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Found an engine, what is the choke mechanism?

Discussion in 'V8 Engine' started by gbvona, Feb 7, 2018.

  1. gbvona

    gbvona Member

    I have been struggling with my 1971 NADA 3500S for some time. The original engine blew, was replaced (before I bought it) with an Oldsmobile engine, I subsequently replaced with a 3.9L from a 1982 Range Rover, but that engine does not work well with the bodge of a fuel delivery system that I have. It also has other problems due to poor maintenance during its previous use.

    I chanced into a real 3500S engine from a guy whose father moved here (USA) from GB many years ago. He had brought the 3500S with him. Around 1992 a tree fell on it and it was totaled by the insurance company, but before they hauled the carcass away the engine and tranny were recovered.

    So now I have the chance to put a correct engine in the car, but I don't quite know what I have and how it is set up vis a vis fuel delivery. The number on the engine is 43000325A (located over the flywheel) and there is a barely visible 10.5 punched above it, which I assume is the CR. This is most likely a Home Market engine, and I think it is pretty early. The carbs are HS 6's (as opposed to the HIF 6's I currently run), and while they have levers to drop the jet for choking, there is nothing to activate the levers. A photo is appended.


    The question is, how does this engine enable choke?? Am I missing something?

    Thanks as always for the wisdom of the forum.

  2. harveyp6

    harveyp6 Well-Known Member

    Maybe it had an AED fitted.
  3. unstable load

    unstable load Well-Known Member

    There are some bits missing from that set-up.
    Another, from a Land Rover, I think, but it should work.
    With the choke cable in place.
  4. clive P62

    clive P62 Active Member

    Hi unless you wanted a matching numbers car you will be much better off using a later engine and HIF 6 carbs.
    That early engine with the 430 is the federal one.
    It has rope front/ rear seals and relied on the AED or auto choke to work
    The federal emission system if still fitted to the old engine would have had a special vacuum retard distributor and switches / etc.
    Keep it simple with standard later engine/ carbs.
  5. mikecoombs

    mikecoombs Active Member

    If you look on the far right of your photo there is a plate attached to the carb with a hole in the bottom corner. That is where the choke cable sleeve terminates. The inner cable keeps going and connects to a crimp fitting on the spare lever on the chock mechanism. I think SU, bresco or Holdens (UK) sell the crimp fitting (I can't remember which). The usual suppliers have the locking cable new. there is also a sleeve endpiece and keeper clip.
  6. gbvona

    gbvona Member

    For the record, I have done some research. The carbs are AUD412L & R, which on the oldengines site map to 69/70 P6 HS6AED, indicating that (sadly) this unit was afflicted with an AED. There is no evidence of the remains of same in the heap of greasy junk I got save a number of pipe stubs sticking out in odd places. I think the embryonic choke bits on the carbs are there merely to hold the jets in place. Apparently the AUD312 was the same carb with a manual choke, so the 412s may be convertible with cam levers, but these are doubtless made of unobtanium. As for the engine number, if one assumes it is related to the car number, the 430 prefix maps to a Home market series (according to Rover-Classics), but that assumption about car and engine numbers lining up may be drivel.

    Just trying to understand what I have before piling into it. I am aware that in many ways the 3.9L block may be a better choice, but one challenge is that I have no idea what needle to use with that displacement, and being in uncivilized territory I can't just go to my nearest motor factor or rolling road shop for advice. This is Holley country, son.
  7. mrtask

    mrtask Well-Known Member

    I only run twin SU HIF6 carbs because the regulations here in Germany concerning 'historic' cars are very strict. When I lived in London I put a 390 Holley on an Edelbrock Performer intake manifold on my car, and immensely enjoyed the instantaneous response the four barrel provided. If I lived in the US I dare say I'd do the same again, and there are a great many further tweaks or alternatives on the American aftermarket. I gather California is also a tough state regarding emissions but I'm led to believe elsewhere you can run a modern injection set-up that fits in place of a four barrel carb. Sorry I can't assist with identifying SU bits'n'pieces, just rambling. I understand wanting to retain originality, that is the route my restoration took. Best of luck!
  8. So Cal V8

    So Cal V8 Active Member

    I plan on using a throttle body setup whenever I get that far... probably the day after never.

    California is fine for most of the cars on this forum as they are mainly pre 1974. This means that you can do whatever floats your boat with your engine with no gubermint oversight or interference whatsoever.
  9. cobraboy

    cobraboy Well-Known Member

    3.9 with an Offy and 390 Holley would be my preferred way.
    I have exactly this on another car, If I have the jet sizes written down I would let you know what they are.

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