Arguing engineering with an engineer can be almost as frustrating as arguing law with a lawyer.

The infinitely strong perfectly insulated engine will perform as its creator described. Think of it as a heat engine, its purpose is to convert heat energy into mechanical energy.

There are only two ways for energy to get out of the perfectly insulated engine.

1                 Mechanical energy out the crankshaft

2                 Heat out the exhaust valve

Anything that reduces heat out the exhaust valve increases mechanical energy on the crank, assuming the same mass of fuel is burned in each case.

Burning all the fuel at TDC and expanding all the combustion products through the full compression/expansion ratio of the perfectly insulated engine will result in the lowest EGT and maximum mechanical energy.

The greater the expansion ratio the better until cylinder pressure drops close to outside pressure.

At the risk of clouding the issue let me introduce a semi-ideal engine. Imagine a real engine with a cylinder head that contains multiple direct high pressure computer controlled fuel injectors with integral spark plugs. We wait till TDC, then fire all plugs and fuel injectors to bring cylinder pressure rapidly up to maximum safe pressure, determined buy mechanical and/or detonation considerations, then reduce fuel flow to maintain that pressure until all the oxygen is consumed. This would eliminate the energy absorbing buildup of heat and pressure from combustion before TDC and produce maximum crank power. For less than max power we cut off the fuel flow before all the oxygen is consumed, lean of peak operation.

The real world heat transfer to exposed surfaces will vary as a function of temperature and pressure of the combustion gasses, and that effect may alter the optimum pressure vs. angle curve, especially for slow turning engines like ours.

In the real world there are many variables some of which conflict. The best engineer, degreed or not, is the one who chooses the optimum compromise.