I would be interested in opinions on the value of converting my 4.2 sII from the stock double zs carbs to the triple su configuration being that I do all my driving between 8000 and 10000 ft elevation. seems t me like at this altitude there would not be that much benefit.


thanks all bill m

 

Considering the cost of the carbs plus the intake manifold I do not think it is worth it to switch to SUs. Either keep the 2 ZS ( and do the Strangleberg fix/ Crespin fix) or go for broke and get the triple Webers.

 

You will get more horse power and torque. I have the triple su on my 67 e-type. It is perfect i think with the strombergs the e-type is underpowered. If you like the power you have right now don't change it. it will be around 3K to do the conversion.

Cheers Jeroen

 

i guess it would depend on which su"s you would put on?

 

SU carbs are a contsant depression operated carburator, therfore will be fast to adjust (automatically) to changing altitudes..........
The HD8 model that is usual on a xke has a diaphram jet mount in the base so it doesn't need needle centering like the earlier SUs and earlier Strombergs.
So when considering what to use XKE owners have the luxury of using either brand in groups of 2 or groups of 3. WE don't worry about swapping one type for the other because of this "CONSTANT DEPRESSION" feature that is designed into these instruments. Think of Eledbrock, Carter, or Holley always
having to be matched in CFMs 500, 600, 750 etc where this is not ever discussed with SUs or Strombergs because of there constant depression feature. Of course we know they have to be 13/4" for Strombergs and 2" for the SUs. So use what you have in any altitude and use 3 SUs for more power
overall.