Last night I decided to put the schrick cam into my new '83 CGT engine. The engine has 250 miles on it. New block with stock crank, rods and pistons (should have used different pistons). The head was completely rebuilt (only the aluminum body was reused) and it was ported & polished with most of the work done on the "short side" radius of the intake and exhaust ports and the air flow through the valves was "cleaned up". I can discuss more about that later... Being an '83 I am using solid lifters. The larger CIS-E throttle body was used, as well as 4kq exhaust manifold. Exhaust is 2-1/2", currently w/ cat, and one single borla turbo muffler (straight through design). Also, K&N filter is in the airbox. The head was milled to minimum height spec. This should have the same effect as advancing the cam timing by about 2 degrees. An adjustable cam gear was also fitted to the car. With the stock camshaft the difference between the new engine and the old engine was night and day. Of course, so many things were changed you'd expect that. My first "data point" was taken with the cam gear set for 2 degrees of retard. This should be close to stock given the head milling. Spark timing was dialed in to stock specs (6 ATDC) per Bentley. Torque felt higher through all RPM ranges compared to old engine. High end breathability was magnificent and the car would accelerate very well at all RPM's. It would pull very strong starting at 3700 to 6000 (I didn't venture higher than 6k on such a new engine). Feel free to flame me about proper break-in procedure... Additionally the car would idle well at 600 RPM's. The next data point was taken with the adjustable gear set at 0 deg. This should be about 2 degrees advance. Idle was a little rougher. Spark was readjusted to 6 ATDC. Slight but noticably less low end torque. At 4k RPMs, the engine really started to breathe and you could feel the HP difference. There was a noticable difference in performance above 4k. High RPM accel. greatly improved. The final stock cam data point was taken at 3 degrees advance on the cam gear (~5 deg total adv.) Spark timing again was reset to 6 ATDC per Bentley. Idle rough below 850 and adjusted to 850, 'cause car stalled once. Low end torque was definitely lower. Felt like towing a trailer through 2k. From 2k to 4k felt like stock. From 4k on it felt like a tiny little turbo was kicking in; this was a very noticable difference from the last setting. Then I swapped in the Schrick cam. All said and done this took 70 minutes. I left the cam gear on 3 degrees advance and had difficulty getting the car to idle. Reset the cam gear to 2 degrees retard and it would idle at minimum of 1100. (Ok, it would kinda idle around 850 but it wasn't a friendly idle). Let the car idle at ~1500 for 30 minutes for the cam to break in again. There was no discernable difference in low-end torque between the schrick and stock cam on this setting. After 3k RPM, there was a slight difference that appeared to grow as I approached redline. I set the cam then to 3 degrees advance and reset spark timing to stock. Idle was a little rough at 1100. Idled well at 1400, but left it set to 1100. Absolutely no low end power. My pushmower could beat me to the 100 meter line if I did a 2nd gear start. Under 3500 performance was lackluster. Car would cut out if RPM dipped below 1k when stopping at stop signs. However, at 4300, performance was phenomenal. On the highway a 4th gear acceleration from 65 to 85 would be done instantly. Absolutely a blast, but probably only useful for the track or auto-X. Finally I set the cam to 0 degrees advance. This seemed to be the best compromise between torque and HP. The car will idle at 1100. Acceleration in any gear below 3500 RPM's feels like stock. Above that mark, you know there is a big difference. Car pulls very strong through to 6k, and tach needle visibly accellerates faster and faster the closer to the red you push it. The sound out of the exhaust is definitely different too. More of a rumble-grumble than with the stock cam. So, is a Schrick cam worth it? Maybe. It depends on what you've done to the car. I don't think it would work nearly as well by bolting it into a stock engine. I'd say first you should do the simple stuff, like throttle body, filter, no cat, and adjustable cam gear. Then move to 4kq manifold and better exhaust. To make the manifold job easier, go ahead w/ the P&P on the head a the same time. It's a costly way of doing it 'cause then you need to do the head work, new manifold, and exhaust all at the same time. Only after all this would I suggest going with the cam, since it does cost so much. Anyway, my $0.02. Sorry no numbers or HP/Torque curves, just seat o' the pants observation. Feel free to argue or question anything I've said. Later,
'83 CGT
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