HPR 50 is too heavy for a Sprite motor which is designed to run on a 30
weight oil. In Australia's climate a 50 weight is ok because ambients are
generally higher. You are right in your startup concern, most engine wear
occurs in the first minute of running. 40W-70 puts too much strain on the
oil pump and will not pump to the top of the engine quickly enough.
Another thing is that oils that are too viscous for an application can
actually reduce effective lubrication by not allowing an oil film too fully
penetrate a bearing clearance. If your engine is in good condition you can
expect 50psi hot at highway speeds. The viscosity of oils is standardised
in the weight, or second number, the W rating indicates how well the oil
flows at low temperatures. Mobil 1 5W50 is ideal for Sprites- if the
engine is in good condition but if it's not no oil will help. Also don't
forget the S rating ie SG, SH, SI, SJ. The further up the alphabet the
better the oil.
I don't use mineral oils anywhere in any of my cars.
Peter
----------
From: Andy Webster <trunkie@hotmail.com>
To: spridgets@autox.team.net
Subject: oil
Date: Sunday, 23 May 1999 0:39
Greetings list.
I have been a devout PENRITE user (HPR50) since I forked out $2100 to
rebuild a 318-V8 a few years back and have always used it in my sprite.
The
only concern I have with it is its 'starting' ability.
As a 40w-70 oil I would expect that its going to be pretty slow in getting
to the top of the motor. Is this not a problem because it tends to cling
and
it will already be there when I start up?
I know some people are using mobil 1 synthetic in their spridgets...any
opinions on it? I thought it was really for modern multivalve cars with
ultra tight tolerances etc. I'm attracted to the 5w, runny when cold side
that suggests that it will be at the top of the engine in no time. What
kind
of pressure does it maintain when its that light and at temp? Can you folks
outside of Australia get Penrite?
Thanks in advance
Andy
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