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
Identifying cams
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="davidd" data-source="post: 178628" data-attributes="member: 1177"><p>Jim,</p><p></p><p>The standard for comparing cams requires measuring the four valve events at either 0.040" lift or 0.050" inch lift. Thus, your timing card should look like this:</p><p></p><p>At 0.050" lift:</p><p>IO 26 degrees (Intake Opens)</p><p>IC 78.5 degrees (Intake Closes)</p><p>EO 48 degrees (Exhaust Opens)</p><p>EC 35 degrees (Exhaust Closes)</p><p></p><p></p><p>This cam is a factory Mk2 cam, Equal Lift is at 0.1695". The base circle drops 0.002" just before it opens. This is not a good thing, but it is common. It causes a lot of acceleration as the valve opens.</p><p></p><p>If you take readings from your dial indicator at the degrees mentioned above and the results are close, the cam profile is a Mk2. </p><p></p><p>Welding the pinion on the camshaft was done to prevent the cam from shifting in the pinion. The practice has never worked with consistent results. It is difficult to weld the hardened steel pinion and shaft with decent penetration and the weld tends to break, in practice. I use a small roller bearing to pin the two parts together and it has proven very reliable.</p><p></p><p>[ATTACH=full]61890[/ATTACH]</p><p></p><p>Otherwise:</p><p></p><p>[ATTACH=full]61891[/ATTACH]</p><p></p><p>David</p></blockquote><p></p>
[QUOTE="davidd, post: 178628, member: 1177"] Jim, The standard for comparing cams requires measuring the four valve events at either 0.040" lift or 0.050" inch lift. Thus, your timing card should look like this: At 0.050" lift: IO 26 degrees (Intake Opens) IC 78.5 degrees (Intake Closes) EO 48 degrees (Exhaust Opens) EC 35 degrees (Exhaust Closes) This cam is a factory Mk2 cam, Equal Lift is at 0.1695". The base circle drops 0.002" just before it opens. This is not a good thing, but it is common. It causes a lot of acceleration as the valve opens. If you take readings from your dial indicator at the degrees mentioned above and the results are close, the cam profile is a Mk2. Welding the pinion on the camshaft was done to prevent the cam from shifting in the pinion. The practice has never worked with consistent results. It is difficult to weld the hardened steel pinion and shaft with decent penetration and the weld tends to break, in practice. I use a small roller bearing to pin the two parts together and it has proven very reliable. [ATTACH type="full" width="803px"]61890[/ATTACH] Otherwise: [ATTACH type="full" width="812px"]61891[/ATTACH] David [/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
Identifying cams
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