The Engineered 1UZ V8 Datsun 620 Build

[MKII_Supra]

The Engineered 1UZ V8 Datsun 620 Build: An Exercise in Engineering By Mike O'Brien

Welcome to the build thread for my ongoing Datsun 620 truck. If you are here, you most likely love cars, engineering, fabrication, and all things CAD designed and optimized. You may know me as my alter ego 3D_Magic_Mike on Instagram, as the lead engineer for The Roadster Shop, or from my previous build threads for my 1UZ turbo V8 1986 MKII Supra. While I have been actively working on this build for the past year, it's time to lay it all out in graphic detail, and share this build as I continually make progress through the future. To not get too lengthy with the introduction, let me answer two questions i get alot about this build that will serve as a good intro to the build, while sharing some pics of the current progress on the truck. I tend to ramble sometimes, so if you want to miss out on my well-placed humor and long sentence structure, just ignore my long-ass "preface" and look at these pics I made for you instead:

Mike, why are you doing this? What gave you the idea? Whats going to happen to the Supra?


I get asked this alot when people find out about this build, mostly from people who have watched and helped me through my Supra build through the years. My Supra will always be my favorite car build, it was my first car since it was bone stock when I was all of 16 years old. I grew up learning how to wrench on it, with my Dad, brother and friends teaching and helping me along the way. As much as that car has become a greater extension of myself over the many years and countless hours of labor, it always leaves me feeling as though it is a bit incomplete. The car is a head turner and an absolute blast to drive, but the process of me working on it over the timeline of being inexperienced with beginners skills, to taking on much more advanced tasks as a more experienced and methodical fabricator have left the car in an awkward state in my mind. I love the car for its faults and character, as the progression of my obsession with car modification and design can be seen through it from various beginners and advanced projects that exist on it to this day. The car is great, but its not perfect.

The car is so far along that it is in my eyes completed, so far perhaps that it makes it difficult for me to backtrack back to the origin and redo things I would like to with my more advanced skill set. While it has an awesome paint job, the underside of the unibody is still left with the original gooey and crumbling undercoating, with dirty spots and imperfections a-plenty. There is wiring on the car I did when I was just an eager young pup, and while it's dependable and worry free, its not to the perfection level I feel like I would like to see on my projects now, even through it is hidden. There are so many examples of what I use to think was the best work i could possibly do, which now seems trivial to what I would expect to do. While working on the car as a silly young kid, who then went on to college for a Mechanical Engineering degree, and then to go to work at one of the most prestigious American hot rod shops in the country, my tastes and experience have evolved through the years and left me wanting to do something bigger. There are so many things I would like to do different now that my skills, available tools, and experiences have been considerably upgraded, but the car is such a living example of my progression that I would hate to clean slate it, as much as I would also love to.

I knew that after years of working at The Roadster Shop, I wanted to sink my teeth into a fresh, colossal project. I wanted something that could be designed and engineered with the end goal in mind right at the beginning of the build, as a proper ground-up approach while starting from complete scratch. I wanted to push my fabrication experience past what would be available to me with my Supra that was already 98% complete, and try new things that would help me evolve even further. Chassis, suspension, interior, electrical, all pre-designed with a common goal and theme right out of the box, and this time I didn't want it to be such a pretty car. I wanted it to be something angry, and vulgar, and abuse-ready. I wanted it to confuse and scare my grandparents, while leaving normal car guys scratching their head trying to figure out "why does that thingy go there and what the heck is this linkage going to?"

To be honest, the Datsun 620 wasnt my first choice for a build. What I really, really wanted to do was an 80's Toyota Tercel 4WD SR5 wagon build. Floor cut out, sitting on a custom chassis, absurd matched wide track widths front and rear, designed as a track-focused 1UZ V8 RWD hoon machine. I'm not joking, I dreamed about doing it for years, and still want to. And I didn't want to do it because of the BS annoying "I think it would piss people off" method, I truly think those intensely boxy wagons are so practically-ugly that they might be the coolest cars that came from Toyota in the era, and I think it would be so awesome to do one in a manner that no one else has. Once I had the money saved up to start a project, I scoured Ebay and Craigslist to try and find a good candidate. Every couple moons or so one would pop up on Craigs, but only to find the body was seriously gone. While I was after the patina look, I wasn't willing to start with a garbage body.

