Stick Racers !!!

[DeuceCoupe]

Originally Posted by Stan Weiss

Did you ever see this thread?


"Old School" Stocker Cams

http://classracer.com/classforum/showthread.php?t=75027



A few things were done by Lunati. NHRA checked lobe lift. The Chevy cam used a valve lash of 0.030" By reducing the lash ramp height they were able to add both duration and lift. Also if you look at my original post you will also see a picture and how dwell was added at max lift.


Stan

Great thread thanks.

I thought the "stocker" (cheater) cams would have more duration at .050 though. Looking at the graph on pg8, it looks like the .050 duration is about (295-55)=240, which is actually less than the stock early Z28 duration of 254 at .050, right?

I get the idea, and that thread discussion confirms it - I just thought the graph would show fatter numbers at .050 and even .100 lobe.

[oldskool]

"..."bombing" the record...guess that would only affect eliminations, not the class winner?..."

Yeah, in class elims, the 1st car to the finish line wins, unless they tripped the red light. Don't matter how slow the cars are, at a particular race. They don't have to be capable of running anywhere near the nat record. They're only running against the other cars in their class, at that particular race.

BUT, once Stock elims begin, it was a different story. A car that couldn't run the nat record didn't really have much of a chance at a big race, where lots of the other cars could run their nat record & quicker.

That rule had to be changed for Stock racing to survive. Now, any legal car that can run it's index can win any race, as long as it don't have a heads-up race with a car in it's class.

[Stan Weiss]

That graph is based on numbers I got using a degree wheel and dial indicator. Not only was that cam raced but it also had a number of miles put on it from street diving. The car / cam was not mine. I just got to work on it. This was in the early / mid '70s. So not sure how this cam relates to the late '60s. At this time a similar engine / car from the same build ran in the high 11's. I don't remember what this car ran.


These numbers are from from the Chevy cam which someone got from a Cam Doctor and was nice enough to share with me many years ago.


Stan