Progress shot 14 Oct 1999
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With the final assembly
of the engine complete, including the valve push rods, I
mounted the entire engine in a 1/2" 5C collet on my
Hardinge lathe. There was perhaps 1/8" of clearance
over the bed! Just dumb luck there, but it did allow me
to chuck the engine. I turned a temporary stub
"tailpost" which secures the back of the
crankshaft to a live center. The engine is shown here
with no rear cover or rocker box covers, but otherwise
complete. The two brass tubes next to the tailstock are
the oil inlet and outlet pipes, with some vinyl tube
attached and routed into a fresh quart of 30 wt motor
oil. A rubber covered brass rod is secured to the
toolpost and slipped next to a head to keep the engine
from turning. I equipped the oil pump with a pressure relief valve. The tiny pressure guage magically floating at 1:00 is secured to the oil pressure tap. |
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A better view of the impellor, oil pump housing, rear main bearing, and temporary tubes to carry the oil for the motoring-in. |
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Success! Oil pressure
came up at 100 RPM, peaked at about 55 PSI at the oil
pump outlet at 2000 RPM, and was relatively stable at 50
PSI or so through most of the running-in. Knowing that
cool 30 wt oil will thin considerably when heated, I
tried diluting the oil with some very thin jet-engine
oil, which is maybe the equivalent of 3 wt. oil. Pressure
fell off 10 PSI almost immediately, which was expected
and OK. The only problem I saw with the motoring process was excess oil being slung from between the impellor and the rear main bearing, where the oil pump drive gear is keyed to the tail of the crankshaft. I hope to correct this with either a bronze washer or perhaps a disk of Rulon-J synthetic bearing material. |