There is no greater topic to generate a holy war in vintage motorcycle circles than oil. You can pick almost any topic on a vintage motorcycle forum and there will be some "experts" citing "X" is the only way a topic should be handled and immediately someone will profess if "X" rather than "Y and Z" is done your bike will be reduced to a pile of goo and every knowledgeable Greybeard will immediately exile you for life. Still, you as a rider must make some choice.
This Franz and Grubb post is exactly the sort of information I like to consider when I make those choices. Is it right? I'll never ride and teardown enough "trial" engines to know for certain but those guys might. In my opinion it's worth reading. From
the Franz and Grubb post:
"New Federal regulations led to the creation of a new oil standard that
is intended to improve fuel economy, lower emissions, and extend the
life of catalytic converters. The new standard is ILSAC GF-5* and API
SN. While these new standards may be good for your new
passenger car, it is not good for your vintage motorcycle. Triumph
motorcycles along with other flat tappet automobile camshafts need more
protection from oil than these new formulations can provide."
"The most common antioxidant/ anti wear additive in motor oils is ZDDP.
It works by forming a sacrificial film on the surface it protects, which
is extremely important in preventing wear on tappets and camshafts.
ZDDP has been found to harm catalytic converters, and more legislation
has led to the reduction of this additive in passenger car oils. This
means that the oil you buy at the auto parts store may no longer protect
your engine. Any oil with the API SN, SM, SL ratings along with ILSAC GF-5, or anything labelled ”energy conserving” or “resource conserving”
should never be used in a vintage motorcycle. There are however many
oils on the market today with high levels of ZDDP, you just may not find
them at your local auto parts store."
The article later also recommends looking for oils labeled as "Racing Oil" if you have to buy something at an auto parts store as off highway use oil is not bound by the same regulations.
Is anyone else with a stake in the game saying anything similar? This is from an older
British Cycle Supply oil recommendation post:
Barb Dour of
Megacycle Cams specifically warns against usage of current Castrol GTX and of
Mobil 1, which in her experience have resulted in a disproportionate number of
badly worn cams and followers, and says best results have been encountered using
the following motorcycle specific lubricants with her cams. As a matter of
interest, Megacycle may void warranty if other brands than those below are used
and damage has been caused by lubrication failure:
*Redline Synthetic
Motorcycle Oil
*Joe Gibbs Racing Oil
*Brad-Penn # 1
*Kendall Oil
*Valvoline Motorcycle Oil
I've been using the Valvoline 4-Stroke Air Cooled Motorcycle oil in my bikes for the last several years. Is it the best? Probably not but it's more important to me as a rider to be able to find a quart of oil in small town Somewhere USA if I need it than to provide protection for repeated 7,000 RPM passes at Bonneville. That said, I'm no expert.
To me the cream of
the Franz and Grubb post is the understanding that vintage car/motorcycle people are on the fringe of automotive culture and it's up to us to understand how it affects our decisions as Gearheads:
"Since the overall percentage of vintage vehicles on the road is so
small, almost no consideration has been given to the owners of these
cars and motorcycles by anyone in government. There is no money in
keeping old vehicles on the road, it is considered a hobby and as
witnessed with the “cash for clunkers” program the mentality is just
about the opposite of how most vintage motorcycle owners think. No one
cares if your cams go flat from bad oil or your vintage fiberglass tank
turns to jelly from ethanol. It is up to you to keep track of what is
changing and how it affects you."