283 leaky after highway run (long)

[xaircav]

Originally Posted by xaircav

The '62 283 in my '53 3100 will drip a few drops of oil after a run around town but after an extended highway run (75-80 MPH at 2500 RPM) it will leave a puddle about 4" in diameter. The engine has 8000 miles since the rebuild and has always done this. I run a PCV from the road draft tube hole to the carb and an intake with a fill tube and breather. The factory vapor can in the lifter valley is in place. My theory is that at highway speed when vacuum is low pressure builds in the crankcase and pushes oil out the rear main seal. I've ordered a road draft tube and mounting kit and will report the results. I'll bet the pic is upside down.

I installed the road draft tube and removed the PCV and the oil drips are greatly diminished after an extended hi way run. I think my theory in the original post was correct. At idle I see just a wisp of blow by coming out of the tube and ventilated oil fill cap. Will one of the more computer literate flip my pic over please?