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Caretaking and progress updates for my '73

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Hi everyone, I'm starting a thread to document my progress and share my experiences in the caretaking of my '73 240Z.

I don't remember the first time I saw an S30 Z-car, but I've been preoccupied if not obsessed with them for several years. After taking some advice from Carl Beck and taking into account 1) that any project takes me months longer than it should and 2) my limited mechanical and fabrication skills, I decided I should shop for a running Z in fair to good condition. I had resigned myself to the fact that I would have to travel cross country to find such a car when I found this one while perusing random Craigslist cities in Michigan.

First to introduce the car: I bought this car from its original owner (who was also named Brian) this past May. It's VIN HLS30-151534, it was built in March 1973 and purchased in Massachusetts in February 1974. It was daily driven for almost a year, then shared driving duties with the owner's wife's car in the winter of '75-'76. In 1976 he and it moved to Michigan, at which point it was garaged in the winters. The car has 63k original miles and is almost completely original & stock, down to the spare tire from 1973, the flat top carbs (boo) and emissions equipment. For some reason, he even kept the original wheels and tires when he changed them, and wrapped the hubcaps up in newspaper dated 1977.

Picking up the car



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The car and I made the 150 mile drive home from the PO's house, despite tires so old they didn't have a DOT code that I could read. I drove the car all of three times on short trips around town before the left rear tire finally gave up. As I've mentioned in another thread, this happened during my girlfriend's first ride in the car :)

The tire shop dated these to roughly 1985!


Due to the aforementioned spare tire from 1973, a flat bed was required to get the car home. Whether it was coincidence or negligence, the key decided to stick in the ignition as the flat bed operator was pull the car off. We pushed it into the garage. Not a glamorous day.

So the car went up on jackstands so I could get new tires and troubleshoot the ignition.


With the car up in the air I got to see just how much work I get to look forward to! The bushings are cooked, the ball joint and tie rod end boots are ruptured and dumping grease everywhere, and the steering gear bushings fell apart when I removed them. I couldn't get the joints separated so I took the whole filthy assembly to a friend's shop for separating and cleaning. These pics were taken after I'd already removed a third of a pound of gluey old ball joint grease from the joints.






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The car has 63k original miles and is almost completely original & stock, down to the spare tire from 1973, the flat top carbs (boo) and emissions equipment.


First off, that car is a beauty! I love the color and the original condition.

Also, very glad to hear your ’73 has the flat tops and smog equip. That usually means the previous owner hasn’t messed with the car too much and you have a very nice original vehicle…sweet.

I am guessing the ‘boo’ reference to the flat tops is that you have previously owned a Z with flat top carbs and they did not perform well for you. If not, you have most likely heard from others on this site who have never owned a Z with flat top carbs, and they have bad mouth the flat tops. In my opinion, they are given a bad rap. I had a ’73 with flat tops and they performed wonderfully, even in hot LA traffic. No way I would trade them out. It is getting very rare to see a ’73 or ’74 with the flat tops, so you would do well to keep them, in my opinion. Just my thoughts

Anyway, congrats again on a beautiful find. I love it. All that baby needs now is those hubcaps installed. I love hub caps….as long as they stay on when you rip around the corners.

Best regards,


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Very nice 240z Bacarl and congrats on taking over the ownership and care of her. Looks like you have ALOT of things going for you on it. The paint and body look great, chrome bumpers look awesome in the pics, and if the interior looks as good as the body you are in a great spot with it. Bushings and ball joints are just par for the course with these cars. Luckily all the parts are readily available and not very expensive. It just takes time as you are already experiencing but the payoff will be 10 fold in the way it handles and performs. Good luck and keep us posted on your progress!

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Thanks for the nice replies, guys.


Also, very glad to hear your ’73 has the flat tops and smog equip. That usually means the previous owner hasn’t messed with the car too much and you have a very nice original vehicle…sweet.

