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Re: [Land-speed] Bad vibes

To: "LandSpeed List" <Land-speed@autox.team.net>
Subject: Re: [Land-speed] Bad vibes
From: "John Burk" <joyseydevil@comcast.net>
Date: Tue, 31 May 2011 14:18:45 -0400
Don

Custom 180 deg crank or Ford 90 deg ? 90 deg would give non-symmetrical 
firing spacing . 292 Chevy 6 drag engines shake flywheels loose  but Ford 
300 6s don't because of compatible / incompatible crankshaft harmonic 
frequencies . Small dia multi disc clutch would help . Some Chevy racers use 
tapered shank flywheel bolts and  holes .





> Anyone silly enough to cut an engine in half should probably expect  to 
> encounter some "unusual" problems along the way. During a recent  dyno 
> pull, our half Windsor (3 liter inline four) sheared off all six  Locktite 
> secured 7/16" ARP flywheel bolts, and almost welded the  flywheel to the 
> crank. Seems that we have a harmonic vibration  problem that has created 
> more force than our system can tolerate.  So.......... we probably need to 
> strengthen the parts and reduce the  "bad vibes".
>
> The most obvious action would be to strengthen the parts by  increasing 
> the bolt diameter, adding some dowels, and making sure  that everything 
> fits. Reducing the the force could be a little more  difficult.  The 
> balancer (cheapo fluid type) is clearly not up to the  task and should to 
> be upgraded to something more in tune with this  engine's harmonic 
> characteristics.  I really don't have any  experience in this area and 
> would  greatly appreciate any thoughts  that list members would care to 
> share.
>
>                  Thanks, Don
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