Senior Tech Team
Join Date: Apr 2012
Location: Yerington, Nevada
Re: This Will Make One Think Twice Before Winding One Up !
Modern day MotoGP inline and V4 cylinder engines are all overhead cam, 4 valve, and RPM limited to 18,800 rpms. There is NO comparison from a push rod Chevy to one of them in valve train geometry, valve float, nor operation, as they do not have lifters, push rods, rockers, nor undampened valve springs, and the valve weight is absolutely minimum in comparison.
I know this for a FACT, as one of my other jobs is engine designer for one factory team, there are 5 of us ouside services engineers located all over the world. I have been doing this work since I left working directly for Duntov at Skunk Works, on both two and four stroke engines. This included the older Yamaha 5 valve 4 stroke engines as well, (two exhaust, three intake valves per cylinder), and the Honda 500 and 750 OVAL BORE engines, no round cylinders, they were straight edge oval, and 8 valves per cylinder (4 intake, 4 exhaust).
NONE of the above engines spun with RPM limits less than 18,000 RPM's.
The heavier the valve, the heavier constructed a valve spring has to be, and with that weight, more oscillation, spring issues/problems, outright failure.