Technical Oil loss, where?

One of my clients has a 34 Packard 1101, an engine I'm quite familiar with. It's whisper quiet, no rattles or knocks, passes a compression and leak down with flying colors, the worst of the leak numbers being 8% on no 5 (or 6, don't 100% recall). Compression is also down about 3-4 PSI in that one cylinder, but with 95 on the rest I see no reason for concern. IT DOESN'T SMOKE A LICK, idle, load, cold, hot, never. Starts so nice and quick you can't hardly believe it. The problem, it went through 4 qts of oil in just under 400mi. Yes, 4 qts. He and I are both in WTF mode because while it does have a couple minor leaks, 4 qts would look like automatic rust proofing under the car (as in oil everywhere, it's not). I'm stumped which is a weird place for me regarding an 1101 engine. I had initially suspected the oil cooler gig but there's no oil in the coolant or vice verse. I'd hate to tear it down to bare and back exploring the issue so I'm asking for a bit of feedback. Thanks in advance.

 

WTF is an understatement. What is the capacity? 5-6 quarts I'm guessing. Was it checked again after the initial finding? Thinking a drain back to the pan issue.

 

I once had a BBC engine that would go thru 2 qts of oil in 160 miles and never visibly smoked. At least from the drivers seat.. Perfect compression readings. Turned out to be a broken oil ring expander that allowed the scraper rail to collapse into the piston ring groove.

 

My 388 sbc did exactly as you describe , 2nd ring upside down....

 

in an article i read about piston rings, the author gave an example for oil use. he wrote: if one, eight hundred of a drop of oil leaked past the rings per stroke, the engine in question, in an average car, would use a quart of oil every thousand miles.
it must be burning it.

 

Have a look inside w/a boroscope , if the perimeter of the piston crown is shiney clean , that's a sign there's oil coming up past the rings...

 

Just to add, I've watched it and followed behind it, as have several others. No smoke, not a trace. I also didn't build this from scratch and we don't have any background as to how it was prior to his getting it. Did the tests to decide condition, went ahead with proper year of manufacture parts like head, oil cooler, water jacket, manifolds, etc. No manifold leaks either. And the capacity 8 qts + the filter (!), all the drains are wide open. These additions to the 'story' should explain my being stumped for now.

quick edit; when the head was off the pistons looked essentially dry and carboned up across the crown. This isn't to say things developed in use. He has put a few thousand miles on it.

 

That much oil the plugs should be oily no?

Will oil travel down loose exhaust guides and not burn in the chamber?

 

Try running at night with lights into the exhaust stream, that will show smoke that's not visible to the naked eye during the day. My bike only smokes at night

Sorry I'm not familiar with the set up- Does it have a road raft tube?

 

you said he has put a few thousand on it...
the oil is being vaporized / mixed so perfectly with the fuel

past the rings


it just is GONE.. i have a modern 4cyl that does the exact same thing
probable LESS than a drop (1/2-1/4th of a drop) on EACH stroke...
put oil in it CONSTANTLY..

plugs white clean , no noticeable fumes (ever)

 

just the micron of oil so FAST -n- poof its gone

 

Maybe that's it, because the plugs are never more than gas fouled. They're never perfect but always dry. It does run rich for the 1st 2 min, any less choke and it's pretty miserable. I'm pretty familiar with oil burning plugs and that's not us so far. I don't want to think rings, but then you never know. He says it runs so good he's almost willing to let it eat the oil but that's not right. Hoping I get a light turned on in my brain from this topic.

Safari-wagon would tell you no chance, been unplugged too long. There! Beat you to it...

 

Y a i hear ya...you'll ger er figgered out i have faith in your ability brother

 

What kind of oil are you using? If it's one of the newer formulations it might be so thin when it gets hot that it just burns away. I'd try a different brand and weight of oil, maybe even a quart of Lucas in it. I figure the clearances are probably larger than what is in use now, so a thin oil would slip right on through.

 

We thought of that too. He switched to Amsoil straight 50W race oil but it used that up too. Not as bad but at $7.00 a qt... Now he's running Rotella, 15-40 I think.

