2025/2026 Hybrid Powerunit speculation

[wuzak]

Depends on what the goal is.

Maximum efficiency/power is the goal.

If the heat lost to coolant is reduced, there is more energy left to turn the crankshaft.

I do not fully understand the statement regarding heat loss. The coolant system in an internal combustion engine is designed to prevent overheating by maintaining the engine below a maximum operating temperature. While I understand that heat is a form of energy, it is unclear to me how residual heat within the cylinder contributes to power generation. In practice, the intake air is cooled after leaving the compressor and prior to entering the cylinder. Additionally, one of the motivations for using direct injection is its ability to maintain lower fuel temperatures. Lower temperatures of the intake charge and engine components increase charge density, improve compressibility, and enable greater expansion during combustion. Maybe you mean fuel that is burned that turns into heat is energy lost ?

There is a set amount of fual energy supplied to the engine (3,000MJ/h).

Some will go to driving the crankshaft.
Some will exit through the exhaust.
Some will exit through heat transfer to the coolant and oil.

You want to maximise the first and minimise the last.

You want to minimise the second too, but there is some energy recovery with the turbo, transferring the energy from the exhaust to compressing the intake air.

Lower heat loss through the coolant has the additional benefit of requiring smaller radiators, and similar for oil and oil coolers.

Cooling the intake air is also wasting energy, but there are limits to how hot the air can be without causing detonation.

[BassVirolla]

Maximum efficiency/power is the goal.

If the heat lost to coolant is reduced, there is more energy left to turn the crankshaft.

I do not fully understand the statement regarding heat loss. The coolant system in an internal combustion engine is designed to prevent overheating by maintaining the engine below a maximum operating temperature. While I understand that heat is a form of energy, it is unclear to me how residual heat within the cylinder contributes to power generation. In practice, the intake air is cooled after leaving the compressor and prior to entering the cylinder. Additionally, one of the motivations for using direct injection is its ability to maintain lower fuel temperatures. Lower temperatures of the intake charge and engine components increase charge density, improve compressibility, and enable greater expansion during combustion. Maybe you mean fuel that is burned that turns into heat is energy lost ?

There is a set amount of fual energy supplied to the engine (3,000MJ/h).

Some will go to driving the crankshaft.
Some will exit through the exhaust.
Some will exit through heat transfer to the coolant and oil.

You want to maximise the first and minimise the last.

You want to minimise the second too, but there is some energy recovery with the turbo, transferring the energy from the exhaust to compressing the intake air.

Lower heat loss through the coolant has the additional benefit of requiring smaller radiators, and similar for oil and oil coolers.

Cooling the intake air is also wasting energy, but there are limits to how hot the air can be without causing detonation.

Plus hotter air requires more energy to fit a determinated mass into a volume.