Search Results

This paper summarizes work performed to define the range of recreational boat engine operation for the National Marine Manufacturers Association (NMMA). Sixteen boats were tested on-water with data acquisition systems to measure engine parameters. Boat types included sterndrive and inboard (SD/I), outboard (OB), and personal watercraft (PWC). Each boat was tested with low loads and at its rated load carrying capacity. Each boat was run at prescribed engine speeds from low to maximum speed during data collection. Maps of each boat's engine operation were produced in order to identify the lowest and highest engine load at each engine speed, based on intake manifold depression (for SD/I and OB) or throttle position (for PWC). Each engine type was then installed in a test cell where the lowest and highest engine loads from on-water testing were duplicated in order to measure the engine's output.

Propylene glycol (PG) is gaining acceptance as a viable base fluid in engine coolant applications. PG formulations are currently available which rival the performance of those based on ethylene glycol (EG) and have the advantage of being safer products. However, concerns have been raised that because of its higher viscosity, PG might impair vehicle operation in cold weather. This paper examines the low temperature performance of PG base coolants as compared to those based on EG using a combination of laboratory bench scale and actual vehicle testing. No measurable differences were observed between the coolants at temperatures as low as -40°C.