[Mgs] Excessive Oil Consumption

Joel Martin jmartiniii at yahoo.com
Fri Jun 9 07:06:01 MDT 2017

I rebuilt my 1973 engine last year.  Every thing all new except pistons .030 (AE) but installed new Hastings rings.  Valve job, cam etc.  I have had excessive oil consumption ever since.  Breakin oil used for first 500 miles with no more than 1/2 throttle during those first 500 miles and constantly up and down through RPM's up to 3500, back down then up again.  With over 250,000 miles on car and now 4th engine rebuild, this breakin procedure has worked fine, at least until now.

Assuming valve seals and piston rings are good ( I do not want to remove  engine to investigate at this point), lets approach from possible crankcase blow by.
The emission pump and hardware has been removed since 1974 when the car came out of warranty, original owner.
All new hoses, new oil cap etc.  The charcoal canister is still in place and was renewed about 4 years ago with new charcoal and filters.  Gas tank venting still in place and functioning with no gas smell in trunk and lines clear.
I do not have gulp valve or PCV any longer and no oil separator on the crankcase breather tube.  The crankcase breather tube comes up with hose then y connector and splits into hoses running to the carburetor.  The gulp valve is the only thing removed this last rebuild and the PCV valve has been gone since 1974.  I have no run on after key turned off and no popping in exhaust.

The one thing I have noticed is the front carburetor has oil/grease residue on the dash pot (not oil from top of dash pot but oil residue) and even blowing back to the clutch and master cylinder.  

Pulled the plugs the other day and they are perfect.  No compression test done.  With electronic ignition and carbs rebuilt professionally this time, (IE: not by me) due to throttle bodies leaking, the car runs and idles fine with easy starting.

All hoses are tight and clear of obstruction.
I am currently thinking something to do with crankcase ventilation pulling oil past rings.    By the way, I cut off the crankcase breather hose in front of the 'y' connector and have installed a white filter assembly on the breather hose to take most of the system out of play to see  what that does but only have about 60 miles on car since, so nothing concrete as yet and taped up the hose assembly going to the carburetor and zip tied the hose and connector out of way.  Need about 140 mile run to determine if this has any effect on test.
Any and all thoughts about what to try would be greatly appreciated.
Thanks in advance.
Joel Martin

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