RE: [Chevelle-list] Back in the Day / Float the Valves?

[Brad Waller]

As others have already said, floating them is not good in most cases.  If you have lots of valve clearance, this can self limit the revolutions so that you don't break something really bad, like a rod or crank!  Since the valves don't seal the cylinder, you will lose power and should not over-rev the engine.  Of course, most high performance engines only have a tiny bit of clearance, so this is usually a bad thing.  Also, floating the valves stresses the valve springs big time and can lead to failure.  This could be breakage or weakening - which will mean they will float even earlier if you keep doing it. The power drop is just from the system design.  Valve timing, air flow, and other factors determine the torque at each RPM, and the torque starts to drop at some point and it continues to drop as RPM increases from then on because that is how the dynamics work.  Because the formula for horsepower is based on torque and RPM (HP=TQ*RPM/5252), horsepower peaks later, but also eventually drops off.   Valve float would kill power, but generally would happen after red line, and long after all peak power numbers - unless the springs are bad or incorrect. Brad Waller ([EMAIL PROTECTED]) '66 Corvette | 327/dead | 4-speed   | Wilwood Brakes | 245/45/16 BFG R1 '67 Chevelle | ex-SS396 | 355/700R4 | F-Body Brakes  | 275/40/17 Kumho MX From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of jim Sent: Thursday, October 13, 2005 1:00 PM To: The Chevelle Mailing List Subject: Re: [Chevelle-list] Back in the Day / Float the Valves? I use to road race motorcycles and floating the valves wasnt a good thing. it meant your valves springs were no longer doing there job and the valves werent seated when they should have been and compression and horsepower were going out the exhaust.I always thought  when looking at  dyno run charts in magazines that the horse power dropped at or just before"Red Line" because the valves were starting to float ?.    It would be nice to hear more about it from all you knowledgable guys on the list. Jimmy.C