I am guessing the ‘boo’ reference to the flat tops is that you have previously owned a Z with flat top carbs and they did not perform well for you. If not, you have most likely heard from others on this site who have never owned a Z with flat top carbs, and they have bad mouth the flat tops. In my opinion, they are given a bad rap. I had a ’73 with flat tops and they performed wonderfully, even in hot LA traffic. No way I would trade them out. It is getting very rare to see a ’73 or ’74 with the flat tops, so you would do well to keep them, in my opinion. Just my thoughts

Rich, you're right, the PO didn't mess with it hardly at all. He seems to have taken great care of the car but I don't think he was particularly mechanically inclined so he didn't mess with it or install aftermarket parts. You're also right that my opinion of the flat tops has been colored by what I've read here as well as input from a local Datsun shop and ZTherapy (which must be taken with a grain of salt since they're trying to sell a non-flat top product). But also, the car runs pretty terribly and definitely exhibits the difficultly with warm starts that I've learned is common with the flat tops. The carbs need an overhaul, and I'm not sure whether to refurb the flat tops or change over to SUs. I didn't go into this intending to keep a very original car but given this one's condition it doesn't seem right to mess up too much.


The paint and body look great, chrome bumpers look awesome in the pics, and if the interior looks as good as the body you are in a great spot with it...

Thanks Hardway! The car is pretty solid but there are soft spots in the floors and you can tell there's rust in both rockers. I'd like to completely re-do the car eventually but I have neither time nor money for that now. Since the car is pretty solid I just want to put the suspension back together and address driveability and have fun with it.

The chrome is decent, just a little dull and slightly pitted. I haven't looked into polishing products/techniques yet.

The interior is really nice, I'll get some shots since I just finished putting it back together.

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Re: flat tops and smog, just look at this mess. Wouldn't you rather have a shiny set of properly sorted ZT SUs sitting in there without all that other nonsense?


I'm lucky to have a facility nearby that allows all kinds of DIY machining and fab work. I'm trying to get in to use their powder coater for my front suspension but there's a long wait to take the certification course. So the suspension has been apart for weeks. In the meantime I've been working on the interior. The passenger window wasn't working well and the driver side lock wasn't working so I removed the trim panels and poked around inside the doors. I was able to fix both issues and added a bunch of RAAMmat (Dynamat type stuff) to the door panels.


The choke lever was so stiff I could barely pull it back, so I also removed the console and choke cables, cleaned and greased them, and reinstalled the choke lever assembly welded onto a metal plate as suggested by ZTherapy. The lever feels so smooth now! Unfortunately I failed to take any photos of this process, I don't know what I was thinking. "While I was at it" I replaced the completely MIA shifter bushings, so the shifter feels much better.


Once I get the powder coating done I'll really be able to make some progress. My bead blasted control arms and knuckles are just sitting and waiting (and rusting).


Here's the before... gross.



Edited by bacarl
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I don't know if this product is suitable for powder coating, you could probably ask Eastwood. I use Eastwood's "After blast" on parts after I strip them. It is an acid product with some other additives it works a lot like "Ospho" but with out the varnish like finish. It turns the parts blueish gray like Phosphoric acid does and they can sit for months in my shop and not develop any surface rust. You might want to look into it... FWIW no relation with either company...


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  • 4 weeks later...

Time for an update. I finished my first batch of powder coating! Everything turned out well I think, for my first time. Here are some before & during shots while sandblasting the parts:


Sandblasting is great but awfully time consuming.


Everything sandblasted!






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After sandblasting, the parts should be cleaned with Tri-Sodium Phosphate then wiped down with acetone. They rust extremely quickly at this point so it's important that they’re dry and to get the powder on quickly, then get them into the oven. I didn't get many pics of the process since I was working alone and getting parts cleaned and in and out of the ovens was keeping me busy.

Here's raw powder on some parts:


And some of them cured:


All done! Pretty pleased with these results.


