VALVE STEM INSTALLED HEIGHT CBC AUTOMOTIVE TECHNOLOGY

INSTALLING VALVES IN THE HEAD Inspect Valve spring seats Install positive valve guide seals Prelubricate valve guides

CHECKING VALVE STEM INSTALLED HEIGHT Valves will sink into head after valve job Additional stem extension will change rocker arm geometry Stem height can be checked two ways –Depth Micrometer or Vernier Caliper –Dial Indicator 13-2

STEM HEIGHT SPECS Hard to find specifications Measure stem height before doing service work Compare reading with a similar reading taken after valve and seat work is finished.

DEPTH MICROMETER OR VERNIER CALIPER Measure with Valve spring removed Measure spring seat to upper end of installed valve. 17-1

CHRYSLER METHOD FOR STEM INSTALLED HEIGHT 17-4

DIAL INDICATOR Measures stem height in thousandths of an inch Some tools supply original specifications Calibrate Tool Install gauge over stem and measure stem height 17-2

CORRECTING VAVLE STEM INSTALLED HEIGHT Subtract original reading from finished reading This amount will be removed from stem end Stems usually hardened.030 deep Maximum that can be ground is.020 If more reduction in stem height is needed, replace valve seat.

VALVE SPRING INSTALLED HEIGHT

RESULTS OF INSTALLED HEIGHT CHANGE SEATS SINK INTO HEAD AND CHANGE SPRING LENGTH AND PRESSURE LACK OF PRESSURE WILL RESULT IN BURNED VALVES 12-1

To Correct Spring Height To correct installed height, you must shim spring Shims come in three thickness' – lbs change – lb change – lb change Serration's go next to head 17-6

METHODS TO CHECK SPRING INSTALLED HEIGHT 17-5A 17-5B

THAT’S ALL FOLKS !