Nissan S30Z Chassis Datum Points

[gav240z]

Hi Folks,

Does anyone know of any documentation that has datum points of reference for measuring "trueness" of a chassis? I am having difficulty with bonnet alignment on my Safari Gold car and I bought a reproduction bonnet - which looks good but I still don't think I can easily get to fit without possibly "tweaking" it.

 

I'm looking to get a plumb bob and use this to make sure the car is true.

[AndBir]

I understand the Service Manual has,  Section BF : Body,  that has the underbody alignment.

 

This is the one for the 260Z (probably USA as well) : 

Edited November 4, 2017 by AndBir

[gav240z]

Ok found these.

 

http://www.viczcar.com/forum/topic/3204-rs30-chassis-dimension-plans/

http://www.viczcar.com/forum/topic/3204-rs30-chassis-dimension-plans/?p=32117

http://www.classiczcars.com/topic/33933-chassis-and-body-dimensions-for-us-240z-available/

http://forums.hybridz.org/topic/47601-z-virtual-tape-measure/

http://www.vord.net/cars/240z/chassis-jig.htm

http://www.vord.net/cars/240z/240Z-chassis-jig.pdf

 

http://www.xenonzcar.com/s30/fsm.html

http://xenonzcar.com/s30/files/1971%20FSM%20Supplement.pdf

[zed74]

its also not unusual to have to "tweak" the original factory bonnets...

[gav240z]

its also not unusual to have to "tweak" the original factory bonnets...

Yes, but how so? It sits high at the rear currently and a little too far back. I see evidence that a few things were tweaked on the car previously from the minor front-end love nudge.

[zed74]

Yes, but how so? It sits high at the rear currently and a little too far back. I see evidence that a few things were tweaked on the car previously from the minor front-end love nudge.

I have had previous issues & my panel man has effectively induced extra curve in bonnet shape to achieve smooth consistent lines of bonnet/fender junctions. It looks frightening to witness!

sitting too far back just sounds like you need to slot the bonnet holes for the hinges?

[gav240z]

haha, yes I can see why it might need extra curvature and I thought of the same thing perhaps with a block of wood underneath, but didn't want to do that on a reproduction panel, especially if the rest of the car was not quite right.

 

I did notice the reproduction hood mount holes appeared smaller (less adjustment) than the factory ones. So may make a template of the factory ones and transfer that onto the reproduction hinges (using a file).

 

I've run out of adjustment on the hinges themselves where they mount to the car.

 

Another thing I noticed was that the grille mounting brackets are way out of whack compared with the grille itself, but I wasn't sure if that was because I 'rebuilt' a grille or because the body had moved around at the front.

[gav240z]

These photos highlight the issues I think well.

 

I haven't spent hours adjusting this 1 (reproduction), but when I borrowed a hood off someone else. It almost fit like a glove.

 

Which is why I assumed this shouldn't need much tweaking...

 

I can elongate the mounting holes to move it forward a little, but the raised section at the rear might be because it needs more curvature.

 

Just a bit worried about tweaking a hood to fit the car, if the car is slightly out.

[zed74]

I think another original bonnet maybe the answer if fitment was spot on..

Edited November 9, 2017 by zed74

[gav240z]

Yeah I'm inclined to agree, thing is the car has had a light front end nudge. So I know at least it's partially out on 1 side, this is the bonnet I borrowed off someone and it fit better than my repaired hood and the reproduction hood.

 

[gilltech]

Whoever you borrowed that bonnet off needs to get some rust neutralizer on there asap. Just saying. Unless it's the ratrod look he wants of course.....

Curious, Gav, in your last photo there, your grille lower fixing brackets turn downwards. But they turn upwards on my early '74 260, I'd thought the radiator support & slatted grille would be the same as 240, or is yours different being an early car?

[gav240z]

240z/260z Grille mounting points are a bit different.

http://www.viczcar.com/forum/topic/14975-sold-260z-grille-240z-jul-72-onwards/?p=178244

 

Having said that I need to tweak them a little to fit my rebuilt grille!

[gilltech]

Oh, thanks, now I see. FWIW my original grille is different again from those two, I have 3 lengths of slat not two.

[Timwell]

Hey All, Long time no posts. I'm after some help with my current project and was hoping someone here could help me out. 

restored my last one 20 years ago, this time I want to make a chassis jig to make sure its all straight prior to putting in the new (many) panels. 

I have gone through all of the documents that show chassis dimensions, mainly BF-3 and BF-5, but...... my car seems to be quite a bit off. In particular my strut tops, (point A to point D).

I measure mine at about 2378mm, but the documents show 2348.3mm (450 + 1585 + 313.3). What am I missing here, surely my car hasnt stretched? Should I build the jig to the dimensions in the document, cut out the panels and then weld it all back together at the advertised dimensions?

 

Thanks in advance all.

Tim

 

[C.A.R.]

Is there any evidence of accident damage?
What are the panel gaps like?

[Timwell]

16 hours ago, C.A.R. said:

Is there any evidence of accident damage?
What are the panel gaps like?

Hi, yes, it's taken a hit to the front. Bent chassis rails in the engine bay. They will be removed and replaced.

Panel gaps were fine.

What has me confused is that the towers, top to top, are LONGER, than the dimensions in the diagram. If anything it should be shorter. 

 

The car is properly bent/twisted, hence the chassis frame I'm making. Plan is to bolt the car up to it, then bold the frame to the floor with jack screws. Then all said and done torqe it down with jack screws to get the twist out of it.

 

My question is, I guess, am I looking at the right diagram? Am ai missing something?

 

If the diagrams are right, then I'll build the mounts to those numbers and then bend/force/twist it on.

[Timwell]

A few photos of bent rails

[Timwell]

Hey All, Back again on this topic. As of now i have built a chassis jig/frame and am in the process of bolting up my bent 240z to it. And here is the rub.

I spent countless hours pouring over the only chassis dimensions document out there. That being the BF-3 204z dimensions PDF. 

As described previously I was thinking that the dimensions are wrong, or my car is very, very bent. With what I describe below, I don't think the car can possibly be 'that' bent.

Some framing of the problem, with a crap pun:
I have used four mounting points (described from rear to front): 
(1) Rear diff mount (not mustachio bar), (4 lateral bolts) 
(2) Front mount to the rear lower control arm, (4 lateral bolts)
(3) Transmission mount, and then (two lateral bolts)
(4) Front Strut Tower Top ("A" point).

The dimensions (that don't work):
(1) Reference point.
(2) 465mm from ref. (1). this one is 15mm to short. (closer to 480mm)
(3) 1427.5mm from ref. (1). This one lines up.
(4) 2381.3mm from ref. (1). This one is 20mm to short. (closer to 2401.3mm)

To my point......what the heck is going on here??!!

Between point ref 1 and 2 my car is 480mm. In the BF-3 document, there is no reference to a 480mm dimension.... The car cannot be warped by 15mm, it's all structural mounting points. So, what am I missing? 

Moving on to the dimension between 1 and 4. Again, too short by 15 to 20mm... So, what is the actual dimension?

All of the lateral dimensions are correct. 

I scratch my head. It's great though as it gives me something to talk with my wife about over dinner.

Thank you in advance!