Subaru Reworks Its 21-Year-Old Boxer Engine

(From Articlee In New York Times,September 24th 2010 edition)

 

 

The new Subaru engines are coming in the same sizes as the old ones, but the United States will get only the 2.5 liter.

Now that Subaru’s engine is old enough to drink, the automaker has taken steps to make it less thirsty. Subaru announced on Thursday that it has redesigned the horizontally opposed 4-cylinder boxer engine that has been a key component of its vehicles for many years. This reworking marks the first substantial change to the engine since the current version was introduced in 1989.

 

Horizontally opposed engines incorporate two banks of cylinders. But unlike most other engines, where the two banks rise to form a V, the cylinders of a horizontally opposed engine lie flat on each side of the crankshaft. When the pistons move they push out to either side, like the punches of a boxer -– hence the “boxer” name. Because a boxer engine is flatter than a conventional design, the vehicle’s center of gravity can be lowered -– a factor in vehicle handling.

 

Like the current Subaru engines, the new dual overhead cam engine will be built in 2-liter and 2.5-liter versions. But only the 2.5-liter will be available in American-market vehicles.

 

The power plant’s most significant new feature is a lengthening of the crankshaft stroke and a reduction in the size of the cylinder bores. While the overall displacement is virtually the same as that of the earlier engine, the move to a longer stroke reportedly improves combustion efficiency and fuel economy, while generating more low-speed torque. Other changes include revised intake ports, variable valve timing and the implementation of exhaust gas recirculation for combustion chamber cooling. An overall reduction in the weight of moving parts contributes to fuel efficiency

 

Dominick Infante, a Subaru spokesman, said that the first application of the new engine design in the United States would be in the 2011 Subaru Forester. In that vehicle, the engine is rated at 170 horsepower, which is the same output as the previous engine. However, fuel economy has improved by 1 m.p.g. to 21 city/27 highway. Emissions were said to be reduced as well.

True

 

http://www.autoblog.com/2010/09/23/subaru-debuts-third-generation-boxer-four-cylinder-engine/

 

And the heads cooled by their own water jackets solves the HG issues.

true

 

http://www.autoblog.com/2010/09/23/subaru-debuts-third-generation-boxer-four-cylinder-engine/

 

and the heads cooled by their own water jackets solves the hg issues.

 

hopefully!!!