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620KC Project Blue - "Less leaks, more looks" PIC HEAVY


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 Been a long time since my last post, but the truck was running great so there was no need. That was until I started noticing blue smoke in the rear view mirror and I lost compression on cyl #4. Oh well, winter is here and it was time to start my own Project Datto anyway. Some of you may remember this Windows 95-esque photo from a local canola field. Here's what I'm starting with:



Shes a '77 with factory AC (not working) Weber 32/36 on an L20 and a 4 speed. Picked it up June 2020 for $2000 in Tacoma, WA. Had some rust in the rockers, and it ran pretty rough when I got it but I lurked around on here enough to get it running smoother. I did a typical tune-up (plugs, wires, battery and cables, points, condenser, rotor cap etc.) but eventually threw a Pertronix points replacement "electronic" ignition in and that cleared up most of the issues. I "rebuilt" the Weber with everything short of new jets and it ran pretty well all summer. When I pulled the top of the carb off I found a jet rolling around in the bowl, so... IMG-8148.jpg


Winter in Pullman means no driving Ol 2wd Blue:





Over winter 2020 I ordered the disc conversion kit from mklots and got some HB discs up front. No more carrying a fire extinguisher for fear of brake fires because I'm too lazy to adjust the drum pads. I know I'm preaching to the choir here, Mike at BlueHands makes a seriously quality product. I sourced the hubs from a local junkyard and ordered new calipers, rotors and pads from Rock Auto.






And here they are installed:






At the time of the brake upgrade, I put in a new drag (center ) link, tie rods, and re-bushed the front end. I've never had more trouble removing tie rods in my life. No amount of heat or striking from any angle would break them loose. I ended up drilling them out. Rock Auto only had R side tie rods in stock so I ordered 2 and had a local fab shop cut and rotate one end to make it fit the L side.



I found the 8.5x15" slotted mags locally and the guy had a tire mounting machine so he let me mount and balance some 205.50.15 Kumhos on there for free when I bought the wheels.

I put 4" lowering blocks in the rear and re-indexed the torsion bars. Went with  pinto shocks up front and some air assist shocks in the rear so I could haul landscape material around for our house and it worked pretty well. 






I wouldn't recommend lowering and putting low profile tires on a yard truck, but you gotta look cool right? Seen here with 1/3 yard of river rock.


These low profile tires also severely reduced the comfortable highway cruising speed so I began my search for a 5 speed in about May of 2021. I found a donor in the form of a '79  620KC farm truck down in the middle of nowhere Central Oregon so in July I tossed an extra  transmission cooler into my 3rd gen auto 4Runner and the wife, dog and I made the trek from Pullman, WA to Kimberly, OR. This was during that "heat dome" week we had here in the PNW last summer and I was at right about the towing limit of the 4Runner but we made the trip with no problems. 


The $250, clean titled donor at the farm and when we got it home:







I bought the donor in a non-running condition. The kid thought the L20b was blown but it was still in-time and had 150lbs compression on all cylinders. I didn't bother trying to get it running because it was so covered in grease and grime and the wiring under the hood had been so scabbed together it was probably a fire danger. I did notice the positive stud on the coil was busted off and the lead was electrical taped to the remaining stud. Wonder if that's the root of the kid's "blown motor" claim?



This truck came with some single wheel duals, 6x5.5" that I wont be using so if anyone is interested hit me up.







Take note of the little 10'x20' carport behind the sliding cedar doors because that's where all the "magic" is gonna happen in a minute.


Not much work got done on Blue between July and October of this year. My father and I built a pergola in the back yard from some bridge timbers i picked up in Kendrick, ID which eventually became a very useful gantry crane for another project I picked up:





1955 Hollywood 15' Puget Sounder Hardtop plywood on oak frame with the original Johnson SuperSeahorse "Fat 50" 50 horse engine. Engine runs boat has no rot but needed new paint, so we used the new pergola to roll it over and it got new paint bottomsides.




It was my first time working with 2-part polyurethane paints. Its a PITA, but the finish is pretty incredible for a brush-on application. 


