Morris Minor Owners Club

Photo of both sides of one of the pistons from the recent post regarding piston slap.

All the pistons are very much the same

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Hi Chris - I'd expect them to look a bit worse than that, (although I'm not saying that they are good)
One side will normally take more wear - the side that gets loaded on the firing stroke, which is clear to see on your pics.
However, the amount of wear hasn't removed the original slight chamfer at the bottom of the piston, so it would make me check measurements to see if the pistons were made sightly undersize (e.g. bottom of tolerance) relative to the bores.

The scoring in the pistons looks like many I've seen, and not what you want to see. This can have come from contamination, but more liklely from overheating (close to seizing temp) where the piston starts to pick up on the bore. I'd certainly recommend to check the block water jacket is not silted/rusted up and that the radiator, pump and thermostat are ok.

I agree with Ray, they don't look too bad and I'm surprised they were slapping unless the piston to bore tolerance is wrong.

I've put worse looking pistons back with new rings and having run a fine file over them to remove any high spots.

I think they look terrible - BUT they could probably be salvaged if the ring grooves are ok. And yes - I think it has partially seized.

Well the engine was put back together last weekend, with new pistons & bearings etc. & runs beautifully quiet now.
I did not take any core plugs out, at that time I was not aware that this was a "good idea".
I can say that all the waterways I saw looked very clean..I've seen old engine blocks which were far, far worse.
Radiator, pump & thermostat are OK, Ray. Water flows well & I replaced the missing t/stat a while ago.

The opinion of the (very experienced) chap at Lancaster Engines was that the car had seriously overheated at some time...ignoring a loss of coolant would be an example.
That scenario fits with some others of neglect I have found & rectified .The previous owner was in no way a Morris enthusiast or even a person who believes that you have to do any more that put petrol in to make a car work.

The engine always had the noise, for which I now know the reason, since we bought it last July..it just got louder slowly...or so it seemed to me!
Wife thinks it's a lot of fuss & expense about nothing...I think the improvement is life changing.

Well, thanks to all for the comments, help & advice on this subject.

Chris

Wife thinks it's a lot of fuss & expense about nothing...I think the improvement is life changing.

Beauty is in the eye of the beholder.

As for the overheating with coolant loss - that could well be a major factor.

I've cooked one so hot that you'd never believe it would go again (foot flat to the floor, fast lane M1, completely unaware of a coolant leak right up until it died) - but it started and ran after cooling down, albeit a bit more "rattly/graunchy". The noise is hard to describe but to anyone with mechanical sympathy it's the equivalent of tooth ache.