The Spares Company
Club Shop/Regalia
Parent Website
Contact Officials
Machine Registrar
Club Secretary
Membership Secretaries
MPH Editor and Forum Administrator.
Section Newsletters
Technical Databases
Photos
Home
What's new
Latest activity
Forums
New posts
What's new
New posts
Latest activity
Information
Bike Modifications
Machine Data Services
Manufacturers Manuals
Spare Parts Listings
Technical Diagrams
Whitakerpedia (Vincent Wiki)
The Club
MPH Material Archive
Flogger's Corner
Obituaries
VOC Sections
Local Sections
Local Section Newsletters
Miscellaneous
Club Assets
Club History
Club Rules
Machine Data Services
Meeting Documents
Miscellaneous
Essential Reading
Magazine/Newspaper Articles/Letters
Adverts and Sales Brochures
The Mighty Garage Videos
Bikes For Sale (Spares Company)
Log in
Register
What's new
New posts
Menu
Log in
Register
Install the app
Install
Home
Forums
Forums: Public Access
Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Camshaft design
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Deleted member 3831" data-source="post: 92224"><p>When discussing camshaft design, no one as yet has made comment on rocker flex, and how it will affect the valve lift curve. The Vincent rocker is extremely weak from the stiffness viewpoint, and the amount of flex that occurs in a running engine is considerable. If this is not allowed for in the static design, the end result will always be considerably reduced dynamic valve lift curve</p><p>Has anyone tested a rocker to see how much it flexes ? For those interested the attached illustration shows the method. If the X1 dimension is 300 mm, and the X2 dimension is 50 mm, an 8 to 10 Kg weight is sufficient, but the measured flex will be an alarming amount.</p><p>For a really stiff rocker, the flex should ideally be 0.002" but up to 0.007" is passable, and above 0.007" the valve lift loss will start to become excessive. </p><p>The flex is due to the lack of depth in the arms, and the inadequate material around the pivot.</p><p>This situation is impossible to realistically improve on while still retaining the stock installation arrangement, but the modified rocker mounting illustrated in an earlier post presented an ideal opportunity to improve the rocker stiffness dramatically. Unfortunately in the photo it seems not to have been done.</p></blockquote><p></p>
[QUOTE="Deleted member 3831, post: 92224"] When discussing camshaft design, no one as yet has made comment on rocker flex, and how it will affect the valve lift curve. The Vincent rocker is extremely weak from the stiffness viewpoint, and the amount of flex that occurs in a running engine is considerable. If this is not allowed for in the static design, the end result will always be considerably reduced dynamic valve lift curve Has anyone tested a rocker to see how much it flexes ? For those interested the attached illustration shows the method. If the X1 dimension is 300 mm, and the X2 dimension is 50 mm, an 8 to 10 Kg weight is sufficient, but the measured flex will be an alarming amount. For a really stiff rocker, the flex should ideally be 0.002" but up to 0.007" is passable, and above 0.007" the valve lift loss will start to become excessive. The flex is due to the lack of depth in the arms, and the inadequate material around the pivot. This situation is impossible to realistically improve on while still retaining the stock installation arrangement, but the modified rocker mounting illustrated in an earlier post presented an ideal opportunity to improve the rocker stiffness dramatically. Unfortunately in the photo it seems not to have been done. [/QUOTE]
Insert quotes…
Verification
What was Mr Vincent's Christian Name?
Post reply
Home
Forums
Forums: Public Access
Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Camshaft design
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top