Moss Motors, Ltd

I have a '68 2-Stromberg XKE with a relatively fresh 4.2 liter engine. Has anyone out there installed 3-webers on a 4.2L, and/or have any advice to compare the advantages of going with 3 webers v. 3 SU's (power, reliability, maintenance).  Heck, should I just leave the Strombergs and be happy?

Not on an XKE, but I switched from two (2) SUs to three (3) SUs on a Big Healey (SU conversion was first done on a 2.6 and then a 3.0 engine), and then went with three (3) 45 DCOE Webers (on the 3.0).  I can tune and synchronize carbs pretty good, so I didn't have any teething issues with any of them. 

I just did a whole spread with pictures in the Healey Performance section http://www.mossmotors.com/Forum/forums/904/ShowThread.aspx#904

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Randy
57 Healey 100/6 BN6L-942
61 McCulloch R1 go kart
99 M Roadster (supercharged)
01 M Roadster
11 BMW X5 35i

A friend of mine spent several years fooling around with a 3 weber setup on his TR 250.  He finally gave up on them and went with Goodparts 3 Stromberg set up and is very pleased with the performance.  I supose the Webers are fine if you really know what you're doing seting them up.  I think you will find a lot more people that are familiar with SUs.  Just my opinion.

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72 MGB 80 TR8
Pittsburgh PA

Hi James,

I have a 67 E-type, with the standard 3 SU carbs.  It has mods: 3/4 cams, SS headers and elctronic ignition.  The SUs are adjustable enough to be retuned for the mods, and if you take your time, you can do a good job of tuning them yourself, following the instructions posted on the " E-type lovers.com" or the JCNA website, or the videotape available from the usual bandits (vendors).  From a few years of reading the different Jag "lists" online, I gathered the general opinion that Webers are more difficult than SUs to setup, and tune, and no better on the street.  They may give a little more horsepower for racing, but they are more complicated to adjust (for the average tinerer) than SUs.  Randy is probably a much better mechanic than me, if he can set them up.

Also, you can find a used E-type manifold and triple SUs-usually- for a lot less money than a triple Weber setup.  Be careful, don't buy a triple SU setup taken off any other Jaguar than an E-type.  The angle of the manifold on the E is different. And the others (Mk X, etc) probably won't fit, and vacuum ports may not match, etc.  The air filter is an issue too, as most of the "listers" believe that the original big gray air cleaner can is superior to K&Ns.   Good luck with your project.

Ray

  

James:

The triple SU setup is much easier to tune, although you won't have the same problems with Webers that the TR posters were having. The TR6 triple Weber setup can work well on a street car, but only if you change to much smaller chokes. There is no question that the triple SUs will give a lot more punch than the standard ZS pair, but even though you can find them used sometimes the price is still pretty high.

As Ray noted, there are a lot of triple SU Jaguar setups, but only one will work correctly on your 4.2. That's the one that everyone with a later E-Type wants, so finding a deal is going to be tough.

I've got a Jag Sedan, so finding a triple set up from a Mark 10 was not so difficult, but even so there is a lot of carb rebuilding and cleaning before I'll have the set up ready to bang on the car.

 

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Kelvin Dodd
Global Sourcing Engineer
Moss Motors, Ltd.
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I have a series 2 e-type and had an opportunity to trade the orriginal dual stromberg set-up to an eary triple SU system when I was restoring the car.I ordered rebuild kits for the SU's and installed and tuned the system as per the Jaguar manual. The performance increase was impressive to say the least and the reliability has been excellent! I would highly recommend this conversion .

I have done the Triple Weber, and Triple SU thing on my Healey.  It now has an Isky hot cam, bored .125" with everything balanced etc.  I ran three DCOEs with some very rare 28mm chokes which were never listed.  I did this to get back some bottom end grunt; but still had some spit back due to the cam timing.  It ran very well with you foot stuck in - but was a pain when playing 'Boulevardier'.

I switched to three SU HD 6 carbs, and would love to run three 'long neck' SUs from the TR 4; but I did not want to run without aircleaners or modify the body.  It was immensly more pleasureable to drive with the SUs; and has gobs more torque.  I rev' to 6,500 rpm (12 lb.alloy flywheel), and it is a monster throughout the range.  I will smoke an E type with little effort.

For the street you need gas speed low down.  I modify Healey heads on the side and pay carefull attention to keep the ports on the small side.  Most people make the mistake on a street motor in boring out the intake ports, big tube header and oversize carbs- this equals zero gas speed needed to push the fuel in and out.  If you want to race hog it out - but for the street you have to keep some perspecitve on how you do most of your driving.  My car will start in second gear (no clutch), and pull right on up through the rev' range, and its a hot motor.

On the Jag I would look for some HIF 7s which will take some auction patience, or get something close.  You will find them in the U.K.  I like the HIF type as it makes synchronized linkage a snap.  Don't get the smog type as you will have to modify them to run right.  I think the 38mm range would be good for the street.  I run K & N filters with the internal stub stacks.