While scrolling through Craigslist to look for more kick-ass Toyota Tercels, I happened across a listing for a 620 king cab very close to me. While I wasn't directly looking for a Datsun, I have always really loved bullet-sides, for their character and their size. I was scheduled to go and look at the truck just for shits and gigs later that evening, but alas the truck sold before I ever got a chance. The disappointment of not even being able to see it left me randomly searching 620's on the internet, and after about 16 hours of continuous binge reading through 620 builds and pictures, I was getting hot and heavy for a 620 build. It accomplished everything I wanted to do with the Tercel, and was much more realistic. It's small, simple, light, and the community support and availability of trucks for sale was so much considerably better than the AWD SR5 'Yota. Plus I just kept thinking about how absurd it would look as a beefcake muscle junkie. It didn't take long to get a hold a decent pair of 620's semi-close to me, and the rest is history.

Mike, what are your goals for this project?

What I wanted was pretty simple. I wanted something low, fast, over-engineered, and not-polished enough to not care about beating the crap out of. I really wanted to find something with good patina so I didn't even have to touch the exterior paint, something where I could let the design and engineering be the focal point of the build, and not attempt at all to bring home the "Best Paint" award at any car show. I wanted to drive the thing, as much as possible.

While there was going to be a large level of complexity, there was still a defined budget, not getting too carried away with any unneeded frills. I wanted a bare bones, essentials driving machine that would look and feel the part on the road without looking like a priceless gem that is too afraid to see sunlight. It was going to be aggressively wide, with track widths and wheels/tires that ignored the obvious usable overall tire diameters that suit the truck. I wanted simple 15" steel wheels that looked proportional to the size and style of the truck, but I wanted them absurdly wide with an aggressive matched drag-radial tire front to back, with a nice profiled aspect ratio and sidewall shape/bulge that looks all the business while playing the part.

Design and engineering needed to be the focus of the build, while not being over-dramatic. I didn't want your car show killing "Kustom with a K frame with 300 lightening holes and triangle gussets, spider webs and air brush murals." The chassis and suspension design, among all things on the truck, needed to be over the top and convincingly complex, but done in a restrained and subtle way. While I wanted the chassis and suspension to be the true heros, I didn't want them to be the only thing your eyes are forced to recon with when you look under her skirt. We embrace this philosophy alot at work. While the chassis and suspension systems are complicated and very well designed, they always look properly at home and blend well with the rest of the car when they are properly finished.

Taking all these things to mind, about mid-way thought the chassis design I reluctantly accepted the anticipated skills of my good friend and co-worker Chris Gray to render the final vision for the truck for me. The basis of the stance and where the tires would sit in relation to the truck body was set in the computer, which was the perfect starting point for Chris to do his magic off of. He is the king of understanding the nuances of many different and desired design elements, and combining them into exactly what you never knew you needed to see in a final image. He took all my input, requirements, and goals, and as always added his own flair into the melting pot to come up with a render that absolutely blew me away. Simplicity is the virtue on the exterior of the truck, with a matte tan paint job, contrasting glossy flares, and a well-versed mix of JDM and USDM character. The truck looked like a 70's American stock car got knocked up by the plucky Asian kid down the street, and this was their teenage brood who was kind of a dick for no reason, but they knew was going to do great things in his life. Maybe.

While much of the design has been done and well photographed to this point, it will take me some time to catch up on the build as I update chapter by chapter through the progress on the truck. Here are a few shots of the truck in it's mostly current state, where I will explain the details of why and how as I progress through the updates later:

Table of Contents

Chapter One: An Updated List of All Details Concerning the Build
Chapter Two: Bringing Home the Two Trucks
Chapter Three: The Chassis and Suspension Design
Chapter Four: The Chassis and Suspension Fabrication
Chapter Five: A Little Baby 3-D Printed Scale Chassis
Chapter Six: Preparing the Body For the New Chassis
Chapter Seven: Mounting The Body To the New Chassis
Chapter Eight: The 1UZ V8 and CD009 Transmission
Chapter Nine: Modifying the Rear Bed For the Cantilever Suspension
Chapter Ten: A Really Complicated Shifter
Chapter Eleven: Exhaust and Custom Manifolds
Chapter Twelve: ITB's and a Custom Airbox
Chapter Thirteen: The Transmission Tunnel
Chapter Fourteen: The 3D-Printed Gauge Cluster and Interior Concept
Chapter Fifteen: The Fuel Cell and Pump

 

[Zuffen]

I plan on following this one.

