Originally Posted by
cathurga
Sr T, the cylinders are placed 120Deg apart, but the TDC of each cylinder is NOT 120Deg apart, as a result of the crank design, so the TDC's are as follows:
Cylinder 1 at 0Deg on the crank, Cyl 2 TDC is at 126Deg on the crank, Cyl 3 is at 108Deg after that (or 234Deg on the crank) and back to Cyl1, 126 degrees after Cyl 3 to 360Deg on the crank.
So yes, what we are saying is the the TDC's of each cylinder are NOT 120 Deg apart. The Morris ring has the magnets spaced according to the above, all you have to do is time No1 at 30deg BTDC and the others will automatically be inline with what is above.. make sense?
What does "crank design" have to do with this?
Originally Posted by
JieM
It does not result in 120deg firing order, it result in 30deg BTDC on each cylinder. And it works fine. Engine runs smoother, and iddle can go to 900 rpm. Just impossible with a 53deg BTDC.
JM
https://www.yellowbullet.com/forum/s...d.php?t=490494
A snippet from the above linked article.
"but he did not realize that
the piston is on TDC when the centerlines of the crankshaft, crankpin and piston pin are all in alignment. "
To whom it may concern, this occurs at 120* intervals in Saito radial engines.