AMSOIL Break-In Oil is an SAE 30
viscosity grade oil formulated without friction
modifiers to allow for quick and efficient
piston ring seating in new and rebuilt
high-performance and racing engines. It contains
zinc and phosphorus anti-wear additives to
protect cam lobes, lifters and rockers during
the critical break-in period when wear rates are
highest, while its increased film strength
protects rod and main bearings from damage.
AMSOIL Break-In Oil is designed to increase
compression, horsepower and torque for maximum
Quickly Seats Rings
The primary goal during engine break-in is to
seat the rings against the cylinder wall.
Properly seated rings increase compression,
resulting in maximum horsepower; they reduce oil
consumption and prevent hot combustion gases
from entering the crankcase. To achieve this,
however, the oil must allow the correct level of
“controlled wear” to occur between the cylinder
wall/ring interface while maintaining wear
protection on other critical engine parts.
Insufficient break-in leaves behind peaks on the
cylinder wall that prevent the rings from
seating. The deeper valleys, meanwhile, allow
excess oil to collect and burn during
combustion, increasing oil consumption. Too much
wear results in cylinder glazing due to peaks
“rolling over” into the valleys and preventing
oil from collecting and adequately lubricating
the cylinder wall.
AMSOIL Break-In Oil’s
friction-modifier-free formula allows the sharp
peaks on newly honed cylinder walls (fig. 1) to
partially flatten. The result produces more
surface area for rings to seat against, allowing
formation of a dynamic seal that increases
compression, horsepower and torque (fig. 2).
Parts from Wear
New flat-tappet camshafts and lifters are not
seasoned or broken in and must be heat-cycled to
achieve proper hardness. During the break-in
period, these components are susceptible to
accelerated wear because they are
splash-lubricated, unlike other areas of the
engine that are pressure lubricated. AMSOIL
Break-In Oil contains high levels of zinc and
phosphorus (ZDDP) additives designed to provide
the anti-wear protection required during this
High-performance and racing engines often use
aftermarket parts designed to increase torque
and horsepower. The added stress can rupture the
oil film responsible for preventing harmful
metal-to-metal contact on rod and main bearings.
The base oils in AMSOIL Break-In Oil provide
increased film strength to protect bearings from
AMSOIL Break-In Oil is designed to effectively
break in high-performance and racing engines
requiring SAE 30 oil, helping maximize
compression, horsepower and torque.
The engine builder’s or manufacturer’s break-in
recommendations should be followed if available.
Break-in period should not exceed 1,000 miles.
When the rings fail to seat, the exhaust ports
will have a large area of oil residue (Fig. 3).
As the rings begin this process, less oil is
passed and the oil residue area begins to shrink
(Fig. 4). When the rings are fully seated and
have formed a tight seal against the cylinder
walls, no oil residue will be evident. Other
common methods to determine if rings have seated
include performing a leak-down test or
horsepower measurements over time. Break-in
duration will vary between engines. Afterwards,
drain and fill the engine with an AMSOIL
high-performance synthetic oil that meets
builder or manufacturer specifications.
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). MSDS’s are
available upon request at 715-392-7101 or on the
Corporate AMSOIL website MSDS page. Keep Out of
Reach of Children. Don’t pollute. Return used
oil to collection centers.
For AMSOIL warranty
information, visit the
Corporate AMSOIL website warranty page.