Regent,
I agree with Steve on this one, the first thing you want to do with this
is make sure of the problem. Check to make sure the pressure really is too
high before you spend a lot of money chasing it. If the pressure really IS
high, the first thing I would look at is the oil pump. It should have a
bypass built in to it to allow excess pressure to return to the pan, and
this is likely not working. Oil pumps are positive displacement pumps
(move a fixed amount of fluid per revolution), and are designed to provide
slightly more than enough oil at all expected operating ranges: the excess
should return through the bypass. It has been a while since I worked on
these, so I could stand to be corrected, but that is how I remember it.
Bon Chance!
Michael
Steve Laifman <SLaifman@SoCal.rr.com>
Sent by: owner-tigers@autox.team.net
2004-06-28 09:42 AM
Please respond to
Steve Laifman <SLaifman@SoCal.rr.com>
To
Rigent Gagnon <regentgagnon@rogers.com>
cc
Tiger list <tigers@autox.team.net>
Subject
Re: High oil pressure
Rigent,
I do not know the oil temperature related to your observations, but even
at 75 F my 260 registers 50 psi at idle. Unless it is very hot, it
rarely drops below 35 psi. This is with 30,000 miles on the engine. I
do not know if your rebuild included bearing surface wear and roundness
for select fit of standard under sizes. The days of machining bearing
inserts for proper fit are long gone, and only thin wall bearing
surfaces are sold. The proper size being purchased, rather than
machined, after any necessary crank grinding to the next standard size
is done.
Of course a "plasti-gage" check is usually done to re-sized rod
bearing/main bearing clearances for final fit check.
Your mechanical 30 something year old gauge may be out of calibration,
or offset about 10 psi. I would be much more concerned about the oil
leaks, not a 65 psi hot oil pressure.
Clogged lines, or obstructed oil passages, could - of course - be a
contributor to abnormal pressure.
Get a "T" fitting and an accurate calibration gauge to check the
pressure, and fix the leak.
Steve
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