The Variable Valve Timing System - Application on a V8 Engine

A. Titolo

SAE technical papers on CD-ROM/SAE technical paper series · 1991 · 29 citations · 0 references

Concepts

Abstract

<div class="htmlview paragraph">Analyzed are the final test results obtained on the Ferrari V8 engine featuring engine heads having the Fiat variable valve timing system.</div> <div class="htmlview paragraph">Maintaining the base architecture of four camshafts overhead and four valves per cylinder, the VVT (regarding the intake and the exhaust) has provided record-level results at medium-to-low engine speeds, without penalizing the engine performance at high engine speeds.</div> <div class="htmlview paragraph">Improvements have also been made in fuel consumption as well as reducing the exhaust pollutants.</div> <div class="htmlview paragraph">Under analysis is the improved effect on both the “effective compression ratio” and the “expansion ratio” which together with the “volumetric efficiency” justify the high levels of the brake mean effective pressure (BMEP) obtained.</div> <div class="htmlview paragraph">Introduced here is the concept of the “sluggish area” of the standard sport engine performance, comparing the immediate response of the VVT to the partial loads at low-to-medium engine speeds.</div> <div class="htmlview paragraph">The final considerations on the racing engine applications complete this study.</div>