Motor rebuilt less than 8000 miles ago, burning 2qts oil per 3000 miles. Besides the valve stem guide ? or rings upside down, any suggestions? A few thousand miles ago, I checked the plugs and they weren't fouled, looked like normal wear. Can't take the engine back to the builder, he's a complete idiot, heard that one before?? I appreciate all reply's - thanks!

oil rings work either way and if the compression rings were upside down, you would be getting massive amounts of blow-by. matter of fact, it would probably blow the dipstick out every time you revved it up.
it could be valve seals
it could be cylinder glazed
if it has been doing it since you got it back from the builder, it could be the oil rings are not aligned opposite from each other.
how bad does it smoke?
are you sure it ain't leaking?
what weight oil are ya using?
was it bored out?
if not what were the micrometer readings before the rebuild?

seems i always have more questions than answers
lol , Dallas

Gents, could this in any way be related to his overheating problem?

Per the builder "of course the cam was properly degreed" She doesn't smoke, no leakage, just a little bit of seepage, nothing major, no puddles or spots in the garage.10-40 oil, bored .30 over, don't know the micrometer readings before the rebuild. Also, she's kinda sluggish, I would expect more. Any suggestions?

What kind of rear main seal did your "builder" install? And is your PCV hooked up with a properly working PCV valve?

Don't know what kind of rear main seal was installed. I removed the PCV, and installed a push in chrome breather type - you're talking on the valve cover, right?

Someone with a '67 correct me if it's different, but on my '69, the valve cover grommet is for the air cleaner breather tube. The PCV valve is in the valley pan.

the hose connects to a 90 degree fitting in the intake in front of the carb.

Valley Pan on the '68s.

-Jake

The reason I asked is becasue the B-O-P Engineering rear main seal will let oil run out the back of the motor if there's any pressure inside the crank case. The seal is designed to work with higher pressure on the outside of the motor.

You might expect a leaky rear main seal to leave quite a puddle under the car. However, this leak isn't constant. It only leaks when the motor is being driven hard. (Not what you'd usually do in your driveway or garage.) See if you can look up inside the bellhousing for evidence of oil spray from the rear main seal.

I once had a pcv that was connected to a vacuum hose that was too long and the kinked hose caused the oil loss you described. Check the simple things first.

Vic

Just bought a car with the PVC unhooked and it left a substancial puddle every time I parked it in the garage even if I didn't beat on it. It would be hard to ignore. Also, it smoked every time I nailed the excellerator. Your problem seems to be more internal. Is this a Chevy engine? They have the PVC in the valve cover. Makes a difference because Chevy doesn't have the rear main problem as much. More than likely valve guides. Many builders do a poor job on the heads. You probably have at least one guide/seal that is really bad, fouled the plug and doesn't even combust the oil anymore so no smoke. I would give it a compression check. If it has good compression focus on the valve guides and seals. A close look at the plugs will narrow down the problem. You said your plugs were not fouled but the oil has to either go past the plugs or on the floor.
Jim

One thing to consider is that a quart every 1.5k isn't huge oil consumption, and with that consumption rate, the plugs won't be fouled. Let's take rear screw into factor: A thousand miles with a 5:13 screw, cannot be compared to a thousand miles with a 2:56 screw.

Also, if there is an overheating problem, that would cause higher oil consumption.