I have a friend of mine who collects microcars. A couple of years ago he owned a Niki 650 (Fiat 126) which he was going to restore but eventually sold. Last week he discovered a box of 650 engine parts that came with the car in his shed, and knowing my interest in Fiat 500s, he kindly gave them to me. All of the parts were from the same engine, and this poor little motor must have had a hell of a life.

I'm no forensic mechanic, but this is what I found -

At some time in the past someone has dropped a screw into one of the combustion chambers and left it there. The engine has been run with the screw embedding itself repeatedly in the soft alloy roof of the combustion chamber. After cleaning off a lot of carbon, the imprint is so clear that you can measure the pitch of the thread and the length of the screw.

On the same cylinder, the head is cracked near the exhaust and the exhaust valve on that side badly burnt. Maybe the valve was being held open by a screw fragment and cooked itself whilst the engine backfired repeatedly.

Both inlet valves are badly pitted most likely a result of running the engine in a dusty atmosphere without an air filter.

One of the bigend bearing is heavily scored, as is the crank on that side. I guess a piece of that screw fell down there and jammed in the copper/lead babbitt.

The other bigend bearing is heavily pitted. Maybe the oil was full of particulate matter.

The oil pump and oil pickup, as well as the inside of the crankcase, were covered in thick, black muck. The centrifugal oil filter was gummed up with the same stuff. The oil was probably never changed.

Many of the sump screws had been overtightened and stripped the threads in the soft alloy crankcase.

Both piston crowns were thick with carbon and both bores heavily scuffed on one side.

The carby bowl was full of varnish and rust.

This engine had suffered a lot and the remaining parts are completely useless, unless you are looking for a unique boat anchor. None of this is my mates fault - he gave me the parts in good faith, obviously never having inspected them himself.

These motors are tough, resilient and built to work hard. A change of oil, a new air filter and a check on the tappets now and then is usually all it takes to keep them healthy. If there is a moral to this tale of woe, I guess it is that an ounce of prevention is worth ... You know the rest.

I've attached a couple of photos.

Tread your own path,
Chris

A tale of woe indeed. What a waste.

I guess the screw was probably dropped down a spark plug hole?

We had a 126 years ago, and once when I was doing some routine maintenance, oil top up and new points, I managed to drop the screw that secures the condenser to the outside of the distributor stright down the oil dip stick hole.

Now, if I had *wanted* to do that, I'll bet a million bucks it would have been impossible.

I cannot repeat my comments at that time on a family forum!

However it was simply a case of dropping the sump pan off and fishing out said offending screw!

Lesson learned however, and something I will hopefully never repeat!

oopsadaisy said:

I cannot repeat my comments at that time on a family forum!

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£$*? *?!#£*! £*$*?#* perhaps?

Euro Mike said:

£$*? *?!#£*! £*$*?#* perhaps?

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Probably something like that!

It was a bitingly cold January day and the car was parked in the street outside our house, so being unable to start the engine, I did the whole thing there and then!

So, no actual € $ or £ involved, (apart from a new oil pan gasket) but made up for it in discomfort and grazed hands!

oopsadaisy said:

So, no actual € $ or £ involved, (apart from a new oil pan gasket) but made up for it in discomfort and grazed hands!

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At least you got it out.

I've attached a couple of photos of my mates microcar collection.

Chris

Fantastic - and they look to be in superb condition.

The engine photos reminded me of one 500 we had (in the early 1970's)where a ring had broken through its housing on the piston. I guess it had broken before finally breaking through the skirt whereupon it made a machine gun noise as the broken ring was battered between pison and head until we switched off the engine. On stripping down the(top half of the) engine the other cylinder was fine but the fragments of piston ring had become embedded in the head of cylinder one. Funds were low so we bought just one new piston and a set of rings. After removing the embedded pieces, re-assembly was carried out using a ring compressor made from a bean can and wire. The whole thing went back fine. No time to skim the head but a generous coating of Hepolite gasket seal and a new gasket worked fine. These engines are pretty robust in many ways but a heavy handed spannerman who rips threads like Bambinos pal obviously test them just a bit too far.

Bambino, what part of Oz are you from? I'm originally from WA but I've lived in the UK for 4 years now.

I live on the Sunshine Coast, north of Brisbane in Queensland, though the name is a bit of a misnomer at present as it's been raining solidly for about a fortnight ...

Chris

Bambino said:

I live on the Sunshine Coast, north of Brisbane in Queensland, though the name is a bit of a misnomer at present as it's been raining solidly for about a fortnight ...

Chris

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Ah

My parents live in Perth still, my dad has a nicely restored 500f in the back shed which never turns a wheel. Pity!!!!