"Mechanix Menace": An LS7-motivated, chopped and heavily modified 1973 Datsun 240Z

[chevyz240]

The square tubing that acts as the base for the rear suspension towers have been welded in place. It was quite a bit of work getting everything aligned correctly, and the welding positions were also a bit akward. In order to get as little distortion as possible, I fully welded the top end before welding the bottom end to the square tubing that is the rear subframe base.

On one side, I had to force the tubing back a bit to get the alignment perfect. As expected, the rear subframe base bent upwards slightly, since all the welds are on the top side of the tubes. When I create the rest of the suspension towers and the wheel wells, the distortion probably can be contained a bit. In the end, I will not weld in any suspension pickup points before the tube frame is fully welded.

Today I started making the shock absorber mounting flanges out of 3 mm high strength steel. In order to grind them to shape, I purchased a disc grinder the week before Christmas. As (almost) always, it needed some modifications. I had to cut part of the cover away to be able to reach all the surfaces to be ground. In order to grind the concave shapes, I put a sanding drum in my benchtop drill press. It seems to work out pretty well. Ideally I would like to have an oscillating spindle sander, but they are a bit too expensive for the few parts I will have to grind.

Slow, but fairly steady progress!









A lot more pictures at https://www.facebook.com/MechanixMenace

[chevyz240]

I would like to have the fender openings as tight as possible to the wheels. In order to optimize this, I took the time to create some cardboard patterns of the tire shoulder from a Porsche we had at work this week. It had Michelin PS4S tires, which is what I am planning to use. The rear tires were 305/30-20 on 11" rims, and since I will use 305/30-19 on 11" rims in the rear and 255/35-19 on 9" rims in the front (which has almost the same diameter), I guess the shape must be very similar. In the CAD, I have then updated my tire models and made an envelope model of the front tire, lock to lock. This will be used to check fender lip clearance.

I have also welded the shock absorber flanges to the cross tube, and started to rig that in place. I guessed that the tube would bend 2 mm, so I made the flanges 2 mm taller. In real life it bent 1 mm. Not that this has any effect, but I will probably correct the CAD model to keep it as correct as possible anyways!







More pictures at https://www.facebook.com/MechanixMenace

[chevyz240]

This week nothing has happened in the garage, but this Friday I picked up the Corvette C7 front suspension parts that I ordered. The lower A-arms have been on backorder for a few months, so I will have to wait a bit more before I get them. I did order the better SKF X-tracker hub bearing assemblies. They are a lot stronger and stiffer, with less camber loss and brake pad knockback.

[carbuff]

Such a fun build to follow... Can't wait to see you enjoy driving this one someday!

[chevyz240]

Such a fun build to follow... Can't wait to see you enjoy driving this one someday!

Thank you very much Bryan! Yeah, I hope this happens before the dinosaur juice runs out or is more expensive than gold! ;)

[-KILO-]

cant believe its been 9 years now!

[chevyz240]

cant believe its been 9 years now!

Time flies!

[chevyz240]

The rear shock absorber crossmember is now finished and fully welded in place. I have also begun welding in the first of the 1.5 mm thick sheet metal pieces that will make up the rear suspension towers. For fun I tried to adjust the camera settings in the CAD system to copy the perspective of one of the pictures I took. It came out pretty close after some trial and error.







A lot more pictures at https://www.facebook.com/MechanixMenace

[chevyz240]

This week I have designed and 3D printed a couple of TIG torch package holders for my welder. Previously I just had a couple of bent pieces of steel, but this caused the torch package to bend quite sharply. With the new holders, I get a nice radius, preventing damage to the torch package.

I have also cut out sheetmetal pieces that will be the front part of the rear suspension towers. I reinforced the hole for the suspension bellcrank with 4 mm thick high strength steel plate. I made a small bevel on the edge to ease installation of the bellcrank. The hole is drilled undersize, so I can correct it's position if necessary when the chassis is fully welded.







More pictures at https://www.facebook.com/MechanixMenace

[chevyz240]

This week I have tacked the front sheet metal pieces of the rear suspension towers in place, and during the weekend it was heavy physical work!

Soon, I'm going to roll some sheet metal for the rear wheelwells. Therefore, over the weekend I assembled my old slip roll machine that I used when I widened some steel rims in the mid-eighties. It has been dismantled for over thirty years. Judging by the spelling on the nameplate, the machine is perhaps 100 years old, or older. The spelling "af" (of) was officially abandoned in the Swedish spelling reform of 1906.

On Friday I started collecting all the parts. Amazingly, I found everything in just a few minutes! Nothing was missing! The stands have been outside in the old trash can room. Strangely enough, they have hardly rusted at all. The rollers have been standing in the garage against a wall. They have been rusty since I bought the machine. I moved everything into the garage and weighed everything. The heaviest stand weighed 108 kilograms (240 lbs) . In total, the entire machine weighs 520 kilograms (1150 lbs). The stands were quite heavy and exciting to juggle into place.

Quite a large part of Friday and yesterday was spent cleaning all the sliding surfaces. In addition, I chose to grind off the rust on the rollers. The rust dust was incredibly fine, and it even got into closed drawers and cabinets! It will take many, many hours of cleanup before everything is reasonably clean again! It took many hours before the red mist in the air settled.

When everything was cleaned, I figured out how everything would fit together. Unfortunately, I didn't have any pictures of it assembled, but in the end I was pretty sure how the stuff would fit.

