Not a bit of wonder that the poor thing wouldn't run...

Are there any bits of steel embedded in the aluminium piston ?

Maybe someone dropped a screw or something down the inlet manifold but that would knacker the turbo as well

On that note, have you inspected the turbo? It's best to get all the bad news out in one go. Suppose you've also got to get the valves out to check the seats.

Thanks for the photos, keep us posted

I will be going against good practice and buying a single new piston kit and getting the head skimmed, valves seats etc. Really I should just start again. I will check the other bearings on each con-rod and replace all the gaskets. Only thing bothering me is the timing chain looks very very new. I might risk re-using it..

Yes there are many pieces of ferrous metal imbedded in the piston crown and head face, sorry the picture should show that but I had to compress the image.
I am yet to inspect the turbo. Inlet side looked fine and the turbo is not seized.

afroking said:

I will be going against good practice and buying a single new piston kit and getting the head skimmed, valves seats etc. Really I should just start again. I will check the other bearings on each con-rod and replace all the gaskets. Only thing bothering me is the timing chain looks very very new. I might risk re-using it..

Click to expand...

:yeahthat:

Given the obvious amount of shrapnel embedded in the piston crown, I'd wholeheartedly agree the engine should be scrapped - it's the mechanical equivalent of a cat A writeoff.

You have absolutely no idea of how much other debris got into the oil & circulated round the rest of the engine. Who knows what might be lurking in an oil gallery somewhere deep inside, ready to dislodge & shred the bearings after it's been rebuilt?

Sorry, but I don't think this one's worth the candle.

As the bore is OK then there should be no contamination below the piston, it's obviously a bit risky to repair but then again it may well be worth the chance.

My concern would be what caused it in the first place.
Agatha Christie Plot?
How did the steel bit get into the combustion chamber ?
Through the inlet valve, or the exhaust valve, or the injection port, or the glowplug hole.
If it was through the inlet valve how did it get through the turbo without damaging the blades, or is the debris from between the turbo and the valve seat, such as a valve guide.
Or was it already in the combustion chamber ?
Why didn't the other combustion chambers suffer the same affliction?
We'll just have to wait for the last chapter........

Seeing as you obviously have the know how and tools to remove and strip an engine, I would suggest carrying on with the repair work.
Great satisfaction at a job well done would count in my book as far better than junking it at this stage.
Life needs achievements!

It is probable, given no signs of damage to the other combustion chambers, that in an earlier life a glow plug broke up and was replaced with no thought to removing the bits left behind.

Don't worry, I made up my mind when I stripped the engine; I was going to rebuild it.
I teach mechanics and engineering at a local technical college so will be documenting the rebuild for my students. If it has a short life after reinstalling it will be win win because my students will have learnt from the exercise.
I know good practice as an engine builder, however, technically; if I purchased another used engine if would be 'good practice' to completely strip that engine to inspect for wear also.
I'm not into 'fitting' I like repair regardless of economical sense.
So far:
Piston kit £85
Timing chain kit £85
Head skim etc. £50+

~£230 +

afroking said:

Don't worry, I made up my mind when I stripped the engine; I was going to rebuild it.
I teach mechanics and engineering at a local technical college so will be documenting the rebuild for my students. If it has a short life after reinstalling it will be win win because my students will have learnt from the exercise.
I know good practice as an engine builder, however, technically; if I purchased another used engine if would be 'good practice' to completely strip that engine to inspect for wear also.
I'm not into 'fitting' I like repair regardless of economical sense.
So far:
Piston kit £85
Timing chain kit £85
Head skim etc. £50+

~£230 +

Click to expand...

Yup, sometimes you can learn more from doing things 'not by the the book'; certainly it helps you appreciate just what you can, and can not, get away with when departing from 'ideal practice'.

It certainly helps when restoring classics, when it may simply not be possible or economic to obtain the parts you need to do things 'by the book'.

The only thing I'd frown on is folks bodging stuff like this back together in the back of an old shed to sell on to some unsuspecting punter - but your intentions are clearly light years away from doing such a thing .

Oh, and remember also to add the cost of a gasket set to your budget.

If that's a big end shell in the picture it's looks worn to me and with bad wear there the turbo will be prob be shot as well,

I will be taking precise measurements and use plastigauge to check all bearings.
I will also check the crank for ovality of the journals.

Just a quick update, been incredibly busy but have somehow managed to fit in this rebuild.

I have replaced the piston, all engine gaskets, timing chain kit, all engine bearings, deglazed the cylinders, replaced the head with a rebuilt head, assembled using engine building paste, not to mention the copious amount of accurate measurements around the engine to insure it is within tolerance.
It has all gone together really nicely, even the gearbox slotted in beautifully.

I struggled applying 230NM of torque to the lower crank pulley bolt, but got there in the end.

As it stands now, the engine is mounted in position and just needs final plumbing in.

That's a lot of work! Hope the end result is worth it.

Knock out the Egr valve while you can still get to it!

What do you mean when you say knock out? Blank it? won't this bring up engine management?

Yes it possibly will, but a little light on the dash display is no big deal.
Seems to vary from one installation to the next.
Mine turned the light on - I knocked it off. It came on again - I knocked it off again. Did this a few times and it stayed off.

If it's an old model fit a blanking plate ... no problem. Well done for having a go

Well, I've bought a restrictor plate as dashboard lights stress me out.

Thanks for the vote of confidence, will post a running video in a couple of days.

Oh and forgot to mention to the skeptics; I cleaned out every single oil channel, what did I find? Nothing.

I had to order a new dipstick because the end had been snapped off, putting two and two together, was it was this that was dropped into cylinder 1.

anything that gets on top of a piston comes through the valves so would look closely at turbo / heater plugs

I have checked the turbo and heater plugs, other than number 1 being bent, all is fine.

I'm suggesting something was purposely dropped into the cylinder, through either the glow plug channel, or the injector channel.

Why would it only affect one cylinder if it had passed through the turbo?