Having pinging problems in the high load range of 1200-2400 rpm @ 60+ kpa.
I have found some issues but can't get it all to stop.
Pulled timing to the point it had no power these areas.
1993 Chevy Blazer
5800 lbs.
home elevation 2600 ft
short block GM crate L05
heads Summit Racing Aluminum 162108 62cc chambers
head gasket Felpro 1010 8.9cc .039in
cam GM performance 14097395 aka HT383 cam
bored throttle body and bored stock TBI intake
JBA small tube headers with their 2 into 1 pipe
flowmaster 3" cat and muffler
Tuning with TunerPro RT v5
Plan was to build a L31 vortec clone with aluminum heads.
Reading from the net lead me to believe this cam would work but in practice it holds dynamic compression close to static.
Looking up the specs on a stock L31 cam seems to be even more conservative...
Logic to me is says 9.25:1 in a heavy truck with these cams equals too much static compression.
I have played with 87,89, and 91 octane and lower timing to the point of no power.
It still pings even on Power Enrichment at 12.3:1 fuel
Suggestions are greatly appreciated
Here is the latest .bin and a log from today's drive home
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