As I understand it, there are two main reasons why Honda switched the rotation direction on the RSX and new Civics:

1) Move gearbox to other side of the car to improve L/R weight distribution

2) Move exhaust manifold to rear to reduce distance between the engine and catalytic converter, thus increasing the temperature of the cat and speeding its "light-off time." ULEV requirement?

Any other ideas?

 

3. To follow what the rest of the industry does. Everyone but honda i believe has engine rotating in this direction so it only made sense to conform. Plus, rumors persist that GM is interested in buying engines from Honda in the future and understanding that it's obvious that Honda would need to conform to the rest of the industry standard in order to make that a future possibility

And on #2, the cat and exhaust manifold stuff is independent of the rotation of the motor, that's just for emissions concerns mostly and crash safety.

 

true, but i think he is right. cant have the cat closer with a counter-clockwise motor... ive heard the ulev thing as well.

 

Huh? It's just a question of designing the head, intake manifold etc to conform the engine rotation configuration. Case in point. Look at all VW 4 cylinder 75-92. Intake on the back of the motor, exhaust manifold on the front. Then in 93 (using essentially the same block) they swapped the intake to the front and the exhaust manifold to the back (for emissions, crash safety, etc.)

That obviously required some redesign to the cylinder head, but it's certainly possible and Honda could have done that instead of switching the engine rotation direction.

 

ya ,guess it doesnt matter, but for some reason i cant picture it..