Namerow

Agree with Mark on this easy-to-do-and-reversible experiment. That said, I continue to believe that the evidence points to the cause of the problem being heat conducted into the fuel in the delivery/return lines by way of the fuel rail assy's mounting straps (which, don't forget, connect to the cylinder head -- arguably the second-hottest piece of metal under the hood). The problem certainly doesn't seem to be convectional heat transfer caused by hot underhood air temps. If that were the case, the factory 'fix' of adding insulation along the steel lines should have cured the issue (and it apparently didn't). I don't think that the success of Jeff's strategy of replacing the OE steel with rubber hose comes from the better insulation qualities of the rubber walls against convectional heat transfer from the air. Instead, I think it succeeded because either the rubber hose or Jeff's hose mounting scheme -- or a combination of the two factors -- provided a better barrier against heat being conducted from hot engine parts into the fuel in the lines. BTW, I find it interesting the the E-Type Jag's (fitted with triple SU's and probably generating equally-high underhood temps) didn't seem to suffer from fuel starvation problems -- even though they were notorious for high coolant temps and overheating. Anybody know how the E-Jag's fuel lines are mounted? So, JAlex: In the absence of a bulletproof technical diagnosis (we still don't have one, after 8 pages of input), you're just going to have to experiment in a methodical way until you/we find either the cause or a solution (preferably both). Try Mark's suggestion and see what happens. Then report back to us here with your findings. Until you do that, you're just going to get more conjecture (mine included) about possible causes and possible cures. Note that there is no over-the-counter 'kit' that you can buy to follow Mark's suggestion, so don't ask us for parts numbers or suppliers' names. Here's what I would do. Buy a couple of lengths of automotive-spec fuel line (1/4" for the supply hose, 3/16" for the return hose -- buy 'traditional' low-pressure rather than 'EFI' high-pressure hose). Also buy a length of 1/2"-width steel 'strapping' (plumbing supply shop -- comes in a roll). Use the existing steel fuel lines to provide mounting points for the new hoses. Use automotive hose clamps (screw-type) to mount the hoses to the steel lines. You'll need T-fittings to split the delivery hose into two paths (one for the front, one for the rear carb). Same goes for the return hose. Be tidy with the hose mountings and routings. Keep the hoses away from moving parts (like the fan and the throttle linkage) and off of hot parts (like the exhaust manifold). Be sure that the clamps at the fuel pump, carburetor, and 'T' connections are tight. Be sure that the new hoses won't snag the throttle linkage. Once you've got your new 'experimental' fuel hose set-up in place, post a few pictures here so the members can warn you if you've done anything wrong. If you get the 'all clear', the next step will be starting the engine and doing final checks before you try it out on the road. IMPORTANT: If you are in any way concerned about your ability to do this type of work safely and successfully on your own, do not attempt it. Instead, get a licensed mechanic to do it for you.

I watched that auction and consider the result to be an anomaly. It seemed to capture and build on the enthusiasm of a couple of guys who thought is was, 'a great build'. Which it was. However, on most days a modified Z only draws contempt from the BaT audience. High praise and high bids are reserved for mint examples. So put that paint brush and masking tape away.

Nice photos. The latter two raise once again three of the ongoing Z 'style' debates: stock vs lowered ride heights; over-under vs. single exhaust tips, and; plain bumper vs. over-riders. (If anyone asks, there is no correct answer.)

As someone from the era pointed out, they were just used-up, well-past-their-prime race cars at the time. He even used it in the winter to take his kids to school! If you want a really good read about Mason's car addiction, find his comments in "Into The Red" (a wonderful purchase, if you can find a copy) about owning one of the even-fewer-built early-50's BRM V-16 grand prix cars. In the way that only a well-to-do Brit can manage, he estimated that it cost him as much per yard to drive that car, "... as laying the finest Wilton carpet".

This looks very interesting (I've been using bubble-wrap packing sheet as protection for the fender-tops). Any signs of adhesive residue or paint clouding after the sheet has been removed?

Just make sure that you use fuel-rated hose and mount it so that it won't chafe on a sharp edge. The CZCC members have too much invested in this car to lose it now .

Don't forget to check the condition of the connector terminals in the male and female plugs that join the headlight's wiring pigtail to the front wiring harness. These can get corroded. Each plug has three wires/terminals: hi-beam, lo-beam, and ground. Try to clean both the male (easy) and female (not so easy) terminals. A shot of 'De-Oxit' electrical contact cleaner will help, but use of a small, thin flat file (hobby shop item) will be better.

