Jas T28D.....3!!!!! do you have any hair left??? Sure do I love round engines.
One of the real misunderstandings about round engines is they are said to be unreliable.
Absolute poppycock, once a round engine is running in steady state they are remarkably reliable, fact is if you consider the firing order 1,3,5,7,9,2,4,6,8 it becomes obvious there is less stress on the whole engine than say a horizontally opposed engine.
They fire sequentially around the master rod so the forces are not across the engine rather tangential to the output in simple terms.
Most big radials have quite sophisticated magneto systems which control any pre ignition.
My Wright 1820 is 52.5 inches 2700 rpm at takeoff developing 1425 HP, climbs at 36 inches 2400 rpm, cruise 30 inches 2000 rpm and coming home 1700 rpm 20 Inches
Oversquare all the way.
Likewise the Pratt 985 are 36 inches at 2300 rpm for takeoff, climb 33inches at 2100 rpm, cruise 29 inches at 1850 rpm and come home 20 inches at 1700 rpm.
Never a hint of detonation, why one must wonder ?? well because it is well within the thermal limits of the engine and there is no internal overcompressed mixture or overload on the engine.
BTW the Auto Mixture on the Wright 1820 is set LOP as they all are and I get a really nice soft grey exhaust colour, CHT 150 degrees C engine happy and leakdown pressures all above 75/80 .
So 38 what am I doing wrong with my engine handling ??