Could be very interesting.

It looks pretty cool at this point.

 

[cribbj]

Mike, you've managed to raise the bar again!

Can't wait to see what else you have in store.....

 

[Yotarip]

Dude. You make me ashamed to post my 1uz builds.

 

[MKII_Supra]

Thanks everyone! I'm pretty stoked about this build, lots left to do but lots left to catch up on also with this thread.

-Mike

 

[MKII_Supra]

Chapter One: An Updated List of All Details Concerning the Build.

Here is where I intend to keep a continually updating detail list on the build, for quick access to the "stats". I receive frequent basic questions like "what wheels are those" and "what is the wheel travel" often, so hopefully this will serve as a quick-start guide to the easy info on the metrics and individual components.


::more info to be inserted, just want to get this on the front page::

 

[MKII_Supra]

Chapter Two: Bringing Home the Two Trucks.

In my quest to find a good starting basis for the 620 build, I was scouring over Craigslist and Ebay every day, relentlessly. It has been my tale too many times to find something that just came up on Craigslist a few hours ago, call or text the seller, only to hear that the item had sold within an hour of the listing. I was looking within about a 8 hour drive search radius on Craigs, hoping something would pop up. Trucks would come up from time to time, but I couldn't believe the money some people were asking for trucks that didn't run, had no title, and were comprised of 85.987% rust. I was in an awkward spot for trying the perfect candidate, due to what I was planning to do and the area I was in. Some basic criterion I was looking for in a starting truck were:

-It couldn't be too nice. As you can tell from the intro, I was going to be savage with the originality of the truck, and molest everything. Looking for a complete truck with perfect body panels, trim, lights, and clean metal yielded quite a few examples around my area, but for the money you would expect to see them go for. The money wasnt the biggest hurdle, as much as condoning destroying a clean survivor truck to the level I was going with the build. I left the big fishes alone, and kept looking for something a bit more ratsun.

-The original chassis needed to be decently straight. As most involved builders know, finding a straight car with no accidents, sags, or structural damage can sometimes be the hardest battle in finding a project car. The Datsun 620 was a cheap truck, and looking for a 40 year old example that was treated like the little price we know they deserve to be over those years is a tall order. Although a new custom chassis was going to be designed and fabricated, having a clean and straight original chassis ensures the body panels had been held in the best stress free way over the years, and is the best starting point to properly measuring for a new chassis.

- The cab and bed sheet metal needed to be just OK. Fixing small rust and imperfections like dents and creases wouldn't be the hardest thing in the grand scope of the build, so I didn't concern myself too much with finding mint tin. When the plan first started in my mind, what I really wanted to find was a truck with perfect patina. It may be a bit over-played now a-days, but doing a project to this level and not having to worry at all about the exterior paint or metal work is a godsend. I also have come to really appreciate the subtle look of a stock faded paint truck, wrapped around a completely reinvented and modern stance and platform. The mix of old and new is a great dynamic when done right, and it feels so good to drive your project around with the tattered exterior and not concern yourself with rock chips, caked on tire rubber on the rear fenders, or even washing it to present it.

-The cab and bed mounts and general support structures on the truck needed to be in good shape. I'm sure everyone here knows how difficult it can be to find a truck this old with clean body mounts and hat channels, especially in our area. Years of debris and moisture traps around these critical areas can eat away at all the vital metal that connects A to B, and they tend to be complicated pressed forms that are more difficult to accurately remake from scratch.

-The glass needed to be in decent shape. This wasnt the biggest concern, but I wanted to start off right with a decent full set of crack and scratch free glass. It's amazing how the final presentation of an expensive car restoration with a fortune in paint, can be visually degraded by the look of old abused glass. Its a simple step alot of people skip, but it can make a huge difference.

-I didn't care about anything else. Cracked dashboard? Missing steering wheel? Hasn't ran in 15 years? Your dickhead cousin Trent left his lunchables in the car for 2 months and now you have to sell it because it reeks? You killed your cousin Trent for leaving lunchables in the truck for 2 months, and used the truck in some kind of sick twisted irony to dispose of his body and need to get rid of the evidence? You think the truck might be haunted by the dickhead ghost of your late-cousin Trent and cant be bothered to deal with his shitty sense of ghost humor? I didn't care. As long as I had the solid starting platform I needed, I could deal with Trent.

