"Gold Seal" was the BMC brand for their top-grade rebuilt engine (i.e.
Factory rebuild). I am pretty sure that this grade included all new wearing
parts. There was also a Silver Seal that may have retained used parts.
The motor was a pull from a seriously rusty driver that had been imported
into California, but could not be registered as the motor was not CA spec
for the model year (74). It allegedly had less than 10K miles on the motor.
I had the pan pulled and the big end bearings inspected at the time, and
they had no visible wear, but we replaced them anyway.
So I can only indirectly vouch for the "break in", but I think I can draw
two conclusions:
1. As a non-smog "Euro-spec" rebuild, it did not feature hardened valve
seats, hence the valve recession;
2. Castrol 20w50 (actually, several different formulations over the period;
I am guessing SF through SL, at least; so it's hard to say at which point
the problems began) did not adequately protect the cam and tappets in a
spirited driving regime, even with moderate valve spring pressure and all
stock components.
Have you inspected your cam and tappets recently? Mine was driving "fine", I
would have said, before I tore it down for an unrelated problem.
I'm just sayin'...
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the primer red one with chrome wires
on 9/24/09 3:24 PM, Stephen West-fisher at steve@coastaldatasystems.com
wrote:
> So absolutely all other possibilities were ruled out?
> I don't know what a "Gold Seal" engine was, but perhaps a replacement
> overhauled engine? Were the old tappets used or replaced with new? Were
> the tappet faces tested for the proper hardness (regardless of old or
> new)? How about the camshaft itself? Was the engine properly pre-lubed
> before the first start (probably at overhaul facility)? How many times had
> the cores been used before this overhaul? Even a brand new engine can be
> put together with substandard parts unknowingly.
>
> The quality of metallurgy in replacement parts is not what it used to be,
> and even high end overhaul facilities can make mistakes. My point is only
> that there are many, many reasons for failures such as you experienced, of
> which oil is only one.
>
> My engine has never been overhauled, has 120,000 miles, and no symptoms of
> problems with always using the current formulation of oil and unleaded fuel
> since at least '84 when I bought it.
>
> --
> Stephen West-Fisher
> Coastal Data Systems
> 727.599.4271
> http://www.coastaldatasystems.com/
>
>
> -----Original Message-----
> From: mgs-bounces@autox.team.net [mailto:mgs-bounces@autox.team.net] On
> Behalf Of Max Heim
> Sent: Thursday, September 24, 2009 12:33 PM
> To: MG List
> Subject: Re: [Mgs] [Mgb-v8] Kendall Oil
>
> Let's throw in some actual user experience, then.
>
> When I took the head off my B engine, it had serious valve recession and
> extreme cam and lifter wear (several cam lobes were worn down almost 0.2
> inch). This was a non-smog high compression Gold Seal engine from the late
> 80s, with around 85K miles, almost all on Castrol GTX 20w50.
>
> So, I am convinced that current formulations of the factory recommended
> lubricant are inadequate for tappet protection. The service manual no longer
> applies.
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