The Engineered 1UZ V8 Datsun 620 Build

[2wheel-lee]

I really wish I could have gotten into karting as a kid, but my parents weren't too keen on it. We had a neighbor who always had karts on stands in his shop when we were very young, and we would always spy on him tinkering on the weekends. I'm definitely going to explain the details I think you and alot of people would be curious about when I get into the design chapters, but I just have to be careful not to step out of bounds with work-related info. I'll explain it in better detail when I get into the chapters about it, but this truck design isn't entirely geared toward performance and auto-x exclusivity. I am an experienced designer, but I am a beginning welder and fabricator. I am trying to do alot of new and interesting fab projects on the truck to challenge myself and try to get better, but I will be working exclusively with steel for almost all of it for the familiarity and cost. Admittedly, the truck will be heavier than a proper competitive truck, and considerably underpowered. I will be lucky I think to see past 300HP/TQ to the rear wheels on a junkyard 1UZ V8, even with the ITB's, cams and a standalone. The goal wasn't ultimate power or numbers bragging rights. I really am doing this truck for the experience and to have a fun truck to do some events in and try to improve my short track driving, but also cruise and enjoy whenever I can. 

 

Its somewhat sweet revenge/humor for alot of the guys in the shop to see me struggle with fabricating and welding the more complicated designs I make for them on a daily basis! Hopefully I can earn more of their respect in the end!

 

-Mike

 

 

Well said. Just by that, it's readily apparent that you're a person with good character. Enjoy your project!....As I will enjoy reading about it and working on my own to a much lesser technical level - albeit with the same fun factor.

[paradime]

I've been away for a few days, so was very excited to check back in on the goings on here. I didn't think it possible, but once again, I'm floored by the level of design detail and forethought thats gone into this project. For me, this has been an introduction to a whole new level of pre-planning and visualization for a one off 620 build. Sure, I knew this technology existed in very high end applications, but never in my wildest dreams did I think I'd see a Datto mini truck under this level of attention. The depth of detail in each chapter, patience in answering criticism with humility and a sense of humor, and offering his 3D rendering on line free of change is all just icing on the cake. Personally I'm drowning in a "my cup runneth over" experience here. 

 

My only criticism is that it wasn't a 510.  :hmm:

[straightpipez]

I don't think anyone cares about 4 link in this build thread, specifically. He is a lead engineer.. and based on his design and fab skills, I think he's got it under control. 

 

If he had a hand in this, I'd say you are correct...

 

[Icehouse]

Awesome build thread!  I've also followed your project on Instagram.  

 

I have a request.  We have a "How to" area on Ratsun.  It would be awesome if you made a how to scan and render models using a laser scanner.  I have access to one at work and love designing on Solid Works but lack the skills to make a point cloud into a model.  

[mklotz70]

I second Jeff's suggestion!!

 

I'd also like to thank you for taking the time to share all of this with us.  It's one thing to share as you're going, but to come back "after the fact" and catalog the details is a whole different level of dedication and sacrifice!  Thank You!! :)

[3d_magic_mike]

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:

 

 

 

[3d_magic_mike]

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:

 

 

 

[3d_magic_mike]

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

[3d_magic_mike]

If he had a hand in this, I'd say you are correct...

 

 

Oh Rampage, you beautiful monster! Indeed the chassis, suspension, and alot of billet aluminum part design was on my end for Rampage. Our Designer Chris Gray did the fantastic design work for the visual elements and aero on the car, including the crazy carbon wider widebody and the styling for the entire car. Lots and lots of hours in that car for our entire shop, but certainly one of our proudest creations. Obviously alot of style and know-how picket up from the Rampage build is bleeding into this build, but only at about 1/2 the horsepower and .0012548% the budget.

 

You can see a decently detailed build thread on the car on lateral-g here:

 

http://www.lateral-g.net/forums/showthread.php4?t=48116

 

-Mike

[3d_magic_mike]

Awesome build thread!  I've also followed your project on Instagram.  

 

I have a request.  We have a "How to" area on Ratsun.  It would be awesome if you made a how to scan and render models using a laser scanner.  I have access to one at work and love designing on Solid Works but lack the skills to make a point cloud into a model.  

 

 

I second Jeff's suggestion!!

