After installing a new turbo charger in a 1961 M20B its time for a high altitude test flight. At 16,500 feet the MP started to drop indicating that some leaks exist in the system, which is a common complaint. Apart from this and some overheating issues, also common, it was a successful flight. With a TAS of 177 to 180 kts at an estimated 13.5 GPH.
A completely manual system, with independent waste gate control, it certainly takes a lot of care and planning to use correct. One interesting aspect on my descent for landing, was at 10,500 feet when i brought the turbo off line and suddenly the engine ran very rough. This was due to having the mixture at the full rich position, something that is required to keep CHT and TIT at an acceptable level while using the turbo charger.
After a 30 minute descent with a ground speed at times of 235kts I arrived back at CYPQ for a wonderful sunset a night touchdown. I am looking forward to some more turbo Mooney adventures soon.
17 сен 2024
