View Single Post
WERK I WERK I is offline
Forced Induction Junkie
 
WERK I's Avatar
 
Join Date: Jan 2003
Location: Wisconsin
Posts: 3,267
Garage
There could be other factors at play here. A/F contamination, carbon build up could be at play. A/F contamination can come from oil getting into the mixture. This will lower the octane of the incoming mixture. Valve guides, PCV and turbo bearings are the most common causes.
Carbon build up comes from over rich conditions or oil contamination. Carbon will raise the compression ratio bringing on pre-ignition or detonation.
Geez, even an improperly adjusted valve can give you headaches. If the valve has little time against the seat or is prevented from seating on seat due to carbon buildup, that valve will start glowing like a glow-plug.
__________________
Dave
'85 930 Factory Special Wishes Flachbau
Werk I Zuffenhausen 3.3l/330BHP Engine with Sonderwunsch Cams, FabSpeed Headers, Kokeln IC, Twin Plugged Electromotive Crankfire, Tial Wastegate(0.8 Bar), K27 Hybrid Turbo, Ruf Twin-tip Muffler, Fikse FM-5's 8&10x17, 8:41 R&P
Old 05-04-2008, 05:46 AM
  Pelican Parts Technical Article Directory    Reply With Quote #24 (permalink)