[VintageLambo] Re: 4 liter V12 cam adjustment

In a message dated 06/01/03 12:14:44 PM Pacific Standard Time, lambojambo@aol.com writes: So my buddy Steve (who used to be the machinist on the Shadow Can Am team) says that he"s used the "advancing the cam" trick to bring torque up on other cars, but that there is usually an negative effect up around the redline area.(And Laust has found we get a "zero" effect at redline with our lambos.) Bill, do you guys mess around with that in racing at all?(Why you"d want less torque at redline in a race is beyond me....but maybe you"ve played around with the concept) Normally you have an engine that is suited to the gear splits in your gearbox and don"t have to play silly-bugger with the cam timing. My race car, for instance, has splits that result in about 1100 rpm between the gears. The problem, of course, is that in the classes where every little bit counts, you never know if the cam will work the way you want it until you hit the track (a phenomenon known as "suck and see"). You may well find that advancing (or less frequently retarding) the timing will give you a bit of a torque boost. Usually this is accompanied by a slight drop in power at redline, but the net effect on lap times is all that counts, and if those drop, you change the cam timing. Many engines have vernier adjustment wheels on them, and even quick opening timing covers so you can "play" with this stuff - personally, life is too short (and driving is so much more important in the sort of vintage racing I do) to go to all that work, but if you are in "real" racing, you do what you have to do. If the Lamborghini engine with stock everything else benefits from such an adjustment, I"d have to say that they dropped the ball, either intentionally in order to quote slightly higher ultimate horsepower (though they never seemed to let little things like real dyno numbers complicate their press releases, and Laust says there was no change anyway), or unintentionally. Given the normal use of our older cars, you might well find that if you were willing to allow a slight drop in high end power (where you never take the engine anyway, say above 7000 rpm), you could get significant improvement in performance below that rpm level. Personally, mine runs so flexibly that I am happy not to play around with it. Bill