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 The 2002
Firebird Trans Am was the last in a line of powerful Pontiac muscle cars.
Introduced in 1967, the Trans Am competed with the Chevy Camaro, Mercury
Cougar, and Ford Mustang during the golden age of big-block engines. In 2002,
Pontiac added an 8-cylinder, 16-valve LS1 engine for the
Trans Am's final model year. This 5.7-liter, 347-cubic inch powerplant featured
an aluminum block with aluminum heads, and a robust compression ratio of
10.1:1.
Trans Am Engine Restoration
For fans of
the Pontiac Trans Am, restoring a used LS1 engine is a labor of love. At ls1tech.com, an
automotive website with forums for gearheads, a mechanic named ckpitt5 shared
an engine rebuild story that's familiar to many do-it-yourselfers. After making
a build list and sending the big V8 engine out for machining, ckpitt5 explained
why he chose to re-assemble the engine himself. "I have too much energy and
money invested to trust that process to someone else," the engine builder said.
Honing Stones vs. Ball Hones
After cleaning
and installing new cam bearings, ckpitt55 checked the cylinder bores and made
an important discovery. Honing stone "residue" left in machining marks would
"eat" his new piston rings. Wiping down the cylinders was easy enough, but the bores
still had burrs and "high spots" that would interfere with proper piston ring
seating. That's when this experienced engine builder used the Brush
Research Manufacturing (BRM) Flex-Hone tool, the engine
hone for a superior surface finish.
Flexible Cylinder Hones for Deburring
BRM's ball hone is a flexible cylinder honing
tool that mounts in a handheld electric drill and removes cut, torn, and folded
metal to produce a long-wearing surface. Self-centering and self-aligning to
the bore, this flexible engine hone is great for deburring, a post-machining
operation that's critical in more than just automotive
applications. By smoothing peaks and eliminating ragged metal edges,
machinists and mechanics alike can remove burrs that impede the performance of
machined parts.
BRM Ball Hones for Plateau Finishing
The BRM Flex-Hone
tool also produces a cross-hatched pattern that helps oil adhere to cylinder
walls. To promote optimum lubrication, the flex ball hone uses a soft cutting
action that leaves the base metal undisturbed. The low-temperature abrading
process produces a plateau
finish that helps piston rings to seat properly - and without damaging
their edges. BRM pioneered the concept of plateau honing, a surface finishing
technique that also reduces seepage in hydraulic and
pneumatic applications.
How to Hone a Cylinder
For ckpitt5,
running the Flex-Hone "very briefly on the cylinder bore" produced a surface finish
that also eliminated a stubborn cam bearing problem. Rebuilding a Trans Am
engine takes time, of course, but honing cylinder walls with the BRM plateau
hone is a job that engine mechanics enjoy. Have you used the BRM ball hone for
deburring, plateau finishing, or cylinder wall deglazing? Share your automotive
story with us by commenting on this blog entry.
Author's
Note: The CR4 blog entry originally appeared in BRM's
Flex-Hone Blog.
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Re: Engine Hones for Cylinder Bore Deburring and Plateau Finishing
