I want to go to three carbs on my '69 series 2. One piece of advice is to go with SUs as they are easy to tune and run well at idle. The other is to go with Webber, which i hear can be twitchy at low RPMs. Any advice as the Webber conversion is much cheaper than the SUs.

 

You might as well ask Hillary or Donald!

There are people who hate, Hate, HATE Webers and say all kinds of bad things about them. The people who love their Webers say that people who hate them havent tried them or are incompetent tuners.

ClassicJaguar in Austin sells a Weber kit. They are a credible vendor and probably worth a call.

You can get a lot of the triple benefits with the Crespin Strangleberg trick.

 

I agree with VR, try the Crespin mod first before spending thousands on the other two options...unless you really need to see three carbs when you open the bonnet.
Alfred

 

Agree. Have the S2 also. ZS carbs, dont know why people say all these bad things. Yes, SU's are more elegant and offer more playing room, but if you understand what you're doing the ZS's are just fine. Mine are fixed needle/fixed jet so really nothing to adjust apart from the bleed screw. Bought some replacement needles recently and came across an aftermarket mod to replace the fixed jets by "SU style adjustable jets". Havent bought those yet, but its on my Xmas list. With those in place you will have plenty of room to adjust.
And yes, my 2ndaire trottles plates are also locked open. Much better.

 

have tried to do the crespin trick but can't figure out how to do it. Does the carb have two butterflies as indicated in a drawing i found or is it just a linkage I have not figured out yet?

 

I was able to find a set of Webers and manifold on line very reasonably, so I took the plunge....
My advice is don't even think about this, unless you are just using the car for racing.....
Without having a tuning expert at your side at all times, you will not be able to get the carbs tuned so that they will idle and run...
You can make them idle, you can make them scream, but you can't do both.....
(That is unless you are an expert, which obviously you are not)....
It's a tremendous amount of work to get them on the car, and get everything set up....
You will spend hours and hours tinkering with things like accelerator return spring rates, and linkage...You will make all kinds of mods to make things work right...
In the end , you will hate yourself for doing it, and can't wait until you go back to your old, stodgey ZS carbs. (Oh, they look really sexy, but looks aren't anything here).
Now, if you really want to improve performance, and don't want to spend a dime, take the secondary throttle plates and rod, and secondary linkage off the manifold, plug the openings on each end of the manifold, and the car will run like a scalded cat....AND, you can easily put everything back to stock in and hour or two.....
You will learn to love the ZS carbs again.
Just my experienced 2 cents.
Edward

 

I went into my shop and took a couple pics of the mod. The first pic is from the back of the rear carb linkage, the second is at the front of the forward carb. You want to remove the link and jam it (it is under spring pressure) below the aluminum water jacket.

 

Thank you all for the advice. The Crespin mod worked great.

 

Happy it worked for you!
Just one last thing - If you have removed the round valve plates in the manifold themselves be careful when "jamming" the 2ndairy spindles. I have seen them coming undone allowing horizontal movement of the shafts. This allows air to be sucked in through the gaps. Or worse - they vibrate out and you loose them on the road! Best solution is as Edward suggest (remove spindles & seal the gaps), but at a minimum use something (tie wrap will do) so movement is restricted.

 

It really was an easy fix, just to remove the rods...Once the plates are out, no big deal to slide the rod out, and remove the linkage....
Once you commit to this, you will be happy you made the change.
Let us know how it works out.
Edward

 

Well first off , congrats to making the decision to triples, you have now added testosterone to your ETYPE!
I might be biased and would be hard pressed to see anyone else on the site that has driven more than me in the last 20 years in their etype....
A 1970 etype coupe ,please look below, do I have to say anything else!
GTJOEY1314
Drive on my friend, drive on!

 

Sadly you went the cheapy route, just make sure once you removed the butterflies that the gas doesn't back out the vacuum retard line to the ELETRICAL DISTRIBUTOR!
Just a thought, please follow the line........I'm old enough to remember those fires back in the day.
Just saying.
GTJOEY
Just follow the line..........

 

If your car has the vacuum retard (I didn't know they did that in '69), then just cap the manifold connection, and don't use the line....Reset the timing to 10-12 degrees BTDC, and that will take care of it....The vacuum retard works mostly at idle anyway, and the weights take over after that.
Edward

 

Hello all. Have to agree with triple SU approach taken by [gtjoey] and many past others . . . often using the option of sourcing 2" carbs and manifold from the UK, UK or Euro 'bay etc . . . much cheaper and often readily available. Interesting that none mention the Lynx conversion . . . alas, no longer produced but fitted to near as many as triple DCOE side-draughts on race bred XK engines out here.

So much has been written here in past threads about the terrible woes that befell the performance of the North American E-Type, its strangled breathing and gearing, and its constant weight gains . . . that comparison with the Series1 has always proved disappointing. Sobering that from original Series1 weighing 1ton, the final Series3 weighed 50% more . . . despite the alloy V12 short engine weighing 20lb less than the 3.8L XK6. Final gearing was altered to restore some lost acceleration, but this further compounded the loss of top speed.

Somewhat tongue in cheek, my final observation is that the pic of 100MPH is nice . . . but not startling . . . perhaps your brakes were dragging! Hahahaha! Please don't be offended . . . I'm biased . . . 135MPH was quickly achievable on our ROW road car . . . 150+ only once through the downhill radar trap at the foot of Conrod Straight on our famed Mt Panorama race circuit (under closed CAMS conditions).

I well recall the UK Autocar road test that recorded their E-Type setting a benchmark record for their fastest ever acceleration in any car tested from 30 to 130MPH in top gear only!

So, after 37years in my hands as 2nd owner . . . and complete with every original manual, full tool kit, and even the original 1964 export, shipping and delivery documentation . . . my very good mate made me an offer I couldn't refuse, for a "money no object" ground-up full re-manufacture that I would never be able to afford or undertake. It's now off the "rotisserie" and the gleaming tub is now paint-ready. Pics to follow.

Best wishes,

Ken

 

Ken; you mentioned sources of cheaper Su triples for my '69 series 2 but I have done a bunch of searches and come up with $5k deals only. A more detailed reference would be appreciated.

John