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Re: OHC vs OHV



In a message dated 1/7/2004 9:41:56 PM Eastern Standard Time, egrohe@xxxxxxxxxx writes:

> Another reason BMW probably uses rockes and push rods is because the engine
> would have to have the intake valves at the top of the head and the exhaust
> at the bottom if they wanted to do OHC direct actuation or 
> even a central
> SOHC with rockers. Sorta like the Goldwing.
> 
> Eckhard Grohe

The reason they are like this on the goldwing is because there are multiple cylinders.  The only place there isn't an adjacent obstruction is on the top and bottom.  The Single cylinder on a bmw is round, with no adjacent obstruction, hence the intake and exhaust and be placed anywhere.  I even read about someone who reversed the flow, making the exhaust side the intake and the exhaust on the down stream side ( old intake location) The theroy was that the air flow would follow the flow of air over the bike at speed.  Sounds logical doesn't it?   Apparently it had no advantages and some disadvantages.  Machines don't always think like we do.  And the laws of Physics are a Bitch!.  Fortuantely they are the only laws Congress haven't been able to MUCK up!.

paige

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