Mike Hughes draws our attention to the following article: "More than an Oil
Change". by Jonathan A. Stein, reprinted courtesy of HagertyPlus, LLC,
copyright 2008, at www.hagerty.com.
Formula modifications could mean it's time to reexamine the oil you use
in your collector car. Most car enthusiasts can probably rattle off the
automotive products that they've relied on for years. But when it comes to
oil, recent composition changes driven by environmental concerns could mean
your preferred brand of oil may not work so well in your collector car
Many older vehicles use
overhead valve engines with flat tappets that contact the camshaft lobe on
one end and the rocker arm assembly on the other. The rocker arm assembly is
relatively heavy and generally has a big valve with a heavy spring,
resulting in a lot of pressure on the tappet and camshaft.
oil companies and automakers discovered that zinc dialkyldithiophosphate
(ZDDP) was effective in reducing cam and lifter wear, as the compound
interacts with the iron of the cam lobe and creates a sacrificial barrier.
As of 1988, the ZDDP concentration in oils certified by the American
Petroleum Institute (API) standardized at up to 1200 PPM (parts per million)
phosphorous. However, phosphorous levels were brought down to the 800 PPM
level by 2004 because high phosphorus concentrations shorten catalytic
converter life in modern cars, and modern roller cam engines don't require
Soon, rebuilders of flat-tappet engines -
particularly those from the 1950s to the 1970s - were noting increased cam
failure on newly assembled engines. Many engine builders have tied the
failures to the reformulated oils, although API spokesman Dennis Bachelder
asserts that API-ranked oils are compatible with older vehicles and the ZDDP
levels in current SM-rated oils are sufficient to protect flat-tappet
PPM SM-rated oils, try these options:
- Oils rated for both diesel and gasoline engines (up to 1000 PPM) are available from Shell
(shell.us/views/consumers. html) and Chevron
- Valvoline's VR1 Racing Motor Oil
(valvoline.com/racing) has up to 1300 PPM of ZDDP.
- Castrol's SYNTEC
20W/50 full synthetic product (Castrol.com) has 1200 PPM of ZDDP (check that
the rear label says Recommended for Classic Cars), and Red Line Motor Oils
(redlineoil.com - also synthetic - have about 1300 PPM zinc and 1200 PPM
phosphorous, although synthetics aren't suited for the break-in period.
- BRAD PENN Penn Grade 1 Racing Oil (bradpennracing.com) is a mineral-oil
alternative with nearly 1500 PPM of ZDDP.
- Classic Car Motor Oil
(classiccarmotoroil.com) from the Indiana Region of the Classic Car Club of
America manufactured and bottled by D-A Lubricant Company, Inc.
(email@example.com) contains 1500-1600 PPM.
- Use a ZDDP additive such as
ZDDPLUS (zddplus.com) or Cam-Shield (camshield.com) with every oil change.
- Additional protection, essential during the start-up phase for any fresh
engine, can be provided by generous use of an assembly lube with a large
dose of ZDDP like GM E.O.S. Assembly Lube (PN 1052367) (newgmpartsusa.com).
With these options, there's no need to worry about your camshaft. But
it's always a good idea to line up supplies along your route before you take
to the road."