I am putting a carby kit through my twin su carbies in a 65 3.8 S Type. The kit I got is CRK217 . My carbies fitted to the car are different from drawing in kit and manual . Mine do not have this diaphragm.
MAIN JET AND DIAPHRAGM
MORE PRODUCT INFO
PRODUCT CODE: AUC8155
QUANTITY OF FIT: 2

Where can I find a drawing and why is mine different

 

start here?

Diaphragms - SU Carburetters

 

The 3.8S was fitted with SU HD-8 carburettors when new, which are below.

Do you have something different fitted to your car?

 

Mine does not have the flexible diaphragm that replaced the jet gland

 

This is one of the carbs that's fitted to my car

 

The other possibility is the car was fitted with SU HD-6 carburettors similar to the Mk2.

 

Mine is not the HD6 as it does not have the diaphragm

 

I think you have the float bowl on up-side-down there.
My Bentley has no diaphragm in it, there are two seals around the main jet, a cork one and one fibre one impregnated with graphite.
The main jet moves up and down on these seals allowing for the manual choke operation.
The mixture is also adjusted by adjusting the nut on the bottom of the carb where the choke rests up against when it is in its fully "off" position.

If someone has changed your carbs out for a different pair, it's going to be tricky to find which pair you have.

There should be an aluminum tab on the banjo bolt that holds the float bowl lid on.
The tab has the model number of the carb on it.

 

May have. Just put bolt in for photo

 

I added some more to my post.

 

I've been mulling around on the SU carb site trying to find something with an H8 designation and with no diaphragm and the only thing I could find was for the XK120... ???
This of course has a manual choke, the 3.8S should have the thermostatic automatic choke and the additional starting carburetor running off the front carb.
Is yours automatic or did someone convert it to a manual choke ?

Parts for AUC 702 for Jaguar 1946 onwards XK 120 3442 cc - SU Carburetters - SU Carburetters

 

Hi Bendougy,

Probably no help at all, but I have twin HD8's fitted to my 1968 340.

Attached some pictures of said items.

She goes pretty well too!

 

I highly recommend that when your SU's are really worn and in need of a rebuild to NOT attempt a DIY as even all of the Z shops and performance shops send their clients SU carbs to "Z Therapy" they are the best shop to do it right and you will get carbs better than new and they can tailor the SU's with tailored jetting and other modifications for your specific needs. I have been into Z's for over 20 years and most DIY rebuilds are never close to the performance of pro's like Z Therapy. To me it is like the wood of a Jag you can get it half *** and better than it was but not where the pro's can get it to so why get aggravated and waste your time and money?
Welcome to ZTherapy.com

 

Is this the manual choke you are referring to JEFFR1 there are no tags under the banjo fittings

 

It looks like there is a way to adjust the mixture, but no way to choke it.
I've never seen that arrangement before.
I would either go with Primazs' recommendation, or contact Burlen Carbs and ask them.
Send them some pictures.

The only thing that I'm certain of is that someone put some carbs on your 3.8S that were not there when it was new, at least according to all the kits from Burlen.

 

I found this from Burlen.
I went through all of the Jaguar listings and this isn't supposed to fit any jaguar, but it's the only one that appears to match your picture. It's model number is simply SU H6, and it has the typical starting (choke) carb off to the side that runs off the front float bowl.
Strangely through all the searching, I found this model on the XK 120 and 140 _ which isn't supposed to be on there either.

You need to contact Burlen and sort this mess out.


Rebuild Kit - For a Single H6 Thermo Carburettor - SU Carburetters

 

Thanks JeffR1
That does look my like carbs. Not sure how it came to be on the car and unfortunatly dont have any history on previous owners.I have a lead on the correct carbs so will look into that option

 

Or just leave those ones on there, I don't really see any advantage on installing the H8's if the ones you have work and are not worn.

However the ones you have are a PIA to adjust the mixture, the H8's have a slot screw that's accessible from the top of the carb as apposed to reaching down below with a wrench or in you case, a flat blade stubby screw driver.

 

See post number 6 above. These SU HD-6 carburettors were fitted to the Mk2 and may well have found their way into early 3.8S models as well.

 

Yes the HD-6 were fitted the Mark 2 and my 340.
The ones on Bendougies car are H-6 (as far as I can tell after searching around, there is no letter "D" in the designation number).
The main jet has no diaphragm on Bendougies carbs while if you look closely at the ones in your screen shot, the bottom end houses a diaphragm that the main jet is attached to - his is absent on Bendougies carbs _ that in which is the problem.

If you look at the bottom end in my screen shot on post 16, you can see they are very different.

But yes, you're right, there certainly nothing to stop Bendougy from fitting some HD-6 carbs as long as he changes the main jet needle to suit the 3.8 litre displacement.

Of all the carbs that I've worked on over the years, I think SU carbs have the most variations of design _ there are way to many different models just to do the same job.