Anyone have experience or knowledge about converting a early V12 e-type to Webbers (40 idf or 44 idf is what I hear works). The biggest issue I can see at this point is finding the correct manifolds. Thanks

Submitted by NE52-32043 on Tue, 07/13/2004 - 10:00

Michael,

Doug is right about Jay Leno's car. I've seen it in person, and it's awesome. But that engine had a major rework by XK's, as I understand it.

Simply changing the ZS's for Webers probably won't do much for you. Unless you change the manifold, open up the breathing, and open up the exhaust, you won't see much increase in bhp.

If you're looking for increased performance, take a look at "The Book" by Kirby Palm on the jag-lovers.org website. You'll find it in the library there or on the XJS lovers site. It's a free download over the internet. It contains a lot of discussion about V-12 engines and how to improve performance. Even though it's written for the XJS, much of what they say about the carb engines (vs. fuel injection) applies to us as well. Also, do a websearch for Wayne Estrada's website. He has a couple of good articles that he's written on how to get the most from a V-12 engine. Again, although he is XJS oriented, a lot applies to our V-12's.

There's a lot you can do to a V-12 E-type to improve performance without going to Webers. Remove all the polution equipment, air rails, etc. Remove the air pump. Remove the A/C. Change to a gear reduction starter (save 25lbs.). Install a better ignition system. Consider cam modifications. I seem to remember someone advertising a conversion of the 4 ZS's to 4 SU's, as an alternative to Webers. Put in a bigger bore exhaust. If you have a slush box, convert to a 5-spd with a lighter flywheel and competition clutch. And so on, etc.

IMHO, changing to the Webers should be the last modification you should consider, as they are very expensive and you won't get much out of them without all the other stuff. My $.02.

Regards,
Steve Weinstein, JTC-NJ
'72 E-type 2+2
'70 XKE FHC

Submitted by dougi@shaw.ca on Sun, 07/11/2004 - 01:40

Have a look at the May 2004 issue of Classic Motorsports magazine - their is an articel about Jay Leno's Series I/Series III E-Type which has a 5.3 V12 and 6 Weber IDF carbs. You could likely get the most information from Jason Len of XKs Unlimited, who did the conversion.

Doug Ingram