Namerow

Here's a little math for you to ponder: According to the Sunoco article that is referenced by CO in an earlier post, their then-current 'Supreme' fuel blend had a density of 5.95 lb/gal, while their then-current 'Regular' blend was heavier at 6.06 lb/gal. So the Supreme weighed about 1.8% less than the Regular. To make things easy, let's say that the Hitachi-SU float has a cylindrical cross-section and is constrained to move vertically. In this way, a change in fuel density results in a change in float height that is directly proportional. Let's now say that we're starting with the light Supreme fuel in the float bowl. The top of the cylindrical float rises to a height of 'Y' mm above the floor of the float bowl. Let's make Y = 50mm. Then we drain the float bowl and replace it with the heavy Regular fuel. The float doesn't need to sink as low in this heavier fuel in order to displace its weight, so the top of our cylindrical float now sits higher (relative to the floor of the float bowl) by 1.8% and 50mm becomes 50.9mm. That is, the float has risen by 0.9mm. That kind of math doesn't fully explain the crazy float angles we see with the Hitachi-SU's in practice. I think what's going on is a combination of a few geometrical factors: The immersed part of the float is sightly conical, rather than cylindrical. The Hitachi-SU float doesn't actually move in a pure vertical direction. Instead, it's vertical path follows an arc (which may explain why the bottom part of the float was made slightly conical) Once the float passes some particular 'tip-up' angle (relative to horizontal), I suspect that the change in the cross-sectional shape of the immersed part as a function of immersion depth begins to get really non-linear. To add to the non-linearity of the float behavior (hydrostatics?), the contact surface of the metal shut-off tab also travels through an arc (which may explain why its contact surface is curved, rather than flat). It's not clear whether that curve accurately compensates for the arc in the travel path. There may be, once again, a point-of-no-return, beyond which the tab-to-shutoff pin contact behavior goes non-linear. This would be an interesting simulation exercise for someone with the time and the curiosity to pursue it. It's mostly 2D geometry (the conicity of the float makes it somewhat 3D), but it's hard to do on paper. Easier with a CAD-CAE program (which I don't have).

Your willingness to destroy an old float 'to see what's inside' has led to an important discovery: they're not hollow. If someone ever proves that the specific density of modern fuel has changed relative to that of 1970's-era fuel, then this process of ballasting the floats might become a standard part of rebuilding Hitachi-SU's. I'd be curious to know what Z Therapy have to say about this, though. One assumes that they've successfully set the floats on hundreds of H-SU's by now and I don't think I recall any discussion on their part of special tricks being used to cope with modern gas.

I did a similar bench-top experiment a couple of years ago (I was bored and curious -- a dangerous combination). I discovered that it didn't take much tab-bending to generate some pretty wacky float angles at shut-off. The 'cam-to-follower' geometry seems to be pretty sensitive. I thought about creating a little trig simulator on my laptop, but decided that I wasn't quite that bored. Or curious. I also tried weighting the float as a secondary adjustment strategy. It worked, but I didn't like my chances of gluing a dime onto the float and having the adhesive last more than a week or two. It would be fascinating to learn how the Skinner-Union and Hitachi folks did the design layout for the float and linkage in the first place. The whole thing just begs for an external adjustment screw. But were would the charm be in something that sensible?

Suggest you layer or sleeve the tab.

Different customer demographic, for sure. Both vehicles rusted out at the same (rapid) rate, though*. As for the proportion of each marque's new-vehicle numbers written off from collision damage, that would be an interesting statistic to know. We could speculate, but actual numbers would be better. Might make a good undergraduate thesis topic for somebody enrolled in Business with a minor in Sociology. (* Kudos to Porsche for eventually becoming one of the first in the industry to introduce galvanized panels into the construction of their products.)

I read the Hagerty article this morning. The author tries to argue that younger buyers aren't interested in buying Porsches because they identify more with Japanese brands. There may be a small element of truth to that, I think it's more about affordability. I also didn't see anything in the author's pricing survey that surprised me very much. Good 240Z's in the US$30K-$40K range sounds about right to me. Prices may have gone up over the past 10 years, but they haven't exactly exploded. I think it comes down to production volumes. Nissan made a lot of Z's between 1969 and 1978. Maybe 10 times the production volume for 911's at Porsche? Consider this: A brand-new 240Z cost about US$3,400 in the early 1970's. Most consumer prices have gone up by a factor of 10 over the ensuing 50 years, so it could be argued that the car sold for the equivalent of about $35,000* in 2021 dollars. Which is about what a decent restored Z will cost you right now. Not sure the same can be said for an early 1970's Porsche 911 (which sold for around $6K when new, IIRC). (* Becomes $50K after you add $15K for front and side air bags, DOHC/CVVT/EFI engine, full computer control, comprehensive emissions control equipment, front/side/rear-impact and roll-over structures, leather, modern lighting, galvanized steel body panels, sound-deadening, contemporary electronics and sound system).

