Meet "Bella" - The NICOclub RB25-powered 240Z Project

[AZhitman]

After sitting around here at Datsun Ranch for five years, it was time to either begin the project or let the '75 Z go down the road.

Obviously, as with any major project, cost is a concern, so recouping some of the soon-to-be-spent money would get me off to a good start. With that, the L28 and trans were pulled and shipped off to a good home in Tucson. Lots of other bits that wouldn't be needed were removed, replated, and sold on ebay, and the disassembly was extensively documented with pictures.

At the same time, I had a buyer very interested in the 1972 shell, for a restoration project, so all of the critical components on Bella were removed, catalogued, and set aside for eventual reassembly on the new shell.

With the goal of this build being to recreate the original build, but better, the challenge will be making a 75 look like a 72. With that in mind, anything that *might* not work, I kept both of.

AND, with the intent to do this 100% correct, I started shopping for a rotisserie and a media blaster. This one's gonna get real naked, real soon.

[AZhitman]

The original iteration of this car was somewhat limited by budget, and skills, and space, and timeframe.

Ten years later, there's a little more disposable income, I've learned a ton, I have plenty of space, and there's no hurry (although Becky would probably like to drive this thing before we're all too old to enjoy it).

With that said, a few plans were laid out:

* The body will incorporate the SubtleZ widebody fenders made by our good friend John Washington at reactionresearch.com, but with a twist - bolt-on ZG flares will be added to retain the look of the previous build.

* The suspension, rather than being a hodgepodge of various components produced over the past few decades that may or may not play nice together, will instead be the entirety of the Apex Engineered Track Attack kit.

* Modern creature comforts (such as air conditioning, Bluetooth audio, and power steering from Zpowersteering.com) are mandatory.

* Lastly, five-lug rolling stock, sufficient to fill the wheelwells, and capable of managing the RB25's output, will be selected later in the build.

With the disassembly nearly complete, and the original "Bella" shell shipped off to Canada, it was time to mount this shell on a rotisserie for lots of editing!

[AZhitman]

Before any structural work happens on this build, we need to relieve it of some excess metal. Namely, the way-too-small fenderwells.

Yep, we're going to perform surgery on the cleanest, most rust-free S30 rear fenders you've ever seen, so grab your Kleenex and join us as we commit atrocities in the name of purist panty-bunching!

Lots of measurements (all laid out nicely on the Ztrix website https://www.ztrix.com/) before breaking out the Sawzall and the plasma cutter. That made short work of the initial cuts, and exposed the metal that we'd be reshaping to form the inner fenderwells later.

Since we can't weld with all that primer, seam-sealer, and rustproofing in the way, we'll come back to this part later.

[AZhitman]

The very next step - Defunkification!

Not long ago, some of you may have noticed an interloper at Datsun Ranch... A certain green 60's VW Bus being restored by Jason (rotorimp) McCoy. That project got a full rotisserie restoration as well (and sold on Bring a Trailer soon thereafter). As part of the restoration, the shell was dustless blasted on-site, and it turned out great. So, this one's getting the same treatment!

The rotisserie was wheeled out behind the shop, and we welded up a handy rack to hang the doors, hatch, cowl panel, and headlight buckets... and stood back and watched!

[AZhitman]

With the shell completely stripped of anything non-metallic, the rear fender modifications could be finished.

Lots of time was taken to assess the condition of the shell, as well as making notes on what can be removed, what holes need to be filled, and most importantly, what should be reinforced. Look at that gorgeous battery tray!

[AZhitman]

Absolute first order of business? Reinforced frame rails from BadDog.

While this Z won't be seeing a lot of track action, the torsional rigidity (or lack thereof) was what made the previous build so unpleasant to drive. These rails fit perfectly. There were two small areas where the original rails had been dinged and deformed, but heating the affected areas with a torch and returning them to their original shape allowed these rails to slide cleanly in place.

I decided to bridge the connection between the rails and the rear subframe framework. Keeping in mind that none of this is empirically-proven or even supported by anecdotal evidence, it IS an area that would seem to benefit from being tied together. Some 1/8" heavy steel strap was formed to evenly match the profile of the area to be bridged, tacked into place, and then welded in fully. It's not pretty, but pretty is for the top side.

I also added some triangular gussets to the corners of the rear suspension box. Again, if it helps, neat. If not, we'll never know.

