WHY DOES THIS ENGINE STILL BLUE SMOKE

Mickey - d
Thank you for your feed back . You mentioned the block breather might be pluged - would that be the same as the Blow by tube if so I did check it - I took the oil pan off and checked inside the block everything looks new - also the valve cover has slits on top and they are clear and the blow

by tube is clear
The engine only has 3,000 miles on it and it never did burn oil or smoke until I heard that backfire noise from the engine - the block has .040 bore - I took the pistons out and checked the chrome rings and cylinders they looked new but I installed new cast iron rings anyway
The rings have less than 200 miles on them now - the engine runs good but when it warms up it smokes and fouls all spark plugs and burns oil - 40 miles it will use 1/2 Qt. . No smoke comes out of the blow by tube or valve cover even with the oil fill cap removed
Could the oil filter return line be pluged? if so which line is it ? the one on top or the one the bottom of the filter ?
This is a tuff one any feed back would be very much appreicated - thanks mickey
Bob

If you have stp to instal rings the rings will never seat or Lucas oil. Hop this. Helps b w

I have a few ideas and your fast cold idle and very black oil are clues. Is the automatic choke opening fully? If not, you will run very rich under high vacuum and that can wash the cylinders with fuel. The high vacuum can pull oil past the valve seals. Since all plugs are fouling that suggests a common cause. For example, I would not expect all cylinders to fail if it were a ring problem. Perhaps 2 or 3 but certainly not all 6 --- unless the new pistons are missing the oil drain holes in the 3rd ring land. I have to believe that oil is somehow getting into the intake manifold or past the intake valves. It was common on these engines for the internal oil passages to the rockers to become clogged and a fix was to add a kit that tapped oil from the oil pressure fitting on the driver's side of the block and by a 3/16" line to the 1/8" NPT plug in the middle of the passenger's side of the head. If both the internal passages are open and an external kit is added, it's possible that the top of the head is filling with oil and that is getting pulled past the intake valve seals. In any event, I would remove the valve cover and run the engine; anything more than a trickle from all the rockers is too much. Make sure that any oil beneath the valve cover is able to easily drain through the head. There were cases when I had to restrict the oil flow by carefully squeezing the distribution pipe in the middle of the rockers.

If this were a Powerglide, I would immediately suspect a cracked modulator diaphram but clearly that is not the case. Another oddity I once encountered was a Marvel Mystery Oil distribution unit that attached to the intake. It was working far too well and that produced clouds of smoke but since you are burning engine oil that too does not fit. By far, the most likely cause of your problem is worn valve guides. I would not assume that just because the valves were ground that the guides were replaced or that the valve stems were not worn.

Your oil filter is a bypass unit and the bottom fitting should be connected to the crankcase drain. The top fitting tee's off where the oil pressure gauge line attaches to the engine. One 'gotcha' is that the return fitting that screws into the block must be restrictive with no more than about an 1/8" hole in it. If this is replaced by a standard fitting, too much oil is bypassed and the engines loses perhaps 10 psi pressure where it's actually needed in the engine regardless of what the gauge is telling you. I assume no one has added a PCV system to this engine. That could cause your problems if not done correctly. The only other off the wall idea that occurs to me is related. If you had a combination fuel/vacuum pump and if there were a hole if the vacuum diaphram, that could allow oil vapor/droplets to enter the intake.

Finally, are you certain that the engine (especially around the cylinders) is not overheating? If the cooling passages in the block were severely clogged/scaled, the cylinder temperatues could be very high while the passages in the head allow enough flow for the gauge to appear normal. High temperatures can cause oil consumption as well.
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It's difficult to tell from the pictures but I don't see much of a cross-hatch pattern on the cylinder walls. I think I see the traces of a ridge reamer at the top of the cylinder and I would not expect that from a recently bored block. If this was a rebuild of a block that had been previously bored to.040" oversize then it's possible the cylinders are worn but in any event, recently bored or not there should be a distinct cross-hatch pattern in the cylinder walls from a proper honing with this few miles since rebuild --- and I just don't see it. Again, that may be the resolution of the images. I also assume that the rings are not indexed so that the gaps align. The last thing that I can think of is overfilling with oil. Off the top of my head, these engines held 5 qts and your initial oil after a rebuild should be non-detergent to properly seat the rings before switching to your regular oil after 500 or so miles. I would not assume the dipstick is correct for your engine. Make sure that there is no gasoline smell in the oil.