Secrets 4

EXCERPT FROM
"COSWORTH THE SEARCH FOR POWER"
WRITTEN BY GRAHAM ROBSON, 1990
27 MARCH 1992
(REVISED AUGUST 2002)
PAGES 48 THRU 50:

1959: KEITH DUCKWORTH TALKING,

"I hadn't designed many cams - I'd designed a special profile for the 1100 Climax which didn't seem to be much different from the standard one. My problem was that I had read the books on cam design and I had believed them. That was fatal. Even so, those people seemed to be fairly knowledgeable about the various types of profile, and acceleration diagrams."

The result was that Keith and Ben (Rood) completely revised their views on camshaft design, went for constant acceleration curves (" I reasoned that I didn't know what "jerk" was all about, and so I was fairly sure that the valve gear didn't know it either. I thought that all the arguments about "jerk" were grossly over- rated, and produced a completely new profile." - A2 PROFILE - !

" We made our own master profiles, but Leonard Reese used to make the cams for us. Later we made a simple modification - we added 1/32 in of lift and extended the opening period. That was the A3."

Harvey's notes:
THE ABOVE STATEMENTS ARE ABOUT THE FORD 105E ENGINES. A FOUR CYLINDER PUSHROD ENGINE, WITH 1.54 TO 1 ROCKER RATIOS. THE NEW PROFILES WERE DESIGNED TO SOLVE "SURGE PERIODS AT 6,000 AND 7,400 RPM".