Been there, done that -- LHS tow point on one car, RHS on another. Needs an oxyacetylene torch. The flame temperature from a propane torch isn't high enough and the flame tip is too diffused. EZ-outs are the devil's tool (the cheap ones, anyway). Snap one off inside the stud and the degree-of-difficulty for the job instantly increases by a factor of 10.

Interesting. I've had good luck removing frozen fasteners with vise-grips over the years. My theory is that it comes from the shock created when the pliers -- adjusted to a strong over-centre setting -- are clamped closed. You can almost hear the pliers ring when they go over-centre and lock. No penetrating oil required.

$143,000, even with silly wheels and tires! I'll bet Buzz and Todd never thought their ride was going to be worth that kind of money.

I can't recall: Did you do similar weight measurements for the 240Z? If so, what were the front and rear weights? And engine (or engine + transmission)?

These are fiddly devices and maybe not worth trying to fix by yourself. And the repaired unit might just reward you for your work by starting to leak instead of stick. Why not just call ZcarSource and ask them for their price without a core?

Further to Patcon's suggestion, you could also consider sliding a next-side-up extension tube over the end of the longitudinal floor runner of your frame rig and then using that as a reaction structure (i.e. put the bottle jack between the extension piece and the lever arm). Depends on how long the existing frame 'stub' is. I don't think I'd try this unless that stub is at least 18" long (which your pictures suggest to be the case). The reaction load (which would be tension, not compression) would be taken out of the vehicle structure through the front-most support point of your frame rig. Right now, I believe that is at either the front crossmember location -- which is a good distance back from the rad bulkhead. I'd like to see the reaction load being taken up further forward. Maybe you could rig up a chain, looped over the lower part of the rad bulkhead and then anchored to the top of the new extension tube by way of a couple of (sturdy) welded-on eye-bolts. Include turnbuckles in the two chain drops so that you can pre-tension the chain. While considering how this 'adjustment' might take, it may help to stare at the following two pictures for a few minutes while asking yourself, 'What panels deformed during the collision event?' and then, 'How can I un-do that deformation?'. The panel's main strength in the vertical bending plane comes from that long doubler panel (which has been removed by the owner in the top picture). It works with the main stamping to form a box section (which is sometimes referred to as the upper frame horn). However, notice how that box section is weakened near the front by the big hole punched in the main panel to form the fresh air inlet for the car's cabin ventilation system. I suspect that that's where the deformation happens in a front-end collision. In fact, in the lower picture it almost looks like the outer wall of the doubler plate has been kinked. For reference, I've added a third picture showing a pair of virgin OE doubler plates.

I'm astonished that you had enough room to stand far enough away from the target body panel to be able to swing the gun. If I had tried that in those close quarters, I probably would have tripped over the air hose, grabbed the plastic sheeting as I tried to keep my balance, and then dragged it all down onto the freshly-painted panel.

