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
Modern Fuel & Ignition Advance
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="ClassicBiker" data-source="post: 94867" data-attributes="member: 1632"><p>After what I posted(#5) above I got curious what the linear speed of the piston was at 3000 rpm. Well 3000 rpm is 50 rps, which is 314.159 Pi radians a second, with a 90mm stroke is a 45mm throw and equates to 14,137.155 mm per second. As we were talking about originally the reduction in the advance from 38 BTDC to 34 BTDC I went to the table on TheVincent.com under the Magneto tab (by Tom Gross) to see what the linear difference was in how far down the bore the piston was, .11" or 2.794mm. At 3000 rpm the piston covers that distance in .197 milliseconds.</p><p>Taking what Grey One posted above, what I read was similar (20 degrees), and realizing that linear distance the piston travels from 28 BTDC to 12 ATDC is .303 inches or 7.6962mm it covers that distance in .544 milliseconds. Doing the same for 24 BTDC to 12 ATDC is .237 inches or 6.0198mm results in .426 milliseonds.</p><p>So thinking about it a bit more the E-30 has a burn rate of .36 ms and the piston speed at 3000 rpm puts us at the optimal point with .184 ms to spare, if we begin ignition at 38 BTDC and .066 ms to spare if we begin at 34 BTDC. Of course this is just conjecture on my part, but you can see where those that do the actual practical testing get their jumping off point from. This stuff happens fast.</p><p>Steven</p></blockquote><p></p>
[QUOTE="ClassicBiker, post: 94867, member: 1632"] After what I posted(#5) above I got curious what the linear speed of the piston was at 3000 rpm. Well 3000 rpm is 50 rps, which is 314.159 Pi radians a second, with a 90mm stroke is a 45mm throw and equates to 14,137.155 mm per second. As we were talking about originally the reduction in the advance from 38 BTDC to 34 BTDC I went to the table on TheVincent.com under the Magneto tab (by Tom Gross) to see what the linear difference was in how far down the bore the piston was, .11" or 2.794mm. At 3000 rpm the piston covers that distance in .197 milliseconds. Taking what Grey One posted above, what I read was similar (20 degrees), and realizing that linear distance the piston travels from 28 BTDC to 12 ATDC is .303 inches or 7.6962mm it covers that distance in .544 milliseconds. Doing the same for 24 BTDC to 12 ATDC is .237 inches or 6.0198mm results in .426 milliseonds. So thinking about it a bit more the E-30 has a burn rate of .36 ms and the piston speed at 3000 rpm puts us at the optimal point with .184 ms to spare, if we begin ignition at 38 BTDC and .066 ms to spare if we begin at 34 BTDC. Of course this is just conjecture on my part, but you can see where those that do the actual practical testing get their jumping off point from. This stuff happens fast. Steven [/QUOTE]
Insert quotes…
Verification
What was Mr Irving's Christian Name?
Post reply
Home
Forums
Forums: Public Access
Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Modern Fuel & Ignition Advance
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