Engine overhaul (help needed) - 240z with a 280z block | The Z Club of Great Britain
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Engine overhaul (help needed) - 240z with a 280z block

Discussion in 'Engine' started by Graeme - CZ, Sep 1, 2019.

  1. Graeme - CZ

    Graeme - CZ
    Z Club Member

    Hello folks,

    So i've almost completed my body and interior restoration and it's now on to the engine and suspension. Engine first. I'm hoping that some kind people on this forum might be able to help me work out a) what it is I have and b) what parts I should order before sending it to the mechanics to breathe some love on the engine. It's running pretty rough at present, despite changing the spark plugs, leads and distributor cap. I'm also open to any other advice about getting my beloved 240z running and driving better. I'm attaching a load of pictures of the engine bay area, most of which is stuff I know little about.

    Many thanks everyone, Graeme

    IMG_3514.jpeg
     

    Attached Files:

  2. Graeme - CZ

    Graeme - CZ
    Z Club Member

    I've also got a couple of ignition related items which I do not know what they are for. Suspect they belong to a 240z ignition, as i had previously wrongly ordered some 240z parts, only discovering later that what I needed were 280z parts.
     

    Attached Files:

  3. Graeme - CZ

    Graeme - CZ
    Z Club Member

    I also need to work out what type of carbs i have and also the air filter - need a new one of those.
     
  4. Mr Tenno

    Mr Tenno
    ZClub Administrator
    Staff Member Moderator

    What's the block / head combo? The numbers are cast into the side.
     
  5. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    The head cast number is below spark plug 4/5 I think, and the block type is above the sump on the exhaust side.
    N42 block I'd guess.

    Why do you think you need parts? Can you describe the problems?
     
    Mr Tenno likes this.
  6. uk66fastback

    uk66fastback
    Z Club Member

    Are you keeping the K&Ns or going back to the original set-up? I see both in the photos :D
     
  7. Graeme - CZ

    Graeme - CZ
    Z Club Member

    Well, I have a guy who can do the carb strip down, clean and rebuild - this feels like my step 1. Given the hassle of getting parts, i'd rather be prepared - especially if there are obvious parts i should replace. The problems: it's seems to be running very rich (very strong fuel smell in the cabin when driving, unpleasantly so). It's coughing and spluttering when I drive it, with the occasional back fire. Feels like it needs a good re-tune.
     
  8. Graeme - CZ

    Graeme - CZ
    Z Club Member

    Part of the smell in the cabin is coming from the escape filter on the rockar cover - one of the reasons why i switched back to stock. The old filter is back on now, though I do need to replace the filter - though not sure if it's a 240z or 280z one i need.
     
  9. Graeme - CZ

    Graeme - CZ
    Z Club Member

    I'll look for these numbers next weekend.
     
  10. Rob Gaskin

    Rob Gaskin Treasurer Staff Member Moderator

    There is a need for you to go back to basics but I'm guessing it may be beyond your knowledge.

    Compression test
    Ignition timing
    Fuel filter clear of rubbish
    Fuel at the carbs
    Balance of throttles
    Mixture settings
    Spark at each plug
    Valve clearances

    etc

    You need to find an old school mechanic who needs some beer money. Shame I don't live closer.
     
  11. Graeme - CZ

    Graeme - CZ
    Z Club Member

    Hi Rob, you are exactly right. Safe to say all of that needs done regardless. Datsun specialist a bit few and far between in Scotland. G
     
  12. Graeme - CZ

    Graeme - CZ
    Z Club Member

    ...and yes, engine stuff is well beyond my knowledge.
     
  13. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    You definitely don't need a Datsun specialist Graeme, just someone who knows carbs and points and engines from the 60/70s. This stuff was common with British sports cars from that time.
     
  14. datsfun

    datsfun
    Z Club Member

    Whereabouts in Scotland? I know a chap who would be able to support.
     
  15. stuart barrie

    stuart barrie
    Z Club Member

    I am in Scotland could help? Near falkirk.
     
  16. SacCyclone

    SacCyclone
    Z Club Member

    Given the description of how it is running, first make sure your chokes are completely off and then make sure your main jets are fully in the up position. Place your finger under each main jet and push up to make sure the jet is fully seated and not in the down position....this usually will clean up the running rough and sputtering part if the main jets were sticking open.
     
  17. Farmer42

    Farmer42
    Z Club Member

    The rough running could also be caused by duff points and condenser in your dizzy. It looks like you have a mechanical dizzy so you would need those extra ignition items you previously mentioned. Poor ignition will give you unburnt fuel and hence the rich fuel smell. The way to tell if you have a mechanical dizzy is to take off the cap and look to see if you have points. If so i would recommend replacing those and the condenser to start with. Make sure you set the points gap correctly then set the timing. The Haynes manual will give you instruction on how to do this and it is relatively easy even for a novice. I would recommend checking this before you start on the carbs.
     
  18. Graeme - CZ

    Graeme - CZ
    Z Club Member

    Edinburgh


    Sent from my iPhone using Tapatalk
     
  19. Rob Gaskin

    Rob Gaskin Treasurer Staff Member Moderator

    I'm guessing that Graeme isn't able to do the jobs that people suggest. To someone who works on mechanical parts these tasks are easy but to others they aren't. So checking main jet heights and replacing points may be something for someone else to do.

    I think that's how I read the situation.

    It's like asking me to rebuild a PC.
     
  20. Graeme - CZ

    Graeme - CZ
    Z Club Member

    You read it very well. I work in IT. I'd find rebuilding a PC easier ;) Happy enough with bodywork, interior and big stuff like suspension - but when it comes to engine or electrical stuff, i am a rank beginner.
     

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