"spitting back can be caused by cams with too much overlap"
Not surprised. When I had my 67 Austin Cooper S modified by Downton Engr to 3/4 Race setup, the SU carbs would spit out fuel below about 2800 rpm because of the cam characteristics. Common problem for such cams it seems.
Lived with the spitting. For street driving, used air cleaners to smother the gas spray; for competition, used air bells instead for better and smoother intake airflow.
89 Milano (wife's daily driver since 1989, Shankle Sport)
91 164S (my daily driver since 1994)
94 164LS (~Q) (trip Alfa since 2000)
72 Morgan 27 (water time since 1976)
previously owned since 1964:
62 Morris MiniMinor 850, 67 Austin 1275 Cooper S (Downton 3/4 race), 64 Giulia Sprint GT (1st red one made), 72 Fiat 128 Sedan, 75 Alfetta Sedan, 78 Alfetta Sedan, 78 GTV, 81 GTV6, 86 GTV6
Last edited by Del; 02-12-2017 at 11:43 AM.