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Old 02-01-2010, 10:40 AM   #2
goof2
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Quote:
Originally Posted by karl_1052 View Post
Well, those are all big V8s with heavy pistons and valvetrain. Did you expect this 1650cc motor to use the same size valvetrain as a 5000cc V8?
I posted those vids to show with a lightweight valvetrain(which this motorcycle engine could have) can rev to high RPM limits.
It all comes down to the ability to control the valves, and with light valves and good springs, there is no reason that a pushrod engine won't rev past 10K.
While there is no reason it can't be done there are 3 reasons it isn't commonly done. 1) It costs money to make that lightweight drivetrain, 2) the lighter they make the valvetrain the more issues they may run in to with reliability, and 3) with only 2 valves per cylinder it is more difficult to fill the cylinders with air, the benefit of higher revs.

According to the Cycle World article below the engine makes peak power at 7800 rpm. I doubt it redlines much above 8,500 rpm.

http://www.cycleworld.com/article.as...&page_number=2
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