We have type 4 motor and a 1600 AS on our two vans. How do you find the single weber? The missus bay, came to us with a single twin choke weber progressive, which is a nice carb but needs a hot summers day as the type 4 doesn't have heated manifolds, for average temperatures its a pig, for cold days its dangerous, try pumping the throttle to keep the engine going whilst braking for the lights, or the times when it runs away 'cos the manifolds are flooded and you have the idle set to 2000 rpm to try and stop the stalling. Its a rotten starter as you have to flood the manifolds to get fuel to the cylinders. Twin choke Dellortos are the performance carb of choice, and having put these on I can vouch for that. With the carb directly over the cylinder they start on the first attempt any weather. They come second hand, or you buy reconditioned by someone else, its no biggy to do the job yourself. Disadvantages? with a separate pump jet for each cylinder they are tiny and block easily, easy to clean except the twin throttle linkage is mounted off the air filters, AND THEY ARE LOUD, the tiny pancake aircleaners are not silencers. I have twin single choke weber ICTs on the 1600, after mounting and setting up I've not had to touch them since, like the Dells they are easy starters but quieter. I would expect the four chokes to breathe easier at the top end, and the two chokes to be more responsive at lower revs, however do not have a direct comparison on the same motor. The 1600 pulls away easier, the type 4 is faster which fits the theory but there are other differences too. I shall be switching the bay to ICTs one day.
