Thanks neal for doing this test with your dyno. You saved alot of guys head buttons. lol Not every engine guy out there would do this test and post there results. A+ work.

Did u try different configurations? From personal experience , smaller more directing grooves yielded the most gain . One exiting towards the exhaust ;)

I think that IF it can work, it would work better with a very narrow cut, like from a razor saw rather than a big channel but that requires more testing and more heads :D

Worldwide results with bigger engines do no lie, maybe the results on our engines are more related to compression because that is making the ignition timing? I know most onroad engines do come with a very critical compression setting, almost to detonation but it does not comply with my friends 23cc engine with spark ignition.

But then I am wondering how the large teardrop I have seen through the years and even made in the RB C5 production models is actually working on the dyno.

2 towards the front, 1 towards the exhaust.....

I have tested these cuts before and found no benefits, but i did not have the dyno at the time to properly know for sure... Back when XRC did a dyno test of this technique it got my interest...... Now it may be possible that some configurations may work on some engines..But unfortunately the cost to do the testing would be quite significant...But the configuration I tried on this B5 hurt power, so I likely wont be pursuing this any further.....I will be testing a Rody modded button against a standard button very soon, so I will let you guys know what I find.......

I have been modifying head buttons for some time now, but I am more into messing with squish velocity then anything else...

Thanks for the testing. I was looking for better results but what do you do.