Originally Posted by sonoronos
I'm going to be gentle here, apkano. Almost everything you stated is just plain wrong and/or explained very poorly. AFRs around 12:1 is where max power is made under boost. Advancing timing changes where on the piston/rod stroke the power is applied to the crankshaft. Closer to TDC means more average energy output onto the crankshaft. Dieseling is caused by compression of a fuel-air mixture and can happen whether rich OR lean. Too lean of a mixture can cause pre-ignition and/or knock, which is not just dieseling. Pre-ignition occurs due to a lot of things, but in addition to dieseling, it is often due to super-hot carbon deposits. Knock is basically an explosion of the fuel-air mixture, as opposed to a "burn" which one would find in a normal ignition situation.
Again - timing has nothing to do with how much "fuel is introduced into the cylinders." That has to do with your injector pulse, injector flow, and fuel rail pressure. Timing is all about where on the piston stroke the fuel burn occurs. Too soon after TDC and the dynamic cylinder pressure will cause ringlands to blow out or rods to snap. Too long after TDC and the burning fuel/air mixture doesn't have enough time to push on the rods enough to generate any kind of power.
This may just be a case of "you know what I mean vs. what I actually said", so don't take it personally. But compare the information you stated to the information in a book like "Maximum Boost" and statements like "Timing does not = HP" are just plain wrong.
Maybe I wasn't clear enough before, for that I apologize. I was trying to teach a bunch of guys how to convert milliseconds to cycle times, through a language barrier, when I wrote that. I understand all too well how an engine works. I still stand by the fact that timing does not equal horsepower. The basic point I was trying to convey was that you can change base timing, timing curve, fuel, etc., but if you're not generating the highest rate of thermal expansion immediately after TDC, you're just wasting time.
Truth be told, compression ratio is the key to horsepower. Just look to some of the baddest engines around......top fuel. Granted, they burn Nitromethane, which burns slower than gasoline, stoich is somewhere around 1.7 or 1.6 to 1. The timing is at 60 + degrees BTDC. This allows them to achieve a longer combustion cycle. These guys are burning over 3 gallons in a quarter mile. Halfway down the track the spark plugs are basically fried, and they have a diesel engine in effect.
The biggest changes they make in these engines is the CR. Copper head gaskets are sized by the thousandths of an inch, and most teams have a huge selection of them.