After missing out on a few opportunities here and there due to scheduling and work, I finally came across a fresh post for a white 620 longbed on craigslist, about 6 hours south of me in Missouri. I was really on the hunt for a king cab short bed, as the extra cabin room would be ideal with a sectioned in motor, and I wanted to keep the wheelbase appropriate for the overall track and purpose of the build. After talking to the owner, I was under the impression that it was a decent solid little truck, with plenty of blemishes but nothing that couldn't be done. Even if it was a longbed, the price was right as a parts truck and was worth investigating. We hooked up the trailer to my brother's truck, got some beef jerky and coffee from the gas station, and were on our way on a Saturday at about 4 a.m.

Half a day's journey later, and this is what we reluctantly drug home:

She's a beaut Clark.

After the 6 hour journey and some phone-directions from the older seller trying to explain how to get to him, we ended up driving off the beaten path through a huge field into the very deep backwoods of someone's property. The entire situation started getting sketchy quickly, as we hadn't seen another house or person for the last half hour, and kept driving into the abyss. Four possibilities were on my brother and my mind as we trucked on:

1. We were going to be mugged
2. We were going to be raped
3. We were going to be killed then raped
4. We were going to buy a truck

Probably a combination of two or more. Soon enough we made our way to a tiny pre-fabbed housing unit placed almost comically in the middle of a giant open field. We were driving through 2 foot tall un-mowed prairie grass, which also reluctantly got snagged on everything on the trailer and tore out the wiring from the housing on one of the rear lamps. We met the seller, talked a bit, and then were shown to the truck near by. It was not love at first sight. The truck was noticeably sagging in the mid section, and the paint and body work was far gone more than the pictures on craigslist led on to be. The doors almost fell off when I opened them to inspect the cab floor, where I was reunited with the familiar 2 foot tall prairie grass growing into the cab through the rotting floor structure. The grass was too high to easily look under it to inspect the cab mounts, but I went ahead and assumed the worse. Interestingly enough, the owner said that the truck actually use to be short bed, but the bed rusted out so badly that he found the only bed he could (a longbed) to replace it, and made up for the wheelbase difference by cutting the frame in half down the middle and extending it with scrap metal. It was literally the anti-list of all things I wanted in a starter truck. What it did have was a clean and straight front end (minus some barnacle looking scabs growing on the paint in places), surprisingly clean glass all around, and a few other salvageable spare parts here and there. A bit miffed about the waste of a trip, we eventually politely negotiated a cheap price for the truck and bought it for the extra parts. Even though it may not have been worth it, the price was low and we came all the way for it.

Luckily for me, I had a backup prospect on the back burner. I had been looking at a Craigslist truck only an hour away from our home base, and I called him on the way back from Missouri with "White Lightning" to see if we could take a look. I honestly wasnt that interested in the truck, because all the pictures seemed to show my least favorite flat-black primer paint job, and what looked like severe rust all around the bottom sheetmetal of the cab and bed. I went out with a friend to scope the truck out before bringing a trailer into the equation, and our directions eventually led us to small goat pasture filled with a handful of younger gents, who were all sitting on and around the truck in the middle of the pasture with beers in hand, and goats-a-plenty.

I had a good feeling about this one.

My buddy Teddy and I introduced ourselves, and the slightly intoxicated gang around us started chatting for a bit while I was trying to measure up the truck with my peripheral vision. These guys were pretty cool, and funny to boot. I came up tot he truck after a few minutes and was surprised to see that what the pictures led on to be rust and rot, was just discolored mud and caked on debris from obviously driving the truck around in the pasture. As I knocked off the mud, I found very nice clean metal underneath. I kept working my away around the bed and cab, cleaning the crud away and finding more and more unexpected clean sheetmetal. The mud may have been my savior, and why no one was responding to his post. It may have warded off earlier other potential buyer who mistook the crud for rust and rot as I did.

As I was inspecting the truck, I also gained a new friend who by my side almost the entire time. A friendly goat. Wherever I was inspecting and cleaning the truck, he was there to make sure I wasnt up to any tricks. I wish i got more pictures with the goat, but it was getting dark and I never bring my DSLR out to a crowd of people I don't know in the middle of nowhere.

