23-03-2019, 07:54 PM
Since fitting an export fan to my RP I seem to have eliminated a problem similar to yours, Bob. However the SU on my car is more exposed to the draught from the fan compared to where the 22FZB sits. I used to run with the bonnet half open on hot days when climbing, which did help. On a long slog uphill it will get mighty hot under there which is no doubt causing you some vapour lock problems. Another option is a fibre block or extra gaskets between the carb and the manifold to reduce conducted heat.