Help! Leaking tons of oil after ring job

[flapjack]

1.6td with 450,000 miles: my friend says he replaced the rings and machined the head. The head was warped from overheating.
I've got the car now. It spit out the dipstick every time I drove it.
It leaked a ton of oil. (quart per 100 miles)  I've replaced the oil pan gasket twice,  a valve cover gasket.
My friend is a machinist, so I trust him when he says he did the rings, flattened the head and checked the bores to be round.
He said maybe the rings are the wrong ones and theres blowby
The breather is clear
Neither of us knows the condition of the head. I took it to a local place for a leak down test and they said the head was ok.

Could my friend have made any mistakes that would cause blowby?
Would blowby even cause such an oil leak?
Incorrect rings? rings upside down?
Or am I just a retard that can't torque an oil pan correctly?
thanks

[Doug]

The bores need to be deglazed with a hone, preferably a brush type hone. Rings do have a locating mark to indicate top side specifying the installation orientation. Ring lands in the pistons have to be absolutely clean so that the rings will be free to move. Has your exhaust system got too much restriction as in a muffler that has collapsed internally? I have experienced less blowby after replacing guides and valves in a high mileage head. Why don't you vent the crankcase vent on top of the valve cover to atmosphere to see if that stops your leaking. I would tend to think that is where your problem is happening.

[flapjack]

thanks Doug

The exhaust ended at the rear axle  the cat looks pretty good

honing and ring lands:
I asked my buddy and he said he did all that, so for now, I'll trust he did it right

Regarding venting to the atmosphere: I've had the oil filler cap off and there was some pressure, a little smoke, I have no idea if it was normal or excessive. Should there be no pressure/smoke at all?

[Doug]

Pressure at the oil cap is normal. Are you sure that is a catalytic converter and not a resonator?? If it is a cat then it could very well be plugged at that mileage. There is a screen at the top of the valve cover under the crankcase vent. It is possible  to have condensate freeze here under cold conditions that will cause poor venting. Take your cover off and clean in solvent as well as change oil to get rid of condensation. Try running it open with a hose below the car somewhere relieving the pressure to see if the leaks stop.

[flapjack]

cool thanks I'll try that when the motor goes back in. if i finish the 3" exhaust and downpipe a la flapjack, I won't be using the cat
i feel more confident about putting the motor back now.