I kept going around the truck, and was surprised by the condition. Sure, it was beat up with bad window seals, a dented up driver fender. The hood hinge on the passenger side has frozen up causing the hood to buckle slightly when trying to open it. But the metal was all there and clean. The doors opened and shut with a confident single click. The tailgate aligned well and moved easily to the fridge handles. The chassis had plenty of surface patina but was solid, and from what I could see very straight. There were a couple dozen empty beer cans in the bed from the rebellious youths, but once they were moved away I could see the bed floor metal was in great shape. It started right up, and drove around for a while before it seemed the motor would be fuel starved. But i certainly wasnt concerned with the motor or trans. My first introduction to sitting in a 620 was quite the adventure. I couldn't believe how little leg room there was for a 5'10 guy, and how awkward the stock pedals felt to operate. The seats were not original and a bit bulky, which pushed the driving position forward and didn't help anything.

After some talking and goat petting, I agreed to pay the cheap asking price. My brother and I came back the next night with the truck and trailer, and loaded up the truck which mysteriously now had about 4 dozen empty beer cans in the bed (celebration party?), and brought it back home to the shop.

I now had both trucks side by side at the shop, and could really take it all in. At this point I didn't know if this was the worse or best idea for a project I've ever had, and was just laughing at myself for the two lawn ornaments I just bought.

I accidentally must have brought this foreign traveler from Missouri to Iowa.

While the white car was there for parts, the true hero for the beginning of this build was the black truck. Both trucks were listed as 73's, but both seemed to have a hodgepodge of different year parts scattered around them.

Note the wood 2x4 under the hood, keeping the random tall battery's terminals from welding themselves to the hood if it could shut all the way.

Custom windshield wipers also seemed to be installed.

Overall, I was happy with the starting base for the build. This truck was just what i wanted. It was clean enough to make something cool out of, but destroyed enough to not feel bad about cutting into every panel. The metal was all there and mostly straight, and I could replace the battered driver fender with the straight piece from the white donor truck. The glass was pretty scratched up on the windshield from the wipers running without the blades attached, but the white truck's glass would take it's place.

I have always loved the bullet-side sweep line on these trucks, such a simple but handsomely-defining detail.

My exposure to 620's before buying these two trucks had been almost zero, so some of the simple details really stood out to me on these trucks. I love the rear tailgate handles/locks, its suck a perfect and nerdy example of cost-saving simple design. I would love to know if these were honestly sourced from an appliance manufacture, or if they were an intended design for these trucks.

The bed had plenty of patina on the surface, but was rock solid all around. There was your typical corrosion around the seams and spot welded overlaps, but I was happy with the overall shape of the metal. A considerable amount of the floor would be cut out, so it's a great platform to begin with.

The open tailgate structure is begging for a set of folding jump-seats that are flush to the backing face of the tailgate when folded up, and can unfold with a small backrest when the tailgate is down to sit and enjoy some beers with the gang.

Interior components were mostly shot, but none of that would matter. Everything would be remove and thrown out, with only bare metal left.

Check out the trick-ass custom passenger-oriented speaker system. Kustom with a K for sure.

Again, all the dirt and crud on the floor of the interior looks a bit like rust and corrosion, but once its cleaned away there is very nice metal underneath. There wont be any rust-patching needed for the entire cab which is a huge plus.

Someone else but be a fabricator/engineer who had this truck before, because this custom armrest is a nice little piece.

The engine bay is full of treasures from the many previous years. Farming surplus store battery that is too tall for the hood to close, race car chrome Accel coil, And a Webber carb with fancy aluminum Redline air filter assembly. Lots of custom wiring also, with bare wires exposed everywhere, just twisted together with no insulation.

The mechanical fuel pump had been bypassed at some point, and someone installed a cheapo low-pressure electric pump on the side of the frame rail. The truck would run like a top when cold, but would quickly fuel starve after driving for a matter of minutes. The temptation to quickly go over the carb and ditch the electric pump for a mechanical with high, so we could have some more shenanigans driving the truck around the property.

While the truck only ran for a few minutes at a time, it made a great beer-delivery truck from building to building on the property, and became our unofficial cardboard transportation unit for a few weeks.

Stay tuned everyone. I will be getting into the disassembly and some beginning fab/design work in Chapter 2. Thanks for looking!

-Mike

 

[Zuffen]

I like your sense of humour.

This will be fun to follow.

 

[cribbj]

Rod (Zuffen) has always had a soft spot for truck projects He built an insane 1UZ for his Land Rover.

