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Old 02-10-2007, 09:26 AM   #12
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Join Date: May 2006
Location: Northeast USA
Posts: 910
Originally Posted by bmwm750
When you start factoring in the forcres than a reciprocating, internal combusion engine undergoes, the 1G of gravity pulling the engine and its internals downward is a very minscule percentage of the lods that combusion forces place on the engine internals. Also, keep in mind that gravity is pulling on every part of the car and engine in a linear, constant force.
OK, pros are no counterbalancing and lower center of gravity. But I'm not quite convinced the 'con' should be waved off just like that. True, gravity pulls everything with a constant force but the most sensitive to it would be any pieces moving at a right angle to this force (like horizontally firing cylinders). There's nothing compensating for this pull. Combined with tight tolerances (cylinders almost touching the walls around them) this will cause stronger friction and rubbing on the bottom vs the top or the sides of the block walls. Over millions of cycles this has to have some cummulative effect. The only question is how large, I would think.

'06 Boxster S, 6sp, triple-black
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