Thanks for the kind words. I'm posting a pic here that you might find interesting. It is a picture of my Hartman Enduro kart taken around 1977 with a freshly built pipe design that I worked up. As you can see from the pic the pipe is nothing radical. It was essentially an expanded version of a Kendick slippy pipe made from thin wall spun steel cones. It was a nice looking pipe that I was pretty excited about..... until I tried to run it. As you can see from the picture I ran a Hegar axle clutch on the 101 in those days and set it up to engage at around 9,000 rpm. The kart never made it to the track with that pipe as I tried to give it a test run on the street in front of the house and discovered that the engine would not rev enough to make the clutch engage or even begin to engage. It would rev right up to 9,000 on the tach and just sit still! That pipe was one of many steps in the learning curve that provided some fundemental rules.... one of which turned out to be that if you go bigger on the volume you better go steeper on the cone angles! I did some further experimenting with the pipe some time later using a Burco clutch set to engage at around 7,000 and the thing made so much bottom end it would have pulled an oak tree out of the ground but the thing had no top at all. It was much better when the head pipe was shortened by several inches but in the end I discovered the cones were just too shallow to make power power in the rev range I was shooting for.
Happy New Year to all!
Steve O'Hara
PS... Bob, Rob....sorry the pic is not a rear engine kart