I'm a Supra guy, so I thoroughly enjoyed your first build, but will follow this one too. Your dedication and perseverance to pursuing perfection are off the scale, and we're all eagerly waiting to see how you're going to transform this lil truck.

 

[MKII_Supra]

Chapter Three: Disassembly, Front Fender Supports, Headlights and Hood Pins

Thanks everyone again for the kind words. Jumping back into the story, I had the black 620 in the garage, and had spent some time measuring out the critical information I needed for the chassis design later on. Once I had my bearings on everything I needed from the truck while it was still an operating lump, I got cracking away at tearing it apart for the initial dismantling process. All i wanted on the original chassis at this point was sheetmetal, and to get rid of everything else. All the small parts on the truck were so far gone and brutally "customized," I didn't take too much time to categorize or catalog them as they wouldn't be used again. I was careful to remove the lenses and taillights, as they would possibly be used on the truck in some way again, but all the lenses on this truck were in pretty bad shape.

Its amazing how fast and easy it is to strip one of these truck to the bones. They are so intensely simple, it only took a handful of hours to clean it completely down to the bare essentials.

After much snipping and ninja cutting of wiring and hoses, the motor and trans were pulled out as one unit.

This motor ran surprising well with no top end clatter or noise, but the fuel starvation prevented me from really getting to drive the truck very much. It looked as though there was salvage yard writing on the valve cover, possibly another motor swapped in at some point.

After tossing out all the brakes and steering column parts, the engine bay was completely empty. It was at this point I could really take in just how small the engine bay was, even without an engine currently in place. Packaging the new motor and suspension was going to be a big task, but I knew it would be both the fun and challenge of the build.

Gutting the interior was also a pretty easy task, since I didn't have to be careful about saving anything and just went full Donkey Kong mode on it.

Again, floors are very very nice in this cab. Not a single spot of rot or rust, just some very light patina in some spots that will be sandblasted away.

The bed became the temporary graveyard for all the original bits I didn't need, amazingly all the parts barely filled the bed at all.

I finally had the car down to the basic shell, sitting on the stock frame. One thing I wanted to do before removing the cab from the frame was tackle the front fender supports, which would tie the core support to the front of the cab and serve as hanging mounts for the fenders to fasten to when I removed the inner fenders. The door gaps were actually surprisingly good on the truck for how squashed the original body mount and core support bushings were, so it made sense to use the decently straight foundation of the original mounting points to the original frame before bringing in a new unverified chassis into the mix. This way I can fine tune the fender support design and achieve the same fender and core support alignment now when I have a good starting basis, instead of putting everything onto the new chassis at once which will have alot of new elements to deal with.

The inner fenders absolutely had to go for all the packaging I needed, and keeping the front end as a psuedo-unibody would make access to the front of the car difficult for no reason. The truck would be so low and so much of the inner fender structure would have to be hogged out due to the large overall diameter tires, it just made sense to get rid of everything altogether and fabricate a removable support structure to tie everything back together.

This part of the build didn't get too crazy with CAD design yet. While I did bring a fender to work to scan its top profile for the fender mount holes and shape, most of this was done on the fly with 1"x1" square tube, and simply making cardboard templates of gusset shapes I needed. I would then take the cardboard templates and draw them into their final forms, to then be CNC plasma cut from mild steel.

I used the scan data of the driver's fender top to create a simple flange to bolt the fender to. It follows the curved shape of the fender top, and has windowed material removed to try and save some weight.

I drew some simple 90 degree bulkheads that would serve as removable portions of the core support brace to the fender stringers, and also drew the gussets from the cardboard templates in similar windowed detail. Most all of this would be hidden, but I am trying to save weight where possible. I drew some short sections of the 1"x1" square tube for reference as I went along, and soon I had all the bits ready to cut for the front fender stringers.

Once everything was cut, the metal was cleaned of any slag left from the plasma process, and rubbed down with scotchbright pads to expose a clean surface area of fresh metal for welding to. A quick test fit was done to make sure the fender mounts fit to the profile of the original inner fenders. I am actually using the inner fenders at this point as a jig for the whole process. The metal is so thin on the inner fenders, I simply just bolted everything to it and will add a same thickness shims later to space the fenders off as if it was bolted back to the original unit.

Time to get the welder out and try to get my grove back with TIG welding. It's been some time since I did a welding project, and it would take me a little bit to get my rhythm going again.

