Where is the best place for the Advance and retard tube to be fixt to ?
I have a 4.2 inlet manifold , with a metal tube coming out to fix it to , and there is a tube coming out one of the HS8 carbs !
They are always in the front carb body just a hair downstream of the throttle plate.
Depends on if you have a advance or retard module on the distributor. On non fuel injected Jaguars, the advance goes to the tube on top of the throttle body of the HS8 carbs for ported vacuum. On the emission cars, they use a retard capsule which is usually routed to manifold vacuum, sometimes through a temp controller as in the V12 E-Type. http://georgiajag.com/Documents/Vacuum%20Advance%20versus%20Vacuum%20Retard.htm
On my car, which had a 4.2 triple SU HD8s the vacuum advance came out on the front carb. See where the white arrow is pointing on the below photo.
Thanks for the replies , I have a choice carb or manifold , just wondered if there would be a difference in what one I went for !
BIG difference…plenty of reading material available about ported vs. manifold vacuum…