? if a manual choke can be fitted to a 3.4 Mk2 (twin HD6 arbs)

Saloons
1

As tittle, can a manual choke conversion be done on a 3.4 Mk2.
My AED needs replaced and I do not want to replace the troublesome AED unit.
Would love to hear from anyone who has done such conversion.
Thanks in advance.

2

No, you need other carbs for that.
And the MK2 does not have a AED unit, that is xj6.
On the MK2 you have a enrichment device ( Hisser )
You van connect a switch to the hisser device, that way you can manually enable it.

Regards,
Peter Jan

3

Hi Peter, sorry I should have said ED not AED.
I do not have and ‘ED’ device as my car had suffered an under bonnet fire with the previous owner hence unable to reconfigure on off as many do. To buy a used unit it is pot luck whether it would work correctly or not, most likely not. This is why I am very focused on fitting a manual choke during the cars full restoration.
Regards
Eugene

4

The enrichment device, referred to as the ‘auxilary starting carburetor’ is still manufactured by SU and available. Mine went bad several months ago, and I purchased the replacement, wired in with a toggle switch mounted under the dashboard, works very well with the toggle switch. The ‘thermostat controlled’ device installed from the factory never worked very well, and many owners have converted to the toggle switch setup.

1 Like
5

Thanks guys for your responses. All much appreciated.

6

I was waiting for others to comment but apart from re-fitting an ASC, (Auxilliary Starting Carburettor), if you wanted a manually choked setup, you would need HS8, or could try HS6 carbs, (or E-type HD8)

there would be complications and costs involved

I dislike the ASC, and have replaced an HD8 setup with manual choke HS8s

Depends upon your reason for wanting manual choke

If you only care about getting it started and being a useable driver, I would re-fit an ASC, can be purchased new, or someone would probably throw one at you 2nd hand

7

You can do a manual choke conversion; I did, but there are complications.

I did a conversion on HD6’s and made up the parts as per E-Type manual choke.

BTW HD6 bodies are smaller than HD8’s, so you can’t simply use E-Type parts.

I later converted to HD8’s and then used some E-Type parts.

However, a Daimler 250 (Mk2) has manual chokes and HD6’s.

The complication is that they are downdraft, or at least at about 45 degrees. The easiest way is simply to use the choke parts on your existing carbs.

I did this many years ago so my memory may not be so good, but I believe that one of the choke mechanisms on the 250 is on the wrong side for the Mk2 because the carbs face each other in the V of the Daimler head, so it requires some ingenuity to sort.

I think I un pinned everything and remade the brass pivot rod.

Can be done, but not easy.

Paul

8

Thanks for that Paul. I had thought about the HD8’s due to them having manual chokes. Cost is a consideration tho, with purchase price and then a de-tune rebuild with new jets more suited to a 3.4. While I have past the 70 I will not be putting the Mk2 past it. Those days are behind me.