I start tacking the fender mounts to the forward stringers made from vertical saw cut 1x1 square tube. Lots of measuring and varying angles are needed on all the 1x1 cuts to allow the tubes to later sit nice and flush to other flanges and plates. A tight fit is always the best weld, and I need all the help I can get. Note that I also tacked an x-brace to the front and rear of the inner fenders to the cab body. I would be going to start cutting the inner fenders away to make room for the new support bars as I went, and needed to keep everything square and true as the metal stress relieves and wants to distort when cutting.

Once everything measures out and is tack welded into place, I move over to the weld table to start welding the parts piece by piece. You can see the front of the fender support below, where it would meet up and clasp over the lateral support bar for the core support, fastened by 2 bolts on each side. This way I can have the entire front end support system break down into 3 pieces (left, right, front), which makes welding and painting later much more manageable. It also allows a degree of alignment for the new system, to fine tune everything as square as possible. Shims and scrap tube are used when welding to leave it a slightly loose slip fit, to make room for paint build up and not be frustratingly annoying to assemble later on.

Weldy weldy, then test fit test fit. This is the process as I go along to make sure nothing moves around from the heat of the welds, and keep fine tuning as I go.

I also start stitch welding the fender mount to the forward support tube. No need for alot of weld on these to distort things, just careful stitch placement on top and bottom. New nuts that have been stripped of their zinc plating (sitting in toilet bowl cleaner works fast and great) are also welded onto the fender mount for blind fastening.

You can see the core support brace tube in the pictures below, that bolts into the clasp on the front stringers. Since this cross tube will also be used for the top radiator mounts and hood pins, I secured it in two more places directly to the core support with some simple windowed brackets for additional support and triangulation. The top flange of the thin sheet metal core support is very wavy and distorted, and will take some work to smooth out later.

To mount the forward stringers to the cab, I designed these simple mounting plates that will bolt together. The larger flange will have weld nuts welded onto the back for more blind fastening, and be welded directly to the cab. The smaller flange will weld to the stringers, and secure itself to the cab-welded flange.

Nuts welded to the back side of the cab flange:

The area that the support tube flange will weld to the cab is cleaned down to bare metal. I had to cut some relief holes for the weld nuts to pass though on the back side, so the flange could sit flush to the cab metal. The long and tall surface area for the mounting flange is intended as a "crash point." The wide spread for the mounting and surface area contact to the cab metal lets the supports hang with less stress and more triangulation, but doubles as a large footprint that won't easily cut/crush through the cab and stab me in the kidneys if I were in a front end collision. A little SEM weld through primer was also added at this point to the cab and the back sides of the weld flanges, as this bare metal wont be accessible anymore once welded in.

Everything is test fit and aligned properly one more time, then the flanges, gussets, and tubes are tack welded together. Once everything checks out again, everything is welded together.

With the front stinger setup finish welded and true to the original inner fender mounts, It was time to get out the air body saw out and ninja the front end off the cab. I worked slowly and left about a 1" flange on the cab in case I might find it useful for anything. If not it can be shaved down smooth later. In just a few minutes, we are in business:

I then completely removed both inner fenders from the front core support, again leaving a small flange just in case.

I love the stamped triangle gussets in the front core support, such a race car straight from the factory!

With the front end all naked and open, I took the time to test fit everything back together with the new fender stringers to see how it all worked. You can see below how the front of the stringers have gusseted flanges that piggy back into the front fender mounting bolts that sandwich the core support to the new mounts. More blind weld nuts are used here so I can just bolt everything in from the front.

SO much more room for activities! You can also see that I mutilated the white parts truck for it's clean driver fender, to replace the badly dented one from the black truck.

Here you can see how the windowed design of the fender mounts show through the bottom flange of the fender itself. Should be a nice touch once everything is painted and finished.

The whole unit is very easily removed with just one person. This is going to make life a dream to access the fat 1UZ V8 motor and any suspension parts, instead of struggling around the fenders.

I also wanted to take this time while the body was well-aligned on the original chassis to take care of the hood mounting. When I got the truck, the passenger side hood hinge was nearly seized, and was tearing out of the cab metal. This wasn't a real issue, as I had no intention of using the stock hinges, or even the original hood latch. I wanted to go full race car, and quick pin the pivots and the latches to be able to remove the hood in about 20 seconds. Again, just simply using paper templates and some generic design work, I quickly had some nerdy fabricated and "mechanical" looking pieces for the truck.

