While rebuilding the HD8 carbs on my '66 E-Type FHC I realized I needed some spare HD8 parts that were hard to come by, particularly the bronze throttle stops. I took occasion to grab this manifold with triple HD8’s I found on fleabay figuring I could use some parts off these. I ended up brazing and repairing the throttle stops to my satisfaction, so never needed to cannibalize these carbs and manifolds which have remained collecting dust in my garage ever since. I knew the manifold was neither proper for a 3.8 nor a 4.2 Series 1 E-type, but never really figured out what it was actually for. I bet someone here can identify it.
John
Without knowing the part number stamped on the manifold they look like they came from a Mk 10 sedan.
Mark 10 or 420G since they have the starting carburetor that was not used on E Types.
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John,
I am a 150 guy, suggest other member will fine tune your research, also suggest you go on the’ Saloon’ forum as that is the MK 1,2 10 and 420 page.
They are identical in every way to my Mark X 4.2/420G setup. Note that the snout on the bells is extended, the manifold provides for an Otter switch, and there are spring-loaded isolators between carbs an manifold–to provide vibration damping for the heavy cast aluminum air box (not shown). None of these match the E-type manual choke carbies. Plus the hisser and its plumbing are there, of course. I’m not expert on the XK150S setup, the only other possibility.
almost certainly 420G or 4.2 MK10…not a 3.8 MK10, as they had 3 separate intake manifold castings, one for each carb. I believe some XK150 came with 2" tri-carb optionally, but an unfamiliar with the manifold
150 S intake manifold were 3 individual castings about 4inches long, that’s why I knew it wasn’t 150.
4.2 litre MKX or 420G
Thanks guys. That’s very helpful. I didn’t know the saloons had triple carbs.
Is there any particular reason electric choke HD8s from a MK 10/ 420G could n’t be converted to manual choke E Type carb, [ and value add them.]
Here is a HD 8 that wasan electric choke carb that has had the manual choke section added . a straight swap.
Of course , the rest of the conversion to a H8-esque carbie wasdone witha view to confusing future historians
No reason at all, Ed. Except that the “value add” costs money about equivalent to the value add. I would love to do it, but the parts required cost about the same as the MK 10 carbies do to begin with.
the main reason that I can recall;
the brass thru rod that raises and lowers the jet needs to be removed, replaced with a longer one, and drilled to accomodate levers. Accurately drilling & pinning the levers is where I got stuck
Some other mod is required
not all the parts are available from Burlen, as far as I could tell, only some, they are not cheap.
I could be wrong about availabilty of all parts. I used various parts from other SU carbs for my experiment, and ordered a length of the correct OD brass rod.
If I had of made a jig, and the holes need to be interference fit with pins, or the levers wobble
@awg is right.
Because the Hisser is a complete carb, the HS it is attached to doesn’t have any of the bits required for implementing a choke. The bodies have the holes to mount the choke mechanisms though.
To convert to manual choke you need the ring with a jet lowering lever, as well as the cam to open the butterfly, then the linkage rods and bits to join those two.
It’s the rings with the 2nd lever which are hard to come by. You can convert non choke rings to choked, but you need one choke ring as a reference, and some fabricating skills.
Seems to have worked easily enough with the one i have here.
it does, and would be interesting to see a pic from the choke lever side.
it appears similar to what I did, but as I mentioned, accurately pinning the lever to the shaft was my issue…by no means insurmountable
it is also possible that carb uses an off-the shelf Burlen part?
HS8 can be easily converted to manual choke, I have done that
Here are pics. A friend gave me a HD8. I bought a sand cast suction chamber and piston , and a H.V8 float bowl top from Burlen. The local SU guru supplied the 3” sandcast float bowl. And the choke, he had a box of them. The choke part is a straight change over, using the same bolts. The lever just lowers the jet richening the mixture. The 4bolts are symetric so it can be put on theoretically in 4 positions depending on the application. This one is set up for what I needed
thanks Ed, I will review my dismantled HD8 carb parts, and see if I can work out whether the issues I mentioned can be easily overcome, It certainly would be good if that was the case!
I have many HD8 carbs, and notice they are often for sale on Ebay for what I consider high prices
If anyone wants the HD8’s and manifold from a MKX or 420 pictured at the beginning of this thread send me a message. I have no use for them any longer and am happy to send them off to someone that can put them to good use.