Been slow progress on this, due to holiday, bereavement, bad back, and numerous other unrelated things going wrong, but I've managed to move it forward a bit, now.
As you've seen from previous posts on this thread I removed all the pistons, and number three was broken. A thorough inspection shows the bores to be as good as new. I cleaned them up with some clutch cleaner, and all the cross-hatch hone marks literally look like they've come from the factory.
I decided to replace all three pistons, with new piston rings. The old ones had engrained dirt in the ring gaps etc, and to be honest, price wise, it wasn't that much more to buy a piston included with the rings, than just the rings themselves (£30 a pop with rings).
So here are the three new pistons, out of the box:
And here is one with the rings fitted (note, gaps not spaced yet)
You'll have noticed earlier on that I mentioned issues removing the
gudgeon pins, but I got there in the end with the aid of some heat and patience -
Here are the pistons and con-rods, with the little-ends fitted
You can see here, there appears to be a little (albeit not excessive) wear, to the big end shells:
So I decided to replace them all for brand new. Here is one of them:
I realised at this point I didn't have a ring compressor, so off to Halfords I trot. They had a Laser piston ring compressor which certainly looked ok, so I went for that. In hindsight, that was a mistake, but it got this job done.
At this point, I installed the number one piston. I followed the instructions in the tech data to the T, and upon advice of numerous video's I had watched, coated everything generously in oil.
Following the confident blow with the handle of my hammer, with everything lined up, it popped smoothly down into the bore with a nice satisfying little noise, leaving me with this:
Here is where the fun started.
Upon attempting the same with number two, I just felt that the compressor wasn't gripping the rings evenly. I couldn't see this, it was just a strange hunch that it was out of round.
I removed the compressor, double checked everything, and it all seemed ok, so went to fit number 2 in the same way as I did one.
This time, the piston didn't go straight into the bore. For some reason the middle compression ring didn't go in, and popped out, meaning the piston didn't go fully in.
I again removed everything, thankfully the rings were unharmed, so attempt number two, this time it went in, as did number three.
Here is the end result with the pistons fitted:
As you can see, the engine is at a safe position just prior to TDC, ready for head fitment.
With the new pistons fitted, and a light smear of oil in the bores, and assembly lube used on the new bearings, the engine turns over very smoothly indeed. There is a bit more resistance than there was before, but I put this down to the fact the bearings and rings are new. There's certainly no abnormal resistance.
Next job is to rebuild the cylinder head and have a big clean up of everything.
It's going slowly, but I'll get there in the end