Yes indeed that is the case...but once again I ask where was the mixture when he shoved up the throttle?
ROP (where he was) things will certainly go from bad to worse. Peak or LOP they will not.
Its called
Peak for a reason. Whether it be peak CHT or peak EGT if you are either richer or leaner things will be cooler. In the above graph ICP is Internal Combustion Pressure - that force trying to lift the cylinder head off the barrel. You will see it tracks CHT to such an extent we can use CHT as a proxy for ICP.
I will give you another example - In my Bonanza (before I started restoring it) I typically cruised at full throttle/2200 rpm/50F LOP EGT. On descent I just leave the power set and poke the nose down - at some point on descent I need to reduce power to keep the speed out of the yellow. Initially I do this by reducing RPM but eventually I need to reduce throttle down around 2000' or so. I reduce throttle from about 27in straight back to just above where the gear warning horn sounds...about 16-17in MP. If it was the case, as some posit above, that throttle controlled how much fuel rather than how much air reached the cylinders then the mixture would get leaner and my EGTs (already LOP remember) would cool further...they dont. Yes when I pull the throttle off that much the FF drops but the amount of air available for combustion drops proportionally more and the mixture gets
A LOT richer. The EGTs all increase through peak EGT and then reduce again on the rich side if peak. They end up around 50F ROP and as this equates to Peak CHT the rate of cooling of the cylinders actually decreases.
They cool at a reduced rate.
So much for shock cooling.
I enter and fly the circuit
without touching the mixture/RPM or throttle much - I will generally only reduce throttle a fraction more, after the gear is down and locked, back to about 14in MP.
As I thought experiment only if I decide to go around on finals and do nothing more than firewall the throttle what will happen?
Well I will merely end up back at my original cruise setting. Full throttle/2000-2200rpm and about 30-50F LOP - about 60-65% power. That may or may not be enough power to successfully go around but even if you crash as a result the engine will be undamaged and running fine right up to point of impact...unless you believe 65% power is bad for the engine
All three engine controls vary mixture. The actual mixture is the only one that can vary power produced from 0% to 100%. The throttle primarily controls how much air is available for combustion but DOES have an effect on FF too. The RPM primarily controls propeller RPM but in our typical non geared engines it has the same effect on engine RPM and fuel pump rpm.
From a mixture/fuel air ratio point of view varying RPM has a
proportionally greater effect on fuel flow than mass airflow. Less RPM leaner/more RPM richer. That is one of the reasons why achieving redline RPM on takeoff is so important.