The design of the S30 suspension and unibody make sit a little less-likely candidate for the "strut tower brace" that you're used to seeing on, say, a modern strut-suspension car. It simply doesn't benefit as much from tying the tops of the towers together. However, the upper frame horns relative to the lower rails leaves a little to be desired. I recalled from my MazdaSpeed Miata build that "frog arms" were a hugely-effective modification, and I suspected they would help here as well.

The suspension on the S30, much like the MIata, is cantilevered out from the front bulkhead (which, on an S30, is terribly weak). If we can support the upper frame horns, my theory was, I can transfer some of the cornering load into the bulkhead, the A-pillars, and the lower frame rails. If not, nothing of value has been lost, and I got some much-needed practice with my welder.

1x3 rectangular steel tubing with gussets at each end (to match the profile of their tie-in placements) were fabbed up and tacked in place, then welded properly. A small L-bracket joins the brace to the inner fenderwell about halfway up.

[AZhitman]

A quick detour, if I may...

I'm not sure if it was the three weeks of inhaling welding fumes, the July AZ heat, or that I'm just a dumbass - but against the advice of several trusted advisors, I decided this car needed to be separated from its drip rails. Hell, it rarely rains here.

Yep. Th drip rails were going away. I read every old hot-rodder's account of how to successfully shave the drip rails, and several said, "Don't do it." That's the surest way to get me TO do something, so here comes the Sawzall.

To be clear, this was a much more delicate and carefully-completed operation than that. I actually used a small electric jigsaw to cut about 1" at a time, then followed that with a gentle clamping of the three metal layers and a tack-weld every 1/4".

The challenge is to connect the three pieces of metal without warping the roof skin (or blowing through 45-year-old thin Japanese steel). Practicing on a few chunks of a scrap car certainly helped, and while a TIG would have been the preferred tool, we work with what we have.

[AZhitman]

Lots of stitch welding and seam welding followed, while awaiting delivery of critical components (namely, suspension). There are loads of resources and articles online pertaining to the critical areas to weld on an S30, so let those be your guide. Obviously, it's not hard to get carried away.

With the stitching reasonably complete, and some known-redundant holes filled in, it was time to fill in that gaping hole in the deck where the spare tire well used to be - that's where we're going to put our new fuel tank.

With the car flipped on its back, the underbody becomes an easily-accessible work surface. I started by making a cardboard mockup of the tank I intended to use, so that I could design the filler neck, straps, bracing, and access hatches. As it turned out, a UT-N-2HT model (Universal Pickup Truck Fuel Tank with Fuel Injection Tray from Tanks, Inc) was the perfect size for this application, and it's already nicely baffled and set up for fuel injection.

Extra bracing and relocated straps will center the tank neatly under the deck, and the access panels will allow servicing the pump and sending unit in the future. BTW, the access panels are steel electrical box access panels from Home Depot. They're strong, square, and perfect for this purpose.

During this process, I thought long and hard about how to handle the fuel filler situation. Keeping it stock-appearing would mean somehow incorporating the fuel door into the extended fiberglass fenders, which would mean a lot of engineering just to retain the fuel door. Filling the tank via a cap inside the hatch is tacky, unsafe, and not appropriate for this level of build.

"Boy, remember the good old days, when the fuel filler was hidden behind the license plate?"

Damn right I do. And that's perfect. A musclecar-style filler port behind the license plate would be perfect. In fact, let's get really trick and use a spring-loaded plate frame AND a modern push-through fuel cap (so no need to remove the cap).

More to come - Gotta get back in the shop and make some more sparks!

[AZhitman]

Not a lot of progress to report, but the components to build the rear-panel filler have all arrived.

The internal bracing behind the hatch latch had to be removed, but it'll get replaced with something more robust.

The angle of the rear panel should put the filler neck in a perfect position for fueling. I'm thinking I'll build a flange to attach the filler neck to the body, if only for serviceability later on.

The spring-loaded flip-down plate bracket sounded like a great idea in theory, but the springs were WAY too stiff. Deleting one spring would bend the mechanism and stress the hinges, so I decided a couple small neodymium magnets would be a way better idea.

[AZhitman]

The flange to attach the filler neck to the body was proving to be a huge pain. Cutting a perfect circle out of 12ga steel wasn't exactly a job for my plasma cutter, so I found a blank plate for an electrical panel that was the perfect diameter.

Media-blasted the paint off, found the center, bored a hole to match the filler neck, welded it on, and it's ready to install.

Found some time this week to test-fit the rear subframe and fuel tank, so the rear suspension should start coming together soon!

