questions about high compression 4kq's with NG/NF/Hybrid and CISE

[Derek]

Thanks Javad, James, Carter, Gary, and Nate for your responses.  I am
heading for the garage now to fiddle with the car based on your input.

My setup:

rebuilt JT block, new bearings, rings, seals, etc
used '85 VW Gti pistons (HT engine), 10.0:1 compression
rebuilt NF head, ported/polished, manifolds matched to head
272* cam, timing sprocket being added today
2.5" exhaust, 1 muffler, catalyst re-installed (straight-pipe sounded ricey)
5kt oil cooler, single-filter variety, Mobil1 15-50 synthetic
15K/mi since rebuild, 180~190 psi on all cylinders
new W7DTC plugs, recent cap/rotor, wires were fine in the donor vehicle...
stock '85 4kq CISE
base mixture at 10mA
base timing, with vacuum advance connected, 4*BTDC
airbox warmup thermostat disabled, additional cool air ducted in, K&N
premium fuel always

Gears 1-3 will pull to redline quite nicely.  In 4th or 5th I get knock
usually around 3500 to 4000 rpms at anything over 1/4 throttle.  Sometimes
it feels like the knock dissapates after 4500 or 5000 rpms, though that
could be the exhaust note overwhelming it.  The knock is present when cold,
though not nearly as bad as when warmed up.  I've been reducing ignition
advance over the last few days, from 10 to 8, now it's at 4 degrees.  I'll
try 0 degrees briefly just to see if the knock ever vanishes, though 0
degrees defeats the purpose of the motor in the first place.  I also
increased the mixture in 1/8th turn increments, up to 1/2 clockwise turn
total.  That reduced knock, didn't eliminate it, and added a host of other
drivablilty problems.

It sounds like I should be able to run at least 8 degrees advance and normal
mixture settings without issue.  Something is wrong.  I'll report more
results in a while.

Thanks.
-Derek
'85 4ksq  '86 4kcstq  '87 Gti 16v