Hi John,
I'm as confused as anyone.
The listed results are quite old, considering that oil content &
published numbers are changing very rapidly.
the published numbers that you quote which are quite high, certainly
enough to do the job. It's my belief that any oil that actually meets
API service SM for 2007 will of necessity have it's ZDDP content
significantly reduced from this level.
If I'm wrong, it has only cost me a few bottles of EOS. If right, a
new cam & lifters have been saved. I doubt if we will ever get a
straight answer from the oil companies. They MUST cater to the
majority of customers. The folks with flat tappet cams who might be
affected by the newest oils are an insignificant percentage of their
whole customer base. I believe the manufacturers started using roller
tappet cams which don't require the high ZDDP levels in the mid
1980's. Not many older cars are on the road.
I note that the small specialty sellers of oil for race & off road use
are not hesitant to publish right up front what the ZDDP content of
their oils are.
I think each of us will have to make a decision & hope for the best.
Regards,
Dave Russell
John Soderling wrote:
> Help, I'm also confused now regarding Castrol GTX. The website
> http://www.lnengineering.com/oil.html lists test results on a
> number of engine oils including Castrol GTX 20W50. The test was
> conducted 11/05 and The GTX is listed as Type DINO and API SM. Yet
> the ZDDP seamed good unless I don't understand them - P(ppm)=1157 &
> ZN(ppm)=1422. These are at a level of .1157% & .1422%
> respectively. Since the tested GTX is listed as API SM, can I
> assume that the tested GTX is the most current oil some are saying
> does not have sufficient ZDDP levels? Thanks. Confused. Vrooom
> vrooom, John Erika the Red
>
> ----- Original Message ----- From: "Robert Blair"
> <rnbmail@yahoo.com> To: "John Sims" <ahbn6@optonline.net>; "Healey
> List" <healeys@autox.team.net> Cc: "Tom Collins"
> <collinsclassics@comcast.net>; "Paul Schwartz"
> <lucashly@comcast.net> Sent: Sunday, May 13, 2007 10:36 AM Subject:
> Re: ZDDP and our oils / ongoing
>
>
>
>> John,
>>
>> Good work. Interesting and practical findings.
>>
>> There is no reason why this should be a Healey only matter. It
>> looks like the old car world has woken up to the moving oil co Zn
>> standards and that the cam follower/high wear surface probelems
>> are emerging all around the old engine world - US and Euro.
>>
>> I think this is ging to be a very long and valuable [$$$] thread
>> .....
>>
>> I have just started my rebuilt BJ8 on castrol GTX - maybe 30 mins
>> run time. But I am not going to run the first 500 miles on it. I
>> an very convinvced that I need an oil with an appropriate level
>> of Zn/about 0.1%/1000ppm. I am not up for another rebuild within
>> 10k miles.
>>
>> Question we all want to know now is which is the best oil to use
>> that meets the required additive spec for the older engine
>> designs. It seems from discussions thus far that about 1000ppm
>> is the historical/min required to avoid wear, but such a level is
>> now defined as a cat killer and is therefore being reduced
>> dramatically in oils used for modern [post '70] engines.
>>
>> I will be watching and reading ....
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