[AZhitman]

Fuel tank fully plumbed and secured in place:

Super-handy tool for making fuel and brake lines - Highly-recommended!

Fuel lines routed to engine bay:

Another super-helpful tool.... After struggling with several different solutions for making perfect brake line flares, I decided to splurge on this bad boy... AND it's a total game-changer. I can make a perfect Nissan inverted flare every time, with no hassles.

Speaking of brake lines, they've gotta start somewhere, so we're going with the Chase Bays booster eliminator. It's compact, clean, and should perform perfectly with the big rotors and calipers that she'll be getting.

[AZhitman]

Here's the BBE in place with lines:

Decided to route the brake lines as cleanly as possible to eliminate clutter, shorten the run, and... well, because it looks freakin' cool:

Rear junction:

These stainless clips are awesome when coupled with a nutsert tool and some 6 x 1.0 inserts... I could build 100 cars and still not run out of 6 x 1.0 fasteners!

[AZhitman]

Fabbed up a little shield for the fuel filler... This will have a couple concealed attachment tabs and will eventually be painted body color, to bring some of the outside into the cabin.

That kinda wraps up the plumbing... Next up, finishing the front and rear suspension so we can get this thing off the rotisserie and on some rollers!

[AZhitman]

Rear suspension takes a lot of trial and error, fitting and refitting, assembly and disassembly. With no real order of operations, it's not hard to put things together, only to realize you can't get to certain fasteners afterwards... but, it also gave me an opportunity to really understand the engineering and design that went into this setup.

For the rear uprights, I wanted additional structural rigidity and also wanted to minimize any stress points. So, rather than bolt the crossmember to the top of the strut towers, I reconfigured the tops of the towers.

The top of the tower was cut off, retaining the double-layer of spotwelds from the factory setup. The removed piece was used to make a pattern for a beefier tower plate, which will give me a more substantial platform for the cantilevered coilover mounts.

370Z front and rear hubs are used (for serviceability and availability), and with the rear all buttoned up, the front is next.

The front crossmember is designed to be a bolt-in affair. The more I installed and uninstalled, the more I realized I wasn't going to be happy with fasteners alone holding the whole thing together. As such, the frame braces and crossmember were carefully positioned, measurements checked, and welded in place. There's really no reason to need to remove the crossmember assembly later on (engine servicing provisions will be discussed later in the build), and I'm happy with the outcome.

I know, I know... my welds aren't pretty. I'm still learning. Just shake your head and keep reading.

Strut towers got some tackwelds, and in chatting with Ohm from AE, I suggested a plate to reinforce the inner strut tower from the underside. I wound up making my own, but wouldn't you know, a week later, he sends me a picture of proper ones that'll now be included with the kit.

The ones he makes are much nicer... I'm working with a plasma cutter, an angle grinder and an antique Miller welder.

The front coming together.... slowly.

Another area that has to be addressed is the front sway bar mount. The factory used a blind nut, welded inside the frame rails, with a very narrow spacing (for a skinny bar). This car would be getting a beefy front bar, and bolting a massive bar through those holes is a recipe for torn metal. So, the entire frame rail was boxed on three sides with 1/8" plate and redrilled to accommodate the larger bar and brackets. No chance of these fatiguing under heavy cornering!

Here's the front, complete with hubs, almost ready to flip and put on the ground.

[AZhitman]

Getting the RB and trans in and out once is a big job, especially with the flimsy radiator support in the way. Almost every Z I've seen has a beat-to-hell support, and I wanted this one to be simpler. Since the drivetrain would be making a few trips in and out of the bay for the build, I decided the radiator support needed to be rehomed.

30 minutes with the plasma cutter and a grinder and it's off to the dumpster. Time to fab up something that'll be removable, and also allow a clean, serviceable design for the radiator, compressor, condenser, and whatever else needs to hang off of it.

The top rail is 16ga 1/2" x 3" rectangular steel, and the frame is 16ga 1" x 1" tubing, and the whole thing bolts in for easy removal. I've since added a couple more outboard braces to attach just in front of the wheel tubs. It's strong, unobtrusive, and again, I can pop it out in 30 seconds when it's time to pull the drivetrain.

With that out of the way, let's get that engine in place!

[VStar650CL]

I know, I know... my welds aren't pretty. I'm still learning. Just shake your head and keep reading.

Aw, c'mon Greg, quit it. I boated for three decades the Navy way, "If you can't tie good knots then tie lots of knots." Never had a boat wander away. Those welds look plenty strong, they ain't gonna wander either. On the greasy side of things, neat is nice but Da Vinci is optional.

