I have been asked to find out how many degrees advance I need for my 1914cc bug engine. I guess you good people will need some specs so here goes:
thanks in advance
30 degrees max advance is safe. (measure at 3000rpms or "until it won't advance any more")
You left out one of the most important values, your compression ratio. More compression means you can use less advance, and vice versa.
What is also important is the advance curve, but that's trial and error.
How much in advance? :D
Jan
im quite new to all the technical stuff how do i calculate my compression ratio?
To be able to calculate it, you need to know (the builder should have measured during assembly and written these down)
1) combustion chamber volume (Stock head is around 55cc? I think) 2) distance from piston top to cylinder top at top dead center (somewhere around 1,5mm is common I guess) 3) stroke (Stock stroke is 69mm, and that's what you have) 4) bore (yours is 94mm with that engine size)#1 and #2 are critical, no guesswork accepted. Values I gave are there only to give you an idea of what ballpark the values usually are in.
Armed with this information, you can go to
one very important "spec" you left out was what kind of distributor you have installed...Jan's answer will get you there, but it is kind of a "one size fits all" type thing...as he said compression ratio would be nice to know as would fuel quality and octane that is available to you...
------------------- Chris Perdue
*All opinions are those of the author of this post* "Sometimes you're the windshield, sometimes you're the bug"The dizzy is a bosch 009 as for the fuel quality im not quite sure what you mean, all i can say is it runs on unleaded.
-- Paul Soames
sorry should say the original message was posted by me from my workplace!
-- Paul Soames
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