Rapid engine wear is one of the most serious problems associated in the commercial exploitation of carburetter, straight methanol spark ignited engines. The existing lubricants are reported to be deficient in the control of cylinder bore and piston ring wear. Whereas, extensive efforts have been made to develop improved lubricants, the problem of increased wear of methanol has not, as yet, been satisfactorily addressed. The various mechanisms proposed for this increased wear have been examined in this paper. It was recognized that the conditions which aggravate the wear of methanol engines are encountered during cold start and warm-up due to the differences in the volatility characteristics of this fuel.
In this study, cold start wear tests were conducted in a cold room with temperature control ranging from +25°C to −40°C. Wear data of methanol engines, under starting conditions typical of the Canadian environment, are compared with data of a gasoline counterpart. The analysis of these data so obtained suggests that a temperature dependent theory is valid to explain the cold start wear results. Further, the cold start wear can be a significant portion of the total wear and is attributed to the direct attack of methanol on the cylinder walls in the first few seconds of engine operation.