Given the difficulty with messages stripped from headers, thought I
better repost this--still looking for a bit of advice.
Hello, all--
A quick look at the engine of my recent acquisition confirmed some
suspicions... Roger (rgb@exact.com) was dead-on concerning the rockers.
Pulled the valve cover off and the rocker shaft set screw was missing
(not previously installed, or now somewhere in the oil pan, I'm not
sure). The front two rockers are showing signs of grinding against the
wear washers and front pedestal, and all the rockers need to be
rebushed. Can't believe that some shop would do a valve job and then
slap on that set of rockers. But, found a replacment screw and installed
it. The lash on several of the valves was quite wide, which accounted
for some of the noise, but the existing wear accounts for the rest.
Anyone know of good prices on rebuilding the shaft and rebushing rocker
arms?
Roger also would be interested to know that the compression readings in
the high cylinders suggests that a big shave was done on the head--highs
were in the 185-195 psi range.
Anyway, I pulled the rocker shaft, retorqued the head (hoping it was
just a little loose, accounting for the oil leakage at the rear of the
head), but the later compression readings suggest that the stock head
gasket probably isn't up to the pressure in that cylinder, or was
installed badly, or the head surface wasn't milled properly. Inspected
the rocker shaft (slightly bent), cleaned out the grit on the rockers
and got some oil on them. Should have snapped to the compression ratio
increase, I suppose, when I took out N9YC plugs instead of N12YCs.
Put a new valve cover gasket on, since the old one had squeezed out from
under the sealing flange and was leaking. Replaced the plugs (numbers 4
and 6 very badly oil-fouled). As a consequence, the oil smoke has
increased notably, now that those two cylinders are firing properly.
Looks as if the engine will have to be re-ringed, just to get by without
nasty looks from the environmentally-conscientious folks.
And, the oil pressure reading is still down after fixing the bad power
lead to the oil pressure gauge (wonder why a #10 wire spade end fitting
was used on a 20ga. wire?). Another question--in the list's general
experience, is there any frequency to weak oil pressure relief springs
and/or sticking oil pressure relief plungers?
[An aside from the previous message--tonight, I pulled the plunger and
spring and had a look--the radial land of the plunger is _extremely_
well-scored and polished from dirty oil passing the face. It is cut to
0.020-0.030" around about 40% of the land, which suggests that it has
been passing oil quite freely for some time. Part of the problem
answered. Difficult to assess the tension on the spring--it seems a bit
wimpy, but that is a completely subjective measurement.]
This engine almost behaves as if there's no plunger in it. No
significant changes in the pressure reading regardless of engine speed,
and the pressure drops almost immediately after the engine runs well
enough to push in the choke. How about rates of wear in the oil pump? I
am already trying to reconcile myself to rolling in another set of
bearings as a stopgap measure, but really don't want to be surprised by
something else after doing so. I'm going to change oil and filter soon
(only have a filter for a two-liter engine on hand, and haven't verified
if it's the same for the 2.5 liter), but I don't think that will help
the oil pressure situation.
And, cobbled up a means of installing a PCV valve--when I picked up the
car, it had both carburetors directly connected to the valve cover port.
Which didn't seem to me like a good thing, especially with the valve
cover leaking to atmosphere. <g>
Cheers, all.
--
My other Triumph runs, but....
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