Topic: big 180 degree twins

[James360]

Any good reason nobody made a 180 degree twin bigger then 500cc, was it just that everyone wanted the british 360 degree sound to the engine. I bought a new 1983 LTD 750 kawasaki 360 degree twin personally i did not like it.

[Don R]

What would a 180* look like, BMW?

[kirkn]

No, one looks just like an ordinary parallel twin.  That just refers to the crank orientation - 360 means the pistons rise and fall together but fire opposite each other, one firing every 360 degrees of crank rotation.  180 means one piston is rising while the other is falling and they have a non-symmetric firing order, one fires then 180 degrees later the second fires, then 540 degrees when none fire.

AFAIK, each had their plusses and minuses.

Nowadays, Triumph makes a large twin with a 270 degree offset, which is supposed to give a sound more like a V-twin.  Yamaha's TDX850 (a non-US variant of the TDM-850) of the mid-90's was the same.

[James360]

Noticed triumph used a 270 degree firing order on the high pipe scrambler version kept the 360 degree on most of them. to me the 360 compaired to 180 shakes a lot worse, does not seem to rev as quickly. Have not tried anything 270 degree, but it costs big money for the kits to change the XS 650 yamaha's to 270 degree.

[bryanj]

Laverda jota had a two up one down crank