Installation started today. If I didn't have my home-made telpher, it would be basically impossible to assemble the machine. My homemade lifting yoke also came in extremely handy because you can adjust the center of gravity of what you are lifting. It's something I'm surprised that they rarely or never use on any of the car building shows on TV! If you have one, you can easily lift an engine in and out yourself.

First I fit the two lower rollers into one of the stands. I thought correctly regarding which direction they should fit, but I executed it wrongly! I discovered that, of course, when they were in place! Sigh! I had to start all over again... They sit in cast iron sliding shoes and it was extremely nerve-wracking trying to hold all the parts by myself and guide them into each other. I was afraid of cracking the fragile castings. Thankfully it went well. Then it was time to fit the second, heaviest stand in place and guide 6 things into different holes in the stand at the same time. After much juggling back and forth, I succeeded.

The crankshaft itself was very tricky to get in place. I had to lift the machine up and angle it heavily to make room to get the crankshaft in without hitting a wall or something. Of course, I mounted a gear in the wrong direction so the top roller wouldn't open, which meant I had to remove the big gear again, which was a pain to both get on and get off.

In the end, everything was in place and I was able to testroll a piece! After this I showered and cleaned my aching body and had lunch at 4:30 p.m.

Great that I found all the parts, that I got it together, that nothing broke and that it works as it should! Victory!!!!!







Many, many, many more pictures at https://www.facebook.com/MechanixMenace

[TANKMASTERJ]

Every time I look at this build iam both intrigued and impressed with the design and build quality along with the tenacious attitude to keep it up
It really is inspiring Henrik.
I like others hope you actually get to enjoy it unlike so many people who never get to finish
Jason

[chevyz240]

Every time I look at this build iam both intrigued and impressed with the design and build quality along with the tenacious attitude to keep it up
It really is inspiring Henrik.
I like others hope you actually get to enjoy it unlike so many people who never get to finish
Jason

Thank you very much Jason!

I really hope (and think) so too! As I have previously described, this initially was a car I bought as a substitute for a tube framed twin turboed Volvo Amazon that never was finished. When the Z will be finished, it will actually be the first really big car project I have really finished.

I did tell a little bit about the Volvo Amazon (and other projects) in a previous post, but for anybody interested in knowing more, look here:

https://www.facebook.com/Henrik.Schi...WNrtp6TfcUTjwl

[chevyz240]

The inner wheelwell walls are now roll bent and cut to shape. Since they aren’t flat, but have a radius for stiffness reasons, I couldn’t just make a projection of the wheel well to get the shape to cut out. I had to unfold it. The arc shape is a spline, which I simplified to three radii. If I would have used just one radius, there would have been too big an error for my liking. (This can be seen in the drawing with the red arc in one of the pictures on Facebook.)

Due to the high strength steel, there is a lot of springback, so you have to overbend it quite a bit. I think you can see that in the picture where it’s in the roll bender. So far it looks pretty good. We’ll see what happens when I weld it in.







Many more pictures at https://www.facebook.com/MechanixMenace

[chevyz240]

I have seam welded the front part of the rear suspension towers and tacked the inner wheel well walls in place. Due to poor ergonomics, some of the welds are a bit crappy. I am not worried about them from a strength perspective, but it would be nice if they looked better! Today I made room for the wheel wells themselves by cutting away part of the rear quarter panels. Less and less remains of the original car...

As I have said many times, if I would have known how far I would take the project, it would have been better to sell the car when it had the 350 engine in it and ran. After that I should have started from scratch, building a tube frame and a full fiberglass body. But, when a project goes on for as many years as this has, you incrementally tend to change the plans, as I think many will recognize.

In the pictures, you can see how I placed the main hoop between the outer and inner quarter panel sheet metal many years ago. That took some work...







Many more pictures at https://www.facebook.com/MechanixMenace

[Motown 454]

I love the job your doing on the fab work !

[chevyz240]

I love the job your doing on the fab work !

Thanks again, Wayne! Normally, everything looks pretty good until seam welding starts...

[chevyz240]

I have jig sawed four pieces of particle board that will act as jigs for the rear wheelwells. The rear part of the chassis jig had to be modified to make room for them.

I unfolded the wheelwells in the CAD and made drawings of the shape I needed to cut out. Instead of trying to draw the large radii directly on the sheetmetal, I made small scribing templates that were a lot easier to handle. To make the templates, I used a tape measure as a pair of compasses.

After scribing and cutting out the shape of the wheelwells, I rolled them to the correct radius in my slip roller. I used my large carpenter square to make sure they didn't end up crooked. I then screwed one wheelwell to one of the particle board half circles and mocked it up roughly in the position it will be.

One part I am a bit worried about is shaping the radiused inner edge of the wheelwell. It has quite a complicated shape due to both the angled wheelwell and the radiused inner wheelwell wall. I think I will have to make it in small hand shaped pieces. And in order to ease the shaping, I will make them from mild steel, not the high strength sheetmetal (Docol 800) I'm otherwise using.







A lot more pictures at https://www.facebook.com/MechanixMenace

[chevyz240]

The work on the jig for the left rear wheelwell has continued. I have also seam welded the rear cabin crossmember to the brackets on the b-pillars. Since I didn't manage to get a tight fit there, I filled the gaps with some steel pieces to try to reduce the amount of distortion after welding. The welds didn't turn out very nice lookswise...







A few more pictures at https://www.facebook.com/MechanixMenace

[rat_rod_russell]

I need to poke over here more often. Much easier that FaceTubes to view.

[chevyz240]

I need to poke over here more often. Much easier that FaceTubes to view.

Do you think so, Russell? The downside is that I don't post nearly as many pictures here due to the limited storage and the long time it takes to upload and insert pictures.