1987-02-01

Using an Optical Proximeter to Phase Cylinder Pressure to Crankshaft Position 870478

ABSTRACT

The use of an optical proximeter to determine dynamic top center in a motored engine is demonstrated. Design criteria are formulated and a data reduction procedure is presented. The method is shown to have an accuracy of Δθ = ± 0.1°. Variations in dynamic top center with engine speed that can be attributed to structural flexing and finite bearing clearances are shown to be less than ± 0.05°. It is also shown that the compression ratio during gas exchange is slightly larger than during compression-expansion.

Other methods of finding top center are discussed and contrasted with optical proximetry. In this context a rational means of examining pressure records is presented and shown to be accurate to within Δθ=±0.3°.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.
X