Balance factor for a twin flywheel?

[Big Sid]

To fully blueprint conrods they must be made equal in several ways . Identical in total wt ., held horizontal both small ends and then big ends are the same . No friction in the suspending . Two snug fitting dowels for small and big ends must enter the two side by side to ensure they are identical in length .
Rarely you will find one that is a bit bent at the small end and it can be often " set " with a long steel bar . Sid .

 

[riptragle1953]

Balancing includes everything that reciprocates with the flywheel. When I found an Omega piston with a crooked small-end pin bore is when I started having pistons made to my own design by Wiseco.

 

[riptragle1953]

Why do connecting rods need to be of equal weight? True and straight yes indeed....but a few grams one way or the other matters little when balancing has to due with the total weight on a single crank-pin. On the other hand, if you want to go to the
trouble it doesn't hurt either.

 

[Vincent Brake]

vspeet at vsmmetaal dot nl

 

[Big Sid]

Why are rod weights of concern , also pistons ? Because it's simply good building and tuning practice , the way to go if serious .
Were a heavy rod to get the heavier piston by chance the results would not enhance smooth running , and suggest poor attention to details . Care in such considerations are a sign of a good build quality throughout the powerunit . Sid .

 

[riptragle1953]

The reciprocating mass is what's important and there are theories on what percentage of the rod weight should be considered reciprocating weight when the top half is weighed. I built a jig for the purpose of weighing small ends
on the dead level from a frictionless centered big end pivot. The theories revolve around how much of that weight is factored in with the total of the pistons, pins, spiral pin retainers and rings.

 

[Big Sid]

When the likes of cycle Worlds own Peter Egan put in print in his big spread and went even further to us on how smooth and vibrationless our Vincati was after riding it over 100 miles on local back roads , called it like " being flung up the road by the Hand of God " then that's friggin smooth . All the few others who we let sample it enc Jay Leno felt the same , loved it .
Theory is one thing , reality is quite another . Sid .

 

[riptragle1953]

I only said there are theories. I did not say they were my theories.

 

[Big Sid]

I'm not too much on theory , experiance and logic guides me , what long years have proved to be best , and what Irving told me personally in long conversations . In my old Classic business and now here I've built 60 or more motors , stock ones and hot ones .
They instruct me . They run hard and strong and don't break . Good enough for me and the owners . Sid .

 

[riptragle1953]

Theories are ideas. A good idea put into use to improve something is a fine thing. If it were not for ideas or theories (if you will) there would be no Vincent Motorcycle in the first place.