New Honda Engine Spinning With Rest of World
WardsAuto.com, Sep 20 2005
Honda is phasing out an esoteric quirk in its 4-cyl. engines.
EAST LIBERTY, OH – There is plenty to like about the new 1.8L SOHC 4-cyl. powering most versions of the all-new ’06 Honda Civic.
The engine is 10%-21% more powerful than the 1.7L 4-cyl. it replaces; it is the most fuel-efficient 4-cyl. in the compact segment; and there are numerous clever design features, a hallmark of Honda Motor Co. Ltd.’s engine design.(See related story: Honda Couldn’t Wait to Crank Up New Civic)
But one esoteric aspect of the Civic’s new 1.8L SOHC I-4 particularly will please those responsible for engineering the myriad components that go into the engine, or must work in conjunction with it: This engine’s crankshaft rotates clockwise.
Since the beginning of Honda’s transportation-engine development, its engines of less than 6-cyl. have turned counter-clockwise, a practice at odds with every other modern production-line automotive engine.
There have been other engines with crankshafts designed to rotate counter-clockwise, but they have been rare – General Motors Corp.’s horizontally opposed 6-cyl. for the Chevrolet Corvair turned counter-clockwise. There are none today.
The story goes that early Honda engines were designed to run counter-clockwise to facilitate certain package constraints and to simplify transmission design. The layout became the legacy of all Honda transversely mounted automotive 4-cyl. engines.
But when Honda engineered the K-series DOHC 4-cyl. engine family launched in 2000 for various Honda and Acura-badged models, it was designed with a crankshaft that rotates clockwise.
Engineers, suppliers and makers of some aftermarket components long have complained Honda 4-cyl. engines’ counter-rotating was counterproductive to standardizing components.
Other problems developed when engineers used Honda engines with transmissions and other components, assuming the engine would operate with clockwise rotation.
If Honda was to supply 4-cyl. engines to another auto maker, as it does with V-6s for General Motors Corp. (all Honda V-6s have been designed from the start to run clockwise), the difficulties in mating the 4-cyl. to many components, chiefly a non-Honda transmission, would make such an arrangement highly problematic.
Now, by ditching the Civic’s old counter-clockwise 4-cyl. in favor of the new 1.8L that spins in the “right” direction, Honda aligns itself with the rest of the automotive world.
All Honda 4-cyl. engines built in North America now have crankshafts that spin clockwise. The move also facilitates Honda’s own sharing of transmissions between engine families.
There remain some Honda automotive engines in other markets and for niche models that continue to run counter-clockwise, a Honda powertrain source at a media event here says, but those engines apparently will be superceded some time in the future.
“The clockwise rotation makes it easier to develop more domestic (North American) suppliers,” the powertrain engineer adds. He says while many suppliers in Japan have adapted to Honda’s quirky engine practice, those outside Asia often have found it difficult to adapt.
Meanwhile, in addition to several unique new casting features in the block and cylinder head, the new all-aluminum 1.8L SOHC I-4 also benefits from a new “plateau honing” technique for its cast-iron cylinder liners that engineers say reduces friction by about 1.4%.
That reduction translates into a fuel-economy improvement of about 0.8%, they say.
The plateau-honing process, which creates a mirror-like finish that better retains lubrication, adds an extra machining step and a marginal amount of time to the total machining process, but engineers say it is not enough to adversely affect throughput times.