FWIW - Wiki has a post for Marvel Mystery Oil. In it there is reference to an NTSB report done after an aircraft crash from engine failure. MMO was added to the aircraft engine oil and was determined to be the cause of the failure. NTSB did a chemical analysis of MMO and found it to be: 74% mineral oil, 25% petroleum distillates, and 1% lard.
Petroleum distillates is a somewhat generic term for various combinations of naphtha, kerosene, white gas, mineral spirits, paint thinner, etc.
Aviation engines are a very different animal from autos and are designed to run at maximum performance for long periods of time. Take off can be red line rpm at max egt for 15-20 minutes. It's a different loading than the constantly varying throttle of road driving. That said, it's still a cautionary tale about using this type of product in crankcase oil. Replacing lubricant with solvent is not normally wise and proportions of solvent measured carefully.
Prior to reading the Wiki article, I used MMO in a 3FE and was amazed at how dark the oil got from gunk that was being cleaned off the inside of the engine. It does work and for cases with stuck rings it can save an engine. But at a cost to other components. The lighter distillates also tend to evaporate off when the oil gets hot. Before broad temp range synthetic oils were available, bush pilots flying in extreme cold, -40*, would add gas to the engine oil to lighten its viscosity so the engine could be restarted after cooling. The gas would evaporate off at operating temperature.
Uses in fuel systems make more sense but starving a fuel pump of lubricant to clean the injectors, which can be removed to clean, might be a diminished return.
Petroleum distillates is a somewhat generic term for various combinations of naphtha, kerosene, white gas, mineral spirits, paint thinner, etc.
Aviation engines are a very different animal from autos and are designed to run at maximum performance for long periods of time. Take off can be red line rpm at max egt for 15-20 minutes. It's a different loading than the constantly varying throttle of road driving. That said, it's still a cautionary tale about using this type of product in crankcase oil. Replacing lubricant with solvent is not normally wise and proportions of solvent measured carefully.
Prior to reading the Wiki article, I used MMO in a 3FE and was amazed at how dark the oil got from gunk that was being cleaned off the inside of the engine. It does work and for cases with stuck rings it can save an engine. But at a cost to other components. The lighter distillates also tend to evaporate off when the oil gets hot. Before broad temp range synthetic oils were available, bush pilots flying in extreme cold, -40*, would add gas to the engine oil to lighten its viscosity so the engine could be restarted after cooling. The gas would evaporate off at operating temperature.
Uses in fuel systems make more sense but starving a fuel pump of lubricant to clean the injectors, which can be removed to clean, might be a diminished return.
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