Based on Jeff's experiences, it sounds like the ambient air temp in the engine compartment is irrelevant and the real culprit is engine heat conducted through the metal fuel rail mounts. I wonder if the solution might be as simple as thermally isolating the rail mounting points from the engine by using rubber standoffs? (I'm thinking grommets in the range of 1/4" to 1/2"-thick). This would seem pretty easy for JAlex to try and probably 100% reversible if it doesn't work out.

I hired the services of a local specialist. Their only business is extracting snapped off fasteners. Primary clientele are dealer service departments. Apparently, there are chronic, high-dollar fastener failures on certain premium vehicles to support this kind of trade. The tech showed up at my home with a roll-in cabinet filled with specialty tools. Job was done in 15 minutes. Cost: about $150. For me, that was money well spent, as it allowed me to move on to more rewarding steps in my restoration project.

This car was a great build. I would go with Bring a Trailer first, with a reserve set at $30K (nothing ventured, nothing gained). If you have no luck there, you'll be stuck with eBay. FWIW, I don't think that this is the right kind of vehicle for the big-name winter auctions in Arizona. GLWTS.

Don't overlook the possibility that the 'reverse-rotation' fan may be just a flipped photo image. Does this look better?... What's your goal in changing to this style of fan? More CFM? Less noise? Weight reduction? Hi-tech look?

Fine looking lathe in the background there, Jim. Details?

OK, I may have found the answer myself. Eric Neyerlin's excellent ZParts.com site includes a pair of photos that document three different shapes of S30 choke knobs, as well as variations of 'with script' and 'without script' (irrespective of shape). It looks like my 'mystery' items are actually one of the two different 'shape' versions that were used for the 72-73 Z's. Probably from the early part of the 1972 run, since their shape is kind of 'in between'. If you're interested in more details, go to the ZParts.com site and click on the tab at the top marked, 'ZP TECH'. Then look for the link, "S30 Parts Comparison Index". Then search on 'choke knob'. Eric's notes also document the use of at least three different types of set screws for the S30 choke lever. This would make a great display collection for the 'driven' 240Z/260Z enthusiast: a complete set of all the different choke (and hand throttle) knobs used between 1970 and 1974!

As near as I can understand it, the conventional wisdom is that there are only two versions of the choke knob for the 240Z: an early, rounded version and a later, more square-ish version (the knob in the 260Z had a more slender design than either of the 240's, and I guess the fuel-injected 280Z didn't have a choke knob at all). In all of the many pictures that I've seen of the 240 choke knob, never does the design include the script, 'CHOKE' in addition to the icon. My small assortment of choke knobs (see photo) includes these three items: right - a new, later-style knob left - two used-condition knobs of an unknown origin, both of which include both script and icon. The two mystery items are slightly asymmetric in design, but not to the same extent as the no-script 'round' and. They each came with identical slot-head set screws that fit nicely into the recess on the leg. The thread diameter measures as 3.0mm. However, I don't know whether they actually belong to the mystery knobs or not. One final note: The mystery knobs fit well on the metal S30 choke lever in two respects: 1) the slot for the lever is the correct width and depth, and; 2) the set-screw hole in the plastic knob lines up with the set-screw hole in the metal lever. In a third respect, the fit of the mystery knob is off a bit: without the set screw in place, they rock a little, fore-aft, when fitted onto the lever. So: Does anyone know where these two knobs come from? They match the known S30 knobs' graphic quite well and the set-screw location is spot-on. In shape, they seem to be halfway between the 'early' and 'later' S30 designs. Maybe they came from a Datsun Roadster or a truck?

hmmm... My car's VIN is 5/70 and the tab that came unsoldered was the lower pssgr side. I think that what we have here may be a process or material problem, rather than a worker problem. Fortunately, the fix is easy. And on the 'glass half-full' side of the equation, I can't think of too many other places on the 240Z where things just 'broke'.

For our American Z-car friends, you have no idea how much more expensive it is to have a 'car habit' when you live outside of the USA. We never get access to those 'free shipping' specials that those of you who live inside the USA enjoy and we get absolutely killed by FedEx and UPS brokerage fees when parts come across the border. Add to this customs duties and local sales taxes and -- here in Canada, anyway -- you can pretty much take any advertised price for a part from a USA vendor and add over 50% to figure out what the delivered cost will be. As an example, the premium that I paid over vendor's list price for a set of Wesco seat belts was 68%. And then there's the currency exchange. But that's another story.