[AZhitman]

Took a break from moving heavy stuff to mock up the radiator. Turns out the frame rails on the later Z are a touch closer together (probably wider) than the '72, so some notching and re-welding was required.

I'll keep playing with this configuration, but I think it's pretty close to how I'll want it. I still need to build a lower support for the rubber pegs, and fab up some sort of removable brackets for the upper mounts.

The condenser can sit inside the opening for the rad support, and the intercooler will be mounted separately (likely bracketed off the front lower radiator support, in V-mount fashion). That's next week's project.

[PapaSmurf2k3]

Coming along very nicely. Can't believe I somehow missed this thread.
ALSO, I THOUGHT WE HAD AN AGREEMENT that I would get first dibbs at old Bella

[AZhitman]

DOH!

We'll talk. It's for the good of the tribe.

[float_6969]

I've seen this thread years ago, but apparently never commented. Subbin' now!

[AZhitman]

With the prospect of using a fiberglass hood (thanks to John Washington at ZTrix), we won't be needing this piece...

Now's a good time to start fitting engine peripherals and intercooler / oil cooler. With limited underhood space, it's critical to make sure everything's going to play nice once final assembly happens, and of course there's always something overlooked. I fabbed up the intercooler piping, got it all situated the way I wanted, and then realized (totally by accident) that it would interfere with the hood hinges.

So, more measuring and fabrication... here's the intake manifold and intercooler in place:

The intercooler sits on a custom bracket I built and lies perfectly parallel with the angle of the grille, which is a custom aluminum unit from Skillard.

With the radiator, condenser, and intercooler occupying the entire nose of the car, I really needed a unique solution for oil cooler placement. The solution? The oil cooler is mounted horizontal to the ground, utilizing the aftermarket air dam to route air up and through the cooler. Here's the preliminary layout (it's not near the sway bar, but it sure looks close!)

The turbo manifold from SINCO CUSTOMS (https://www.sincocustoms.com/) of New Zealand fits nicely, and leaves lots of room for servicing and maintenance.

The AC condenser fits cleanly in the custom core support. I'll fab up brackets for the lines, but here you can see the hood hinge interference I had to overcome.

The original battery tray will need to serve two functions instead of one, in the interest of saving space. I made a cardboard mockup of the Braille battery we'll be using, and its small size leaves me space for a custom-fabricated radiator overflow tank.

[AZhitman]

Designing things with the intention of adding air conditioning is way easier than trying to shoehorn n AC system into an existing build, and Vintage Air makes it super-easy.

This mockup unit is simply a plastic "plug" that's identical to the actual unit, so you can easily test-fit, build brackets, route hoses and ensure no interference.

Since the intercooler piping turned out well, I figured I'd fabricate upper and lower radiator hoses (media blasted for eventual powdercoating) and a very, very complicated and convoluted intake.

And of course, fabrication of the downpipe...

[VStar650CL]

Designing things with the intention of adding air conditioning is way easier than trying to shoehorn n AC system into an existing build, and Vintage Air makes it super-easy.

This mockup unit is simply a plastic "plug" that's identical to the actual unit, so you can easily test-fit, build brackets, route hoses and ensure no interference.

I had no idea anyone made such a thing. That's beyond cool.

[AZhitman]

It really is. It weighs like 13 ounces and the best part is, you get your deposit back ($50, IIRC) when you return it.

[VStar650CL]

[AZhitman]

With the front air dam sealed off and ducting air directly into the engine bay, plus the big grille area, there's going to be a LOT of airflow...

Except, it has to have someplace to go. Becky looked at several different hood options, but her heart was set on a fiberglass OEM-style hood with no vents.

So, it was time to modify the inspection lids (since they really don't serve a purpose once the car is modified).

I selected a nice straight set and grabbed a cutoff wheel and some expanded metal (to test my idea).

Then, I TIG-welded the expanded metal into place. The grid will be painted to match the flares and mirrors to tie everything together.

[VStar650CL]

Hey, AZ, speaking of air... I dunno how fancy you want to get with the radiator fans, but my buds at Widget Man make a couple of kick-a** products for both brushed and brushless fan control using the existing ECT or gauge sender. Drop a hint if you're interested, I can give you personal tech support.

[AZhitman]

A really important exterior theme throughout this build was to incorporate subtle changes that wouldn't distract from the original beauty of the S30. Sure, the RocketBunny kit and IMSA widebody are cool, but they tend to overpower the nearly-perfect design.

