[Geebee]

Originally Posted by TELVM

Please notice the graphs in the second pdf aren't horsepower curves, but in-cylinder peak pressure curves.

Less peak pressure at the right moment of piston travel can make more torque than higher peak pressure at the wrong moment of piston travel.



Two cylinder heads were used. The highest difference in combustion chamber volume is 3.3%. No two cylinder heads of same type are identical due to casting and machining tolerances, see that the intake runners had larger volume in the non-grooved head. I don't think that's enough to discard the experiment as dramatically flawed, but that's just my opinion.

He could have used just one and the same cylinder head, first without grooves, then grooved. But he didn't.

I was refering to the tables/charts showing brake horse power and corrected horsepower as stated in the test result units.
As for the differing combustion cambers, it stops any decompression effect from showing and even with that the grooved head HP dropped.