 |
PM |  | |
Quote | | |
Reply | | |
Full Topic | |
| Joined: | 05-01-2005 |
| Location: | Minneapolis, Minnesota USA |
| Posts: | 575 |
| Status: |
Offline
|
Cam ID .......... Duration........ Lift...... Overlap... MOP
C or 101 cam...... 272° ........ .340" ..... 52° ...... 110° / Red dot
D or 102 cam...... 270° ........ .350" ..... 50° ...... 110° / Red dot
E or 103 cam...... 260° ........ .344" ..... 55° ...... 102.5° / Yellow dot
107 cam............. 252° ........ .378" ..... 44° ...... 104° / Green dot
104 cam............. 272° ........ .410" ..... 64° ...... 104° / Green dot
DS-2 Cam........... 280° ........ .415" ..... 72° ...... 104° / Green dot
The C-cam is the stock J-H cam
Comparisons by the numbers alone are difficult. The E, 107, 104 and DS-2 cams all use much more aggressive opening and closing ramps. The seat to seat durations may not be too impressive, but their effective open times are better than some cams quoting significantly longer durations. Compared to the C & D cams, they are all performance improvements.
The E-cam addressed the 907's "torqueless wonder" reputation. The milder timing produced a noticeable improvement in low end torque, while the more aggressive ramps and higher lift kept top end horsepower the same (usually you trade one for the other). No more power, but the torque made the car easier to drive in traffic and it "felt" more powerful.
The 107 is the "Turbo" cam. Forced-induction engines don't like a lot of overlap since it's hard to force-feed the cylinder when the back door is open. However, they do like lift. In a naturally aspriated engine, the higher lift really pays off. The cam gives an even stronger bottom end than the E-cam plus a mild increase in top end power. The useable power band is wider so the car is easier to drive in traffic. A good street cam, but not a hot-rod or track cam.
The 104 cam gets back to the C-cam's duration, but with the aggressive ramps and much higher lift. This is a good street-performance cam, however the top end performance does come at the expense of low end torque. Overall, performance is way up... just don't get caught in the wrong gear at low speeds. Great in the torquey 2.2, but not everyone's cup of tea in the torqueless 2.0. I've got a pair of 104's in a 2.0, 4-seater Lotus Eclat and have no problem with it.
The DS-2 by Dave Smith is similar in character to the 104, just more of the same. I've got a pair of them in a 2.2-907 Esprit S2. Great street performance cams when combined with the 2.2's torque.
The Excel SE & SA and the Esprit S3 HC (2.2 912 HC) used a 104 cam on the Intake and a 107 cam on the exhaust. That was a compromise set-up that gave some top end improvement without sacrificing anything on the bottom end.
Tim Engel