Our Cars- So, I Bought a Datsun


Every once in a while we like to share the cars that we actually own. You may remember this Jeep from Longroofian, or the Uberbird owned and raced by perennial five o’clock shadow wearer Tim. Or, perhaps you’re familiar with Jeff’s pride and joy, which has taken him on many an adventure.

Well, now I’ve added to my own meager collection, and I thought y’all might like to know about it. Joining my 1962 Austin Healey Sprite and 1974 Jensen Healey is a 1970 Datsun 240Z, which makes a nice Japanese filler between the two British bookends. The car is rough, and in fact I had a bit of a challenge bringing it home last Friday night due to a pair of uncooperative carbs. Regardless, I am determined to bring it back from the other side, so join me after the jump to see what’s been going on with this orange coupe so far.


Okay, so first off I should note that it’s been punched in the nose. That dent occurred – or so I’ve been told – when someone backed into the poor car in a parking lot. It was just minding its own business! The crease in the hood pushes it out against the fiberglass sugar scoop of the right-hand headlight, which brought to light the fact that there’s a butt-load of Bondo in that fender. Oh well, for the price I paid the whole car could be made out of body filler.


In case you are unfamiliar, the S30 240Z is powered by a 2,393-cc cast iron block, alloy head, single overhead cam straight six. That was good from the factory for a claimed 151-bhp and 141 ft-lbs of torque. This one didn’t put out anything near that, because, despite a bunch of new stuff under the dented hood, there was still a lot of bits that had seen better days – or at least hadn’t been maintained  as they should.


In the case of this car, the parts that had seen the most neglect were the twin SU-style Hitachi side-draught carburetors. I’m not going to delve into the nuances of these carbs, other than to note that SUs are my personal favorites, and the ones with which I have probably the most experience. A major issue of this 240Z was that it refused to start without the aid of starting fluid, and then had trouble holding an idle until the temperature came well up. The 240Z has the anachronistic feature of a manual choke – bless its heart – and in this one’s case, one that didn’t seem to be working at all.

In the case of the SU carb the choke works by dropping the jet, thereby creating a larger opening around the needle which, sitting in its center, allows more fuel to be sucked through the venturi. On this car,that wasn’t happening. What then needed to happen was for me to pop the lids off the carbs and undertake a massive cleaning. The bodies of both units were coated in carbon build up, and hence blacker than a cat’s soul. It took a whole can of carb spray, and a swim in my cleaner bath for the cruddy parts to return to any semblance of proper motion.


You can see in the above picture a ring of darkness that is the top of the carb body. You’ll also see that these are 4-flange carbs. The choke operates off of two cables worked from a single lever on the console, rather than the more traditional single cable with an interconnecting shaft between carbs – like on my other two cars. A gentle tap on the top of the jet allowed it to break free, while a half hour soaking in cleaner will hopefully mean it’ll stay that way for a while at least.


Everything went back together with little issue and the car started the first time after reassembly without the aid of ether. Woot! The carbs still need to be tuned – making me rue having lost my UniSyn (go look it up) a few years back – and eventually will require a rebuild. Still, the throttle shafts seem okay, and the rest of the engine appears to be without problem.

What is a problem is the car’s electrical system. When I purchased it, the car had a number of burnt out bulbs and no brake lights! The 240Z has a rather complicated wiring arrangement for the brake lights – taking a circuitous route through the hazard switch and then turn signal switch before wending back to the twin clusters. It turned out that the hazard switch in this car was broken, and messing up the continuity. A new switch sourced from a swap meet vender (more on that swap meet another time) and now the car has brake lights. Up next, turn signals!


The car came with a few extra parts, including a factory set of front overriders that look to be pretty pricy according to that that bay of E. It also has a bra, unopened and likely to stay that way because I prefer to go braless. Nicely, it also has an ancient spare as well as the jack and lug wrench so I don’t have to hunt down those parts.


The more I work on the car hopefully the better it we be. My plan is to keep you all informed of its progress with occasional updates here on the Hoon. Until then, I’ll leave you with a shot from the hatch, because, well that’s the last picture I have right now. Wish me luck, and hope I haven’t made a terrible mistake.


All images ©2013 Robert Emslie, All Rights Reserved. 



  1. Sweet! I just bought a Z32 after being outbid on a 75 280Z. Good to see this thing enter the stable. Now get those ponies groomed and ready to run. 😉

  2. Yeah, well, I…uh…hung drywall and did the first round of joint compound in my laundry room.
    Guh…house work is so much less fun.

  3. Very nice! Best color too. I look forward to seeing more updates on this, as watching other people make progress on their projects helps shame me into actually making progress on mine…

        1. As a person currently on his work computer…. I really, really, really want to hear that…

        2. As a person who is no longer at his work computer… That sound… That glorious sound…
          I really need a high strung, small displacement screamer in something at some point.

