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Old 03-04-2011, 07:17 PM
franka franka is offline
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Location: Lakewood
Join Date: Jan 2006
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Mein Auto: E39 540i Sport
Originally Posted by bobdmac View Post
Franka, in thinking about this, the fuel vaporizing rationale for the "power grooves" might be more of an issue for carburated engines than for the finer and more readily vaporized fuel injected mixtures.
My thoughts on grooved valves are ...its a nice theory and maybe good on a small, long throw crank engines where rpms are low and fuel economy is the priority and therefore there is time in each cycle for the theory to work.

But otherwise velocity and volume rule.

If grooved valves did work we would see it used in some quantity but some auto mfgr. But like I said, I'm not aware of them being used by anyone and/or anywhere.

Regarding carb vs FI power differences...there is no significant difference in high power, high rpm engines.

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Last edited by franka; 03-05-2011 at 07:18 AM.
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