An update before I leave for vacation….
About that pushrod that didn't rotate: that really bugged me, and today I confirmed what I suspected was the cause for that, or at least seems to be the most reasonable explanation at this time. The answer was in plain sight. When I first fired up the engine, what did I have? A relatively cold engine with relatively cold oil, even after running it for 30 minutes. Then later on in checking it out, the engine had never truly been run up to warm/hot. Then when I hit the panic button, I had just changed out the break-in oil (heavy in zddp) to swepco 15/40, and the engine, again, was up to temp but not truly hot as the weather was mild. So today I drove it down to sacramento - first long road trip in that Scout - freeway speeds around 60 mph and it got up to temp as it's pretty warm outside. Put on the cut-out valve cover and what do you know - that pushrod now turns while idling. Not real fast but faster than before. I suspect that the oil was thick and dragging the lifter's inner body, still is, probably, to some degree, but the oil needed to warm up and thin out. My theory, anyway. However, I'm including a couple shots here of the engine turning around 1,000 rpm. The exhaust "boats" don't seem to fill up a lot, but the intakes do. Anyone noticed this before? I think it is oiling well enough, but I was surprised to notice the valve side of the boats not awash in oil.
Mileage: wow. I filled it up as much as I could before I took off down the hill, to sac, and back. Then filled up again. 70 miles on 3 gallons. No matter how I cut it, it's over 20 mpg. This at steady highway speeds at 1,000 foot elevation down to sea level, and back. I know it isn't the best test but still….
Turbo: yesterday I drove by spd in rancho cordova and picked up some mandrel bent 2.5" exhaust tubing to begin fabbing the first few feet of exhaust pipe downstream of the turbo. I need to graft the new tubing onto the old section that is configured for the packing that fits into the trw turbo's exhaust outlet. That piece was salvaged from a corvair spyder. I'm including a pic of an original 152t installation. The corvair piece doesn't stick out near as much as the IH piece before going into its bend, but it will work. My dry fit-up confirms the need to make the first 18" horizontal because of clearance issues with one of the exhaust retainer's nuts and also due to the oil fill location on the valve cover that didn't exist on the original 152t engine. I also will need to weld on a bung for a wide-band o2 sensor.
In the 152t pic you'll see a primitive heat shield surrounding the exhaust housing. Those are of course unobtanium at this time, but I have fashioned an approximation of that piece from the firewall shield of a 90s volvo turbo-diesel. Similar material and formable.
