Schrick Camshaft - Review (long)

[bbell@csn.net (Bruce Bell)]

Review
Schrick 272 deg. Cam in an '87 4000 CS Quattro.
Applications: all hydraulic lifter Audi's and VW's both 4&5
Cylinder.

Summary:
Prior to installing the cam my performance expectations were
moderate. I had no delusions about turnning my car into an
S4 eater with gobs of torque. Cams just don't work that way.
Performance cams don't make more torque, they primarily
define where (in the rpm range) the torque is available. My
expectations for this cam, were to give up some bottom end
torque in exchange for more power at higher rpms. I expected
idle to be considerably rougher. What I got was a much
smoother idle than anticipated. Up to around 2500 rpm there
is definitly a softer feel. From 2500 through 4500 rpm it is
almost impossible to tell the difference from stock. At 4500
rpm where power used to start fading away into the sunset,
there is the slight sensation of a surge while the engine
pulls with authority all the way to redline at 6300 rpm.
One surprise with this cam is how the exhaust note changed!
It sounds like the car is gurgling with pleasure, all in all
a pleasent and unobtrusive sound. . My reccomendation? If
you drive spirited and want to spend the money go for it. If
your style is to shift at 2500-3000 rpm, then save your
money unless you just want the cool sound.

Background:
Last October I sufferd the indignity of breaking my timing
belt. With the car in the garage and rental tools in hand I
began the chore at hand.. I'm generally a little impulsive
and heck the valve cover and cam gear were already off the
car so, credit card in hand I called Ron's Parts in
Vancouver, BC and ordered a Schrick 268 deg cam for my car.
I've known about Schrick cams for some time. Most notably
from the hydraulic camsaft comparison test tectonics and
"VW&Porsche" (EC) reported on in April, 1988.  According to
the article, "[the 268] is best for a street cam because the
supurb torque characteristics are accompanied by a stock
smooth idle".  This was the cam for me.  The cam arrived
and, behold, it wasn't the 268. I called Ron and he said
this an updated cam with 272 deg. on the intake and 268 deg
on the exhaust side.  The cam has 110 deg. lobe centers with
an 11.2mm lift. Valve timing is 26 and 66 degrees for the
intake and 24 and 64 degrees for the exhaust. Valve overlap
is 50 degrees. This cam uses the same profile for both 5 and
4 cylinder motors.

Installation:
One of the benifits of a hydraulic lifter cam is ease of
installation since there are no lifters to adjust. Start
with the #1 cam lobes up (i.e. both valves closed) and
follow Bentleys advice in removing and replacing the bearing
caps (sequence is important). With the schrick all you need
to do is lubricate it with enging oil prior to starting the
engine. Many aftermarket cams are regrinds or soft (softer)
steel with a hardning on the exterior.  For them a god cam
lube is considered essential. The Schrick on the other hand
is a chilled billet just like the oem cam. If it makes you
feel better go ahead and use cam lube.

Driving Impressions:
Starting the car for the first time gave me the jitters,
after all, what if I did something stupid? Don't ask my
wife. At first, all I heard were the lifters in a cacaphony
of ticks and tacks; but as the oil pressure came up and the
idle settled down, I could hear the gentle thump of overlap
in the exhaust. Perhaps It's the extra cylinder; but the
idle seemed smoother than my Jetta was with the Euro GTI
cam.

Time for a ride. I entered the street in first gear and
listened while I accelerated to 4000 rpm and shifted into
2nd gear. At 3500 to 4000 rpm I began thinking about how to
explain my frivality to my wife when even I couldn't feel
the difference. I watched the tach as it climed at almost a
linear rate through 5500, 6000 then redline. Ah I thought,
vindication, this will help me pass tourists in campers on
two lane roads. In first and second I found watching the
tach was a worth while activity since for the first time
ever I experianced the fuel pump shutting down at 6500 rpm!
In third It will easily pull to 6500 but you have a little
more time to shift.

In town, I tend to shift early, keeping engine rpm between
1800 and 3000. This is where I feel the softness in low end
performance the most. It still pulls smoothly from 1200 rpm
in 5th, but the lack of torque is noticable untill close to
3000rpm. Lately I've noticed a tendency in me to drive in a
lower gear keeping the rpm in the 2500 to 3000 range. On the
highway, for as long as I can remember I got around 26-27
MPG. Now, It appears milage has dropped off to the 24-26 MPG
range. This is probably a combination of the cam and my new
driving habits.

On cold mornings starting is a little slower. I find using
full accelerator while turning the key works best. It then
takes about a half mile to shake out the cobs. I also notice
more oder from the exhaust (gas) on cold mornings.

Performance by the numbers:
Several years ago, when I was building my Jetta, I came
across a method for computing road horsepower.  This method
computes power based on the time it takes to accelerate from
one speed to the next. I modified this in my excel
spreadsheet so that I could simply enter the acceleration
times from one rpm to the next. In this case I did it in
500rpm increments using third gear. the spread sheet then
computes the speeds at the rpm and averages those into road
horsepower figures. Whether these numbers would compare to a
chassis dynometer or not, I don't know. They do; however,
provide a basis for comparing performance changes. If any of
you would like this spreadsheet, you can get it via ftp from
"ftp.csn.net/bbell_assoc/rdhp.xls".

As you consider these numbers and my comments above, keep in
mind that I live at 5300 feet in elevation. While I doubt
the basic torque curve would change very much, those of you
at lover elevations should experience a little better low
performance due to volumetric efficiancy. (my guess)

                 time         Horsepower       Torque
Rpm Range    Stock Schrick  Stock Schrick  Stock Schrick
1000-1500     1.90    2.22   16.6   14.2    69.7    59.6
1500-2000     1.74    1.95   25.4   22.6    76.1    67.9
2000-2500     1.70    1.83   33.4   31.0    77.9    72.3
2500-3000     1.67    1.72   41.5   40.3    79.3    77.0
3000-3500     1.67    1.67   49.1   49.1    79.3    79.3
3500-4000     1.67    1.67   56.6   56.6    79.3    79.3
4000-4500     1.67    1.65   64.2   64.9    79.3    80.2
4500-5000     1.71    1.65   70.0   72.6    77.4    80.2
5000-5500     1.79    1.66   73.9   79.7    73.9    79.7
5500-6000     2.25    1.71   64.4   84.8    58.8    77.4
6000-6500     3.42    2.00   46.1   78.8    38.7    66.2

I computed these torque figures using the standard
(hp/rpm*5250).

By the way, I burned a considerable amount of gasoline to
get these numbers. Being consistant with a stopwatch while
watching a tach and the road ahead isn't easy. These numbers
(times) are the results of many runs over many days in
sometimes wildly varying conditions. I can guarantee that
vehicle weight varied since sometimes I had a full tank and
sometimes it was nearly empty.  Hence, most of these times
represent averages that I have confidence in for future
comparisons on my car.

The Future:
Well I beleive only torque can make a man truely happy.
Since the intake valve doesn't close until 66 deg. ABDT
there is less time for the compression stroke and volumetric
efficiancy is a concern. So my next step won't be to port &
polish or trade in the 38mm valves for 40's. Those changes
would no doubt improve top end a little more; but I suspect
they would really hurt at the bottom. Next is at a minimum
to increase the compression to over 10:1 with a piston
change. Hopefully I'll be able to change the crank too.
This, I think will also help cold weather starting.

Disclaimer: I have nothing to do with Schrick or Ron's Parts
other than being a customer. A very satisfied customer.


Bruce Bell
bbell@csn.org