New head, results

[rdh@sli.com (Robert D. Houk)]

It occurs to me that I never posted the results of the new head...

I've had the car back for a couple of weeks now, with nearly a thousand
miles on the new head (and pistons and ...). [As with the S4 turbo
upgrade, I went for new/factory parts as much as possible. So it's
a *new* *Audi* head, valves, pistons, etc.]

The only real difference I have noted is the engine is a bit smoother
on the top end (still running stock cams, compression, computer, boost,
etc.), but is probably more due to tracing some bad grounds causing an
erratic leaning out condition than the new head. I had an adjustable
cam gear put on, and it's set 2-degrees advanced. I *think* the engine
picks up a little quicker than it used to. I think it's a little torquier
(more torquey? what is the adjective form of torque?) on the low end
say from 2500 to 3000, but only a little (and might just be the new
clean head/valves...). It does, however, work, without injecting coolant
into the number four cylinder, and that is a substantial improvement!
Overall, the engine feels a little "tighter" (not in the friction sense,
although it is that too, what with new everything expect crankshaft and
main bearings, but rather in the responsiveness/tracking the throttle/
willingness-to-rev feeling, perhaps "more smooth/taut" feeling, or even
simply the torque curve is broader), but again that may simply be a de-
sire on my part to feel I got some sort of improvement for my kilobucks.

It definitely shows that understated competence at highway speeds that
Audis are good for (when they work), and that S4 turbo sure spools up
nicely. [Drawback: the cruise control has always had a tendency to hunt
a lot; with the S4 turbo the hunting surges are really serious - serious
boost (say, 8psi) to full-vacuum to serious boost every coupla seconds!
Takes four to eight cycles to settle down; every stupid hill and dale
sets it off again! Can't win for losing! New speedo cable (tranny to
stupidalarmboxinplenum) fixed a lot of this -- and made the speedo it-
self much steadier as well, but it still hunts a lot.]

It is "prepped" for a hotter cam one'o'these days (if I ever pay off
the bills from the new head) with "sport" valve springs, and the porting
and polishing job -- all I will need to do is pop the cam cover, pop off
the bearing caps and swap cams... I've heard much good about the Schrick
cams; has anyone tried the Kent cams? They advertise a whole slew of
Audi 5cyl turbo cams, from "mild street" .400 lift though .420 and .430
serious street to race cams (I misremember the duration/overlap/timing
numbers, I don't even know why I remember the lifts!)  For just a stock
cam, I'd say the port/polish job money would be better spent on choco-
late fudge, mole poblano, and other such ephemeral thrills. 

Someone had asked me about the cost for this little [mis]adventure.
Roughly speaking, new head, valves, springs, gaskets, bolts, etc. and
so forth, including the adjustable cam gear, ran about $1,600 for the
parts. Add $700 for port/polish job. Add about $600 for new pistons,
rings, rod bearings, gasket (oil pan). Add $1,350 for 30 hrs labor (and
that is an significant undercharge!), and a coupla more C-notes for as-
sorted miscellanea (plugs, wires, distributor rotor and cap, oil filters,
fuel filters, oil, antifreeze, etc. and so forth). Total right around
$4,500 for everything. You could get by for half that (especially if you
scrounge a used head, recycle valves/springs, etc., and don't have to
replace a bunch of toasted pistons to boot!) easily. (The mechanic spent
a *DAY* on "why is this F****R leaning out!" Stupid corroded CRIMPED
ground connectors!) But I figure anything worth doing is worth doing to
excess, and I have, for practical intents and purposes, a new engine
(block/crank/bearings/flywheel being "old"). One that I *KNOW* is ready
(damn near perfect) for -- and capable of -- computer/boost enhancements
and a sport cam.

I think I might want to replace/upgrade the radiator first though. I
vaguely remember a thread a while back on radiators, mostly on plastic
connections breaking, but also on getting beefier cores (more capacity/
rows) in the main radiator. [One of the drawbacks of instrumenting your
engine is that you can see what it is doing, and worry about it. It's
amazing to watch the water temp jump 20degrees in just five seconds of
high-boost/power highway running -- 11psi boost at 4,000 to 5,000 for
example! I'm not sure I'd want to take it on a race track for an ex-
tended run at high power until I had a way to shed all that heat]. Any
info on coupe-style radiators appreciated! Are most of the 5-cyl cars'
radiators "interchangeable", or is each one different? e.g., will an
S4 radiator fit an '83 UrQ? Are there any aftermarket high-performance
radiators available? What would it cost to have one "custom made" with,
say, 50% greater heat rejection capability? How about just buying one
of those "little" auxilliary radiators? (Given that the UrQ actually 
has a secondary radiator already, would this be a tertiary radiator?
For that matter, how about fan-cooling the secondary radiator? Or in-
stalling a beefier secondary? Paranoic minds want to know! Before they
have to fix another toasted head!)

					-RDH