[AMC-list] IT RUNS.

[tom jennings <tomj@xxxxxxx>]

OK, I'm driving my little American now, the new 195.6 OHV is running fine
and not puking oil everywhere. I got a new (electric Stewart Warner) oil
pressure gauge from Summit and in the dash, and cold or hot the oil pressure
is 80 PSI. Drops to 60 at idle.

I'm not sure why the oil pressure is so high, but it's not the external
oiling. If anything, that would RESTRICT oil flow to the main gallery. The
"90 degree fitting" problem I mentioned before isn't -- the two 90's are on
the INLET side of the oil filter, the outlet side is straights and 12" of
1/2" hose, so the more-restrictive plumbing is TO the filter. (I did think
this out...)

I did substantially improve the oil pump; I squared and polished the ends of
the new, not used gears, and milled and filed the case and Plastigage'd it
to .002" clearance instead of the factory sloppy .008" - .009". THAT
probably increased flow esp. at low RPMs where the leakage around the gears
would be a significant portion of the flow. (.002" is plenty for lubing the
top of the gears.)

The other thing I did was eliminate the bypass filter; hence 100% of the oil
in the tube from the block to the head goes to the rocker shaft. THAT
lessened overall volume upwards and increased pressure. I didn't think of
this beforehand.

The other possibility is a partial blockage of the relief hole into the pan
by Right Stuff when I put the pan on, but I was paying attention to that, so
I'm not really worried about it.

And seriously, who in recent memory has done a full detailed rebuild of one
of these motors with all new parts, to know what main gallery pressure
really is when new?

I think that the source of the high pressure was simply the ridiculuous
relief spring selection/problem. I clearly had the wrong spring(s) in there
and I'm sure the stiff/tall one made the pressure crazy high and popped two
gauges and the filter gasket.

I don't like the gauge running at maximum (80 psi full scale) so I'm going
to experiment with shimming the threaded plug to drop the pressure. If I can
get it 60, 70 I'll be happy, then I'll have gauge "headroom" to make me less
nervous. I've not revved the new engine past 2500 yet (total of 12 miles on
it) so I don't know what the p[ressure/volume will do at 3000+ rpm. I put in
a second copper gasket and it seemed to drop about 3 - 4 psi so I'll grind a
3/32" steel washer very flat and try that. It's a 5-minute job.


The carb is out of whack, I can feel a flat spot etc but that's fine, its
new-out-of-the-box and working great and I'll dial that in soon enough. The
alternator charges the battery at idle, imagine that. I got used to seeing
the idiot light come on I was wondering if the bulb burned out when it
didn't! The clutch shudder is gone now that I have a non-crumbled pilot
bushing. I apparently left the wires off the OD unit as it won't engage,
etc, but that's all typical minor stuff to sort out.

With admittedly not much time on it yet, the 20W-50 oil in the T-96 is very
nice; this trans seems to be sensitive to lube type and the synchros seem
most cooperative with it.

Since this all took weeks longer than I intended, I spent a LOT of time on
the fancy fan controller (umm, at work). It's F'ING SWEET. It varies the fan
speed smoothly and slowly depending on coolant temp, does a proper cooldown
cycle, there's a knob for set point, a blinky LED to tell you what it's
doing etc. For example, the engine's fully warmed up and the fan is running
close to full speed, you turn the car off, the fan speed drops slowly to
about 50%, runs at that speed for 5 minutes, then tapers off to 0. No huge
power surge or load dumps.

What a relief!
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