Its pretty off the scales crazy I agree!
The benefits are nuts as the valves are smaller
the spring rates are probably equal to big valves
with big springs. The shafts are very simple and
the pushrod to the valves acts like a pivot lever
therefore less stress than direct actuation.
Exhaust valves being smaller also help.
It would be lighter than 2 extra camshafts overall
and because there are two roller shafts where the
lever action occurs with lubrication there is very
well distributed forces separating both in and ex.
valves and seats can be lifted from factory
honda, suzuki, yamaha or kawasaki take your pic!
Quote:
The cam grinds used are a lot milder than traditional 2-valve big-block cams because of the extra valves' greater flow window area. For example, a standard high-performance big-block Chevy 2-valve motor uses one 2.19-inch intake and one 1.88-inch exhaust valve per cylinder; these valve sizes have a circumferential window area of 3.44 and 2.95 inches, respectively. By contrast, the Thunder Power head use two 1.75-inch intake and two 1.50-inch exhaust valves per cylinder for a total circumferential window area of 5.50 and 4.71 inches, respectively.
standard A12-A15 cams would be all they need :) cheaper than twin cam custom grinds
62% increase in valve circumferential window area over 2 valves with same bore.
Relatively flat rocker covers as well due to less lift required therefore shorter
rocker shaft towers etc.