That's the accepted way of stopping crack growth. Because you're going to have the crack welded, though, doing this might be either: a. even more important (large thermal stressing), or; b. not necessary (welding solves the issue). You won't know the correct answer until after the heat hits it. Because of the fear that the correct answer may be 'a', a compromise solution might be to drill a hole to half depth. Looks like a 3/16" bit would be about right. If your welder buddy has a lot of experience with aluminum casting repairs, he should be able to offer a better opinion.

NAPA

Some time ago, Blue posted a nicely-illustrated piece on rebuilding a MasterVac unit. However, I think it was on the Atlantic Z Club site (nla?). Maybe he can re-post it hear. IIRC, his problem was a ruptured diaphragm... which he repaired using some kind of sealant. As for me, I decided to just buy a rebuilt unit from NAPA. It wasn't that expensive and it spared me the grief of taking the old unit apart.

I think that the compliancy of the Great Stuff foam may actually be a plus rather than a minus. After 40+ years, the original foam has about zero compliancy left, so the stuff that goes in to fill the cracks has to be able to give as the dash surface grows and shrinks with radiant heat and changes in interior temperature. For my repaired dash, my biggest fear is that the top, skim coat of 'Bumper Bite' repair compound won't have the same degree of compliancy as the foam underneath it. The top coat is only bonded to the original vinyl skin by the width of that skin, and if the bond fails, a crack will emerge. I beveled the OE vinyl skin so as to increase the width of the bond line, but that still only makes the bond along each seam about 3mm in width. Only time and sunlight and temperature will tell the tale. Since I completed the repair, my dash has been stored in the basement for 2 years, waiting to be re-installed in the car.

Here's a link to an article in EngineBuilder.com that provides some great insights into the difference between the fuels that are sold today vs. those which were the standard back in the day when the original Z's were designed and used... http://www.enginebuildermag.com/2013/11/impact-of-todays-fuels-n-carbureted-engines/ Among other things, there are some interesting points raised about fuel volatility and ethanol drop-out and the implications these fuel characteristics have for long-term (or even shorter-term) storage of vehicles with vented fuel systems. The EngineBuilder.com site looks like a great resource for owners who like to pursue performance improvements for their stock engines.

I successfully rebuilt the Harada antenna from from my 5/70 Z about a year ago, using Mr. Purcell's excellent write-up as a guide. My antenna does have the bullet tip. In addition, the motor housing 'can' does not have a model number stamping. Instead, it wears an embossed, circular mftr's plate (same as Purcell's, IIRC). Maybe we have an 'antenna expert' in this club who knows if/when Nissan switched to an updated Harada antenna (which I assume yours to be). I don't know whether your unit has had a non-Harada mast substituted or not. I kind of doubt it, because I think it would be a difficult swap (the nylon drive 'rope' is attached to the base of the center section of the mast in a fairly permanent way, IIRC). On the other hand, maybe these things all used a generic mast design, regardless of mftr. I can tell you that the disassembly/re-assembly of the clutch is pretty straightforward and there's nothing spring-loaded that's going to explode out of the casing. The main thing to observe during disassembly is how the (black) plastic 'guideshoe' pieces for the nylon 'rope' fit into the casing. I've got lots of pictures stored away if you get lost. BTW, as you explore the innards, you'll find out why the outer casing rusts. There's a rather poorly designed drain in one of those guideshoes that's supposed to give an exit path for water that weeps down the chrome mast. It probably clogged after about Month 3 of use in most Z's.

BTW, when I just made the post above, an advert placement appeared in the middle. I have no idea how that happened. New feature for posts?

Here's are links to a couple of good introductions to things that may need attending to in a Z... http://datsunzgarage.com/probs/index.htm http://www.zparts.com/zptech.html Keep in mind, though, that comprehensive list of things to watch out for might run to several pages in length . The CZCC website has some great articles posted by members on recommended repair and upgrade strategies, as well as sources for OE and upgraded parts. The 'Search' tool is your friend. If the floor of your fuse block has melted (and there's a fair chance that it has), it is possible to do a repair. A better solution, though, might be to buy a replacement or an upgraded unit. Motorsport Auto ('MSA') can help you out with this. They also supply upgraded headlight and park/turn wiring harnesses (as do a few other vendors, including the one you for which posted the link).