According to the MSDS, 1-4% by weight. Which is pretty damn vague. But seems
like that would be up in the 10,000 to 40,000 ppm range. It comes in a 15oz
bottle. So, very roughly, figuring in an oil change it is diluted by a
factor of 8, and assuming no ZDDP at all in the motor oil (which is not
true), you would wind up with a minimum of 1250 to 5000 ppm in the sump.
Makes me wonder why it doesn't have a warning on the label "do not use with
catalytic convertors".
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the primer red one with chrome wires
on 8/30/10 8:39 AM, riverside at riverside@southslope.net wrote:
> how much ZDDP in STP??
>
>
> art d
> ----- Original Message -----
> From: "Max Heim" <max_heim@sbcglobal.net>
> To: "MG List" <mgs@autox.team.net>
> Sent: Saturday, August 28, 2010 4:30 PM
> Subject: Re: [Mgs] OIL
>
>
>> It's not the bottom end that suffers, it's the cam and lifters.
>>
>> When my B motor had approximately 70-80K miles the cam lobes were worn
>> down
>> to nubs, and the lifters were spalled all to pieces. I didn't do the
>> initial
>> breakin -- it supposedly had under 10,000 miles when I installed it (I did
>> pull a main cap at the time and the bearings looked brand new). While I
>> have
>> had it it it has used 20W50 Castrol. But over that period Castrol reduced
>> the amount of ZDDP several times.
>>
>> Since I put in the new cam I have been adding STP with every oil change,
>> since I can't find a motor oil with a documented adequate level of zinc. I
>> won't run racing oil because it's a year-round daily driver (over 210K so
>> far), not a 500 mile/year driveway queen.
>>
>>
>> --
>>
>> Max Heim
>> '66 MGB GHN3L76149
>> If you're near Mountain View, CA,
>> it's the primer red one with chrome wires
>>
>>
>>
>> on 8/28/10 12:35 AM, Barney Gaylord at barneymg@mgaguru.com wrote:
>>
>>> Chuckle. Something wrong with "the average LBC"? My MGA fairly
>>> often does 500 miles in a single day. 385,000 miles and
>>> counting. So far I do not worry about ZDDP, except during a new cam
>>> break in period. I run NAPA 20W50 in summer and 10W40 in
>>> winter. Current engine has 75,000 miles, going strong, never had the
>>> bottom end apart.
>>>
>>> Barney Gaylord
>>> 1958 MGA with an attitude
>>> http://MGAguru.com
>>>
>>>
>>> At 11:23 PM 8/27/2010 -0500, "Ron S" (<iverside> wrote:
>>>> The street version does not contain zddp. VR-1 does contain zddp
>>>> and is labeled for off-road use only but does not contain the high
>>>> milage additives of the street version. It is meant to be changed
>>>> after every race, or about every five hundred or so miles. This is
>>>> about the milage the average LBC `weekend tourer' does in a driving
>>>> season in a moderate climate area.
>>>> ....
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