Engine knock (detonation) is an important phenomenon, as it sets the upper limit of workable thermal efficiency. Detonation onset depends on several constraints which may well be altered by late intake valve closure. This paper examines the detonation characteristics of two valve closing systems; late intake valve closing versus the conventional one, by analyzing experimental results. It was found that there are some differences in the detonation characteristics of late intake valve closing engine system (LIVCES) and the conventional engine system (CES). The LIVCES enhanced detonation, which had to be compensated by advancing the spark timing. A maximum of 12 CA degrees was found to be the average value necessary to avoid detonation at light-loads. At high-loads the spark timing advance of the LIVCES becomes almost the same as that for the CES. Also, the maximum cylinder pressure was found to be less than that in the CES.
Knocking Phenomena in a Gasoline Engine with Late-Intake Valve Closing
Sae Technical Papers
International Congress & Exposition ; 1992
1992-02-01
Conference paper
English
Knocking phenomena in a gasoline engine with late-intake valve closing
Automotive engineering | 1992
|Effects of Intake Valve Closing Timing on Gasoline Engine Performance and Emissions
SAE Technical Papers | 2001
|Ignition timing and knocking of gasoline engine
Engineering Index Backfile | 1934
|Controlling Engine Load by Means of Late Intake-Valve Closing
SAE Technical Papers | 1980
|Controlling engine load by means of late intake valve closing
Automotive engineering | 1980
|