Quote:

Quote:

How about something closer to 90 degrees to give you a real "lope".



A 270 degree is a 90 degree.
360-270=90.



360-270=90 ?? hmmm. That would be okay if we're riding two-strokes. A four-stroke cylinder takes 720° crankshaft angle (i.e., 2 revolutions) to complete 1 cycle of 4-stroke operation. In other words, it fires once every 2 crankshaft revolutions. The standard Bonnie 360 engine has both cylinders traveling in the same direction, but they aren't on the same phase. One cylinder fires every 360 degrees. This results in the even cadence you hear when it runs.

Follow me here:

360 DEGREE ENGINE
a piston fires
the next piston fires at 360 degrees
there is a 360 degree gap
a piston fires
the next piston fires at 360 degrees
there is a 360 degree gap
and so on...

270 DEGREE ENGINE
a piston fires
the next piston fires at 270 degrees
there is a 450 degree gap
a piston fires
the next piston fires at 270 degrees
there is a 450 degree gap
and so on...

HARLEY DAVIDSON ENGINE
a piston fires
the next piston fires at 315 degrees
there is a 405 degree gap
a piston fires
the next piston fires at 315 degrees
there is a 405 degree gap
and so on...

180 DEGREE ENGINE
a piston fires
the next piston fires at 180 degrees
there is a 540 degree gap
a piston fires
the next piston fires at 180 degrees
there is a 540 degree gap
and so on...

90 DEGREE ENGINE
a piston fires
the next piston fires at 90 degrees
there is a 630 degree gap
a piston fires
the next piston fires at 90 degrees
there is a 630 degree gap
and so on...

'05 America - Tec 2-1 (from a Thruxton)/ 4 pot caliper/ Kurt's Rearsets /