Guess it is not gonna make a huge difference, but why do you fill it to the top of the spark plug hole? Or is it okay to assumme tthat the cavity of the spark plug holds almost as much volume as the hole?
F1 Moto are pretty secretive in this video. To calculate compression ration, its as stated in the video, filled to top of spark plug hole, but, you MUST deduct the volume in the spark plug hole (2.5cc is a good number to use). If you don't deduct the spark plug volume, the compression ratio figure will be higher then what it actually is. In other words, your compression will be low. Example: YZ250 18.5cc to top of spark plug hole, deduct 2.5cc for spark plug volume (18.5 - 2.5 = 16c) 249cc + 16cc = 265cc divide by 16cc = 16.5:1 compression ratio If do not deduct the spark plug volume, the compression ratio would be: 249cc + 18.5cc = 267.5cc divide by 18.5cc = 14.4 :1 As can see, the 14.4 : 1 figure is wrong.
@@truthbetold8425 Quick question, wouldn`t it be easier to avoid filling the spark plug hole? that alone would give a more accurate result, don`t you think? I guess you can even take into account if the plug stands out of the hole or not just screwing it in before bolting everything just to get an idea before the measurement.
You didn't measure and deduct the spark plug volume. Its about 2.7cc
Guess it is not gonna make a huge difference, but why do you fill it to the top of the spark plug hole? Or is it okay to assumme tthat the cavity of the spark plug holds almost as much volume as the hole?
F1 Moto are pretty secretive in this video. To calculate compression ration, its as stated in the video, filled to top of spark plug hole, but, you MUST deduct the volume in the spark plug hole (2.5cc is a good number to use). If you don't deduct the spark plug volume, the compression ratio figure will be higher then what it actually is. In other words, your compression will be low.
Example: YZ250 18.5cc to top of spark plug hole, deduct 2.5cc for spark plug volume (18.5 - 2.5 = 16c)
249cc + 16cc = 265cc divide by 16cc = 16.5:1 compression ratio
If do not deduct the spark plug volume, the compression ratio would be:
249cc + 18.5cc = 267.5cc divide by 18.5cc = 14.4 :1
As can see, the 14.4 : 1 figure is wrong.
@@truthbetold8425 Quick question, wouldn`t it be easier to avoid filling the spark plug hole? that alone would give a more accurate result, don`t you think? I guess you can even take into account if the plug stands out of the hole or not just screwing it in before bolting everything just to get an idea before the measurement.
@@truthbetold8425 Also, if this is the uncorrected compression ratio, the corrected one would be taking into account the pipe effects, right?
Why kerosene and not two stroke gas ??????
it`s thicker, won`t go past the rings even though the engine is cold.
TE INVITO A VER MI PROYECTO, DE UNA YAMAHA YZ 1989!