[Mgs] OIL

[Max Heim]

I think you will find that the increase in zinc tracked increasing
compression ratios and higher valve spring pressures.

Even the B engine was high compression and high revving compared to the
typical sedan engine of the mid 50s. The typical 5- or 6-liter Detroit V8
went from maybe 140hp to well over 300hp in that period, almost entirely
through higher CR and higher revs.

--

Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the primer red one with chrome wires




on 8/31/10 12:47 PM, Stephen West-Fisher at steve at coastaldatasystems.com
wrote:

> If you look at the amount of zinc in modern formulations as compared to that
> in the 50's, you will find they are about the same. Zinc in oil started
> rising in the late 60's, I don't recall the reason but I doubt it was due to
> flat tappets.
> 
> My own take on the problems a few people started having has more to do with
> modern "offshore" metallurgy or the number of overhauls the cams have
> survived.  
> 
> --
> Stephen West-Fisher
> Coastal Data Systems
> 727.831.1142
> http://www.coastaldatasystems.com/
> 
> -----Original Message-----
> From: mgs-bounces at autox.team.net [mailto:mgs-bounces at autox.team.net] On
> Behalf Of Paul Hunt
> Sent: Tuesday, August 31, 2010 4:16 AM
> To: Max Heim; MG List
> Subject: Re: [Mgs] OIL
> 
> Both API and ACEA specifications include limits for levels of zinc and
> phosphorus:
> http://www.acea.be/images/uploads/pub/070308_ACEA_sequences_2007_LD_and_HD.p
> df
> http://www.api.org/certifications/engineoil/pubs/upload/150916thAdd10308forp
> rint-2.pdf
> 
> I've seen (but can't now find) a statement that from some official body that
> 
> modern formulations don't cause accelerated wear in older engines - not that
> 
> I believed it given the amount of empirical evidence to the contrary.