AD41B.....looking grim, views and advice welcome!

[dpb]

Sorry, but what are you saying is the cause? I can see a very scored piston, and rusty outer liners, but any ideas of the cause?

Cheers,
Paul

After discussions with mechanic, root cause believed to be bad injector allowing too much fuel into cylinder which washed the oil off the liner walls leading to greater friction, heat and eventually seizure.

 

[TQA]

After discussions with mechanic, root cause believed to be bad injector allowing too much fuel into cylinder which washed the oil off the liner walls leading to greater friction, heat and eventually seizure.

Interesting theory. This would be accompanied by copious quantities of black smoke which would be worse under load.

 

[dpb]

I would be looking seriously at the turbo and intercooler, the intercooler matrix does fall apart at that age , its next entry is the piston tops.

Some year back I had an AD 41 with little compression, after head removal a piece of metal was jammed in an open valve seat.

Been recommended to change the turbo due to its condition and on removal of the intercooler matrix:

[/URL]

Not the matrix disintegrating, but the side panels certainly have, though to touch them they are not at all fragile. Dont understand why they break up unless they break up in th air flow from vibration.
Wondering if the missing metal could have caused the seize by jamming in the piston?
Evidence of leaks is probably from when the cover to the aftercooler was leaking up to a year ago which would explain the pitted inlet valves.
Whilst not tested under pressure, the core seems water tight.
Anyway, having spoken to a couple of firms it would seem a repair is not a problem at a reasonable cost to!

The engine is mostly reassembled and with the boat out of the water from Monday, hope to have the engine back in by the end of Feb.

 

[volvopaul]

Been recommended to change the turbo due to its condition and on removal of the intercooler matrix:

[/URL]

Not the matrix disintegrating, but the side panels certainly have, though to touch them they are not at all fragile. Dont understand why they break up unless they break up in th air flow from vibration.
Wondering if the missing metal could have caused the seize by jamming in the piston?
Evidence of leaks is probably from when the cover to the aftercooler was leaking up to a year ago which would explain the pitted inlet valves.
Whilst not tested under pressure, the core seems water tight.
Anyway, having spoken to a couple of firms it would seem a repair is not a problem at a reasonable cost to!

The engine is mostly reassembled and with the boat out of the water from Monday, hope to have the engine back in by the end of Feb.

Looking at the pic , I'd only say turbo problem if it was drenched in oil, the air flow goes right to left looking at it sat units casing, the debris blockage looks like a salty deposit so I'd be looking at its integrity to keep sea water from entering the cylinders. My view would be to clean it all up, rebuild it into its housing and pressure test the waterways of the matrix before scrapping it.

 

[dpb]

ALL DONE!

Just thought I'd conclude this thread, as often you start following something and never know how it ends.

Having got the engine home from the mechanics I was able to finish it before taking it back to him for testing and dropping it in the engine bay.

I took the opportunity to clean up the inside of the transom shield with the engine out of the way, renewed the seals between the exhaust and water outlet and the shield, fitted remote steering helmet greasing tubes, a new gimbal bearing as it felt a bit rough and just generally cleaned and greased everything.

The test run went OK so I got them to drop the engine into the boat as it would have taken me weeks to coordinate a day off, with good weather and the yard crane.
That just left me to wire and plumb up the engine and refit the water tanks and cockpit floor supports which are now all done.

The total works done in the end was:
New piston and liner.
New rings to other pistons
One new bearing shell
six new inlet valves
one new injector, the rest serviced
Reconditioned turbo
Reconditioned intercooler matrix.
All other matrices checked and cleaned.
New crank shaft seal
Rebuilt air filter housing
New water pump bearings and seals
New gimbal bearing
Renew all electrical connections
New turbo to header tank vent hose.

I did a lot of the work myself, which was interesting but I am none the less looking forward to using the boat again rather than just working on it, and hopefully I will have a break before further major surgery is needed.

Finally thanks to those that gave encouragement through this thread and PM's.

 

[tinkicker0]

After discussions with mechanic, root cause believed to be bad injector allowing too much fuel into cylinder which washed the oil off the liner walls leading to greater friction, heat and eventually seizure.

Absolutely agree with fuel wash. Although bad atomisation, not too much fuel.

 

[rbcoomer]

Good result & thanks for the update - I was looking at this a couple of weeks back and was tempted to ask if there was any update! Awaiting the first trip report now :encouragement:

 

[KevB]

Well done.

 

[Sunseekerinspain]

Unfortunately I am now looking at a similar rebuild on one of my ad41's. Just wondered how much it cost you to do this? Here in Spain most mechanics will tell youit's easier to find another engine. Mainly due to them not having the time for such a large job.

 

[dpb]

PM Sent.