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I had new bushings pressed into the control arms and was getting ready to re-install everything, but my hubs and struts are just as nasty as everything else and I'm having a hard time bolting the nice new stuff back onto it. I can't afford new shocks at the moment but I'm tempted to take the strut housings and hubs in to powder coat while I have everything else apart. I'm replacing the soft brake lines at each corner, so while I have the brakes apart I'd also really like to have my brake calipers refurbished by PMB Performance... All of this of course delays getting the car back on the road so I'm still going back and forth.

Here are some shots of the crusty brake line connections. I wasn't even sure how these came apart but after some PB blaster and some FSM, I figured it out. Can anyone tell if the brackets have been cut? I don't think that slot in the first pic is supposed to be there. I suspect that when the shocks were last changed (in 1975), the mechanic cut the bracket so he didn't have to separate the brake lines to remove the struts... just a guess.


Kind of an amusing story about the shocks - during my first test drive I could tell they weren't doing much so I asked if they were original. Brian proudly told me that he'd had Koni shocks installed "a few years back". I got a lot of paperwork with the car and it wasn't until I spent some time going through it that I found the receipt for the shocks, dated 1975! Yeah, they're basically brand new ;)

I wanted to post this up, too. While I was waiting for the powder coating situation to sort itself out I did some work on the cooling system. The water pump and water inlet both seemed to be leaking so I replaced them. I started sandblasting the water inlet, intending to reuse it and this is what I found. 40 years of coolant-turned-acid will do this to aluminum, apparently. No wonder it leaked.



Edited by bacarl
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  • 3 months later...

Update: It turns out that me and my obsessive compulsiveness are highly susceptible to the "while I'm at it" affliction, which results in me diving deeper into projects than I originally planned and getting hung up on a lot of little details :) I have a hard time skipping steps or leaving things done improperly. Good thing I don't have a time table for this thing.

I had not intended to remove the front crossmember & steering rack, but I ended up doing it anyway. I powder coated the crossmember and partially disassembled, cleaned and painted the rack.

K-member Before






Rack Before


Wire wheeled


After (sorry for the seizure-inducing epoxy floor chips!)


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I had wanted to have PMB Performance restore the calipers, but I found a local place that specializes in caliper rebuilds so I went with them in the interest of supporting local business (and saving lots of money). Before they reassembled everything, I went ahead and powder coated the calipers (like a crazy person).

They're loaded with Carbotech pads, which I've used as track day pads in my daily driver and liked. These are a less-aggressive "performance street" compound which is supposed to provide excellent modulation and initial bite, low dust, and low noise.


Here's a close up of the finish, which turned out really nice. This is a fairly high-temp powder (600F) which recommended a clear coat for exterior use/UV resistance. So yes, I clear coated my calipers. Told you it was an affliction :-/


Here's the before


And most recently, I've just put my struts back together. I used to be a chassis guy at work, so things like springs and dampers are near and dear to me. I wanted adjustable shocks (never had those before) and I would have loved to play with spring rates, coilover style, but I don't want to hack up my struts. So I went with the tried and true Illumina + Eibach combo.



After - powder coated struts and spring seats, Tokico adjustables, Eibach Pro-kit, poly jounce bumpers, and new isolators. You can't really tell in the pic, but I did the gland nuts in a different color - a powder close to "Datsun blue" - just for fun. One of the best things about powder coat (maybe the best thing) is ease of cleanup. Changing colors is as easy as blowing out the gun with compressed air and dumping the new color into the hopper. Makes it possible to do silly things like blue gland nuts with a bunch of other black parts.


Here are some shots of the nice crusty strut housings during the process.




Edited by bacarl
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  • 10 months later...

I can't believe it's been 10 months since I updated this thread, but here's an update on where I'm at with the car. Over the winter I reassembled the front suspension and started in on the rear. I took a lot of photos to help me remember how things go together, but most of them aren't very good for showing progress updates...

Here's the front suspension going back together and the rear coming apart.



I spent the next few months gradually disassembling, cleaning and powdercoating each piece of the rear suspension. Here are a few pretty undramatic disassembly/before pics.



