Metric Mechanic m3 engine series
Posted: Mon Feb 17, 2020 9:27 pm
General Engine Description
Straight from the factory, BMW M3’s are great
performance sedans! With their bigger brakes, better
suspension and more powerful high rev engines, the
M3 engine is strong, well built and reliable even
though more aggressively driven. The average engine
life expectancy is about 140,000 to 150,000 miles.
But some owners feel the M3 lacks low to midrange rpm “grunt”. In other words, it doesn’t pull
to their liking below 4,500 rpms. Metric Mechanic’s “fix” is to enlarge the engine. We up the bore
from 93.4 mm to 95 mm and increase the stock 84
mm stroke to 87 mm. Enlarging the intake ports
from 26 mm to 29.5 mm, helps the engine breath.
The net result is a bigger engine with improved
low end and mid range torque, and expanded top
end breathing - in other words - a 2.5 liter M3
Straight from the factory, BMW M3’s are great
performance sedans! With their bigger brakes, better
suspension and more powerful high rev engines, the
M3 engine is strong, well built and reliable even
though more aggressively driven. The average engine
life expectancy is about 140,000 to 150,000 miles.
But some owners feel the M3 lacks low to midrange rpm “grunt”. In other words, it doesn’t pull
to their liking below 4,500 rpms. Metric Mechanic’s “fix” is to enlarge the engine. We up the bore
from 93.4 mm to 95 mm and increase the stock 84
mm stroke to 87 mm. Enlarging the intake ports
from 26 mm to 29.5 mm, helps the engine breath.
The net result is a bigger engine with improved
low end and mid range torque, and expanded top
end breathing - in other words - a 2.5 liter M3