Hi James,
The pressure out of the pump is regulated by the bypass valve but it harder
to push thicker oil through the pipes, filter, cooler. Usually the thicker
oil means higher pressure since it can't push past the bearing clearances so
easily-- in this case the drag of the thicker oil before it reaches the
gallery could be greater than the positive effect of the thicker oil at the
bearings. cheers, derek
-----Original Message-----
From: owner-tigers@autox.team.net [mailto:owner-tigers@autox.team.net]On
Behalf Of James Barrett
Sent: Sunday, January 06, 2002 6:17 AM
To: tigers@autox.team.net
Subject: Cold Oil Pressure
Folks,
Just had a cold wave hit Florida, got down to below 40 degrees.
(For you Northern folks, remember that "cold" is a relative to what one
is used to.)
I presently park my Tiger outside the garage under a car cover so
The Tiger
was cold at startup. (Working on an Alpine in the Garage).
Now the wierd part: I normally have 65 psi indicated on my oil gauge
when in normal running or idleing at 1000 RPM. When I get in traffic for a
long time, It may drop to 60 psi if water temp start to get above 90 degrees
C.
Today (in the cold) the oil pressure came up to 50 PSI and stayed
that way
until the motor warmed up to 80 to 85 C. At warm up, the oil pressure
returned
to 65 psi. I was driving around 2000 to 2500 RPM in town. I use Valvoline
20W-50 oil due to the normally hot temperatures here in Florida. I have a
remote Oil Filter inside the fender under the driver's side headlight and
1/2" ID hoses connected to the original Tiger II fittings (both at the
block
and at the oil filter). I also have the original two tube Tiger II oil
cooler
in the circuit.
My previous experience has been that when the oil is cold, one has
higher oil pressures than when the oil is hot.
I use a high volume TRW oil pump in my 351C. The pump is less than
a year
old. I also use a modified oil pan that holds 12 quarts of oil without
hitting the
oil hitting the crankshaft.
Any one have an idea of what is going on with the oil pressure
during the "cold".
Note that this "problem" is presently not serious enought to warrent pulling
the
oil pan. Would just like some ideas.
James Barrett Tiger II 351C and others
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