Nice to see that the X-Y laser gave you some encouraging measurements Re your plumb bob measurements, I think you should would be quite satisfied with a discrepancy of only 1mm in your LHS vs RHS measurements. I think that's probably within the manufacturer's original build tolerance (which, in the 1970's was probably on the order of 1.5 - 2 mm for this type of long, front-to-rear measurement). One question, though: Did you measure both longitudinal (front-right to rear-right / front-left to rear-left) and transverse (front-right to rear-left / front-left to rear-right)? If you only did the longitudinal measurements, then you still don't know whether the frame is lozenged (also referred to as 'diamonded', IIRC). The plumb laser will make these measurements more convenient and more accurate. Trying to hang a plumb bob string from the center of a bolt hole or bolt head is not that easy to do with accuracy (especially if you're lying on the garage floor). At the back of the car, you should be using the 'C' points (holes in the rear subframe, just behind where the interior floor pan kicks up) as your reference. At the front of the car, you should use two different sets of reference points: 1) the front (or rear) LHS and RHS crossmember mount holes in the frame rails, and; 2) the centres of the big holes at the top of the two front shock towers. (1) will tell you about the alignment of the lower structure and the lower front suspension pickup points. (2) will tell you about the alignment of the front suspension's upper pickup points. Re the front bumper mount holes, I suggest you wait for corroboration from at least one additional owner of a damage-free Z to feel confident that they're supposed to be 'level'. Although logic says that this should be the case, you just never know. You have a lot of prospective time and effort a stake, so best to not begin until you're as confident as possible about what is 'correct'. Also: I'm leery about the float-level measurement methods that I've seen so far. They measure relative to an inertial level, but you can't be sure whether both cars are sitting at the same pitch angle (aka 'rake angle') relative to inertial (or, for that matter, whether the floors underneath them are properly level). Ideally, 'level' for the bumper mount holes should be judged using a vehicle frame of reference. Your X-Y laser can do that, but the float level measurements may be suspect. Another thing: Note that the front and rear bolt holes are drilled pretty close to each other, which means that any errors made in sighting on the bolt hole centers (or the bottoms or tops of the bolt holes) will greatly exaggerate the measured front-to-rear angle. If I was doing this, I'd use a compass to draw a bolt-hole-sized circle on a piece of wide masking tape and then draw on crosshairs. Then I'd stick the tape on the body panel over one of the mount holes. Now repeat for the other three mount holes. One last idea (which you can take or leave): If you conclude that the bumper bolt holes really are out of whack, you might consider trying a bit of 'caveman' body alignment as a low-cost, low-impact first step. Take some of the square tubing you have left over from your frame rig construction project and cut a pair of 8-foot lengths. For both, drill a pair of correct-size holes at one end that are at the same spacing as the bumper-bolt holes. Bolt the legs in place on the bumper/hinge-mount body panel, one one the outside of the panel, the other on the inside, securing them in place with two pieces of threaded rod (or a pair of really long bolts). Now you have a hefty 8-ft lever that's solidly mounted to the bent panel. If the front bumper-mount hole is higher than the rear one, you'll need to push down on the end of the lever. In this case, I would suggest you build a solid side-to-side wood trestle to put under the front of the front frame rails, right behind the rad bulkhead. Also, put some counteracting weight in car's hatch area (sandbags, more left-over frame-rig tubing, a couple of willing bystanders, whatever falls readily to hand). Now push down on the end of your lever and see if you can get that sheet metal to shift. If the front bumper-mount hole is lower than the rear one, you have a slightly different proposition. In this case, you'll need to lift up on the lever and that wood-trestle support-behind-the-rad-bulkhead idea isn't going to happen. When you lift up on the end of your lever, you'll really just be trying to lift the whole front end of the car (and support frame) off the garage floor. I'm too lazy to do the math, but I expect you won't be able to put more than 100 lb of lift onto the end of your lever arm before the vehicle and support frame start to lift off the floor. Still, 100 lb of force on the end of an 8-ft lever might generate enough torque on the panel to shift the local sheet metal in the process. And if none of this works, you can always move on to Plan B (hammer, dolly, torch). Disclaimer: I haven't tried the lever idea, so I can't guarantee that it will work. Or be safe. Caveat emptor.

That's a superb result, Chris. You have really modest facilities compared with a lot of guys who display their results on the internet, so this is really a great testimony to your skills, ingenuity, and persistence. A great illustration of why this site and its contributors are really exceptional in a world of contracted-out, done-by-others restorations.

I think that you've made the correct decision. There was something wrong with that car. I also think that there's been collision damage. Rust repair for Z's is not easy, but there is a lot of great guidance available for DIY-ers. Conversely, you may observe that there is virtually zero guidance available online -- on this site, or anywhere else -- for home garage correction of collision damage. Worse still, it can take some careful inspection to spot collision damage.

As you continue on this (unwanted) parted of your Z restoration, I think you will be well served by acquiring a couple of laser levels. These have become less expensive since they were first introduced to the D-I-Y community and can be really helpful for checking and restoring panel and fixture alignments. One of the big challenges for these types of alignment measurements is, 'Aligned (or level) relative to what?' For example, the fact that the RHS bumper mount holes are level (as in, inertial level c/o a torpedo level) doesn't tell you whether they're at the same elevation (as in, height above the floor) as the LHS holes. As an another example, ask yourself, 'How do I make measurements relative to the centerline of the car?' I suggest the you buy a 'plumb' laser and a 'crosshair' laser. The plumb laser will let you check whether you car's main structure is straight (use the reference points and dimensions shown in the frame diagram in the 'Body' section of the FSM). The crosshair level will let you check alignments for various surfaces and reference points (e.g. bumper bolt holes) relative to a consistent inertial reference. It will also let you be sure that the whole car is sitting level, left-to-right (front-to-rear can be done, too, but not so conveniently). The combination of both laser types will be useful when you do your frame rail replacements. Of course, you can do all of this work without the lasers. The lasers just make it easier and reduce the amount of guesswork.

