No oil to either head

[Texasdoc]

Just got the rebuilt 40 hp running. Initially it ran well, got it timed, now working on brakes, windows, etc. This motor does have an external oil filter - oil comes out the cover plate, to the filter, then back to the block at the oil gallery. Large AN-10 lines. When the motor starts, the oil light on the dash goes out.

Yesterday I noticed a knocking sound so I decided to recheck the valve lash. Some were tight, most were a touch loose. Now all at 0.006. These heads have the short stud replacement kits with the bolts holding the rockers down.

Problem is that both sides were completely dry. Not even a light coat of oil on anything. It has been sitting for at least 24 hours, only ran for about 1 minute yesterday, and hasn’t been started for about 10 days before that. I get that its okay to not drool oil when the valve covers are opened, but this is concerning. How do I test this? Should I start the motor with the valve covers off and see if oil is coming up the pushrods? Any other suggestions?

[Cusser]

[Texasdoc]

Well, I said to myself, “Self, I’m okay with messes. In fact, I’m pretty much used to messes. Go for it.” So I did. Started her up for a few seconds (10-ish) with both valve covers off. Essentially no oil coming to either head.

I don’t fully understand the oil pressure diverter/relief valve, so I checked that. The plug was stuck and took a good umph to get it off. Spring came out but no piston, it was stuck in the bore. Lots of dirty oil with grit in that area. (PO was a mechanical engineer whose goal was to put as little money into it as possible for the 40 years he owned it.). Eventually had to get a tap to grasp the piston and got it to come out. Scored a bit on the sides but useable. Once the piston came out, new/clean oil came out (about half a cup). When I start it (for 2 seconds) without this plug/spring/piston, clean oil comes out. I know, no oil is getting to the bearings, I won’t do that any more.

Reading the few books (Clymer… I know) I have says that “unloaded length should be 62-64 mm”. This spring is 78 mm. Is that the wrong spring or is my book wrong? I wouldn’t be surprised if the PO just put whatever spring he could find in there.

Would the stuck oil pressure relief piston or the too-long spring prevent oil flow to the heads?

Edit: after researching more, I have the wrong spring. The single valve OG is not slotted and has the 62-64 mm spring. My plunger is slotted and has a long or heavy duty spring. The plunger was stuck in the up position. Still don’t know if this will restrict oil to the heads.

[Texasdoc]

I found my copy of Tom Watson’s book on VW engines. Page 40 explains the oil control valve(s). When the oil is cold, it “should” push the piston down, allowing oil to the bearings (and lifters) without going thru the oil cooler. As the oil heats up, the valve closes progressively, eventually causing the hot oil to go thru the oil cooler.

My theory is that with the piston stuck in the closed position, all the cold oil has to try to go thru the restrictive oil cooler BEFORE it reaches the oil gallery. So, I’m trying to force cold oil thru a restrictive cooler, so I’m likely not getting much flow to the bearings or lifters/pushrods/rockers. I haven’t run it long enough to get the oil hot enough to easily flow thru the cooler.

Am I right/wrong? Any other ideas?

[VWFIXER]

Oil feeds through the pushrods, from the lifters from the main gallery from the pump.
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[Texasdoc]

[VWFIXER]

[VW_Jimbo]

Is everything stock?

Are the pushrods clogged?
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Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[Texasdoc]

[KTPhil]

Tell us a little more about the rebuild. Worst case scenario is they plugged a galley and even though you have pressure and flow for the sender, the galley leading to the tappets might be toast.

[VWFIXER]

Cam bearings wrong?
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[Texasdoc]

I know that not all of this applies but here is all the info on the motor and rebuild.

Not sure about the cam bearings. Not sure this one has them. I believe it is the original 40 hp motor. I took it all the way down to the case, but didn’t crack the case open. (My guess is if it didn’t have cam bearings and the journals are severely worn, it wouldn’t make oil pressure and the light wouldn’t go out.) Original crank, rods, lifters, cam, heads, pushrods, rockers, valves, intake, carburetor, distributor, oil cooler (new seals). I *think* I checked the oil cooler for blockage when it was apart - that was 2+ years ago before COVID.

New coil, wires, plugs, cylinders, pistons and rings (big bore kit), new generator, new voltage regulator. I disassembled the heads, lapped the valves, converted one head from long to short studs. I installed a full-flow oil kit - plugged the normal output of the pump, pump cover to oil filter to drilled and tapped oil galley is 10 AN stainless lines. Valve lash is 0.006 all around. New clutch and pressure plate, stock flywheel, stock starter (new bearing).

Did I leave anything out you have questions about?

[VW_Jimbo]

[VW_Jimbo]

[diablosandwich]

If you do need a new oil pump, here is a 21mm oil pump for 6mm studs.

https://www.ebay.com/itm/114958659328?hash=item1ac411ef00:g:Zl8AAOSwFORhKlWY

I replaced a worn one in my 1300 with a 21mm and had better pressure.

Casey
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1966 Java Greens

[Texasdoc]

I don’t know the status of the motor before I got it. It would run, but not well. I didn’t check the pressure before the tear down. I *think* it makes decent pressure since the oil light goes out immediately and never flickers.

I don’t have a pressure gauge. All the gauges I see for sale are 1/4 NPT but the oil pressure sensor hole is 10 mm x 1.0 (I haven’t been able to find a 10 mm to 1/4” converter but only looked for a bit.) I may have to get a 10 mm plug and tap it for 1/4.

I will try running it without the pressure relief spring to see what that does. I that doesn’t work, figure out how to test the oil pressure in the galley. Not sure how to test flow.

Where does the galley to the lifters start? The oil line from the filter goes into the galley boss on the left (above the oil pressure relief). This gives pressure right into the main galley. If the galley line to the lifters is plugged, where does that originate on the case? (Once I’m sure the main galley has pressure). Where does the oil cross from the left to the right side so it can get to the right head? Since both sides don’t get oil, it would have to be a common line that is blocked.

[Texasdoc]

[VWFIXER]

Lotta efforts going into a clapped out 40hp. Could be a packed peanut inside one of those oil lines plugging it up. If it’s knocking already just shoot it.
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Choose 2

Over a million air cooled miles driven and 15,000+ cars serviced.

[Texasdoc]

[VWFIXER]