Sandblasted rear brake backing plate


Before/After of a powdercoated bracket, pretty exciting stuff...


I was planning on changing to new springs, so just for fun I experimented with a new powder and did the old springs in a Datsun blue color. At least this way they'll look pretty sitting on my shelf!


I'll get some shots of the completed rear suspension and continue my update a little later...



Edited by bacarl
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I don't have any good in-progress pics of completed rear suspension parts, or reassembly, but here are some of the final product.

Rear corner with refreshed brake drum


Rebuilt rear brakes


Rear suspension powdercoated and rebuilt. I had to just paint the mustache bar because I retained its original inner bushings.


And a couple of the front put back together




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And finally, some shots I took just yesterday of the car all back together and actually running and driving.




Here are a couple interior shots to add to the thread. The PO had the steering wheel wrapped in a vinyl cover so I'd assumed the original wheel was worn. I was super excited when I removed the vinyl and saw what good condition the wheel is in.


Dash is pretty good with just one small crack


So that's that! Unfortunately my next projects are somewhat uncharted territory (for me, anyways): the engine. I think over this winter I'll rebuild the flat tops to see if that helps with driveability before I change over to SUs. Of course I've read a lot about how bad the flat tops are, but as was stated earlier in this thread, they should be adequate if tuned properly, and are an interesting orignal part of my car. I no longer have stalling/hot start issues, or dieseling/run on issues, and all I did was change the fuel filter, fill up with 93 oct, and add a can of Seafoam. They're "sputtery" though, especially on start-up, and the car sure smells rich, so I'm sure some TLC would be appreciated.

I'd also like to get the seats re-done this winter. I haven't decided whether I'll tackle that myself or look for an upholstery shop to help me out.




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Almost forgot my most recent addition. I love the hubcaps and have no intention of getting rid of them, but I love Panasports on Z's too, like so many others... And since I have two sets of wheels for my other car (granted they're for summer and winter tires) I decided that having two sets for the Z is totally reasonable :)

This is one of my new-to-me, NOS Panasports test fitted on the car.



I found them on eBay; the seller had just purchased them from an estate sale and was selling them for $700. They're 15x6 et+10. I would have preferred a 7" width, but I hadn't seen a +10 offset before, which is great because I want to avoid fender rub issues. I don't know how long they've been stored for, but they've never been mounted. My plan is to keep the steel wheels, which are refreshed and powdercoated, for an original look, and get some sticky tires for the Panasports. The trouble is finding a 15" performance tire anywhere close to the stock diameter, so I'll probably have to use a smaller tire.


Edited by bacarl
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Good work and progress on the Z! The end result of your suspension rebuild looks fantastic. The new Panasports will definitely enhance the look of your Z as well. On the topic of your seats, recovering them is a total DIY job and will be much easier than your suspension rebuild. Check out my thread of when I recovered my seats. Once you have everything together they only take a few hours each.


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  • 10 months later...

I did very little with the Z over the winter. I got married last year and between that, work, travel, and old fashioned laziness, I didn't spend as much time with the car as the previous winter with my suspension rebuild. Instead, I've been taking advantage of this summer's pleasant temps (you know: when we're supposed to be out driving our cars) to work on my next project, which has been to swap my flat top carburetors to SUs.


I debated for a long time about whether I wanted to do this or not. The engine was totally stock, and a '73 equipped with flat tops, air pump, and all the original factory gear is fairly rare. But in the end I decided I wanted the day-to-day simplicity, reliability and performance that an SU set up could provide. My original plan was to tune up the flat tops properly and see how they ran in good shape. But tearing them down was a daunting prospect by itself, and I was worried that after I'd completed all that, I still wouldn't be thrilled with their performance. They're a very different animal than the SUs and since I have no experience with carburetors in general, I wanted the simplest hardware possible which has the most resources available to try and get the car running properly.


