Fenner
(Ferman Wardell 1971 E-type Series 3 2+2 V-12)
1
I’m covering 3 issues here. Mine is a lovely light blue 1971 Series III V12 with automatic - 95K on the odo. Before I begin, know that my local V12 expert has rebuilt the carbs, and it runs quite well, albeit with that familiar carb exhaust smell, you know what I mean?
First, when idling in the driveway and reaching normal temperature, the idle worked its way up all by itself to 2400 rpm. Couldn’t reduce it by bumping throttle or choke. On the other hand, drove it around town today without that problem. This was after adding the thermo switch below. What’s going on here?
Second, the good news is that my almost overheating problem (water needle would move up near red) is resolved by adding a $35.00 cooling fan thermo switch from XKS Unlimited. It’s temperature adjustable and works quite well. Fairly easy installation, too.
Finally, though my original ZS carbs are working OK, I know there are carb upgrades out there. XKS Un
limited has one. Has anyone had experience with any of there?
Hello Ferman,
There are upgrades for the carbs such as SU’s or Webers and some have installed fuel injection. If I were going to go through this amount of trouble I’d look at fuel injection.
Your High idle is most likely a vacuum leak, a lot of vacuum lines on the S3 so double check and make sure there all hooked up or sealed off.
Glad to hear you’ve solved your ‘overheating’ problem.
Cheers,
Lynn
I also have a S-III and am wondering what familiar carb exhaust smell you refer to? I say this as a matter of safety - there are o-rings at the bottom of the float bowl that seal the jet covers that are all that’s holding the gas back from dripping near the hot exhaust. Every now and again, especially if you’re smelling gas under the bonnet, be sure to run your fingers underneath the carbs and feel for the round plugs on the bottom of the bowls. If your fingers come up wet with gas, you need to take care of this.
Myself, next time I have to do it, I’m going with the newer material and am liable to get o-rings a smidge fatter than what is in there now as they seem to not be quite big enough. If I have to grease them up with petroleum jelly (ROM instructions) and they still are weeping, they’re not big enough in diameter.
Hi: I have a Series 3 also, …great car, congrats ! I’m afraid I am not familiar with a “carb exhaust smell”…might want to get a handle on that. Should be no smell coming back into the cabin. As far as upgrade, save your money. If Strombergs are working well, leave 'em. Ten years ago I changed to SU’s simply because I could get new ones, (no new Strombergs anymore, just good rebuilds) , but no increase in performance because they are both the same size (1 3/4inch) . Perhaps a bit easier to tune, but both are good carbs. Can’t speak for Webers, also great carbs, but don’t think I would spend the money. Glad you got a handle on the “almost overheating”…last thing you want to do is overheat and warp those long heads !! Enjoy !
Fenner
(Ferman Wardell 1971 E-type Series 3 2+2 V-12)
5
Thanks for the help. I am replacing bunch of old vacuum lines and fittings. One fitting literally fell apart in my hands! Boy, that V12 has tight spaces to get into! Noticed the carb damper oil was real low, so added some. That seemed to help, although I’m still getting an increase in rpms to almost 2000 by just idling in neutral in the driveway. Still working that one.
The “carb smell” I was referring to is the incomplete combustion that characterizes carbs vs. fuel injection. It’s fairly typical of most older carbed cars, and not so much in the cabin as just around the car.
I believe you’re right about just keeping my original Stromberg carbs. Replacement kits run about $2000, and mine runs quite well.
Now, on to my next project: replacing some cooling hoses and the two thermostats . . .