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Re: FW: Schrick 272 camshaft review - Updated (long)
Thanks. I remember seeing this before. I've saved it now so
barring a crash or something, I should be able to keep it.
Anyhow, thanks for the info on how you computed power.
1983 ur-q / black / getting a MC
1984 4000 Turbo quattro (Faster than your average 4kq)
1987 4000 quattro / Saphire Metallic Blue/ Girlfriend's
1996 A6q / Volcano / Dads Car
*****1985 5kt / PARTING OUT!
On Wed, 15 Dec 1999, Bruce Bell wrote:
> Seems like I repost this Annually. Does the Schrick discussion really come
> up that often?
> Todd et all; The cam specs are in here as is a basic explanation of my
> methodology for computing HP and torque. Also for those who complain their
> 4kq is hard to start or gets poor gas mileage, there is information you can
> use too.
> P.S. I think my update of this was from 1998.
> [ There were a couple of recent requests for information on the Schrick and
> I sent out my review from 1995 without realizing it needed to be corrected,
> At the time I wrote the review my car had, unknown to me at the time, a
> failing temperature sensor which adversely affected the cars performance. ]
> [ All the new text will be included in square brackets ]
> [ From Jan 4, 1995 ]
> Schrick 272 deg. Cam in an '87 4000 CS Quattro. Applications: all Hydraulic
> lifter Audi's and VW's both 4&5 cylinder.
> Prior to installing the cam my performance expectations were moderate. I had
> no delusions about turning 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 definitely 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
> One surprise with this cam is how the exhaust note changed! It sounds like
> the car is gurgling with pleasure, all in all a pleasant and unobtrusive
> sound. . [As the temperature sensor got worse, and the car started running
> richer, the gurgling became early morning coughing and sputtering] My
> recommendation? 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.
> Last October I suffered 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 camshaft
> 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
> superb 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.
> One of the benefits 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 engine oil prior to starting the engine. Many Aftermarket
> cams are regrinds or soft (softer) steel with a hardening 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 cacophony 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 frivolity to my wife when even I
> couldn't feel the difference. I watched the tach as it climbed 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 experienced 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 noticeable
> until 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 mileage has
> dropped off to the 24-26 MPG
> range. This is probably a combination of the cam and my new driving habits.
> [It was the temp sensor - my gas mileage actually went up in highway driving
> after changing the temp sensor. For the first time with the cam my car
> actually delivered an honest 29 mpg though 27-28 was more typical]
> 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 odor from the exhaust (gas) on cold
> mornings. [This should have been a clue to me. All of these issues were
> cleared up with the replacement temp sensor.]
> 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
> dynamometer or not, I don't know. They do; however, provide a basis for
> comparing performance changes.
> 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 efficiency. (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 consistent 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 believe only torque can make a man truly happy. Since the intake
> valve doesn't close until 66 deg. ABDT there is less time for the
> compression stroke and volumetric efficiency 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.
> [well, plans do change, little did I know then how much]
> Disclaimer: I have nothing to do with Schrick or Ron's Parts other than
> being a customer. A very satisfied customer.
> Bruce Bell