While you are on the subject of stroker engines and "taming" more aggressive cams, where does detonation come in to play with cam selection? Lets say you're running a N/A stroker (0.040 over with 3.750 throw or 0.040 over with 3.875 throw w/11:1 compression on an LT1 engine (reversed-cooled). You can pull more total timing simply b/c of a cooler combustion chamber temp. Now add intercooled boost. According to procharger, you can expect less detonation with intercooled boost (all things being equal...i.e. keeping cylinder fuel levels up for cooling, but counterproductive to power). Look at their chart on root, uncooled and cooled charge. Where does the cam become counterproductive in such an application?...

 

I think it's the higher compression that causes detonation, as the piston gets closer to the heads, it creates more turbulence

 

This come right of ProCharger's site:
"Detonation, or engine knock, occurs simply when fuel pre-ignites before the piston reaches scheduled spark ignition. This means that a powerful explosion is trying to expand a cylinder chamber that is shrinking in size, attempting to reverse the direction of the piston and the engine. When detonation occurs, the internal pneumatic forces can actually exceed 10x the normal forces acting upon a properly operating high performance engine. Detonation is generally caused by excessive heat, excessive cylinder pressure, improper ignition timing, inadequate fuel octane or a combination of these. Of the previous, excessive heat is usually the culprit. As an engine is modified to generate more power, additional heat is produced. Today's pump gas will only tolerate a finite amount of heat before it pre-ignites and causes detonation. Although forced induction engines usually produce far less heat than comparable naturally aspirated high compression engines, the cylinder temperatures in intercooled engines are radically cooler yet. It is rarely boost that causes detonation, just unnecessary heat. An intercooler is such a natural solution for forced induction, that in almost every OEM application, intercooling is part of the package."
I did a lot of research on detonation and flame fronts and octane ratings and compression ratings, etc. What I wish to know now is in a higher compression N/A stroker engine, how does the cam selection come into play once the engine is built N/A in reference to detonation?...

 

http://web.camaross.com/forums/showt...ic+compression

Check this out about Dynamic compression and that will get it started. I'll try to get back to this tommorrow when I'm not so tired.

Bret

 

You'll also find a post titled, "How much compression"... something of that effect. Should answer a few of your questions as well.

Take care,
Chuck Riddeck