I wanted to emphasize the Coke-bottle shape of the Z, so I ordered up a set of the Subtle Z fenders from our friends at Ztrix. Initially, the plan was to use both front and rear fenders. However, the fronts require some pretty radical changes to the front airdam, and I simply couldn't get it to "flow" properly. Trying to stick with the early bumpers made a challenging task even more difficult, and it just didn't look right. An executive decision was made to run JUST the rear fenders.

Thankfully, my good buddy James (greenblurr93) is a pretty talented body/paint guy, and has extensive experience working with fiberglass. Any time you have fiberglass and metal together, there's a potential for cracking due to the way metal and fiberglass respond to twisting, vibration and temperature differentials. We wanted the PanelBond to have a lot of surface area to "bite" to, for maximum adhesion, so we prepped the rear overfenders meticulously so that the back edges mated up cleanly with the original body metal.

The panels were test-fitted repeatedly, and when we were satisfied with their trimming and placement, I used clecos to attach them temporarily. This gave us one last chance to look for ANY areas of mismatch between the metal and fiberglass. We'd be eliminating the original fuel door opening as well, and the overfenders had a cutout for the fuel door. This gave me plenty of practice fiberglassing that opening before installing the fenders.

Once there were NO gaps between the fiberglass and the metal, James laid down a thick ribbon of PanelBond and placed the fenders in place. Yes, I chickened out. The clecos came in handy here, since the holes were oriented exactly where we wanted the fender - Plus, they hold it in place while the adhesive is curing.

After that was completed, the void between the metal and fiberglass fender was filled with 3M Flexible Foam. This is a water-resistant, two-part urethane expanding OEM foam that's specifically for auto body use. Added benefits? Insulation, sound deadening, rigidity, and moisture and temperature resistance... Plus, once it cured, the fenders were rock-solid. There will be no door dings in the rear quarters of THIS car!

Remember the ragged edge created when the steel fenders were sliced up? Well, now was the time to make them into a proper wheelwell. Earlier, the metal tabs had been folded and hammered into place and welded, joining the inner and outer fenderwell. However, this left 20+ pie-shaped voids that needed to be addressed.

With the car back on the rotisserie, we were able to flip it upside down and lay in some fiberglass "blanket" to form a smooth, weather-tight wheelwell - this also bonded the lip of the fiberglass fender to the inner structure, for even more strength and rigidity. Once finished, it should look like no cutting was ever done.

Jumping ahead, this is what it looked like when finished:

With no shock or strut in the way, and with about 3" of additional fenderwell from the flares, there's going to b plenty of room for some massively wide tires!

[AZhitman]

Remember I said earlier that everything on this build was meticulously planned so that everything went smoothly?

Well... Guess what I forgot? The early Z bumpers. 70-73 cars had a clean 3-piece bumper design that wrapped nicely around the sides of the car. But our fenders are now wider.

Widening the bumper was an option, but this would leave the bumper tips flush while the rear corners of the car would have a massive gap between the body and the bumper... Plus, these were brand new, fully-chromed stainless bumpers from Tienbumper Tran in Vietnam (great quality, I've ordered 4 sets!) Cutting them up isn't an option, and thanks to the EPA, almost all rechroming in the US is outsourced to other countries.

[Side note: I can hear it already, someone babbling about "I got a guy that does chrome plating right here in the US." Doubtful. Did a lot of homework on this, and even if they do, it's going to be cost-prohibitive. Might want to take my word for it on this one.]

This could break the whole plan for the car. After a couple weeks for freaking out and agonizing over a solution (no rear bumper was NOT an option), I walked past a 78 Z at a local show (with bumpers removed). The later Zs have an indentation in the rear quarter panel that houses the bumper... EUREKA!

So, the plan was now to cut a recess in the rear quarter that would neatly frame the bumper on each side. Retain the early Z bumper look, add a cool custom touch, and maybe even make people wonder WHY (since the Subtle Z rear fenders are...subtle.)

Lots of measuring and test-fitting, plus measuring of the recess on a friend's 78 Z, led us to this solution:

Of course, these are the rough cuts, and more OEM structural foam and fiberglass would soon be employed to develop a smooth, flowing indentation that will frame the bumper nicely.

Some progress and a very loose test-fit after structural foam (but before the 'glass). Corners will be radiused to match the bumper. I hope this works like I envision it in my head!

[VStar650CL]

Thinking outside the box by trimming the box. I freaking love it.