Engine trouble with Barney a jpoc motoring story.

A short while after I bought the car, I changed the air filter. While doing this, I spotted that the filter assembly was held onto the carb by only three studs. There should have been four. Of course, the car was ten years old and it was not in the best of shape and various screws and bolts were missing all over so I thought little of it. Then, one night on the way home, I found the missing stud. It had lain in the bottom of the carb for some time before making its way through the inlet manifold and into number two cylinder. It rattled around inside for a while but then tried to escape through the exhaust valve.

Now, it is normal that, in a four stroke engine with two valves per cylinder, the inlet valve and port are bigger then those on the exhaust. So it was that the stud could not find its way out through the exhaust. No doubt, if it had, all would have been well and I'd have been none the wiser. Sadly, the stud lodged under the open exhaust valve and the piston struck the valve on the upstroke.

This chipped the valve, made a nasty dent in the piston and cracked the cylinder head. I set out to fix this myself. I suppose that the quick fix would have been to remove the stud from the valve, put it all back together again and quickly sell the car. The sensible fix would have been to buy a new head and valve and then put things back together again and hope that the damaged piston would function OK.

My good idea was to replace the piston as well! All this was done on the street outside my house in Cambridge. I'd taken the head off without any problems and pretty soon I had a new head, valve and piston. How to exchange the piston without an engine hoist though?

Well, my book said that you could do this by lowering the cross member and removing the sump so I tried to do that. I put a piece of timber across the strut tops and roped the engine mounts to this. Then, I undid the mounts and jacked up the front and put stands under the main chassis rails. Finally, I removed the bolts on the sump and the crossmember and lowered the latter from the chassis but keeping the front suspension still attached.

I discovered that, unless I actually dismantled the suspension, I could not lower the crossmember enough to get the sump out. So, I compromised. I raised the engine a little by placing paperback books under the timber crosspiece. It would only go up a little way because the bellhousing hit the bulkhead but it was enough. I could move the sump far enough out of the way to get at the relevant big end bolts and soon I had the piston out on the side of the road.

Now the easy bit. You know, that part where the manual says that reassembly is the reverse of assembly. Try that in the rain when it's getting dark and you have never done much more than change a spark plug before. Well, just as my copies of Galaxy and Analog still bear the marks of the two by two, my bedside lamp still has the oil stains from over twenty years ago.

The hardest part was getting the seal at the front of the sump to stay in place while I lined it up. But, at last, all was back together and I prepared to start the engine. Now, I had read a useful tip about putting a teaspoonful of engine oil into each cylinder prior to starting a newly built engine. Either that this is rubbish or I used too much oil but, even with a fresh battery, I could not get the engine to turn.

My friend Quentin came to the rescue. He lived next door but one and was just starting a courier service in Cambridge. He roped Barney to the back of his big blue Transit van and off we went. I kept dropping the clutch and finally, the engine fired and ran of its own accord! Gosh, the smoke. I guess it was all that oil in the combustion chambers but we were making smoke like the Red Arrows and everyone in the street opened their curtains to look!

If you are thinking that this all sounds like a happy ending, you are worng. That was the last time that the engine ran. There was an awful knocking noise. I had replaced the piston with a standard sized one. I was not aware that the engine had been rebored and needed an oversized piston. The undersized piston soon managed to break a ring and score the cylinder bore. So, in the end, Barney went up to my then brother in law and ace mechanic Michael Browne. It took him just a little while to fix things up with a rebore and four new pistons but the engine that he put together lasted for the rest of the life of the car. It never broke despite being regularly redlined and more by yours truely!

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