Clear Hatch Glass

[Zedrally]

Has anyone have any idea as to why there was a change made from vertical to horizontal wires?

Last post for Xmas 2004, wish all my zed friends that have made life interesting over the past few years on this list a merry merry xmas....

[most of all to Mike G who made this all possible]!

Look forward to more riviting correspondence in '05...

Mike N

[Walter Moore]

Well, my car is clearly what 26th-Z refers to as a "Series 2", build date April, 1971, but it has horizontal line heated rear window glass.

I remember installing aftermarket rear window heaters in both my '72 Pinto, and '72 Beetle, so it is concievable that some of the Series 1 cars sold in colder parts of the U.S. might have had dealer installed rear window defrosters to meet local demand. (Similar to the clearly dealer installed air conditioner that I ripped out of my car... unless Nissan was buying parts from Texas in '71...)

[sblake01]

Like I said, I don't remember much about my 70 except that I purchased it in February 1970 so it had to be built before that. I actually purchacsed it in early January but it didn't come into the dealership until late February. There was kind of a waiting list. But it did have a clear hatch window. That's about all I can remember to distinguish it from my 72. And like I said I would have been toatally clueless at age 19 about the signifigance.

[MikeW]

Has anyone have any idea as to why there was a change made from vertical to horizontal wires?

My early '72 (9/71) has vertical wires but I think that change happened right around this time.

[TomoHawk]

The horizontal wire system is used on many cars now because only a small amount of wire shows- at the top. Otherwise, you'd have to run an unsightly wire down one side to the bottom.

[Mr Camouflage]

Maybe it was something to do with the market the cars were being sold to. I dont think any Australian 240z's had rear demisters. I've owned 2 1972 240z's, and neither of them had a demister. And I had a quick look at the Z day photos from the West Australian Z Register website, and none of the 240z's have them either, only the 260z have them.

[Bambikiller240]

My early '72 (9/71) has vertical wires but I think that change happened right around this time.

My early 72 (11/71) has the vertical wires also.

[HS30-H]

Let the Tomas call me up and harrass me, Alan! I love hearing his point of view and don't you think for a minute that I believe all of it. :eek:

Glad to hear that you are agnostic. That'll be just you and me then. Everybody else seems to take his word as Gospel, or are too afraid to say anything.

Alan, you asked me if I have arrived at a conclusion. No. Here are some thoughts about the subject from my opinion. The clear glass was an intentional decision for the initial HLS30U cars. I used to think that the change of spec came from the North American Testing Program, but evidence of the clear glass in the higher serial numbered cars blows that explanation - perhaps.

I agree that it must have been an intentional decision. The fact that some of the Press Preview event cars were fitted with the HRW means that the system was designed, tested, manufactured and approved well before series production began. That's one of the big points I wanted us to remember, as it might otherwise be implied that the HRW system was 'not ready' for production in late '69 or that there were supply problems. This does not seem to be the case.

I am fairly certain that the NATP cars had clear glass. There is no reason to discount the economic explanation. I am of the opinion that the HLS30 is more closely tied to the S30, however.

......I suspect that the HLS30U (N,V) is a fully independent model specifically geared to a certain marketing profile. I don't know why, but it seems obvious that Datsun marketing thought to "tone down" the spec for the North American market. I think they underestimated what they could have sold for a higher price. I think that this conversation is fuel to argument that Datsun had no idea how popular the 240Z was going to be in the export variant.

Yes, I'd agree that the HLS30U ( and indeed all the other 'Export' market '240Z' models ) was more closely related to the S30 model than the S30S, but there is strong evidence that the spec of the HLS30U was cost-cut to some extent in comparison to the spec of the S30 ( "deluxe" ) model.

I quite agree that NMC USA underestimated their potential market for a more 'loaded' car, and I think this whole question relates back to the crux of the design process, and the fact that massive Export sales for the Z were never a 'done deal' until they actually started happening.....

We have to be careful though. We might get into a Chicken and Egg type of argument. Did the cheap price of the cars boost sales more than a 'loaded' version would have done, hence financing higher production quantities of the more expensive parts? ( I'm probably not explaining this very well, but do you see what I'm driving at? ).

The rear window defroster was a cutting edge feature in 1969. .....Perhaps Datsun did not know if the Americans would appreciate heated glass? Perhaps some cars were fitted as an attempt to judge marketing reaction? I'm going out on a limb, but I think we are going to find that the vertical lined defrosters became standard some time around July through October of 1970. This was a period of major modifications and I think the heated hatch glass was one of them. The production numbers for the Series Two cars are too high to support the idea that the change was made at that time. This seems to be a low serial number thing.

Maybe there was more than one reason why they did not fit the HRW to most of the early Export cars. I would have thought it would be a decision that might have been difficult to reverse quickly; surely it would mean changes to sales literature, owners manuals and Factory service manuals at the very least?

I agree that discussing this kind of thing can sound incredibly anal to some, but I think its all relevant to uncovering more about how these cars came about, what was going on in the heads of the people involved, and the machinations of a big corporation such as Nissan.

Alan T.

[HS30-H]

Has anyone have any idea as to why there was a change made from vertical to horizontal wires?

I don't know if its 100% true or not, but it was explained to me that the horizontal lines actually help to clear ice ( or snow )......

Apparently, the theory is that the ice melts and drops down - hence assisting efficient clearance, whereas vertical lines will tend to leave vertical stripes of unmelted ice that take longer to clear.

I can't imagine this being of any great use when demisting, but there you go. Urban myth maybe?

[26th-Z]

Thanks for all the input, everyone. I have learned that Australia (go figure) commonly has clear glass. Cool! I confirm the part number for the clear glass.

Add that to the hypothesis, Alan. It looks like the intention was specifically export oriented? I also agree with the idea that horizontal lines work better and go back to my statement about Datsun / Nissan on the cutting edge of design in 1969. The hidden hatch hinge sealed in a rubber boot was cutting edge as well. Compare the hinge to the S30's contemporaries.

Now, I am not completely certain that the North American Testing Program cars had clear glass, but all the photos I have show no indication of heater lines. I wonder why Datsun would have not tested the heated glass. It seems like the perfect opportunity. Do we know anything about home market testing programs?

[Walter Moore]

As for the horizontal heat "lines" clearing ice better, I agree that it indeed does do that. All the cars that I have ever had with heated rear windows had the heat lines running horizontally.

Actually, now that I think of it, I have never even seen vertical heat lines...

[Walter Moore]

By the way, Merry Christmas!

I got off easy on the snow this week, only 7 inches, practically nothing compared to what landed just south of here. Evansville (about 120 miles south of me) ended up with over 2 feet of the stuff. It is a balmy -2F (That is -19C for those of you not in the backwards U.S.) So, I have had occasion to use my heated rear windows recently.