 

How about the fuel pump diaphragm? A bad one can suck oil from the crank case and burn it.

 

Has the intake been milled or the heads milled ? Proper intake gasket ? Sometimes a mis match in this area will suck oil .

 

I like this thought, it's a dual diaphragm unit too. We didn't bother with it becuase it pumped proper volume.

 

Thanks, but not in this case. However you got me thinking that a pic or 2 might be a welcome addition so...
Here's the job near the begining, 34 1101 Conv Victoria, wrong head, manifolds, no oil cooler, etc:

All back to 34 spec with proper parts, fresh milled head, oil cooler, proper water jacket and more:

Back where it belongs:

And here she is with everything done, a new top and other minor upgrades. It's back for the body and interior, but since I'll have for some time I'd like to sort this oil issue:


We might just borrow a GoPro and stick it under the hood, go for a nice ride and see what we can see. But I still can't fathom a leak of that proportion and not seeing it everywhere on the chassis. Even though it does have a couple minor leaks nothing of that magnitude, maybe...

 

That´s a beautiful car!
I had a 31 Model A with a B -banger my Dad drove for a while , and one day he called me, because a guy that was driving behind him had honked at him and waved him down to tell him, he was loosing oil. A lot of oil. So he asked me to pick him up, he was afraid to ruin the engine.When I got there, my first thought was, he might have lost the oil drain plug in the pan, I could clearly see where he had been driving, I just had to follow his trace to find him.
Guess what, my Dad had checked the oil level and put the breather on the head and lost it somewhere on the way to the car show. At the show he was showing off the almighty B -banger and noticed the breather was missing. Being that MacGyver type of guy that he is, he did some trash can diving and found a napkin and some kind of plastic cap that he used to plug the oil fill/ breather hole. Even 5:1 cr was creating enough blowby to force a lot of oil out of the rear main seal into the bellhousing , where is just drained to the ground.No clutch slippage, no messy chassis.
I´m not saying that´s your problem, just an experience how to get rid of lots of oil whithout taking any notice...if he had not been honked down we may have thought we have a bad engine.

 

Any fuel smell in the oil, does it look thinned out when changed? You could have the oil tested to see if it has abnormal traces of fuel in it.

 

Try heavier weight oil. And make sure its flat tappet comparable. Brad-penn is great

 

Thanks for the pics. You do some incredible work. Those big cars are really something.

 

If you took a quart of oil and spread it out evenly for the same hundred miles it would would be a pretty narrow line. Using that much oil will not really make a smokey exhaust.

 

I own a shop that repairs OT European cars. Audi had real problem with massive oil consumption in their 4 cylinder turbo 2.0 engines. Like 4 quarts in 1000 or less miles. Turns out the pistons were manufactured a little out of tolerance.
Installation of new pistons totally fixed the issue.
These cars never smoked or leaked either, but they sure used buckets of oil.
Just food for thought...

 

and we ALL know rings roll/rotate --- that's why we install them away from each other 180*'s etc etc etc
so some may have aligned themselves up in the initial (NEW stages of breakin...?) and NOW are stuck,
in a (NOT HAPPY PLACE) just throwing that out there...It's never happened to me, but that doesn't mean it couldn't happen.

 

The first thing I would do is pull the spark plugs and use a boescope to look very closely at the tops of the pistons as said earlier, and as was said pay particular attention aound the edges next to cylinder wall. I agree with you that there should be a lot of oil showing on the bottom of chassis and undercar components if it's leaking. But that car is way up in the air and it just may be falling to the road before it gets on anything under the car.
My God, that's a beautiful machine!

 

Watching this thread. I've got a flathead Ford that uses a quart every gas tank full. Was a fresh rebuild, and then we also re-ringed it. No fix.

 

Sounds like you checked for intake vacuum leaks. One of the cable shows (one I hate.... the Guild) had a 62 vette swallowing lots of oil. Turned out to be an intake gasket not compressing equally due to mismatched angle on the head and intake.
Is that black oval tube on the left hand side a crank breather? Does it vent to the intake? Could it be missing a baffle. Or is the road draft tube blocked and pressurizing the motor?

 

Valve guides / valve seals?