Original PEI Article on parallel twin balance from Motorcycling?

[billirwinnz]

Can anyone post a copy of his original article in Motorcycling (I think around 1936) about 270 degree parallel twin balance? An idea that is now standard practice but took almost a century to become so. I think I've also seen a reprint of the article in one of his later collections.

Some recent and older discussion on the topic.

By Vic Willoughby smoothness.htm

 

[Gene Nehring]

Can anyone post a copy of his original article in Motorcycling (I think around 1936) about 270 degree parallel twin balance? An idea that is now standard practice but took almost a century to become so. I think I've also seen a reprint of the article in one of his later collections.

Some recent and older discussion on the topic.

By Vic Willoughby smoothness.htm

Hi Bill,

I think Phil makes reference to it in one of his books. I sort of remember something about this in his Autobiography.

Best.

 

[billirwinnz]

Hi Bill,

I think Phil makes reference to it in one of his books. I sort of remember something about this in his Autobiography.

Best.

Thanks Gene

I have his autobiography but I'm looking for the original article as it appeared in Motorcycling. I have "Motorcycling Technicalities" but it's not in there. I may have seen it in "Rich Mixture" which I don't have a copy of.

Cheers Bill

 

[Gene Nehring]

Thanks Gene

I have his autobiography but I'm looking for the original article as it appeared in Motorcycling. I have "Motorcycling Technicalities" but it's not in there. I may have seen it in "Rich Mixture" which I don't have a copy of.

Cheers Bill

I have it and ill take a look for you.

 

[roy the mechanic]

I seem to remember 72 degrees being the "reccomended" number. When I was running my DMW typhoon I had extreme vibration troubles, It was so severe you could not see! I asked several experimental engineers from both Ford and Jaguar about it. The general impression was that there was no data as no one had made an adjustable crank. For once I had a trump card, This bike had two engines connected by a splined coupling in the centre. The first attempt was to change from 180 deg to 360. (both together. It sorted the vibration, but was a pain to start as both compressions occured simultaneous. It took for men about 25 yards to bump start it. Next step was 45 deg ureka it was the answer, several other permutations were tried, by altering the angle I could move the vibration along the lengh of the bike. 70 odd degrees was not a good number for this application. Alex George who was riding it for a while reckoned that I beat Honda to the big-bang engine by at least 6 months.

 

[Michael Vane-Hunt]

There is some balance information in Motorcycle Engineering by Irving.

 

[Gene Nehring]

Page 28 in the Col Murray version of Rich Mixture.

 

[rapide049]

Going by the video 284/285 degrees , 76 degrees at the crank is the answer
Not 90 degrees at the crank as others have done = 270 degrees ? I got a little confused reading the Vic Willoughby article
I remember watching a interview with Phil many years ago and He was asked this question His reply 76 degrees

 

[billirwinnz]

Page 28 in the Col Murray version of Rich Mixture.
View attachment 61930

Thanks Gene. Any date on the article?

 

[Gene Nehring]

Thanks Gene. Any date on the article?

This book is one that was published in 1976.