Recently i was watching a slow motion video that was showing a 6 cylinder GA engineat full power and was quite amazed to see the cylinders waving around like leaves in a wind. The amount of movement was quite stagering.
There is a company that claims to have a fix for this. Where they have the rocker covers for all cylinders on each each side as one very solid unit and then have a number of cross brace bolts tying the oposite sides together, much like a strut brace a car.
They claim its very effective in making the engine much more rigid in very high power aerobatic operations, but would it pay any dividends on normal stock engines, especialy in terms of reliability.
The premier manufacturer of performance aircraft exhaust systems and engine components.