Blowing oil

[steven wardlaw]

I hope the Gurus of the vintage VW engine on Samba may have a clue as to why my engine decided to purge about a pint oil out the oil filler vent pipe. Let's start with the basics of what happened.
This past Saturday morning on my trip to our local cars and coffee the little 62 Beetle coughed twice then let go with a white cloud of smoke. I was only 1.5 miles from home and driving about 45 mph. The motor was purring along with no warning of the smoke cloud that was about cover all the cars behind me.
I towed it back home and started the search of the problem, fearing a blown motor of some sort.
I checked the compression, valve clearance, and drained the oil to look at all the metal pieces that were sure to be in the oil.
I found nothing at all that should have caused the problem.
After the complete teardown of the engine, I still haven't found the issue.
This motor has only 2500 miles since total rebuild with NOS pistons, heads rods and crank. The oil was not over filled and the baffle plate under the generator stand was in correctly. This motor is a 1965 D block case. Please help if you can. Just waiting on the gaskets to start assembly and would hate to put it back together without finding something wrong.

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Oh shoot didn't see this post till now lol...Did you check the piston rings if they were good sounds like rings if you were driving and than smoke behind you burn oil = white smoke something was burning unless you were adding to much oil for the judson could be that too ....

[steven wardlaw]

Rings are all in great shape and within the specs on the end gaps. The oiler has always been set at a rate that was a little rich but that hasn't changed. The oil is coming from the crank case vent. I did crank the engine after I returned home with the vent hose and air filter system removed and the vent tube was blowing oil out into the engine bay. I thought I would find a major piston failure but found nothing.

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What oil filler do you have ??? Try a stock one that as the tube that goes down next to the dip stick ...

[tcoop1100]

The only thing I can think of would be blowby building a bunch of pressure in the crankcase. Did you check to see where the ring gaps were when you took it apart? Maybe some got lined up and allowed some massive combustion pressure into the case- and oil into the cylinders to cause the smoke.
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Aloha,
Tim
January '57 Sedan with April '64 40hp big bore

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[earthquake]

Could it have any thing to do with that Oberg Residual oil filter pumping oil in above the vent louvers?

eQ
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74 CLASS 11 LOOK-A-LIKE
69 DUNE BUGGY
79 INTERNATIONAL SCOUT II
05 SCION XB SERIES RELEASE 2[#437]
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Link to Kelly J. Nolte 3/20/53 - 11/6/08
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Wait isn't orberg filters suppose to be full flow or did they make 2 different styles??? 1..full flow 2.bypass ...I know the oberg fullflow has bypass built in to it to tell you the filter is clog ....but he has it set up like a by pass dumbing oil back in the case full flow you want the oil return in the oil galley..check to see if your oberg is a full flow or bypass filler but that still doesn't answer the question on it smoking but than again that's what can cause the engine to have pressure its not flowing right ?? Could be unless the oberg is Universal , fullflow or bypass use ...I've never used a oberg so I'm not really familiar with it but most of the folks I see use them they are set up for full flow ...I could be wrong but it's another question / idea to the problem 🤔

[steven wardlaw]

The Oberg filter is set up just as the canister filter that it replaced. The return line does go in above the baffle plate under the generator stand but the line to filter is restricted down to slow the flow of oil into the filter, so the engine isn't starved for oil. I never had a problem with the canister filter or after adding the Oberg. I had just finished a trip of about 80 miles after adding the Oberg without a problem. As far as the rings they have gaps still as new (.004-.005). I have a 356C Porsche oil filler canister on its way and will add that as I build the motor back up.

[Bub]

I will take a guess...since this happened to me on my 1386cc build.
I think that the oil stand baffle can randomly seal up inside the case and cause pressure to build up.
When initially installed my bypass canister filter setup I had the outlet ported to the base of the generator stand and even though there is very little flow out of the outlet, it would cause the stand to begin to overflow out the draft tube. I replumbed the canister filter outlet and re-bent and installed the baffle and haven't had the problem since.
That's the only explanation I can think of. It was really odd. There was barely a dribble of oil from the outlet, but when the engine was rev'd the oil stand would just start filling with oil quickly- it would fill way faster than the outlet flow could account for.
You don't have a 36hp block, but I can only assume it's the same basic idea...
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[steven wardlaw]

I listed the ring gaps at .004 but that was actually the gap between the rings and the piston grooves. The end gaps are between .014 and .016.
I now have a new gasket set and will start the rebuild tomorrow and will do a compression test just to see how it looks before complete assembly.

[tcoop1100]

Is that .004 for compression ring groove gaps? Should be .0015 to .002 for a stock motor. I admittedly know little about supercharger setup, though- is a side gap that big usual for those?
_________________
Aloha,
Tim
January '57 Sedan with April '64 40hp big bore

[steven wardlaw]

Just had to go back to the shop to check the ring clearance in the piston ring groove. The compression top ring was at .003 and the oil ring was .0015-.002.
Hard to check the gap with such a thin feeler gage but I doubt it makes much difference. Just hope when I build the motor tomorrow Everything goes back without a hitch.

[tcoop1100]

You may want to double check the spec for that- for the NA 1385 I'm putting together the compression rings are at .0015 in the grooves and the oil rings are at .004. That's physical measurement on new parts. Maybe you got the measurements backwards?
_________________
Aloha,
Tim
January '57 Sedan with April '64 40hp big bore

[Bub]

I'm about 99% sure this is just a case venting problem you had.

If the oil from your filter outlet pools on top of the baffle, even just a little, at speed the case can't vent and that oil will fairly quickly fill up the generator stand and overflow.
From my experience it took some time for it to happen just revving the engine in the driveway but it didn't take long going down the road. Something to do with the load on the engine I assume.
Some extra venting or re-routing that outlet would likely fix it. I didn't want to tear the engine down so I just bought a hollow 8x1.5 stud and reamed the inner bore as large as I could. Then re-threaded one end of a brass adapter so it was 8x1.25 on one end and 3/8 npt on the other for the hose. That fixed it.

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[steven wardlaw]

Got the motor back together today and took it for a drive with no issues. I never found a problem with the engine other than a rocker stud that had backed out. I can't see where that would cause the issue. I may have over filled the engine with oil by trying to top off oil level before I drove it last Saturday morning. Today I added the correct 2.5 liters of oil, and the dip stick shows it low, almost to second add mark. I I did add a 356C Porsche oil filler which I really like. I even pulled the oil cap off with the motor running and you can't feal any real pressure coming out that would push out oil. I also changed the restrictor in my oil line to about .030. It was about .060. Maybe that slowed the flow through the generator stand. Thanks to all the people on here for your help.

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Sounds like maybe your engine just had a hiccup lol

[steven wardlaw]

A very large smokey hiccup.