Thanks for the response, I will be staying with the regular oil.
David A. Templeton
mailto:davidt@opentext.com
74 Spitfire "Spit-Six" Comm #: FM10491U
running a '73 MkIII GT6 engine KF1951HE.
----- Original Message -----
From: jonmac <jonmac@ndirect.co.uk>
To: David A Templeton <davidt@opentext.com>; <spitfires@autox.team.net>
Sent: Thursday, September 23, 1999 2:00 PM
Subject: Re: Oil coolers and rocker feeders
> On September 23, David Templeton wrote:
>
> >What about synthetic oil in these engines??
>
>
> This is a question frequently asked by visitors to BMIHT at
> Gaydon and is currently the subject of a leaflet we are in
> the course of preparing in conjunction with Rover Power
> Train and Engine Development to attempt to answer those
> queries. At the risk of bandwidth, a summary of the leaflet
> content is as follows:
>
> 1. What is synthetic?
> AFA the UK is concerned, there are two types. One is a FULL
> synthetic that is a blend of chemicals and additives for use
> in ultra high performance engines. Equally, a mineral based
> oil with some elements of synthetic, is known to be called
> Synthetic Oil without further elaborations as to its actual
> origin or composition. Strictly speaking, this second
> version is NOT synthetic because it only contains "elements"
> also found in synthetic. Castrol GTX Magnatec is a classic
> example of this but Castrol do not pass off their product as
> a full synthetic. Magnatec is a lubricant offering the best
> of both worlds and is far more suited to the sort of engines
> of interest to us.
>
> 2. Synthetic must be a better oil because it is designed to
> cope with higher stresses and its modern.
> 2.1 Broadly speaking, a classic car engine will never
> experience the operating temperatures, pressures and
> stresses found in a modern Formula One Grand Prix engine for
> which synthetic is ideally suited. No classic car engine is
> likely to be run for prolonged periods at 15000 to 17000 rpm
> and it is at these speeds that the properties of synthetic
> oil (special polymers and additives) come fully to the fore.
> 2.2 It should be remembered that full synthetic in its own
> way, like mineral oil, has an ideal operating temperature
> range and this range is substantially in excess of the
> temperatures found in a classic power unit.
> 2.3 Where true synthetic is used in a classic engine at
> lower than normal temperatures for which it is designed to
> be used and to be effective, glazing of the bores can
> result. This is felt to be because the synthetic does not
> reach the temperature where its true worth comes into play.
> The paradox is that this glazing tends to generate unwanted
> friction and consequently this places greater loads on the
> engine and its related parts than it would find with
> mineral.
>
> Rover is generally of the view that MODERN mineral oils -
> 10W/40 or 15W/50 are far better suited to classic engines
> than modern full synthetics. It argues, with some
> justification that the engines were never designed to run
> synthetic anyway. It's also at pains to point out as well
> that modern mineral lubes have properties in their overall
> blend that enables them to remain highly effective at
> substantially higher temperatures and pressures than thirty
> or so years ago when they would suffer from additive
> breakdown. Now they do not and those conditions are far
> higher than most if not all of us are likely to use our
> engine. For this reason alone, it does not feel that oil
> coolers are an appropriate fitment today and they might even
> contribute to running a mineral oil too cool and in such a
> situation, the lube will not lubricate as well as it could
> if it was allowed to run hotter. It acknowledges that in the
> past, coolers may well have proved beneficial but their
> fitment now is almost certainly not necessary. The bottom
> line of modern mineral versus a full synthetic is that
> synthetic will *possibly* not do your engine as much good as
> you think it might, it's considerably more expensive than
> mineral and the long term benefits are highly questionable.
> Summary? Save your wallet contents, use a high grade mineral
> oil and change filter and sump contents regularly.
>
> I've got the CC and API specs at work and will try to
> remember to bring them home. worth mentioning as well that
> these comments are not based on UK operating conditions but
> are global. Suppose you could always emulate the Arabs -
> they tend to change oil and filters daily, but there is a
> price advantage for them.
>
> Jonmac
>
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