I guess that's the problem with "rules of thumbs" which is that they can't
be relied upon for anything definite.
----- Original Message -----
From: "James Nazarian Jr" <james.nazarian@colorado.edu>
To: "Susan and John Roper" <vscjohn@huntnet.net>; "Larry Hoy"
<larryhoy@prodigy.net>
Cc: "Glen Wilson" <rstca@hemmings.com>; "V8 Rover List"
<buick-rover-v8@autox.team.net>
Sent: Saturday, September 02, 2000 9:43 PM
Subject: Re: Rover V8 Oil Pressure
> how does all this relate to the old rule of thumb 10#s per 1k rpm? It
> would seem if an engine only makes 40#s then you shouldn't rev over 4k?
> But the mechanical redline (piston speed assuming no valve float) doesn't
> happen until 7700 rpm
>
> James Nazarian
> 71 B Roadster
> 71 BGT
> 63 Buick 215
>
> "Aerodynamics are for people who cannot build engines"
> Enzo Ferrari
>
> ----------
> > From: Susan and John Roper <vscjohn@huntnet.net>
> > To: Larry Hoy <larryhoy@prodigy.net>
> > Cc: Glen Wilson <rstca@hemmings.com>; V8 Rover List
> <buick-rover-v8@autox.team.net>
> > Subject: Re: Rover V8 Oil Pressure
> > Date: Saturday, September 02, 2000 1:13 PM
> >
> > Actually, 8-10# at idle at operating temp would be quite acceptable.
> Rovers, SD1
> > and later(Ihave no recent experience with pre-SD1 stuff) will not make
> 30# at idle
> > unless there is something unusual in the oiling system. A 3.5L TR8
> engine that I
> > recently sold would make 25# at cold idle, stock 70k engine, but at
> normal temp it
> > was down to 10 as expected. Be cautious about using high viscosity
oils.
> The gear
> > drive has known limits and attempts to make the system produce high
> pressures can
> > lead to failure. The system is designed to move volume, not make
> pressure. My
> > experience with bottom ends for the race car carefully assembled with
> components
> > properly machined, flow restrictors in the heads, relieved passages in
> the block,
> > and a pressure regulator on the relief valve resulted in some very high
> cold idle
> > pressures, which dropped below 20# at temp. John
> >
> > Larry Hoy wrote:
> >
> > > Lets see if I can sort this out. This gets confusing so hang on.
> > >
> > > Glen Wilson writes:
> > >
> > > >Larry,
> > > >
> > > >Pardon me if I'm jumping into this thread in the middle and have
> missed
> > > something, but 8-10 psi oil pressure at idle doesn't sound normal to
> me.
> > >
> > > Glen wrote the above because I posted the following question.
> > >
> > > >John, your reply was regarding the 8-10 pound oil pressure at idle,
> what would
> > > be the typical pressure at driving speeds (2000-3000 rpm)?
> > >
> > > I asked the question because John had posted the following answer and
I
> thought
> > > he was responding to the idle oil pressure:
> > >
> > > >Your pressure is about what is to be expected. The Rover motor does
> not make
> > > high pressures.
> > >
> > > John was replying because David Brown stated:
> > >
> > > >I recently installed an oil gauge and discovered that my NEW (well,
> 17K miles
> > > now) 4.6 block is only getting 8-10 psi at idle.
> > >
> > > And he further stated:
> > >
> > > >my cruise pressure is around 35-40 psi, so not too bad.
> > > >
> > > >What can I do to beef up the 3.5L oil pump?
> > >
> > > Whew, did you figure that out? I did my research and found the *1961
> Buick*
> > > engine should be running about 33 lbs. at 2500 rpm (thanks to others
> who
> > > responded and gave me similar numbers). But I did not find out any
> info on idle
> > > pressure. However the brief time my engine was running it ran around
> the 30
> > > mark at idle. Seems to me that 8-10 lbs at idle is low.
> > >
> > > Larry Hoy
> >
|