Smoking engine

[Ian Williams]

I have encountered this on other rebuilt but smoking engines, can you tell us where the rings were sourced and what is the current gap.

[Peter Naulls]

Very interesting post Adrian.

I notice the "missed" section coincides with the solid part of each ring, is this also the case with the missed sections further round?

Peter.

[Bob Culver]

I was assuming the low spots were mostly opposite the gap. 
But it is as if the rings have been gapped down from some major oversize? 
A quick check of new rings with a light behind is always prudent.
I dunno exactly how rings are made. I understand they finish turned before gap created so some degree of the effect shown (or the opposite) would seem inevitable.

[Ruairidh Dunford]

I am interested to know what the effect on this type of ring would be if the gap was too small or too large - the picture suggests, to my mind, that the ring has opened up beyond circular and the section opposite the gap is not making contact with the bore?

[Colin Reed]

I am interested to know what the effect on this type of ring would be if the gap was too small or too large - the picture suggests, to my mind, that the ring has opened up beyond circular and the section opposite the gap is not making contact with the bore?

If the rings have opened up beyond the circular it would suggest that they are for a smaller bore size, are the compression rings showing the same markings ?

[Adrian Payne]

Hello all
The rings came from The Seven Workshop.The ones shown appeared to be made of black cast iron.They were gapped to 6thou. The rings needed either none of very little removed to correct the gap. The gap now is around 10thou indicating some bedding in has occurred. The other areas of missed wear are also in line with the website. The compression rings have bedded better but still show signs of a slightly triangular wear pattern, 3 high points. Wished I had thought of shining a light from below. The new rings are totally different. They are silver colour and machined on all faces with the two oil control rings of different construction. The bores are all round and still show some crosshatch pattern. I would like to state this is not a supplier complaint. I am only too happy to have the level of spares that our cherished supply us all with.
Adrian.

[Ruairidh Dunford]

Good luck with the new rings Adrian - I am confident that it will all be sorted from what you say.

Do make sure the bores are properly glaze-busted or you will have it all apart again very soon. If you do the torch test, as suggested, I think you will need to do each ring individually.

[Ian Williams]

I am interested to know what the effect on this type of ring would be if the gap was too small or too large - the picture suggests, to my mind, that the ring has opened up beyond circular and the section opposite the gap is not making contact with the bore?

If the rings have opened up beyond the circular it would suggest that they are for a smaller bore size, are the compression rings showing the same markings ?

Colin this was exactly why I asked what gap, I believe that at least one of the engines I have encountered was fitted with the wrong size rings and that one had a large gap. Others were less conclusive so it is possible there was a bad batch of rings in circulation or they were over stretched when fitted.

[Pete H]

Hi
Just found this thread and I find myself in a similar situation.

I have just "refreshed " my engine. It was a mechanically noisy. On strip down the little ends were shot. Its a pressure fed crank with R4 pistons and rods. Through this forum, thanks. I acquired a new set of pistons and rings. Bores showed little wear so were glaze busted. The engineering firm that did the work felt the valve guides were Ok so re cut and lapped existing valves. New set of big end shells and back together. On start up its still mechanically noisy, Its done about 5 miles, noise is too much and its puffing blue smoke although it also has a compression test at 110psi. I decided to take the engine out and strip it , however having taken off the manifolds. I have found the inlet ports are very wet with very black engine oil. Sump oil is still fairly clean Straight SAE 30 running in oil. Any ideas how the oil is getting in to the inlet ports.

---

Sorry forgot to add, Tappet chest looked if anything a little dry.

[Adrian Payne]

Hello Everyone
Many thanks for all your advise. The engine is back together and there appears to be a great improvement already. Previously the oil would turn black in very few miles, now after 50 miles the oil is the same colour as when it went in and no smoke is seen by a following car. Oil consumption will yet to be seen.
I can only conclude that the particular batch of +60 rings were not quite circular and everything else was done correctly.
It is plausible that given enough time the rings may have eventually bedded in.
Adrian.