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
General Chat (Vincent Related)
A STRANGE THING..
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="Martyn Goodwin" data-source="post: 98442" data-attributes="member: 2433"><p>Think of the motor as an air pump. As the piston rises it attempts to create a vacuum in the cases and as it falls it attempts to compress the gases in the cases. Compressed gasses will try to force oil out of whatever openings it can find - and it there are none to find it will try to create them!.</p><p></p><p>So you want the timed breather closed for the full stroke of the piston rising - thats when its generating a vacuum and you want it open when the piston is going down so the gas in the cases does NOT get compresses but instead passes out thru the timed breather opening - BUT the standard slot in the timed piston sleeve ET141 needs to be widened so the breather is open for more of the down stroke; irrespective the open breather must close at or just before the piston gets to bottom dead centre so you get the maximum vacuum effect as the piston then rises- in my Comet this means I have it starting to open at 24 degrees ATDC and closing at bottom dead centre. </p><p></p><p>Here is an extract from "Tuning For Speed" where Phil Irving is talking about Vincent motors</p><p></p><p>[ATTACH=full]23158[/ATTACH]</p><p></p><p>Combining information from Irving, Richardson and Stevens I learnt that the breather spindle needed to be installed in my Comet with the breather spindle slot pointing downwards. In twins the slot in the spindle should be pointing forwards directly towards the top magneto stud.</p><p></p><p>Hope that makes it clear.</p><p></p><p>M</p></blockquote><p></p>
[QUOTE="Martyn Goodwin, post: 98442, member: 2433"] Think of the motor as an air pump. As the piston rises it attempts to create a vacuum in the cases and as it falls it attempts to compress the gases in the cases. Compressed gasses will try to force oil out of whatever openings it can find - and it there are none to find it will try to create them!. So you want the timed breather closed for the full stroke of the piston rising - thats when its generating a vacuum and you want it open when the piston is going down so the gas in the cases does NOT get compresses but instead passes out thru the timed breather opening - BUT the standard slot in the timed piston sleeve ET141 needs to be widened so the breather is open for more of the down stroke; irrespective the open breather must close at or just before the piston gets to bottom dead centre so you get the maximum vacuum effect as the piston then rises- in my Comet this means I have it starting to open at 24 degrees ATDC and closing at bottom dead centre. Here is an extract from "Tuning For Speed" where Phil Irving is talking about Vincent motors [ATTACH=full]23158[/ATTACH] Combining information from Irving, Richardson and Stevens I learnt that the breather spindle needed to be installed in my Comet with the breather spindle slot pointing downwards. In twins the slot in the spindle should be pointing forwards directly towards the top magneto stud. Hope that makes it clear. M [/QUOTE]
Insert quotes…
Verification
The Series 'A' Rapide was known as the '********' Nightmare?
Post reply
Home
Forums
Forums: Public Access
General Chat (Vincent Related)
A STRANGE THING..
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