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Engine Oils


                                            Oils          BY LAKE SPEED JR.

More has changed in oil than ZDDP              up of deposits also helps protect catalytic   What exactly is synthetic oil?
content in the last 10 years. The levels of    converters from “Zinc”, so modern             To answer that question you have to ask
detergents have also increased, and both       passenger car oil formulas now feature        another question. What is in a motor
are contributing factors in the flat-tappet    increased levels of detergents. You’ve        oil? Motor oil is a blend of performance
camshaft problems seen in the engine           probably seen the TV ads that promote         additives in a base oil. The additives
building industry over the last 4 to 5         oils that clean your engine. Those are        enhance the performance of the lubricant
years.                                         high detergent oils, and they are great       beyond the performance of the base oil.
    The oil additive Zinc Dialkyl              for modern passenger car engines. They        Typical additives are detergents, anti-
Dithiophosphate (commonly referred to          are not great for restoration and street      wear agents, friction modifiers, viscosity
as “Zinc” or ZDDP) provides anti-wear          rod engines.                                  modifiers and many other chemicals that
protection for engines — especially flat           The balance of “Zinc” vs. Detergents      help the lubricant meet the performance
tappet camshafts.                              has changed in the last several years in      requirements of an application. The base
    “Zinc” works because it is a polar         an effort to protect catalytic converters.    oil is the other part of a motor oil, and
molecule (it has a positive charge), so the    This shift in the balance away from           the base oil makes up the majority of the
“Zinc” molecule is attracted to steel.         “Zinc” and towards detergents has had         finished motor oil. Base oils typically
Under heat and load, the “Zinc”                a negative impact on flat tappet              come from 3 sources: refined crude oil,
molecule reacts with the steel and creates     camshaft life.                                synthetic base stocks, or vegetable oils.
a film. The film created by the “Zinc”             Why is this important? In the old         The vast majority of motor oils use
prevents metal to metal contact. That is       days, engine builders used SAE 30 grade,      refined crude oil as the base oil. These
how “Zinc” works to protect your               non-detergent oil to break-in an engine.      oils are commonly referred to as mineral
engine.                                        The break-in period is the most critical      oils or petroleum oils. Refined crude oils
    Detergents are also polar molecules,       time in the life of an engine. The non-       provide good lubricity at a lower cost,
and the detergent is designed to prevent       detergent oil was effective at establishing   but refined crude oils have a strong
build up of deposits in the engine.            a “Zinc” anti-wear film in the engine         tendency to oxidize at high temperatures
    As a result, both the “Zinc” and           during break-in because the “Zinc” did        (AKA breaking down). Because
detergents compete against each other          not have to compete against the               petroleum oils come out of the ground,
for the metal surface.                         detergent. As a result, the engine had        they contain many imperfections. These
    The reduction in “Zinc” in modern          better access to the “Zinc” it needed         imperfections lead to breakdown at high
passenger car grade oils relates to            when we needed it the most. Modern            temperatures. When an oil
catalytic converter life. The same coating     engines feature roller follower overhead      “breaksdown” it can create deposits in
effect that “Zinc” provides to protect         cam designs that reduce weight and            the engine. A synthetic oil is a man made
your camshaft also damages your                sliding friction. As a result, these          copy of petroleum oil without any of the
catalytic converter. To extend the life of     valvetrains don’t need higher levels of       “imperfections” that lead to
catalytic converters, “Zinc” content has       “Zinc”, but a Big Block Chevy has push        “breakdown”. As a result, synthetic oils
been reduced.                                  rods, a flat tappet camshaft and big steel    can safely handle much higher operating
    At the same time, detergent levels         valves. These older engines feature           temperatures compared to petroleum
have increased to provide better engine        increased sliding friction and weight.        oils. Because synthetic base oils are made
cleanliness, longer catalytic converter life   These engines need increased levels of        in a controlled environment, they are
and extended oil drain intervals.              “Zinc”. The oils originally developed for     100% pure, and that also allows
    The use of Exhaust Gas Recirculation       Big Block Chevys used less detergent and      synthetic oils to flow better at low
valves cleans up the emissions of an           more “Zinc” than modern engine oils.          temperatures. Synthetic oils can reduce
engine, but the use of EGR valves                  To protect a flat-tappet camshaft,        Cold Start Wear by up to 70%
increases the need for detergents due to       you need to properly break-in the             compared to Petroleum oils. Since Hot
increased temperatures and recirculated        camshaft with a high “Zinc” oil and           Rods and Restoration cars spend a lot of
combustion by-products.                        avoid high detergent oils for both break-     time in the garage, synthetic oils provide
    Detergents’ ability to prevent build       in and service fill.                                               continued on page 39

