False reasons for rejecting the 'Blackburn Cycle' or Ideal Explosion Engine
With 8 strokes in the cycle there is more friction - The only way to get more strokes and friction is to change the overall gearing. This is obviously not needed and not done. There are simply half as many combustions for cruising and idling. Compare one 8 stroke 'Blackburn Cycle' with two 4 stroke cycles for cruising and idling. Think of total losses per mile, not losses per combustion.
BC is the same as 'cylinder de-activation' - Both systems can reduce the number of combustions and raise the compression but 9 of the 10 advantages for BC apply only to BC. The 'Blackburn Cycle' is different to the 4 stroke cycle always used by 'cylinder de-activation'.
Lean burn increases 4 stroke fuel efficiency, while BC runs richer - Lean burn has two effects on 4 stroke engines. Excess air cools the charge at the start of the cycle which helps efficiency, but also cools the combustion temperature which is unhelpful. BC already has a cool charge due to the alternate cool 'air only' inductions, so there is nothing further to gain from lean burn. All heat engines achieves maximum efficiency with a high combustion temperature. This is why BC achieves maximum efficiency in theory and practise with a stoichiometric fuel/air mix.
Emissions - Higher temperature and pressure combustion is more efficient with lower HC, CO and CO2 but produces more N0x. For low power the exhaust is like Diesel with excess air, but with less smoke and particulates. Optional alternate opening exhaust valves and ports separate the 'air only' to suit catalytic converters.
Roughness - BC may benefit from torque smoothing but this presents no problem. It is smoother and quieter than Diesels.
Less power per litre - Using only one of two inlet valves as the early version reduces the max power. High power per litre with 3 or 4 valves per cylinder is available in the later versions.
Evaluation without tests - Engineers evaluating BC, expect to find and are looking for defects. Tests are essential to understand BC and confirm the large efficiency gains.
1,000 tests have been run on a research engine, which can change from the 'Blackburn Cycle' to 4 stroke without stopping. Under identical test conditions average BC efficiency gains ranged from 65% at half load to 92% at a fast idle. This single cylinder engine would not run reliably at a slow idle when the gain would be larger than 92%.
There are no valid reasons to reject the 'Blackburn Cycle'.