Engine - Pcomp vs Pmax Ratio

Ratio of peak firing pressure (Pmax) to compression pressure (Pcomp) - the simplest indicator of injection timing quality on a slow-speed 2-stroke.

EnginePmaxPcomp

PcompbarPmaxbar

Pmax / Pcomp: 1.250 -

Pmax − Pcomp: 35.0bar

Diagnosis: Normal (1.15–1.35)

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

r = \frac{p_{max}}{p_{comp}}

Symbol	Meaning	Unit
$p_{comp}$	Compression pressure (no fuel)	bar
$p_{max}$	Peak firing pressure	bar

Source: MAN ES Operation Manual; WinGD X-Series Engine Data

In short

Ratio of peak firing pressure (Pmax) to compression pressure (Pcomp) - the simplest indicator of injection timing quality on a slow-speed 2-stroke.

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