The Double Crank Engine

I wonder why all engines today use the standard 4 bar linkage when there is a really good option available in the "cartwright straight line mechanism" also know as the double crank mechanism. Refer to

http://kmoddl.library.cornell.edu/resources.php?id=152

for details on the mechanism.

I have also prepared a simple CAD based animation of the mechanism. This is given below.

What you can see here is a possible mechanism for an engine that is conveniently conventional & at the same time, there is no side thrust between the piston & the cylinder liner.

This will have good benefits in terms of

1) Mechanical efficiency

2) Good durability at very high speeds & loads

I believe that this will be the configuration of engines in the future.

Already, a couple of people have built such engines.

1) http://www.neander-motors.com/

2) http://www.patentstorm.us/patents/5595147/description.html

So what do you think of this system?