I really wanted the hood pins to be something different, that could hide away on the truck but be interesting enough to notice. I didn't want your typical aero-catch system or simple muscle car clipped hood pin. After some tinkering with a few designs, I came up with a tiny little fabricated piece that I think fits the build well. It is all made from steel, and uses stainless quick button release pins, which will receive a lanyard so they don't go missing. I added an extra set of tiny holes on the mounts so that when the quick pins aren't being used, they can saddle in the new position out of the way instead of just draping and flopping around on the lanyard and hood. A lower nut plate will provide more blind fastening and distribute the load of the pin mounts over the sheetmetal on the hood.

Once everything was cut out, I welded the baby assemblies together with the bases just tack welded in case I need to micro-manage them later.

Some simple saddle mounts weld to the core support cross tube (again, just tack welded in case they need to be changed later) to house the pins, and I tossed on some medium-rate springs to provide tension to the assembly to prevent any rattles. The springs will need some sort of trick method to hold them in place, but that should be easy.

The pictures might make it hard to tell, but these little guys are tiny! I committed to the pin location and cut through the hood, and installed the pin mounts on top. Some cheapo hardware is used for mock up, but everything went together very well.

Below you can see the mounting pin in the back saddle just chilling while it's not being used.

The nut plate on the underside of the hood:

For the hood hinges, I also wanted something overly nerdy that was a small focal detail to the build. I always loved full front to back quick pin hoods on go-fast cars, but most use conventional pins on both sides and can't be hinged opened like a standard hood. I decided to make an exposed hinged system that would open the hood just like any normal vehicle, but could be removed in a matter of seconds with a pair of dudes.

Again, a nut plate is used to sandwhich the new mount to the original cab sheet metal, and allow for some slight adjustment in position. I used some cardboard as shims when welding the nuts in place to simulate the sheetmetal and paint thickness, to make sure nothing would bind on final assembly.

The damage done to the sheetmetal from the seized original passenger hinge was welded and straightened, and the areas were cleaned and primed. I drilled the holes for the new mounting flanges, which would conveniently hide the original hinge opening in the cab metal. Again, I am just using random hardware from around the shop, so please don't hate on the randomness of bolts being used!

Keeping the hood aligned to the fenders and shimming the gaps from left to right, I prepare to weld the clasps that will hold the new hood hinge to the flanges.

The new hinges are a bit of an optical illusion. I designed them with a trim flange on the top of the hood to make it seem like the hinges are simply bolted to the top of the hood sheetmetal, but they actually pass though a rectangular slot cut into the hood and mount in the original bolt locations. This allows the hinge holes to be slightly oversized and allow for some adjustment also.

And lastly for this chapter, I knew from the beginning of this build that I wanted to do mesh intakes inlets in place of the high beams. After seeing My buddy Chris' awesome render, we knew we had to add in the classic tape X as a bezel on top of the mesh. I ordered the Spectre 5.75" headlight funnel (PN 9789), and grabbed the headlight assemblies off the parts shelf. It was apparent on first mock up that even thought the funnels were for a 5.75" light, the base diameter of the funnel (4" OD) was bigger than the opening in the headlight buckets, so some trimming would be needed.

The design was obviously pretty simple for the X bezels, but I also wanted to make them domed and Convex like a lamp would be. I drew them to calculate the extra material needed to shape the parts into the dome, and carefully spend some hours manipulating and curving both the base ring and the X to be domed. I am no metal shaper, so this trivial task took me some considerable time to get perfectly round and sit just right in the headlight funnels. The results were awesome though, and well worth the time invested.

Not visible, but small weld nut tabs were tacked onto the backside of the bezels to secure them to the funnel housings. I haven't gotten into the final details of these guys, but right now I am thinking brass mesh might look great press formed into the black painted bezels. Stainless steel would be easiest as I could just tack weld the mesh right to the bezels, but if I use brass I will have to think of a more clever securing method.

Stay tuned for chapter 4, where I will be finally getting into the chassis and suspension design.

Thanks everyone,
-Mike

 

[cribbj]

Mike, you're living the dream

You have the engineering and CAD skills, plus fabrication skills, and the facilities and tools to use them. AND you get paid for it!!!

 

[brawls43]

Super interested in your chassis design. This looks awesome!

 

[black_LS]

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