Camshaft - Correlation and Valve Timing
90porsche03 April 12, 1990Subject: Camshaft Correlation and Valve Timing
Model Group
928 GT 1
Part Identifier Number
1505 9008
ATTENTION: Service Manager/Service Technician
Models Affected: 928 GT Model Years 1989 (K) and 1990 (L)
Concern: A. Modified correlation markings on camshafts.
B. 928 GT Valve timing specifications.
Repair Information: A. 928 GT Camshaft Correlation Markings.
The copper-colored chain links must be aligned with the electric pencil markings on the camshaft gears (arrows in figure). Do not align the copper-colored chain links with the casting tabs.
Some early production cars and spare parts may not have the electric pencil markings on the camshaft gears. Use gauges from special tool 9226 to check camshaft correlation and mark camshaft gears with an electric pencil. Spare parts will eventually have correct casting tabs.
B. 928 GT Valve Timing Checking and Adjusting Specifications.
Right cylinder bank (Cyl. 1-4): Left cylinder bank (Cyl. 5-8)1 2.8+/-0.1 mm intake valve lift. 3.1 +/-0.1 mm intake valve lift. Cyl. 1 at 20~ after TDC overlap. Cyl. 6 at 20" after TDC overlap.
Refer to 928 Workshop Manual, Volume 1, pages 15-119 through 15-135 and Technical Bulletin, Group 1, Number 8723, Book D, page 79, for information on valve drive assembling and valve timing checking.