I think maybe proper attention wasn't paid to the bearing clearances. When it ran, it ran well, but (lack of) oil pressure was a problem early on with me now suspecting a large bearing "gap" somewhere (probably on #4 crank journal) not allowing pressure in the system to build up properly. STP oil treatment was used as an assembly lube, a "sticky" oil really, like Lubriplate. Didn't find any evidence of metal particles in the sump, so that is good.
The engine never over heated, I checked it often and have had air cooled VWs for now 40+ years, so I know about that. Actually kind of fun, I am re-kindling my love of engine tinkering and again realizing just how simple these engines really are.
Yes, they are simple and fun. I have been messing with VW's since the mid 1960's and probably have had 20 of them in various flavors and a 1971 bus. I probably have rebuilt a dozen VW engines over the years. When you put that one back together, make sure the crank end clearance is shimmed properly too.
The worst mess I have ever had was with my bus engine. I was cruising along a Connecticut country road one afternoon in the summer of 1974 and at about 45 MPH, the bus started slowing down on its own. When I looked in the rear view mirror, all I saw were clouds of blue smoke and shortly there after I pulled the bus over and had it towed home.
When tore the engine down, the failure was #3 exhaust valve (broke off) and the piston proceeded to beat itself and the cylinder head to death. Pieces of piston rings also got sucked into the remaining cylinders and reeked havoc. What a disaster. Heads were shot, jugs done too. And of course the pistons were all mangled.
The culprit, as anyone could guess that knows these engines, was probably heat. The oil cooler sits over #3 jug and that cylinder must have gotten real hot back there and somehow the valve, over time, failed (head broke off). Somehow, the camshaft and the crank were good.
I dropped in a used engine (they were plentiful for a song back then) and rolled along.
Three years ago, I found a "decent" stock 71 Super Beetle which needed more than I thought,
and I rebuilt over 12 months it and drove it for a while. However, living in a concrete paradise (north of Houston, Texas), I realized these old Beetles are best driven on low traffic, low speed limit, country roads. Around here, Big Truck Country, one feels definitely "at risk" driving amongst the Giants!
So I sold it to a young man that was going to keep it "stock" except for the engine. I at least got my investment back, but not the labor hours I put in.
Oh well.