Dave,
Based on what people have said, I would say you shouldn't worry. The top
end is fine and the bottom end sounds fine to me at this point.
A friend in San Antonio, Texas (where it gets hot) whom I trust wrote this:
"In twenty-five years of driving Buick/Rover V8's, I've always
used 20W50 and never had more than 15 psi at hot idle and sometimes not
enough to make the red light go out."
My Rovers have always read slightly under 30 psi with the same oil, and
several people on the RoverNet mailing list have told me that this has
always been their experience, as well. However, I have also heard from
several reliable people that 15 psi is typical. RoverNet list members are
almost all people coming from the perspective of Rover saloons like the
3500S, the SD1 and the P5B. So, most of the engines are stock factory
installations with OEM oil pressure gauges. I'm not at all sure how
accurate the stock gauges are at low rpm.
Oil pressure at idle can be affected by a number of factors, especially oil
viscosity and oil temperature. However, after all of this discussion, I
would say that the oil pressure at idle probably isn't all that critical as
long as you have numbers like yours at 2000 rpm. I think some people may
also have their idle speed set higher than yours depending on the condition
of the engine and possibly the camshaft installed.
My understanding is that Buick designed the oil pressure relief valve to
open at 33 psi, and that Rover specs say it will open at 34 psi except for
the engines produced for the MGB V8 (which was more of a customer comfort
issue than a matter of what the engine needed). If you already have more
than enough capacity when you're at only 2000 rpm, you should be in good
shape up to the stock rpm redline.
Pre-SD1 V8s had a lower capacity oil pump, and people on the RoverNet seem
to confirm that these engines have lower oil pressure readings at idle. The
SD1 engine introduced around 1975 had a higher capacity oil pump, and the
pre-SD1 engines can be retrofitted with a similar pump. Someone on the BRV8
list pointed out that sometime around 1995 the oil system was completely
redesigned and has its own specs from then on.
There's a difference of opinion about which viscosity oil is best. Some
authoritative people say that 5W30 and similar weights are too thin and can
even cause damage, but some people swear by lighter weight oils citing
improvements in petroleum technology. It sounds to me as if these people
tend to be working with meticulously assembled engines that are frequently
used for racing purposes.
People at the other end who swear by 20W50 oil are frequently people from
areas where the winter temperatures don't go much below freezing. This
includes most of the people in the UK and also the UK classic car magazines.
Where I live in Philadelphia, 20W50 is too thick for approximately 20
degrees F and under, and I really have to switch to 10W40 for the coldest
months.
I think that's more or less the gist of what's been uncovered minus some
pretty interesting technical stuff from some of the people with higher
gearhead IQs than mine!
Glen
----- Original Message -----
From: "BROWN DAVID E (DAVE)" <debrown@srpnet.com>
To: "'Glen Wilson' <rstca@hemmings.com>" <dkern@napanet.net>;
<buick-rover-v8@autox.team.net>
Sent: Tuesday, September 05, 2000 12:17 PM
Subject: RE: Muddying the waters?????
> WOAH! WHAT HAVE I STARTED???
>
> Bottom line: Should I be concerned about my new
> engine with 8-10 psi at 700 rpm idle using 20-50 oil at 100 degree
> Fahrenheit with a warm engine? About 35psi at 2000-2500 rpm.
>
> What should I look for or replace?
>
> What is the socket/wrench size for the bypass bolt,
> 1 1/16"?
> What kind of bolt does Rover use for the oil pump
> attaching screws, looks like some reverse torx with a hole in the middle?
> What socket type and size do I need for this?
>
> Thanks, Dave
> Phone: 602-236-3544 Fax: 602-236-2303
> 6:00 AM - 4:30 PM Mon-Thurs, Off Fridays
> E-mail: debrown@srpnet.com
> <mailto:debrown@srpnet.com> * AM/FM <http://www.srpnet.com/>
> Much of our work should be about planting seeds, not
> putting out fires.
> - Unknown
>
>
> -----Original Message-----
> From: Glen Wilson
> [mailto:rstca@hemmings.com]
> Sent: Monday, September 04, 2000 8:40 AM
> To: David Kernberger;
> buick-rover-v8@autox.team.net
> SNIPPED...
>
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