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IT is generally conceded that the automotive industry has been lagging behind the building trades in the matter of keeping occupants comfortable. The complaints of the passengers of public vehicles, emphasized by the overcrowding of the war years, have resulted in placing a priority on heating, ventilating, and air cooling of vehicles as an immediate postwar development. Messrs. Todd and Gadd present a summary of the developments carried on in this field in the past months by their company.

AN instrument for the accurate measurement of cylinder wear is described by the authors. The instrument consists of a diamond indenting tool, an indentation locator, and a microscope. To determine wear, the length of an indentation is observed with the microscope before and after periods of operation. Wear, which is reflected by changes in the depth of the indentation, is calculated from changes in the length of the indentation. Using this instrument in their experiments, the authors found that most cylinder wear is due to corrosion and occurs during warmup, when cylinder temperatures are low. It appears that corrosive gases condense on cool cylinder walls and attack the surface. Then the corroded film and lubricating oil are wiped away by the piston, leaving the walls ready for further corrosion.

THIS study of the performance characteristics of present-day automotive fuels and engines during the warmup period brings out the following points: 1. Present-day engines vary appreciably in their warmup performance with any given fuel. 2. Mechanical deterioration of an engine through use tends to impair its original warmup performance. 3. Volatility of fuels affects the warmup performance of any engine. The average 65% point measures warmup ability of a fuel fairly well. 4. The increased amounts of high-boiling, high-octane gasoline fractions available from refining equipment installed during the war may be expected to lower the volatility of gasoline. Automobile manufacturers should give this fact due consideration in designing future engines.

DR. HALL presents a chart of arithmetic and logarithmic mean specific heats at constant pressure for dry air in the range from 400 to 5000 R and a series of charts giving specific-heat correction factors which compensate for the presence of water vapor, fuel vapor, and the products of combustion of either lean or rich mixtures. On the specific-heat chart are plotted lines of constant pressure ratio and lines of constant enthalpy change. The chart is designed to permit accurate calculation of heat and work in steady-flow processes without reference to entropy, enthalpy, and internal energy. Correction factors to be applied to the gas constant are also included in this paper.

A METAL-FACE, balsa-core sandwich material being marketed under the trade name “metalite” has been found competitive with the present conventional all-metal types of construction. In this material, cycleweld cement and phenolic resins form the bond. Extremely high joint efficiencies can be obtained with hollow rivets or aluminum-alloy bolts. Metalite construction gives the very smooth surface needed for high-speed, low-drag aircraft and has been used extensively in the XF5U-1 and XF6U-1 experimental Navy fighter planes.

WELL-DESIGNED diesel engines in good repair, the author says, need not smoke while being operated on normal fuel if they are prevented from being overloaded. Unfortunately, he points out, with many types of current injection equipment, effective prevention of overloading over the entire speed range involves a reduction of the low-speed torque; in other words, sacrificing part of the lugging ability of the engine. The author makes the following suggestions to eliminate smoke: 1. For correcting a normally smoky exhaust, the smoke should first be diagnosed. 2. To eliminate hot smoke the mixing of the fuel and air should be improved. 3. To eliminate cold smoke ignition must be speeded up.