          1. It's sad really that such engines are getting more rare… Or NA engines in general for that matter.

  4. Very nice!! Congrats on the new ride!! And Sunset CA plates FTW!! (My MGBGT and the ZomBee also have them).
    Round-Top Hitachi's are awesome. I've got a similar set on my SSS. If yours still have the brass floats, I highly recommend getting a set of the solid black MILSPEC floats instead. And using and early Nissan factory-style fuel filter/separator will help keep a BUNCH of rust/muck out of the float needles. As will a strong magnet just upstream of it..
    <img src="http://i.ebayimg.com/t/Datsun-Roadster-glass-fuel-bowl-assembly-1963-68-SPL310-SPL311-SRL311-/00/s/MTIwMFgxNjAw/$(KGrHqZHJFcFCjZf-P5yBQqqKLS6yg~~60_35.JPG"&gt;
    Also, Unisyns suck ass.
    I've got 5 vehicles with SUs, plus enough extra carbs to supply a small nation, and the first thing I do when I see a Unisyn is smash it with my magic-hammer and toss it in the trash. It's not worth the time or frustration.
    Get one of these instead… they actually work! Rmarkably accurate, smooth as silk, repeatable etc etc. And they don't cost much more than that dancing-pellet piece of garbage either. (can you tell I have no love for bad tools?)
    <img src="http://www.dealparts.com/mm5/dpximages/43-5712-0.jpg"&gt;

    1. When I first bought a Corvair, a friend helped me balance the carbs with a Uni-Syn. It looked to me to be a giant PITA. So, when I had to set them after rebuilding them, I did them the way the factory shop manual recommended, using a vacuum gauge with a tee and hoses (alternately putting a kink in the one going to each side to check the vacuum, and RPM drop), while holding the throttle steady using chain, hooks, and a turnbuckle (another recommendation of the Chevy manual). Much easier.

  5. You know, I usually just use a length of hose to balance the carbs. Of course, now I have to remember where i put my hose!

    1. That works remarkably well, btw! It's what I usually do at the track for a sanity check. I've compared it back-to-back with the Empi vane-sync, and it ends up quite accurate.

    2. Congrats, sweet Z! But how do you use a length of hose? I imagine not wearing panty hose but sticking a flexible hose of a certain length in the throat and listening if tone is same? I just take the air filters off mine and look in first to see the pistons rise equally and similar amounts of fuel mist. Also I can hear the sucking sounds just barely. Then I adjust so that the other stumbles. I guess it's good enough but I'm really interesting the hose technique.

      1. Take a length of vacuum hose (1/4", 5/16", 3/8" etc) and hold it just in front of the throat – I like to rest it just inside – making sure to place it aprox in the same place for each carb. You will be able to hear a difference in pitch/intensity of the air flowing over the bridge quite clearly.
        If you don't hear much difference, congratulations! There isn't any.
        Of course that's just the static idle sync.
        Next is making sure the linkages open both carbs at the same time and rate. I like to check that by jimmy'ing the throttle cable so both carbs are being opened somewhere well above a fast idle, and re-checking the hiss. (or with a synch) . This is arguably the better test, as it bypasses any weird idle variations caused by leaky throttleshafts. Set the sync at 1,500-2,000, and the total ignition advance (32~ish) at 3,500, and let the idle do whatever the hell it wants… leave it alone.
        Because you don't drive your car at idle. 🙂

        1. Thanks! I have throttle linkages, good enough to just hold it steady at about the same spot for the second half, right? Or is there easy way to jimmy the rods in place?

          1. Wherever you jimmy it needs to be at the common-point, of course. It's super easy on an MGB, slightly less straight-forward on the Datsun with its linkages… but still do-able.
            Your ingenuity and available random-crap-on-hand will factor deeply into this.

  6. I'll join in you Datsun ownership one of these days, I swear… I will either be an S30 or 510 with an LS2.
    Then I will die.

  7. Good luck! I just bought a first gen Miata… twice, because it had a sneaky blown head gasket. I have to admit that I'm terrible at buying cars. I love the color on this S30 though and well, it's an S30, so how can you go wrong? And in a beautiful color on top of that.

  8. Very nice. I love the colour too. Those "flat top" style carbs aren't well though of. Might be better to source an earlier set than rebuild them.

    1. Those are the round-tops. The flat top carbs arrived in '73, are fixed jet with the float bowl beneath, and as you note, are utter crap.

  9. Gorgeous car. Good purchase!
    The overspray on the front strut tower makes me wonder how many other accidents it's been in on the drivers' side but as long as the important parts are straight, who cares?

  10. Very nice! I'm extremely jealous right now. I want an S30 in the worst way, and that one's even the right color! But living in the midwest, I either find a pile of rust that generally resembles a Z shape or a lovingly restored showpiece that I could never see cutting up the way I want to cut one up (I want modern everything underneath). Someday I'll find the perfect Z. Someday…..

    1. Eagle Rock Datsun Swap. Pictures next week.
      No rust on the underside, but lots of bubbles in the Earl of Scheib paint job.

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