Just what the Doctor ordered. 1977 280z

[Patcon]

I am assuming that the 280 location is the same or close to the 240 location

[grannyknot]

Thanks Charles,

So the stock hole is the back one then.

[gwri8]

Just to confirm, from a 77'.

[grannyknot]

I have been so busy with the 280 I forgot about this thread, so I got everything down to bare metal, two coats 2k epoxy primer on all surfaces and two coats of undercoat, and now that it's all sealed up I can breath a bit and not have to worry about the coming humidity.

As it was time drop the car off the rotisserie I had a chance to weigh it, this is just the shell,  the only thing left on the car is the vinyl headliner and the 2 rear wheel arch vinyls. 

Now I'm not 100% on this method but I couldn't think of any other way to do it with what I had on hand.  With the car level the rear measurement  was taken with the car hanging from the rotisserie bar that bolts on where the tie down hooks usually are, then jacks were placed under the rear rotisserie bar and the front was weighed hanging from the front rotisserie bar that is bolted to where the bumper shocks attach just in front of the radiator support.

I checked the accuracy of the crane scale by lifting my small anvil which I know is 118 lbs and it was bang on, 

I have to apologize, I forgot to take a pic of the rear measurement but it weighed in at  289 lb, front was 246 lbs

289lbs

246lbs

535lbs minus the 6lbs of the rotisserie bars, is 529 lbs

Someone with better geometry skills than me will have to verify if the method I used is valid.

 

 

[siteunseen]

So a '77 shell weighs 530lbs or there about.  Nice to know that information but now do you happen to know a '72 shell?  That'd be my two cars weight and I'd like to know except I couldn't do what you're doing!  Amazing work Mr Knot.

[grannyknot]

I've always thought that the 240s were in the 550lb range but now I'm thinking 500-510 perhaps.

[Captain Obvious]

15 hours ago, grannyknot said:

With the car level the rear measurement was taken with the car hanging from the rotisserie bar that bolts on where the tie down hooks usually are, then jacks were placed under the rear rotisserie bar and the front was weighed hanging from the front rotisserie bar that is bolted to where the bumper shocks attach just in front of the radiator support.

I'm not sure I'm understanding your measurement technique exactly correct, but it sounds like it should be pretty close.

My geometry sense tells me that as long as the "pulled up" support point was the same distance from the center of the car as the "pushed up" support point, then the summation total result should be accurate. In other words... If you did all of your pulling and pushing from the same bars that connect to the rotisserie, then I think it works out.

This is really hard to do without drawings. 

[Namerow]

I enjoy playing with numbers sometimes (and I know this will drive @Captain Obvious crazy), so:

At 510 lb, the entire S30 unibody would crush down into a block of steel that measures only 12" x 12" x 12" . 

(Which reminds me of the scene from the old James Bond movie, Goldfinger, where the crushed remains of an early-60's Lincoln Continental (an early American unibody) are dropped into the bed of a waiting Ford Ranchero pickup for 'disposal'.  That block was probably about 3 cu.ft. but it included all of the bodywork, interior and glass too.)

The S30 unibody weighs a bit less than 5 of Grannyknot's anvils.

The S30 has plan-view measurements of about 162" L x 64" W.  If the entire unibody was fabricated from 20-gauge sheet (0.036"), you'd need a single sheet measuring about 350 SF.  If you wanted to make your own from 4' x 10' sheets of 20-gauge, you'd need 9 sheets.  But then, allowing for scrappage from the cut patterns, you probably need to actually buy about 30 sheets.  A 4' x 10' sheet of 20-gauge hot rolled steel sheet currently costs about $90, so that means your bill out the door of the metal supply shop would be about $2700.  You could probably recover half of that by selling the scrap to a recycler.  So let's call it $2000 for the material needed to make your own S30 unibody.  Freight, taxes, and labour costs extra, of course.

If you started with a single 348-SF sheet of 20-gauge that was 64" wide (same as the length of of S30) and laid it crosswise and centred under the car, it would extend two car widths on either side of the car outline.

[Captain Obvious]

LOL!   

[AZDatsun]

[240260280]

@Namerow  Brilliant!

[grannyknot]

8 hours ago, Captain Obvious said:

If you did all of your pulling and pushing from the same bars that connect to the rotisserie, then I think it works out.

Yes, that is exactly how it was done, thanks for confirming that.