still burning oil

[vixentd]

Had a friend rebuild a motor of his.

1. The first motor immediatley started blowin blue smoke. Drove it for a couple of hours to see if the rings would seal, or there was another problem. Oil was actually dripping out of the tailpipe.

2. That motor was pulled and torn apart and another friend said the cylinders were egg shaped. We found another block in excellent shape and installed new bearings and rings. He checked the head and after pouring gas in when it was upside down said that one or two cylinders did hold the gas for long, but we didn't have another head so thought we would try and install and see what would happen. Reinstalled and with the new bottom end, still smoked.

That only leaves the head as the culprit.
1. It does not smoke a a constant speed
2. It starts immediately.
3. Going down hill now the motor does not hold the car back, ( Compression related?)
4. Under acceleration blue smoke clouds and oil spitting out the exhaust.
5. No blow by, or oil in the air cleaner.

Would poor valve guides cause this. THis head apparently had new valve seals installed and new exhaust valves. I didnt think a head could cause it to smoke so much blue. Oil is dripping out of the exhaust manifold flange joint where the c type clamps are, so I know it is not oil still in the exhaust from the first motor.

Any thoughts would be appreciated. Getting good at pulling motors now!!

This is a 1.6 hydraulic non turbo motor.

[rwest1]

“That only leaves the head as the culprit. “If I read it right the second motor has same head as first so that would be my first thought also. Since the intake is open to atmosphere these engines don’t draw much vacuum, to pull oil through the guides like most gassers. But if you look at the casting, each cylinders valve pair sets in a depression that holds oil around top of guide/seal. So bad seals and or guides can let in oil. Seals can be checked for problems, and replaced w/motor in car and head on block with right tools. Since you didn’t say how block was prepped for pistons (ridge reamed, honing, final clearance, etc.) I would also opt for a leak down test to see if you have a problem in that area. You could also un-bolt, and push back exhaust manifold from block and see which cylinder(s) is your gusher. Regards

[dieselweasel]

You say that there's no blowby. There'd likely be significant blowby if the rings or valve guides weren't sealing. My thought is that maybe the crankcase breather is plugged or kinked. That would cause oil burning for sure. You could take the oil fill cap off and drive it around to check out that possibility.

[A1-2-A3]

So the head you have on your rebuilt motor is pressure checked new guides, valves, seals? If not then your guides are probably shot. you can put new seals on all you want but if the guides are done it will burn oil. My car used to spit oil out the exhuast when it was worn out, some checking and I found that it was way too far advanced. Check things and compare your specs to the book and repair as nessacary. Putting a motor together three or four times to save a dime really sucks, in the end it costs more money and wastes your time.