Some time ago I asked you how to solve the vapour lock problem, that my PV444/B20F demonstrated with each and every hot start. I got a lot of good advice, but had to find out the solution myself....
Isolating the fuel hose didn’t help and the fitting of a large stainless steel heatshield between the HIF SU”s and the manifold didn’t help anything either, to my surprise. Then I knew it just had to be the fuel pump and mounted an SU electric fuel pump. Problem solved.
The question that remains of course is would a heat shield in front of the fuel pump have been a solution as well. I might try that one day.

What I also did was replacing the rear HIF SU with a slightly different one, that had the vacuum take off for the distributor on top instead of under the carb housing. I never saw it mounted at the underside before and there also had to be something wrong with that particular carb, because often –during hot starting- fuel was leaking out through that “upside down” vacuum take off (and not where you would expect it to leak: through the overflow pipe).
Also I’ve got a choke mechanism now on both carbs instead of one, though I didn’t connect the choke on the rear carb yet. It just doesn’t seem to be necessary as cold starting isn’t a problem at all. And hot starting isn’t a problem anymore either now –to my great relief.