I also restored my dash using this Polyvance system and their products https://www.polyvance.com/Repair-Cracked-Dashboard/ :

This was actually supposed to be a practice dash from the donor truck (it was in worse shape than Ol' Blue's) but it was so much work and turned out so well I might use it in the finished truck:








Anyway, the boat got trailed to a friend's house to sit nice and cozy in a shed over the winter and free up shop space for Ol Blue who by the end of summer 2021 was running on 3 cylinders. Had 60lbs comp. on #4 and here's why. Return of THE PERGOLA to pull a motor and trans:









EVERY compression ring was busted. Cylinders 1-3 were still at 125 psi but 4 was down to 60.  Piston is from cyl #4. Surprisingly, no vertical scoring on any cylinders, but I had a "double ridge" around the circumference of every cylinder. Neither I nor the machine shop had ever seen that, but  the distance between the ridges was equal to the distance between the compression ring and the "oil wiper" ring. We figured the oil wiper ring was functioning as the compression ring for quite some time. When I bought the truck, the guy I bought it from used ether on every start. This is the result. 😩



So with the motor at the machine shop for a bath and bore I got to work on the rust in the rockers and quickly found out they were too far gone for patches. But the Central Oregon  donor truck has no rust... So after a week of waffling between ordering rockers and learning how to weld body panels, I decided ILL JUST SWAP THE CABS! (I know I chose a king-pin chassis over a ball-joint, but those 3 days of battling to remove the tie rods and drag links really left an impression on my and I didnt want to relive that experience in the winter if I were to use the donor truck ball-joint chassis🥴).




I actually didn't take any photos of this but I removed the doors and used a tow-strap wrapped 2x through the cab and lifted  the cab with a chain hoist. It worked pretty slick.


I've always wanted a shaved and tucked engine bay and what better time than now, so I started that process first by filling all the mounting spots that I wont be using in the inner fenders:






Grinding those welds and a body-filler touch-up:






Sandable primer and a final coat of Cummins Titanium Black paint:








And here's how you paint in Pullman in a carport when it's 35F:







With the cab off, I convinced myself it was time for a coil-over swap. I'm aware of the minimal benefits over a properly tuned torsion bar set up, but I've been itching to put my Lincoln 180 to work on a proper fabrication job. So I shamelessly copied Beebani's coil-over mounts for king-pin trucks with some 3/16" plate steel I had laying around (I'm sorry Jason!) :





Single-adjustable QA1 302's with a 7" 350lbs spring. And below is my shameless (yet incredibly grateful) copy of Jason's mounts.







I ordered new input and output shaft seals for the 5 speed, cleaned and sealed it and tossed it back on the king-pin chassis. I ordered new body mounts from a producer in Thailand and they showed up within 5 days! I've ordered other reproduction Datsun 620 parts from this guy and he's great. Cheap, fast and reliable check his Ebay store out -> https://www.ebay.com/usr/coniglio1975?ul_noapp=true


Then I promised my wife and three friends a gourmet breakfast if they would help me drop the cab back on the chassis early morning (in the snow) before we all went to work and it went flawlessly. And this is where my first Project Datto post ends! I'm currently getting creative finding warm spaces in the middle of winter to paint accessories that will go back on the truck, my latest attempt was the fume hood in the biology lab I work in 😁.







Thanks for reading! I'll update this build page as I make progress.









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Got a little work done on the interior before heading away for the holidays. I installed Noico 80 mil sound dampening material and dyed all the interior panels and seats with VHT Vinyl dye from factory blue to black:












This stuff is great, you cant scratch it off, it actually dyes the material. The carpet in the above pictures is a slightly modified 720 carpet kit I bought online.

Door cards are from Ebay.


I'm interested in replacing the steering wheel for this truck. Does anyone know if a Zcar steering wheel will fit the column on a 620?






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2 hours ago, ECS620 said:


I'm interested in replacing the steering wheel for this truck. Does anyone know if a Zcar steering wheel will fit the column on a 620?


Indeed it does, I’m putting my original 73 240z wheel in my 620.


Nice work so far, looking good.

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  • 3 weeks later...

Got some more work done over the last couple of weekends. I extended the wire harness so that I could run it between the inner and outer fender and relocate the headlight and other relays that used to be mounted on the inner fender under the dash. Made a little tool to give me an extra set of hands that made the soldering a helluva lot easier.








With the wire harness modified and fitted I got to work on shaving the marker lights off the outer fenders. There's no reason to, I just felt like torturing myself with some body work, a skill I haven't had the opportunity to practice much.


I applied masking tape over the space left when the marker light is removed, cut a pattern and transferred the tape pattern to sheet metal to make a clean fitting patch.







The passenger blue fender was FULL of body filler, so I modified the white one by filling the holes left from the rub rail and swapping the lower valance quarter.





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  • 3 weeks later...

Time for an update.


I've been really happy with this new welder so I put it to work on a couple more small projects. Started with a roll-pan to replace the big steel farm truck bumper this truck came with.



I've always hated the way the pinch welds on the bottom of the cab make for such an uneven alignment with the bed when the truck is viewed from the profile. These "skirts" attempt to take care of that.



