Hi all,
I've got oil coming out of the road draft tube to the point that at 55 mph, if I go 15 miles, it will run a full quart out on the ground.
Recently freshened a 1955 272 out of a Country Sedan wagon. 46000 original miles. Distributor was frozen and clutch was in need of replacement.
The engine was completely disassembled and sonic cleaned, new rings, bearings, seals, etc. the crank was turned 10/10. The cylinders measured standard bore to 0.0035 oversize without taper so I honed the cylinders and used new cast rings.
Camshaft was reground.
New oil pump, timing chain, and non-loadamatic distributor installed.
The drain tube is completely clear. The new breather filter fits the mounting saddle and is slightly crushed by the lid when tightened down. The oil fill breather is original and free-flowing.
What am I missing?
The engine runs great. No smoke from the exhaust. No miss. I've got 20 minutes of run time with break-in oil and about 20 miles with conventional 10W30 on the car.
I did not do a cranking compression check yet but can and probably should.
Any ideas? Should I install the valley pan with road draft tube, plug the original hole like a T-Bird, and forget about it?
Thanks,
Nick in WI

'60 F100 with '62 4V 292 y-block

I wish I had a bright idea, but I don't. The only motor I ever had do that had the top missing out of a piston, and was smoking like a destroyer laying a smoke screen. I'm going to say both a compression test and a leak down test. If those show anywhere near normal, there's got to be either major pressure (from where I don't know) in the crankcase, or something wrong in the assembly of the road draft breather. Off hand, I'd think with that much oil loss from pressure, the oil fill tube would be puffing like a steam locomotive

Are you sure it's all going out the draft tube, or did I read something wrong? Is the drain back hole in the road draft assembly clear? Having only owned bird's, I'm not very familiar with the pass car version.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

The inside of the road draft tube rusts through to the down pipe frequently from condensation. To check remove the road draft tube from the engine and clean the area below the small tube that returns oil to the crankcase. This area is prone to rusting though the raised area and allowing oil to leak into the large down tube. This raised area is supposed to flow oil by the small bent tube back into the crankcase.
marv

Add this to what Marv has already brought up.  Assuming the blowby from the oil fill tube is minimal, check that the oil return (the crooked tube that goes back into the block hole) is clear.  If stopped up, the oil reservoir within the road draft housing can get too high and dump to the outside.  Also insure that the block mating surface on the road draft tube housing is straight and true as these get bent when the engines are being handled outside of the chassis.  Oil leaking on the outside of the tube can be easily misinterpreted as oil coming from the inside of the tube.

Lorena, Texas (South of Waco)