ended up fitting a yanmar instead.
Cheers
Mick

 

[St.monans]

Thanks for the info guys.
the only reason i was going to change the head gaskets was due to reading on some forum that it is good practice to change the Head Gasket every 2 years. But i was not sure on this. thankfully i got the correct advice on here.
I will do and check as you say regarding the tappets ect.
Really cant thank you guys enough.
If you want to pas you r project engine on in the future keep me in mind Mick.
Having a second engine for spares would be a god send . i could imagine trying to get hold of a 50 year old spare part quite a challenge.
Thanks again guys
Andy

 

[St.monans]

Leave well alone mate if for example you do take the heads off after rebuilding it to the point of checking the head to piston bump clearance if the barrels need to come off you risk breaking rings re fitting the barrels. The head studs on these are prone to stripping threads the manifolds are difficult to get off

I would check the exhaust manifold is clear

do an oil change check tappets new oil .anodes oil filter diesel filter and make the engine work hard which is in my opinion the best way to keep things in good order
I have one of these engines sat in my shed which was meant for a project I waited so long to get parts I ended up fitting a yanmar instead.
Cheers
Mick

How do i do this ? By clear how do you mean ?

 

[mtb]

Check there isn't a build up of sludge in the manifold. First Get new core plugs their not easy to get then take off the hoses and pop the core plugs out then carefully clean out any mud or rust. Use well seal or loctite to reseal the core plugs. Have you checked the water pump impeller they harden with age, their standard jabsco easy to buy after market versions off eBay

 

[St.monans]

Check there isn't a build up of sludge in the manifold. First Get new core plugs their not easy to get then take off the hoses and pop the core plugs out then carefully clean out any mud or rust. Use well seal or loctite to reseal the core plugs. Have you checked the water pump impeller they harden with age, their standard jabsco easy to buy after market versions off eBay

Yeah i have replaced both of the impellers one had 2 cracked vanes think this was the fresh water one as it was a 8mm ID pipe the other is 15mm ID that was ok but i changed it anyway.

 

[ChrisNN]

If anyone has a cylinder head for AC1W I would really appreciate it!