36 OCT-DEC 2009 engine professional

excellent flow when the engine is            oil. The API ratings tell you about the
started after being in the garage for        additive package in the oil. Since
a time.                                      1992 when the American Petroleum
                                             Institute (API) introduced the SM –
Is it safe to use synthetic oil in a         GF1 standard, the “Zinc” content in
flat-tappet engine?                          passenger car grades of motor oil has
After a proper break-in period on            been limited. The level of “Zinc” in
petroleum oil, a synthetic oil with the      passenger car oils was reduced again
proper balance of “Zinc” and                 in 1996 to 1,000 ppm under API SJ –
detergents will provide greater              GF2 standards. In 2001, API SL –
protection than a petroleum oil.             GF3 standards restricted “Zinc”
     Over the years, synthetic oils have     content to 850 ppm, and that is when
been criticized for their performance        cams started to fail. When the API
in older style engines. The problem          went to the current standard (SM –
has been the use of oils designed for        GF4), camshaft failures skyrocketed.
modern passenger cars in older style         In addition to the reduction in
engines. The synthetic base oil is           “Zinc”, detergent levels increased as
superior to conventional petroleum           each new API standard took effect.
base oils, but the additive packages in      An API SJ rated oil contained half the
modern passenger car formulations            amount of detergent that an API SM
will not provide the levels of               oil contains. The increase in
protection a flat-tappet camshaft
                                             detergents and reduction in “Zinc”
needs. The problem is not synthetic
                                             have been a double whammy for flat
oil. The problem is using modern oils
                                             tappet camshafts.
in older style engines. You shouldn’t
                                                  Because NASCAR forces the
use a racing oil in a daily driver, so
                                             Sprint Cup Series teams to run flat-
why would you use a modern daily
                                             tappet camshafts, Joe Gibbs Racing
driver oil in a restoration car?
                                             developed high “Zinc” oils to
Is it safe to use synthetic oils in          properly break-in our flat tappet
transmissions and rear ends?                 camshafts. The Joe Gibbs BR Break-
If the oil has the proper additives for      In oil is the number 1 selling break-in
the materials, it is safe to use             oil in the world. The Joe Gibbs BR
synthetic gear, transmission and             Break-In oil features a low detergent
power steering fluid in a street rod or      and high “Zinc” formula that allows
restoration car.                             the “Zinc” additive to create a
                                             protective film in your engine. Joe
What is an API rating? How is it different   Gibbs also offers a Hot Rod oil that
from an oil’s viscosity rating?              also features a high “Zinc” content
The viscosity ratings of the oil             with a normal detergent level just for
describe the cold start and high             non-emission controlled vehicles
temperature flow rates of the oil. A         (street rods, restorations, etc…). The
0W-30 flows better at start up than a        Joe Gibbs Hot Rod oil also features a
10W-30. The number before the “W”            US military grade rust and corrosion
is the cold start viscosity, so the lower    inhibitor that protects your engine
the number, the easier it is to start the    while the car is in storage for the
engine. The higher the number, the           winter. Conventional oils will run
more power it takes to turn the              down into the oil pan after extended
motor over when you hit the ignition.        periods of storage – leaving the
    The number after the “W” is the          engine vulnerable to rust and
high temperature flow rate of the oil.       corrosion. The Joe Gibbs Hot Rod oil
For example, while a 0W-30 flows             creates a tenacious oil film that will
better at start up than a 10W-30,            cling to the part no matter how long
both oils flow like a SAE 30 grade at        it sits in storage. This oil films
high temperature (212F). The higher          prevents air and moisture from
the number after the “W”, the                attacking your engine.I
heavier the oil is at higher
temperature. A 5W-40 is a heavier oil        Lake Speed Jr. from Joe Gibbs Racing is the son
at high temperature than a 5W-30, so         of Lake Speed Sr., who raced in NASCAR from
SAE viscosity ratings only tell you          1980 to 1998. For more information, call at 704-
about the flow characteristics of an         239-4401 or email

                                                     engine professional OCT-DEC 2009 39

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