Muscle Car Tech

Objective:

Provide facts outlining lubrication requirements of flat tappet camshaft engines and the importance of higher levels of zinc and phosphorus.


Issues:

Flat tappet camshafts undergo extreme pressure and loads, thus requiring an engine oil that is fortified with anti-wear additives to provide premium protection. The severity of higher spring pressure in racing engines also creates the need for additional wear protection.

Click on image to enlarge

Technical Discussion:

The most commonly used anti-wear additive in motor oils is zinc dialkyldithiophosphate (ZDDP). ZDDP contains both zinc and phosphorus components working together to provide anti-wear protection, and is most important during cam “break-in” procedures. Proper break-in lubes should be used during the break-in phase for all new or rebuilt engines with flat tappets. These lubricants provide the extra protection required to reduce wear at the point of contact during break-in and help the flat tappet face properly mate with the cam lobe. Once the break-in phase is completed, AMSOIL motor oils, which are formulated with high levels of zinc and phosphorus, will provide premium protection to flat tappet cams.

The American Petroleum Institute (API) and International Lubricants Standards Approval Committee (ILSAC) have mandated the reduction of phosphorus to extend catalytic converter life. However, reducing the level of ZDDP can compromise protection to engine components, most notably in flat tappet camshafts. Current API SM and ILSAC GF-4 specifications for gasoline engines have maximum and minimum phosphorus levels of 800 ppm and 600 ppm, respectively, for SAE 0W-20, SAE 5W-20, SAE 0W-30, SAE 5W-30 and SAE 10W-30 motor oils. All other gasoline SAE grades do not have a mandated phosphorus limit.

All engines, especially high-performance modified engines, benefit from oils with superior film strength and anti-wear properties. The flat tappet/camshaft lobe interface is the one area in an engine that has extreme contact load. Since this load increases significantly when non-stock, high-pressure valve springs are employed, the use of properly formulated motor oils is extremely important to reduce wear and extend flat tappet/ camshaft life.

Recommendation:

AMSOIL recommends motor oils containing high levels of zinc/phosphorus for superior protection. The table below lists many of the AMSOIL synthetic motor oils that are formulated with high levels of anti-wear additives:

Click on image to enlarge

AMSOIL AMO, ARO, HDD, AME, RD20, RD30, RD50 and AHR all contain high levels of zinc/phosphorus, maximizing flat tappet/camshaft life in stock modified and high-performance applications.

---

AMSOIL 10W-40 (AMO) is a premium synthetic formulation which is recommended for API SL (gasoline)/CI-4 Plus (heavy-duty, on-road diesel) specified applications. It is an outstanding choice where high zinc containing protection is required in late model hot rods requiring extra camshaft protection.

*AMSOIL 10W-40 (AMO) is the offical motor oil used in the Amsoil/Mopar Muscle Engine Challenge*


Tech Article: Choosing The Best Oils For Your Mopar Engine - Lifeblood Picking The Right Oil For Your Mopar Muscle Car

---

AMSOIL 20W-50 (ARO) is a premium synthetic formulation which is recommended for API SL (gasoline)/CI-4 Plus (heavy-duty, on-road diesel) specified applications. It is an outstanding choice where high zinc containing protection is required in late model hot rods requiring extra camshaft protection.

---

AMSOIL (HDD) is a 5W-30 weight combination diesel/gasoline oil with a higher starting TBN to handle the significant stresses from high soot loading and acid generation in modern diesel engines. HDD contains the high phosphorus and zinc required for long life.

---

AMSOIL 15W-40 Synthetic Heavy Duty Diesel and Marine Motor Oil (AME) is engineered for use in a wide variety of light and heavy-duty applications. AME is formulated with high levels of zinc and phosphorus to ensure protection of flat tappet camshaft lobes in high performance diesel engines.

---

AMSOIL Dominator Synthetic 5W-20, 10W-30 and 15W-50 Racing Oils (RD20, RD30, RD50) are all formulated with the same robust additive package. These oils are heavily fortified with zinc and phosphorus to protect flat tappet cams in the most extreme racing conditions.

---

---

---

AMSOIL (AHR) is a super heavy SAE 60 weight racing oil de-signed for alcohol and nitro burning race engines where viscosity loss associated with fuel dilution is a concern. AHR includes a high dose of zinc containing anti-wear chemistry that race engines require.

---

Buying high zinc motor oil? Pick up an oil or air filter for your vintage vehicle and save yourself a trip to the parts store.

Click on image for look-up guide

---

At the Performance Racing Industry trade show in Orlando, Fla. in December 2006 AMSOIL announced its new affiliation with Mopar Muscle magazine to become “Official Oil” of the MOPAR Muscle Engine Challenge.