oily bores

[steve davidson]

Following recent re-builds, both my engine & my Uncle's engine have had similar problems with oiling, both have improved now they have some miles under their belt, my Uncle's was worse than mine, but he will keep fiddling with the spark plugs to check and they are only hand-tight, which I am sure doesn't help, but he won't be told.

The piston ring gaps should all be staggered and they need to be correctly gapped, too wide and they will not be as effective as they should be, too tight and they could break. I would be inclined to put it all back together and give it some decent road use and see how it is after about 500 miles, mine is improving (although I have not had it out of the garage since before Christmas), let the new piston rings bed in and see how it goes.

I don't have oil baffles, lots of engines don't, in some ways, the extra oil up the bores could be regarded as a good thing, but if the rings are doing their job it should not make any difference.

Hi Gary,

Thanks for the rapid response.

I should have noted that prior to me pulling this piston out I had done around 400km since the rebuild with no appreciable improvement.  After 200km I droped in a can of that "stop oil smoke" stuff as I thought that might help things take up as the rings bedded in, but no change was evident.  I gapped all the rings to 0.007" and while the big red book tells us to arrange at 120 degrees I thought that must have been for the 3 ring versions.  I put mine with the compression ring gaps aligned with the crank centerline (one facing forward, the other back) and the oil ring gaps  perpendicalur to compression rings.

But like you said it might just need a few more miles.