LCGB Forums

Hi, do any of you good folk know what 17° equates to in millimetres, & if so, how is the calculation made?

depends on your stroke and rod

use the Ignition Timing in mm Before TDC Calculator here

http://www.lambretta-images.com/archive/porttiming.php


if your running standard crank then 17 degrees is 1.6mm before top dead center

Are you asking how many millimetres around the outside of the flywheel, or how many millimetres of travel before TDC?

Knowledge wrote:Are you asking how many millimetres around the outside of the flywheel, or how many millimetres of travel before TDC?

good question, but surely he means piston movement

I know "Bert" and I think he's asking about the marks on the mag flange, back from TDC. Would the measurement be "as the crow flies" or curved around the housing......if you get my drift

MickYork wrote:I know "Bert" and I think he's asking about the marks on the mag flange, back from TDC. Would the measurement be "as the crow flies" or curved around the housing......if you get my drift

that's a really shit way to measure it!

Yeah, btdc. Going on the calculator it's 1.6mm ..... std' crank & rod (58/107).
Handy tool that ...... another one 'bookmarked'!
Thanks for sharing & thanks one & all for replies

bert one wrote:Yeah, btdc. Going on the calculator it's 1.6mm ..... std' crank & rod (58/107).
Handy tool that ...... another one 'bookmarked'!
Thanks for sharing & thanks one & all for replies

Should have said I meant piston movement, which is what I'm after, as it's for setting the timing with a dial gauge as opposed to the 'positive stop' method prior to strobing