Monday's Science Lab: V-twin Engines 101

[den111]

GREAT visual aid! Thanks much.

[iamz]

Cool. Now I know why my 52 degree Honda is so smooth.

[sarnali]

You forgot to illustrate the 360* vertical twin, that paragon of 4 stroke design from the drawing board of St. Edwin Turner

[smithrob75]

Very interesting, makes more sense now why Harley's "sound" a certain way. (Although I don't like it)



Also seems like a very inefficent engine design though.



I much enjoyed my R1200RT test ride, very smooth motorcycle.

[Tigercub]

That was a hot little engine in 1936! It worked great through the 60s and even made Yamaha copy it.



I still like 'em. I'll never forget the first time I pulled the head off my Triumph Tiger, pushed the kick starter through and saw the pistons come up together. I was sure something broke in the bottom end.



Years later, I learned about the concept of the twingle - a twin piston single engine and realized it was the natural evolution of the torquey singles of the thirties. Firing at 360 degree intervals was like mating two singles side-by side. It made for easy starting, had less mass and took less space than a V-twin and could be balanced to be smoother running. It was the perfect engine for light duty transportation before the car came along.

[Lowrez]

There is a legend that says Harley's design is the result of some incorrect calculations. I don't know if its true, but it feels like it.

[Tigercub]

You need to include the firing order along with crankshaft and cylinder angle to define the sound. Then there's all the other factors, valve timing, exhaust header size, muffling, etc.

[grubz916]

It's there, just scroll to the bottom. 0-deg crank, 0-deg cyl angle

[Tigercub]

Those were great kinetic schematics. It does make one wonder why V-twins still exist. They are big with overhead valves and especially with overhead cams, vibrate without couterbalancing or rubber mounting, and don't cool well in-line. And all those different designs show you why they basically are not a good design. But, they sure are fun!!

[nokneedragin]

I hate to take the grief for this, but HDs "sound" has always sounded more like explosive diarrhea.

Not a pleasant sound