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
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="Nigel Spaxman" data-source="post: 128556" data-attributes="member: 2907"><p>I think the speed of burning has a lot more to do with the turbulence in the combustion chamber than the burn speed of the gas. Apparently without that turbulence the fuel wouldn't even burn fast enough for our engines to work at higher RPM. The mixture in our cylinders if it was static would burn really slow, not even fast enough to be complete in one cycle. Over many decades there has been a change in ideas from engine tuners. It used to be people would set their ignition at the maximum advance the engine could stand without pinging. Now a lot of people set their ignition at the lowest figure that still allows the engine to rev our and produce maximum power. I have a programmable ignition with a vacuum switch so what I do is at high vacuum the engine runs at 38 or 39 degrees advance and I knock it back to 34 when there is less vacuum. My bike has 8:1 pistons and doesn't ping even if set at 38 degrees all the time. Probably I could just set the ignition at 38 degrees. It may be that when I am revving the engine hard and the throttles are wide open that the bike has a bit more power at 34 than 38 degrees. Apparently some Norton engines when run on the Dyno need less advance at high RPM for maximum power than at lower RPM. Probably this is because of the better turbulence at high engine speeds.</p></blockquote><p></p>
[QUOTE="Nigel Spaxman, post: 128556, member: 2907"] I think the speed of burning has a lot more to do with the turbulence in the combustion chamber than the burn speed of the gas. Apparently without that turbulence the fuel wouldn't even burn fast enough for our engines to work at higher RPM. The mixture in our cylinders if it was static would burn really slow, not even fast enough to be complete in one cycle. Over many decades there has been a change in ideas from engine tuners. It used to be people would set their ignition at the maximum advance the engine could stand without pinging. Now a lot of people set their ignition at the lowest figure that still allows the engine to rev our and produce maximum power. I have a programmable ignition with a vacuum switch so what I do is at high vacuum the engine runs at 38 or 39 degrees advance and I knock it back to 34 when there is less vacuum. My bike has 8:1 pistons and doesn't ping even if set at 38 degrees all the time. Probably I could just set the ignition at 38 degrees. It may be that when I am revving the engine hard and the throttles are wide open that the bike has a bit more power at 34 than 38 degrees. Apparently some Norton engines when run on the Dyno need less advance at high RPM for maximum power than at lower RPM. Probably this is because of the better turbulence at high engine speeds. [/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
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