I'm going to Amsoil Z-rod 10 W 30 AS THE zinc and phosphorus compounds have been lowered in most oils...The Z-rod has kept up the zinc and phosphorus compounds to help prevent Flat tappet wear....
Below are comments ,in 2007, about Rotella T 15W40
The zinc compound abbreiviated ZDDP, is an extreme pressure additive that helps keep flat tappet camshafts from wearing out.
About a year ago, all gasoline oils went from the old SL spec to the new "emissions" SM forumulation. This is the grade that is in the little circle on the back of the bottle.
Anyway, this was done because it was found that the anti-wear additives -could- cause problems with catalytic converters if the car burned a lot of oil. This mostly concerns cars with over 100k miles.
The new oils have a lower concentration of zinc and phosphorus compounds. Bad news on the Valvoline Racing Oil... It held onto the older SL rating for a while, but the latest stuff I saw at the store had the emissions SM rating. This was both the 20w50 and the straight 50.
Diesel oil has traditionally had more anti-wear compounds than gas oil. However, with the current low emission diesel engines that also use a form of a catalytic converter, their oil has also changed. The old pre-emissions oil had a CI-4 rating. The new stuff has a CJ-4 rating. The new rating wasn't done THAT long ago, and some CI-4 oil is still on the shelf. THIS is the stuff to use in flat tappet engines! CHECK THE RATING!
Cut/
AMSOIL Z-ROD™ Synthetic Motor Oil is specially engineered for classic and high-performance vehicles. It features a high-zinc formulation to prevent wear on flat-tappet camshafts and other critical engine components, along with a proprietary blend of rust and corrosion inhibitors for added protection during long-term storage. Z-ROD Synthetic Motor Oil is designed to perform on the street and protect during storage.
AMSOIL, the leader in automotive synthetic lubrication, produced the world’s first API-qualified synthetic motor oil in 1972. Trust the extensive experience of AMSOIL, the First in Synthetics®, to do the best job protecting your engine.
Protects Flat-Tappet Cams
The lifters and cam lobes on flat-tappet camshafts common to classic and high performance vehicles slide rapidly against one another, producing high friction and heat. The friction between the two components can eventually wear down the cam and affect valve operation, ultimately resulting in lost engine power and reduced efficiency. In addition, these areas are splash-lubricated rather than pressure lubricated like other areas of the engine, which adds extra strain on anti-wear additives like the zinc and phosphorus in zinc dialkyldithiophosphate (ZDDP).
AMSOIL Z-ROD Synthetic Motor Oil is formulated with high levels of ZDDP to protect flat-tappet cams, lifters, rockers and other areas susceptible to wear. Its high-zinc, high-phosphorus formulation provides the extra wear protection these critical splash-lubricated components require.
Provides Long-Term Protection from Rust & Corrosion
AMSOIL Z-ROD Synthetic Motor Oil is formulated with a unique blend of rust and corrosion inhibitors to ensure maximum protection during long-term storage. To prove its effectiveness, AMSOIL submitted Z-ROD Synthetic Motor Oil to the Standard Test Method for Rust Protection in the Humidity Cabinet (ASTM D-1748). This test evaluates the rust-preventative properties of oil under high-humidity conditions, similar to those faced by a covered hot rod in a damp garage. The metal coupon treated with AMSOIL Z-ROD Synthetic Motor Oil showed no signs of oxidation after 192 hours, while the coupon treated with a leading competitor’s product failed the test after 24 hours.
APPLICATIONS
AMSOIL Z-ROD Synthetic Motor Oil is recommended for older or modified engines requiring either 10W-30 or 20W-50 motor oil. Z-ROD Synthetic Motor Oil meets API SL and earlier specifications, allowing for increased levels of anti-wear additives. ZDDP levels in Z-ROD Synthetic Motor Oil exceed the limits of API SM and newer specifications.
COMPATIBILITY
AMSOIL Z-ROD Synthetic Motor Oils are compatible with conventional and other synthetic motor oils. Mixing AMSOIL Z-ROD Synthetic Motor Oils with other oils, however, will shorten the oil’s life expectancy and reduce the performance benefits. Aftermarket oil additives are not recommended for use with AMSOIL Z-ROD Synthetic Motor Oils.
SERVICE LIFE
Because engines in classic cars, hot rods and other performance vehicles are generally modified, a universal oil drain interval recommendation for these applications cannot be given. Responsibility for determining the drain interval duration rests with the owner. As a general service guideline, the maximum drain interval for Z-ROD Synthetic Motor Oil should not exceed 5,000 miles or one year, whichever comes first. In heavily modified engines (e.g. forced induction, nitrous) the maximum drain interval should not exceed 3,000 miles or one year, whichever comes first.
HEALTH & SAFETY
This product is not expected to cause health concerns when used for the intended application and according to the recommendations in the Material Safety Data Sheet (MSDS). An MSDS is available via the Internet at
www.amsoil.com or upon request at (715) 392-7101. Keep Out of Reach of Children. Don’t pollute. Return used oil to collection centers.
For warranty information, visit
www.amsoil.com/warranty.aspx.
TYPICAL TECHNICAL PROPERTIES
AMSOIL Z-ROD 10W-30 Synthetic Motor Oil (ZRT)
Viscosity @ 100°C, cSt (ASTM D-445)
11.8
Viscosity @ 40°C, cSt (ASTM D-445)
72.5
Viscosity Index (ASTM D-2270)
157
Flash Point °C (°F) (COC) (ASTM D-92)
234 (453)
Fire Point °C (°F) (COC) (ASTM D-92)
248 (478)
Pour Point °C (°F) (ASTM D-97)
-45 (-49)
NOACK Volatility, % weight loss (g/100g) (ASTM D-5800)
5.2%
High Temperature/High Shear Viscosity
@ 150°C, 1.0 X 106 s.-1), cP (ASTM D5481)
3.6
Four-Ball Wear @ 40 kgf, 75ºC,
1200 rpm, 1 hr, scar diameter, mm (ASTM D-4172)
0.36
Total Base Number (ASTM D-2896)
9.0
They recmomend 100 hour gen oil changes....Charlie
