SPORT COMPACT TECH:
GM's ECOTEC Engine Pushes Into New Frontier of High Performance
By Jennifer Chestnut
DETROIT, September 3, 2002 - When GM Racing engineers were assigned
the task of developing a competitive power plant for their new Sport-Compact
Drag Racing program, the ECOTEC 2.2-liter four-cylinder engine provided
a solid platform for them to launch this ambitious program. Now after
almost 16 months of intense research and development work, and with
the completion in sight of GM Racing's first full season of sport-compact
drag racing, the turbocharged ECOTEC 2.2-liter engine used in this
endeavor is rocketing towards uncharted territory.
"The durability of ECOTEC's production piece is unbelievable,"
said Russ O'Blenes, GM Racing engine program manager. "When we
first started on this project, the fundamentals of strength and endurance
needed to get the job done were already in place. We've taken production
engines, abused them and tried to hurt them in every which way, and
it's just hard to hurt one of these bad boys."
Starting with a bone stock ECOTEC 2.2-liter engine in April, 2001,
O'Blenes and Steve Bothwell, engine development manager at Bothwell
Racing, were able to produce 140 horsepower using a dyno at Shaver
Specialty Engines in Torrence, Calif. By removing the exhaust system
from the ECOTEC they were successful in increasing the horsepower
reading to 170. Adding nitrous to the ECOTEC power plant raised the
horsepower output to approximately 250.
After evaluating their data, GM Racing engineers made changes to the
connecting rods and pistons. Using nitrous, ECOTEC's power output
increased to approximately 350 horsepower.
Since the cylinder block on the ECOTEC is an open deck, which means
the cylinder walls float freely, GM Racing engineers machined-out
the cylinder walls and made their own steel sleeves that were pressed
to the block. At 500 horsepower there was also a change from the production
head gasket to a copper head gasket with O-rings.
GM Racing engineers then began weaning the ECOTEC off nitrous, added
a turbocharger, and increased the air flow in the cylinder heads by
opening up the intake and exhaust ports, taking the horsepower level
up to 650. By making additional changes in the cylinder lining and
cylinder heads, GM Racing engineers have been steadily increasing
the ECOTEC's output to where they are now on the threshold of 1000
"A major portion of the parts that we use on our ECOTEC race
engine are currently production pieces," said Bothwell. "We've
performed modifications to the crankshaft, the connecting rods and
the pistons. We've put new cylinder sleeves in the block and we've
reinforced the stock cylinder head in two places to add strength to
it. We've also done some special machining to the cylinder head to
allow more air to flow in and out of the motor.