I have a set of triple SU HD8's and a manifold from a Mk10 that I want to fix on a XJ6 series 3 4.2l in place of the injection system. whilst they physically fit, I am looking for advice on how to install a cable throttle control.

I understand an XJ6 series 2 was cable controlled Any help would be appreciated

 

Welcome to the forums. Please post an intro in the new member area for a warm welcome and advice on where to post your questions. & Yes, this is the right forum for your question.

https://www.jaguarforums.com/forum/n...-intro-must-5/

 

I've done this on a Series 1, but I can't comment much on the S3 setup. The S1 has a cable that goes to a pivot mounted at the rear of the intake side cam. The pivot is attached to the 2 rearmost intake manifold studs.

Even if you can duplicate the S1 setup, hooking up the linkage isn't easy. I've see it done several ways. Don't do it the way I did, which was to link the three throttle shafts together as is done with dual carbs. Use the secondary shaft, and link it to the pivot. Most examples I've seen required some welding.

Also, it's important to pay attention to the way the throttles open as you press the accelerator--it won't be linear but how it is nonlinear varies with how you set it up. Finally, the pedal's range of motion should match the range of the butterflies, so that they open all of the way when the throttle fully depressed.

I messed up all of this...wish I'd known more when I did it many years ago.

 

Thanks Clarke, I have posted an introduction

 

Thanks Robert. I will take your comments into account, somehow I didn't this it would be straightforward, it sounds like I might be fabricating something. The three carbs are linked together with a slave shaft that in turn is fixed between lugs on the inlet manifold, as they are from the Mk10 / 420g. I think it may be acase of setting it all up then seeing how to extend the slave shat and fit it to a throttle linkage from the XJ6 Series 2

 

Howard, Robert, I'm hoping to resurrect this thread and ask for more words of wisdom. I too have a series III (1986) that I'm planning to convert to triple SUs. I just received a MK10/420g manifold. I've got two HS8s with manual chokes on the way; I still need to buy the third carb. I thought about using the starter carb, but having grown up with Triumphs I prefer a manual choke; simple and reliable.

I've read the discussion on the "triple HD8 SU carbs on Series 2" https://www.jaguarforums.com/forum/x...-4-2-a-208638/ and found it along with this thread very educational.

So after all of that, I was just wondering if you had any other lessons learned or things that worked well or wish you had done differently?

Thanks Andy

 

I agree about using manual chokes, Andy. For general expertise RustFreeMike is your guy--he does exquisite work, makes me want to throw my builds into the trash and start over (if I wasn't so old).

One esoteric point he and I discussed recently is the thermostat housing. As you know, the S3 housing is the way to go. But evidently there are two versions of the manifold surface to which it mounts. One has slots into the water jacket, designed to be used with the "slider" type of thermostat bypass. The other (later) has no slots (although you can see indentations where they would be). To fit the S3 xj6 thermostat housing you must block off the slots if you have them.

 

Just a note of caution. Will the float chambers of the HS8 type fit in the small space between the carbs? The HS8 float chamber appears to take up a little more room than the HD8 type. I could be wrong but it is a question worth asking.

 

Mekon, good question. I just put the two HS's that I have on the manifold and they fit fine. Not a lot of room, but sufficient.