And now the bad news is out: It’s today’s “modern” API (American Petroleum Industry) approved oils that are killing our engines: Meaning all flat tappet (cam follower) equipped engines, as used in all BMC products, all British Leyland products, most pushrod engines prior to 1980, early Volvos, American high-performance engines and many others.

This problem is BIG! American Engine Rebuilder's Association (AERA) Bulletin #TB2333 directly addresses this problem.

There has been a reduction of zinc dialkyl dithiophosphate (ZDDP) in the oils supplied with API approval that could affect sliding and high pressure (EP) friction in our cars. The reduction of these chemicals in supplied oils was based on the fact that phosphates reduce the effectiveness and eventually damage catalytic converters and introduce minute amounts of pollutants into our atmosphere. For you science buffs: ZDDP is a single polar molecule that is attracted to Iron based metals. The one polar end tends to “Stand” the molecule up on the metal surface that it is bonded to by heat and friction. This forms a sacrificial layer to protect the base metals of the cam and tappet from contacting each other. Only at very high pressures on a flat tappet cam is this necessary because the oil is squeezed/wiped from the surface. This high pressure is also present on the gudgeon pin (wrist pin) in diesel engines, therefore the need for ZDDP in all diesel engines. Now there is no denying that there is a problem, lack of ZDDP (Zinc Dialkyl DithioPhosphate) in modern oils kills at least our cams and tappets. There seems to be no known alternative.

Comp Cams put out “#225 Tech Bulletin: Flat Tappet Camshafts”. They have both an assembly lube and an oil additive. The telling sentence in the bulletin was “While this additive was originally developed specifically for break-in protection, subsequent testing has proven the durability benefits of its long term use.

This special blend of additives promotes proper break-in and protects against premature cam and lifter failure by replacing some of the beneficial ingredients that the oil companies have been required to remove from the “off-the–shelf oil”.

Our cars are a small percentage of the total market and BIG Corporate, the American Petroleum Institute and possibly government have made decisions that are detrimental to our cars. This problem isn’t going away. The trend today is to lighter weight oils to decrease drag, which increases mileage. Most of these seem to be the “Energy Conservation” oils that we cannot use.

Now the important information: Oils that may be correct for our cars today: (As reported by manufacturers by 12-31-06, NOTE: many have changed their recommendations over the last three months!

Castrol:

Syntec 5W-40, Syntec 20W-50, Grand Prix 4-Stroke Motorcycle oil in 10W-40 and 20W-50,

TWS Motorsport 10W-60*, BMW Long Life 5W-30*

(full synthetic, available only at BMW dealerships)

Red Line:

10W-30, 10W-40 (Synthetic oils)

Valvoline:

VR-1 20W-50 (Conventional oil)

Amsoil:

20W-50(TRO), 10W-40(AMO), 15W-40(AME) & 20W-50(ARO)

Mobil:

Mobil 1 5W-30 and 20W-50 (Synthetic)

Chevron:

Delo 400Shell: Rotella

This list will change in the next months with Castrol and Red Line adding products just for our cars

Courtesy Keith M. Ansell, Foreign Parts Positively, Inc.

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