Date:         Fri, 9 Oct 1998 07:13:03 -0700
Reply-To:     Robert Lilley <vwvanman@MAILEXCITE.COM>
Sender:       Vanagon Mailing List <Vanagon@vanagon.com>
From:         Robert Lilley <vwvanman@MAILEXCITE.COM>
Organization: MailExcite  (http://www.mailexcite.com:80)
Subject:      Re: Engine Rebuild
Comments: To: DJD <dalwin@netinc.ca>
Comments: cc: vanagon@vanagon.com
Content-Type: multipart/mixed;

 The reason that I am planning to use the “cut to fit push rods” is so that I can get a stronger (and lighter) push rod for use with the higher lift rocker arms.  The use of the “Porsche 911” swivel rocker feet is that the arm will require little to no modifications to the rocker arm.  I plan to set up the rockers with the proper ratio.  The use of the swivel feet will reduce the side loading of the valve stem that can happen when the lift is increased.  Another reason I will go with 1.25 not 1.4.  I am also trying to get a different cam profile that would work better with the CPU chip to possibly eliminate the need for ratio rocker arms.  I will probably be boring the cylinders to 96 mm and offset grinding the crank .7 mm this will increase size to 2221cc’s. The compression ratio will also be increased slightly.  The chip enhancement should be able to handle the small displacement increase.


VWVanman

--

On Thu, 08 Oct 1998 16:56:44   DJD wrote:
>You seem to have missed the point on Cut To Length Pushrods and Rocker
>Arm Geometry. The idea is to have the shaft for theSwivelFoot Adjuster
>perpendicular to the valve stem @ 50% lift. The shims move the center of
>the SFA so that at 50% lift it is perpendicular and CENTERED OVER THE
>VALVE STEM. This way the effort to operate the valves isn't excessively
>high=more effective HP, and wear on the valve guides is reduced as the
>valves aren't being pushed away at an excessive angle.
>Either HotVW's or VW Trends recently had a good article on setting up
>rocker arm geometry. Any time I've done any performance work (read: many
>times!) involving ratio rockers, performance cams or compression
>changes, you HAVE to correctly set the geometry or you'll have wasted
>much money on a motor that isn't operating at it's peak potential.
>Good luck, your motor sounds like it's going to be an awesome piece of
>work.
>
>


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