 

I'd also like to thank you for taking the time to share all of this with us.  It's one thing to share as you're going, but to come back "after the fact" and catalog the details is a whole different level of dedication and sacrifice!  Thank You!! :)

 

Thanks guys. I can certainly try to do a writeup sometime if I get the time. 

 

-Mike

[Filthy_]

I've also followed this build on instagram for quite some time. 

 

Everything about it makes me feel like less of a man inside, amazing work.

[mklotz70]

Such an education!  I agree with Filthy......it's making me feel a bit inadequate.......but motivated to do better. :)

[]2eDeYe]

Awesome build thread!  I've also followed your project on Instagram.  

 

I have a request.  We have a "How to" area on Ratsun.  It would be awesome if you made a how to scan and render models using a laser scanner.  I have access to one at work and love designing on Solid Works but lack the skills to make a point cloud into a model.  

 

 

I can help with this and have a kingcab to scan :D

[turboshad]

Scanning can be done on the cheap if you don't have access to commercial equipment. You obviously get what you pay for but it works perfect for spacial recognition and is decently accurate dimensionaly.........for the cost of course. Please excuse the hijack picture, but both engine and front body were scanned with an Xbox Kinect using ReconstructMe and MeshLab which are both free programs.From MeshLab it was imported into SolidWorks. Trying to make a surface was pointless and I can't select any point of the cloud to measure from but visually it let me make sure I wasn't interfering anywhere. I'm at the point where a more detailed model is needed but it has worked great to get me this far. Can't beat $10 scanning. :D

 

Hijack over, my apologies. 

 

http://reconstructme.net/ 

 

http://meshlab.sourceforge.net/ 

 

[datsunfreak]

Can't wait to see how this ends...   :thumbup:

[paradime]

The attention to detail and planning on this build is really on a whole other level. seeing the 3D modeling of individual parts. then seeing it in reality is mind twisting. I find myself double checking to see if the picts are real or not.

 

Having the ability to visualize something, render it, and fabricate it all in house must be an absolute blast. As with most good things though, it's often a double edged sward. I would imagine, like a drug, it must be hard to know where to stop. For me, part of the game and enjoyment in a build is solving and overcoming limitations. With that much power at my finger tips, I'm pretty sure my head would explode. Or maybe that's what I tell myself so I don't keel over in a fit of jealousy. 

 

Sadistic as it might be, man am I enjoying this torture.  

[Stoney]

Sadistic as it might be, man am I enjoying this torture.  

 

But it's been a whole week since an update!! The torture is real

[flatcat19]

This is the first time seeing this project anywhere. Awesome.

 

 

Can't wait to see more!

[Draker]

Better late than never.

[frank88]

The wait is killing me!! 13 more chapters to go

[shiftyXTI]

Been reading Ratsun for years but just created an account to post and subscribe to this thread.

 

Great choice of body, the lines & details of these pickups are classic and some of the best of the era IMO. Really like the choice of drive-train & enjoying the CAD & fab you share with us.

Can't wait for more!

[3d_magic_mike]

Thanks for all the kind replies everyone! I know I have alot of catching up to do with this thread, but I have been a very busy boy these past weeks. We are in SEMA crunch mode for the next month as we get ready for Vegas here at work, so I wont have a huge amount of free time until after the show. I have also been going very hot and heavy with my 1UZ Turbo MA61 Supra this past month, getting it out to the last shows of the season and driving it for the last of the good weather. Now that The Supra is pretty much finished for the year, I can get back into the game with the Datsun and spend some time getting this thread back up to speed. Hoping to have a good update tonight or sometime early this week. Here are some recent pics of my Japanese "foxbody" to hopefully subside the lack of updates, at least I have been working on some j-tin these past weeks!

 

 

 

 

-Mike

[flatcat19]

Best gen of Supras ever.

 

And that's a fine specimen of one.

 

 

I drive a 98 Lexus LS400. Love the 1UZ.

[Draker]

I love the LS400. Almost bought one once.. 

[craig2001]

Just read through to date on this build and I am very impressed.

Your line of work has me quite envious, as a design engineer myself one can only hope to land up working somewhere that both interests and inspires you every day.

 

Your tastes are very similar to my own having once built a custom 4 wheel drive mk1 golf caddy (rabbit truck in your neck of the woods), In which I also let it go due to feeling as though it was not where it needed to be from a design point of view and i would have done so much different id might has well start from scratch.

 

I look forward to further updates as I am sure they will serve as motivation to finish my own 620 build.