So with a strange kind of vindictive pleasure mixed with remorse I started disconnecting the many hoses and lines to begin removing the flat tops. Here's where I started.


post-27951-0-30854300-1439220667_thumb.j post-27951-0-10374900-1439220688_thumb.j


These lines carry coolant through the balance tube and carbs, vacuum to various diaphragms and actuators, fresh air to the exhaust manifold, exhaust gases to the intake, etc. etc. I tried to grasp what these systems do by tracing the various lines' paths and label as much as I could. The idea is to keep everything in good condition so that it can theoretically all be reinstalled some day...


I ran into a snag trying to remove my EGR from the exh manifold. It was stuck and my 17mm wrench was just slipping off the fitting that holds the tube in place. I could have sawed off the tube and used a socket, but since I wanted to keep everything in one piece I went and bought a 17mm flare nut wrench, used lots of PB Blaster, heated the manifold with a map torch... no luck, even the flare nut wrench was opening up and still slipping. Finally I decided the only way I was going to get this fitting out would be to sacrifice the tube so I could get a socket on the fitting. I cut the tube off a couple inches away from the manifold with an angle grinder, hit it again with the torch, put my socket on, and promptly sheared the fitting off in the manifold. Dammit!




The tube spins freely in the fitting so there's no drilling this thing out, and the tube can't be pulled out (I assume it's flared in there). All I could come up with was to try and cap it off and leave it in there. I used vice grips to bend the tube 90 degrees with the hopes of crimping it shut, and JB-welded the tip.




The tube can still spin in there so it seems like it will leak, but it wasn't sealed any better than this to begin with so it must not be a huge leak. I'll have to see what it does once I get it running, then maybe add JB weld around the base of the tube.

Edited by bacarl
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Removing the flat tops was by far the trickiest part of the project. In comparison, installing the SUs was cake. ZTherapy's kit is very comprehensive and includes everything from the correct carb insulators with longer studs, to the right length throttle linkage. And of course all the awesome refinished bits and plated hardware that everyone is used to seeing. I have to give ZTherapy credit and an extra thank you here because they actually sent me an old '72-ish air cleaner from their stash for free. My original square-mouthed air cleaner would not have been compatible with the round-mouthed SUs.


So having gotten the flat tops removed I set about bolting on the new SUs and balance tube and hooking up fuel and chokes - that was it! From this




to this




I did spend some time checking/adjusting the float levels on the SUs, so hopefully I'll avoid issues there once the system is full of fuel. My float bowls haven't got a drain plug so I don't think I can do the clear hose sight glass trick to check float level. I adjusted both floats to start shutting off fuel flow at the ZTherapy-recommended 14mm/0.55" below the float bowl lid. In reality it takes several millimeters of float travel to shut off fuel flow completely, but I got both floats pretty even; flow restriction begins around 16mm and is almost completely shut off by 13mm float height. I was making these adjustments with the float bowl lids off the carbs and blowing through the fuel inlets. This way I could move the floats up and down and check the height with calipers.


The heat shields are still missing in the pic above. I was planning to clean them up and paint them but I no longer have access to the sandblaster I used during my suspension refresh. I started wire wheeling the shield instead, which didn't work very well. It seemed to be melting the original galvanization layer instead of removing it. At that point I wasn't sure if the zinc coating would still prevent corrosion, so I decided to get the shields replated. A local company charges $75 for a minimum order which seemed reasonable; I just wish there were more silver zinc parts on this car I could have added to my order! I'm sure I could have added several more pieces and stayed under the $75 minimum. 


I haven't got the shields back yet but here's a before pic, with the larger shield partially wire wheeled.




I'll take a few more photos tonight and add another update. I'm almost ready to start the car, just need to put coolant back in. When the time comes I might try using a small syringe to add fuel directly to the float bowls through the vent tubes to speed up the starting process.

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Nice work so far, glad to hear you are close to the milestone of starting your car.


In looking at your engine pictures I might be wrong but it looks like your sparkplug wires might be OEM originals, can you read the Yazaki manufacturer's name and the matching year of manufacture on them? If so they might be quite rare.

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