Crower Cam and Headwork Notes:

Things started out with a phone call to Brian Crower at Crower cams.  Ethan Banks had previously sourced
Crower for a re-grind on the stock 2JZ cams, which was exactly what I wanted.  Below is the spec sheet on the
cam.   The regrinds took about two weeks, and were a VERY reasonable price.  The initial reason for the teardown
is that the car was smoking after idling at a stop light.  A quick poof of whiteish blue smoke is the symptom. 
Upon teardown, compression tests revealed poor compression in #4 and #5 with high compression in #1 and the
others.  With 140k on the engine, I didn't expect the top end of the engine to be in great shape, but it wasn't bad. 
A Lexus technician suggested that the rings were just worn and advised to purchase a short block.  A leakdown
test was done before the head was pulled.   This test pushes air into the cylinder through the spark plug hole.  If
you hear noise on the exhaust side, and exhaust valve is not sealing, if you hear noise through the oil fill cap, the
rings or head gasket may be bad.  If you hear noise on the intake, an intake valve may not be sealing.   I could
definitely hear leakage on the exhaust side of #4.   My suspicion at this point lead me to believe the top end was
the culprit for both the oil burning issue and the low compression.  

Upon pulling the head, we tipped the head over, filled the chamber with water.  Sure enough #4 exhaust valve
leaked water.   Other cylinders generally better, though not perfect.    The head went to a local shop for R&R. 
He worked the seats, did a 3 angle valve job with a little extra attention to the back sides of the valves for improved
flow.  He refit the worked valves with Crower HD springs (not the double ones).  Upon receipt of the head, it was
mentioned that the seats looked fairly worn, and had carbon deposits on the back sides of the valves possibly
causing the valve to not seat.  It was not determined whether the valve stem seals leaking oil contributed to the
valve not seating, or just general wear, but I think it may have been a combination of both.

The machine shop installed the Crower lash caps required by the Crower cam regrind.  He did a gross adjustment. 
The head was ported on both sides but the combustion chambers were unaltered.  The top and bottom intake
manifold and the Toyomoto manifold were worked a little bit.  Most of the work was just smoothing.  With the head
assembled, It was placed back on the engine and re-torqued to the block with a stock head gasket in between. 
At this point, I did another leakdown test.  It revealed near perfect compression across the board.  Everything was
sealing very well and was amazing for a thoroughly beaten 140k mile bottom end.   I noted upon teardown that the
cylinder bores were still very new looking with crosshatching still visible and no ring wear noticeable by running a
finger nail vertically up to the top of the bore.

 The intake side componentry was put back on.  The turbo and exhaust sides were installed, and the engine was
buttoned up, ready to run.    The engine fired up within 2-3 seconds and ran perfectly.  A fuel line to the aux
injectors needed a clamp tightened.  All else was uneventful and the car was ready for boost.

Initial driving impresisons were very positive.  With a 5lb spring turned down, the car was holding around 4.5psi of
boost.  At idle with the A/C off at 650rpm, the idle quality is decent if not stellar.  With a slightly lean idle mixture
the engine burbles and bobbles a bit.  A richer mixture causes a very stable idle at 650, but I have no mixture
control right now.  With the A/C on and an idle around 950-1000rpm, the idle is virtually stock, with only an
occasional burp.  All in all, the idle quality on the stock ECU is not objectionable, and with any kind of fuel
mixture adjustment, a stock idle could be had.   As far as noise is concerned, all the headwork has given the idle
a little meaner sound from the exhaust pipes.  Its easy to hear a deeper, more aggressive raspy tone, even from
stock exhaust.   Noise level from exhaust at idle has gone up by perhaps 2-4 decibels, hardly noticeable.  From
under the hood, the increased lift of the cam can be heard.  Its more clattery.  Nothing major, but you know
something is going on that is not stock.  Again, the noise level may have gone up 2-4 decibels.

Initial throttle response is unchanged from stock.  Around town, the car is no more difficult to drive, no odd noises
or surges, etc.  In the midrange around 2000-4000rpms, the engine isn't as eager as with the stock cam, but only
noticeable in back to back driving.   Boost comes on a little later, perhaps 200rpm later.  Engine still generates
around 4psi by 2200 rpm, which is very good.  Positive boost comes at 1800rpm with about 2 seconds of lag at
that rpm.   The stock ECU is perhaps not giving optimum fuel or timing in the 2000-4000 rpm range.   The AEM
guys say that MKIV TTs running aggressive cams can overcome this slight dip with timing and fuel adjustment
yielding stock spool and response equal to stock ECU and stock cam at low rpms.   The ECU seems to run the
engine a little leaner at moderate throttle settings indicating that the fuel trim may not fully compensate for the
increased breathing rate.

Once underway and digging into boost, it becomes evident by 5000rpm that there is alot more punch available. 
The old power curve was very fat with big spool around 4000rpm, decent power in the 5000rpm range, and steady
power to redline.  The new power curve is mild at 3000rpm, starts progressively gaining power in a linear fashion
straight to the redline.  There seems to be no more hump around 4000rpm, just smooth gathering of power as rpm
increases.  By 6500rpm, the engine pulls strongest right as the fuel cut interrupts the fun.  It now feels like the
true power peak would occur somewhere above 7000rpm.    Power-wise, 8psi at 6000rpm feels like 12psi used to.  
12psi now feels like the old engine at 16psi.   It pulls very hard up top.   On a squeeze of the pedal, the wheels
used to break free only if spooled around 3700rpm in 2nd gear.  It will now spin them at 4000rpm, or anywhere
above that.    A squeeze at 5500rpm gives nice squirrely wheelspin up to redline.  3rd gear is now a little squirmy
as well at times.   With the pathetic 6500rpm redline, the true potential will have to wait for the AEM, its tunability,
and the increased rev-limit.