The end all be all compression thread!

[casual]

Theres so many questions regarding compression & octane. How to make this stroker run on that octane. Or will this be ok..am I at the edge. Will it ping or detonate.
So I figured lets make a thread with specs, tips & suggestions regarding the issue! This thread won't be about what knock, preignition, detonation or ping is. If you need a better explainion of that, look here. http://en.wikipedia.org/wiki/Engine_knocking
This thread will cover how to prevent them. Also some basics on the average compression ratio that can be run on a certain octane, obvisouly it won't be 100% accurate but it will give a baseline or the uninformed to go off of!

I'll leave the compression to a certain octane to the more experienced. Usually dynamic compression determines if you'll be safe on a certain octane rating. But some questions that can be asked are whats the relation of static compression to dynamic compression? How high can the static compression be without worrying about engine knock?
Also consider the altitude at which the motor will run. Build your motor for what it will be used for. If your cruising around 2000rpm, then you will want some power around that rpm range. If you build a high rpm motor & then lug in around in the low rpms, chance of knock is higher because the higher load on the motor. If you have an abundence of power in the rpm you cruise, it will require less throttle wich means less load. That leads to a less chance of knocking.

Tips to help prevent detonation or preignition (ping), would be a higher duration cam with more overlap, this will bleed off some cylinder pressure. Lower cylinder pressure - lower chance of engine knock.
Polishing cumbustion chambers and/or the pistons tops & valve faces. This will remove most if not all sharp edges or ridges/valleys. It keeps everything smooth, thus no hot spots on those ridges, edges or valleys. Again that lowers the chance of knocking. It will also reflect the heat off the chamber walls, pistons & valves, thus giving a more effective of the incoming intake charge! Carbon build up will be slower & more carbon will be burnt off because reflec surfaces are usually hotter.
A tighter quench height will also help prevent detonation up to a point. Most "engine builders" say to shoot for a .035-.045" quench height for a motor with steel rods. Obviously most won't get into the .03x" quench height with our jeep 4.0's. So try to get it as cose to .040-.045" as possible. The fresh cool intake charge entering the chambers cools them slightly. Tighter quench = less area to cool = better effectiveness. This help prevent detonation as the temps in the chambers are reduced some. Also on the exhaust stroke, because the tighter quench height, the piston is closer to the water cooled head. In that breif time the piston is cooled slightly & again the piston will be cool for the new intake carge entering. Then the process repeats wit the fresh intake charge! You also get a more complete burn because again the intake charge is being forced & squished in a smaller area. This leads to btter fuel mileage & a more efficient running motor overall!


My questions, as I don't know everything..just the basics + some. But my question is can I safely run a 10.5:1 static compresson & 7.55:1 dyanmic on 91oct at sea level, in the Southrn Cali heat. My quench height is .040"? I know my dynamic is low but the static compression is way up there.
My stroker plans as of now is 9.4:1 static & 7:1 dynamic. But I figured with premium gas only being a few bucks more per tank I may go all out. The differece between the 2 motors is not dishing my pistons & decking the head to reduce combustion chamber size. Any issues with running that high of compression & will it be ok with premium grade gas.