From:Rick Yamane
Subject:RE: OIL Date:Tue May 20 15:46:23 2014
Response to:5167

I picked up my motor at Oley and plan to start it soon. There was some discussion about what oil to use. Someone said they had heard that Rotella has reduced the zinc content in their oil.
What are other people using and has anyone heard anything about the Rotella

Essentially any oil intended to be run in a passenger car or truck is going to have little to no zinc content. The Zinc was found to foul catalytic converters so you know whos going to win that contest. I understand even the diesel oils have lost their zinc.

The zinc is desired because it is made up of elongated molecules that stand on end thus providing a better cushion between moving parts, especially in high pressure situations. I first heard about this probably 10 years ago or more. I first saw it in British car applications affecting high wear in plain cam and tappet engines. While I haven't heard of an engine positively identified as having failed from a lack of zinc, there are numerous reports of prematurely flattened cams and worn tappets. Roller tappet engines seem unaffected as you might expect.

Since even the road going diesels are now running catalyists Rotella and Delo are no longer viable replacements. Essentailly any oil proclaiming a environmental advantage could probably be taken as being "de-zinced".

We've begun running Brad Penn oils which as I understand are the old Kendall formulas. They are specified as off-road racing oil. It goes into Chris' 1915 Harley and the other antique stuff. In the newer bikes and most of those have recirculating oil systems I've pretty much stuck with Motorex synthetics or other motorcycle specific oil.

I would recommend a motorcycle oil in the Henderson by virtue of its wet clutch. The abrasive fibres introduced by the clutch need to be delt with properly by the oil and that is what motorcycle oils are designed to do. Motorcycle oils also still have the zinc ratings. I believe if it is JASO, MA or SJ it will have zinc additives or in the case of synthetics, the equivalent.

The disclaimer is, I'm not a tribologist but this is info I've picked up over the last several years studying the issues through motorcycle and race car contacts and forums.