Tining advance

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:

1914cc engle 110 cam dual twin webber 44idfs electronic ignition (dont know if that will make any difference)

thanks in advance

Reply to
Suffolk TSU
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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

Reply to
Jan Andersson

im quite new to all the technical stuff how do i calculate my compression ratio?

Reply to
Suffolk TSU

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

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example and use their calculator. Jan

Reply to
Jan Andersson

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"
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reply take your PANTS off
Reply to
Chris Perdue

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

Reply to
Paul

sorry should say the original message was posted by me from my workplace!

-- Paul Soames

Reply to
Paul

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