It looks like the owner, John Gubrud, sold the dealership to another local businessman, Don Gordon, 1985. By then, it would have become a Nissan franchise. Somewhere along the way, the business also picked up a Suzuki franchise. There doesn't seem to be a Nissan franchise in Mt Vernon any more, but there is a Nissan-Suzuki dealer called KARmart not far away, in Burlington, so the guy who bought Gordon's business probably decided to re-locate it there. The only likely property that I can see in the vicinity of 1575 Memorial Highway in Mt Vernon is a boat sales & service operation on the river just to the north of the new highway. It seems that Mr. Gubrud was a boater, so it wouldn't be surprising if he sold his old car dealership property to a fellow boater-business person who re-purposed it into a boat sales/service business. The Datsun showroom and service buildings are probably long gone. I visited Mt Vernon a couple of times back in the 1980's, when my company was doing business with the PACCAR test centre. Nice countryside. One of the members of the founding family of PACCAR, Pat Piggot, was prominent in the west coast sportscar racing scene back in the late 1950's and early 1960's. He was killed in a race at Riverside in 1962. I see you got popped for speeding in Moose Jaw during your cross-Canada journey back in the 1970's. The Trans-Canada Highway can get pretty straight and endless after four or five hours, can't it? 'Time to let the car stretch its legs a bit'.

Agreed. That was a fun read (even for those of us who didn't grow up in the Fraser Valley). Nice to a mention of my old racing acquaintance from Kelowna, Keis Neirop (1983 Sebring winner and also responsible for the only all-wood 240Z rotisserie that I've ever seen). I poked around on the internet this morning and tracked down the location of the old Chilliwak Datsun dealership. As someone else on the linked thread pointed out, it's now only a shadow of its old self, reincarnated as 'Campus Auto Sales' and 'Classic Cars'. You can clearly identify the original showroom building by its roofline (looks like a little mini-racecar in the display area), with the service department entry to the left. The building behind the trophy girl with the big 'Datsun' logo would be the long wall on the right, now painted red.

OK, I'll ask first. Who is the trophy girl in the first picture?

Actually, I have seen those Nissan OE snubbers. I bought them from MSA back in the mid-1980's. They were installed on struts that got stored and I didn't get around to using them until 30 years later. When I checked them out, they looked perfect but crumbled to the touch. So much for open-cell, natural rubber suspension bushings. The sad part is that today's no-cell neoprene bushings are not the answer for a lot of owners (unless you are dedicated to track days, autocrosses, or live in a part of the world were roads aren't exposed to frost-heave).

At $55, this looks like a practical alternative to rebuilding your OE Harada (finicky work that may generate indifferent results if the internal plastic bits and the mast tubes aren't in A-1 condition).

Re-shaping those bent sections back to the correct, radiused contour might be a challenge. I'm concerned that the metal won't move much in response to hammer-and-dolly treatment. @ConVerTT did some significant work on this area of his Z and would probably be well qualified to advise.

Sorry about that. I've edited my post.

The Specs tables in the FSM's seem to say that the 280Z got a 15.8:1 rack for the first two years (MY 75-76) before changing back to a ratio similar to that of the 240-260 MY's (18:1 for the MY77 280Z vs. 17.8:1 for the NA-spec 240Z/260Z). This makes no sense, for a couple of reasons: A 15.8 rack (just like the Euro-spec 240Z) is faster but requires more driver effort than a 17.8 rack. Not good for us slow-driving, parallel-parking North Americans. But then the 280Z comes along and it's designed as safer and more luxurious (and heavier) than the 240Z, so as to further cater to the North American mass market. The (numerical) steering ratio for the 280Z should have gone up, not down. And that's exactly what the FSM spec chart says happened -- but not until MY 77 (and not by very much). However... If you look again in the 75 FSM, you'll see that the introductory text at the start of the 'Steering' section says that the ratio is 18:1. That makes more sense. I wonder if the FSM editor forgot to update the Specs table at the end of the section? And then forgot to do it again for the 76 FSM. Of course, this doesn't explain the differences in rack travel measured by cygnusx1 on hybridz for his 240Z vs 280Z racks. At 1.5" (76 280Z) vs. 1.81" (72 240Z), his measurements were definitely consistent with a slower rack in the 280Z (i.e. more wheel twirls per inch of output), but they also suggest a difference in ratios of 20%, which means that the 280Z ratio should be 17.8 x 1.2 = 20.6:1. That's a lot more than 18:1.