Though it might look like...
Though it might look like a nearly stock '02 Collector Edition Trans Am convertible, it's
actually powered by a 454 cubic-inch, 630 horsepower LSX crate engine. The engine will soon be available through GM Performance
As we saw in the last installment of Department X, with its 505-horse LS7 GTO, GM Performance
Parts is getting quite aggressive with its crate engine program, particularly with the LS series engines. By offering car
builders a very viable alternative to the traditional rebuilding of a worn-out engine or sciencing out a high-horsepower combination,
GMPP is putting its engineering assets and expertise in the hands of hobbyists looking for a leading-edge engine combination
without the hassle of ironing out all of the bugs.
Dr. Jamie Meyer, GMPP's product integration manager, has
been heading up the construction of a variety of project cars for the company, which address the types of installation hassles
that both professional and do-it-yourself builders might encounter. The result of this sort of hands-on research has not only
been the finished cars, but also the development of support products like the LS series engine controllers that greatly simplify
the installation of these high-tech V-8s in just about anything with four wheels.
This time around, we are
focusing our attention on the new LSX engines, an extreme-duty, cast-iron version of the LS Series V-8 that offers racers
and street machiners the opportunity to build max-effort engine combinations, which can take the punishment of high-rpm, high-boost
or nitrous combinations developing up to 2,500 horsepower.
Huge Stainless Works exhaust...
Huge Stainless Works exhaust tips barely fit in the stock recesses of the rear bumper. This
particular car is actually an '01 Trans Am and was originally used by the Firebird Brand Team as the prototype for the '02
Collector Edition Trans Am.
The LSX block was designed by GM, with the help of Pro Stock legend
Warren Johnson. "The Professor of Pro Stock" was enlisted to aid the program, as his decades of racing experience
offered real-world insight on building strength into the design without adding excessive weight.
while available in bare form for individualized use, is also the basis of the upcoming LSX crate engine. It's a 454 cubic-inch
beast, putting out nearly 650 hp, at a price that makes it competitive with the more traditional methods of achieving that
power level with a production V-8.
The prototype LSX crate engine is an extremely impressive combination.
Displacing 454 cubic inches, the engine uses a 4.185-inch bore with a 4.125-inch stroke. The cast-iron block uses a siamesed
cylinder wall design to accommodate the large bore. Additional beefing comes in the way of six head bolts per cylinder (the
block still accepts the production 4-bolt configuration) and LS7 steel six-bolt main caps. Reverse-dome Mahle 11:1 pistons
are mated to 6-inch Lunati forged steel rods and a Lunati forged steel crank.
Cylinder heads are specific
LSX aluminum units. They are very similar in overall design to the LS7 version, but feature an additional row of head bolts
for a total of six per cylinder, increasing clamping force and greatly reducing the resistance to head gasket failure due
to excessive cylinder pressures.
The castings feature stock LS7 roller rockers (1.8:1 ratio), titanium LS7
intake valves (2.20-inch) and sodium-filled exhaust valves (1.61-inch). These LSX prototype heads flow 360 cfm on the intake
at 0.700-inch lift. This is significantly more than even the legendary Ram Air V heads could muster in stock form.
the induction side is an LS7-sourced composite upper intake manifold with an aluminum base employing the same 90mm throttle
body and 40 lb/hr Bosch injectors as the LS7. Ignition chores are handled by the familiar LS-series individual coil pack system.
Cams custom-ground a camshaft with 236/246-degree duration at 0.050, 0.630-inch lift, and a 110-degree lobe separation. With
the forged bottom end and rev-happy valvetrain, the LSX 454 can easily withstand a 7,000-rpm redline.