The engine is about to come back from the machine shop. I had it bored .040 over, decked the head, turned the crank to accept new main bearings, and tanked everything to accept paint. With that in mind I polished up the timing cover, ordered a header fro Z Car Depot *queue ubiquitous triggered old-timer* and cleaned up the W58 intake by shaving the mounting points for the heat shield and ditching all the EGR gear for a custom little plate that accepts the PCV valve. 






And the interior got a little attention too. I tossed in the freshly dyed seats, dash and a new Z-car steering wheel! Shout-out @Tank. for that.  You know they add something like 10 hp.





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19 hours ago, ECS620 said:

I've always hated the way the pinch welds on the bottom of the cab make for such an uneven alignment with the bed when the truck is viewed from the profile. These "skirts" attempt to take care of that.









I agree entirely.  I've always hated how the bed sides didn't properly align with the cab.  I have  720s but they have the same problem.  I've long planned to do something about it once I finish my cab build.  I'd really like to see a full profile shot of your truck once you finish welding it in.  You are the first one I've see personally actually do it.  Very nice.



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@Lockleaf Thanks man.  Its a little tough to get the truck any further out of the shop right now for a full profile. Here's a little better shot. I carried the taper back to the bolt that is used to mount the bedside. I originally planned to take it all the way back to the wheel well, but it was a difficult bend to make on my homemade brake. IMG_0399.jpg

Edited by ECS620
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Thanks Tank. Big day yesterday. The parts truck got hauled off, meaning I have everything I need to get Ol Blue back together. Engine comes back from the machine shop this week and hopefully in about a months time I'll have nice enough weather to start the body work on the bed and get this girl in some fresh paint. "The end" is in sight! Or at least, there's light at the end of the tunnel.




Little sneak peak at what's next to come:





I caught the junk-car Datsun bug. A 1978 280z with factory AC and a 5 speed. Found this gem locally, its complete minus the wheels and the 5 speed. Pretty straight too, it was involved in a front fender bender, parked, and partially cannibalized before someone lost interest. No rust in the battery tray, cowl, rear hatch, or spare tire area. Passenger floorboards are toast, someone patched the drivers floor boards, and the floor support "frame rails" are still solid on both sides. Interior of course needs some work. $550 delivered to my shop!


I picked up these OZ racing wheels (15x6) and new tires (195/60/15) for it last night for $125 of Craigslist, so now shes a roller! 




She'll be delivered this weekend and will get her own build page. If I'm not mistaken, the 4 speed I swapped out of the 620 will bolt up to the L28E in the Z right? I plan on locating a Zcar 5speed eventually, but something to mount a starter too and get the L28 to turn over would be nice in the mean-time.

Edited by ECS620
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  • 4 weeks later...
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Got the motor back from the machine shop, assembled and tossed back in. Remember to chase those threads before reinstalling the head! They had a ton of goobers despite the hot tank.















I MIGHT be able to try and fire it up this weekend. Fingers crossed the weather holds!

Edited by ECS620
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  • 2 weeks later...

@sick620 The photos should be fixed now. I tried to cheat and just copy paste, but it looks like it only showed up on my browser. Didn't get around to doing much on the truck since the last post, but I primed the oil pump and got the dizzy installed.

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  • 3 weeks later...

Its been cold and difficult to get motivated to work in a carport.









But I got the truck plumbed with fuel, vacuum, and coolant hoses and tossed in a shiny aluminum radiator. I also finished most of the under hood wire extensions, and got all the accessories mounted. I wish i would have gone with matte black for the engine bay, but the gloss is growing on me.






I welded an expansion onto the header to mate with the ball-and-socket style collector I purchased. I stepped it up from 1&7/8 to 2&1/2" because it was the smallest collector of this type I could find for a reasonable price. The local exhaust shop says they always use this style when doing custom exhaust and I liked the idea of a gasket-less system.  As low as the truck sits, I don't think I can spare the clearance to run 2&1/2 under the cross member of the frame though.











At this point the truck was ready to start for the first time since the rebuild but I was waiting on a new oil pressure sender to be sure It was making good pressure before I started. The sender unit, fan belt, fuel filter and a new shift knob arrived in the mail yesterday. It was making good oil pressure so I gave a start a try.

It fired on the first try!


I ended up getting the timing as close as possible by ear.


My wife made a new shifter boot for me and I tossed the interior back in too. Don't mind the dust:








There's a cool local car show in the next town in June. I'd like to have it on the road for that. I'm getting eager to cruise again.







And the 280 wants a spot in the shop!






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Here's that first start. Sounds a little rough with the open header but I hope to get it dialed in this weekend. I was surprised it fired off so easy being 35 degrees outside and the electric choke wasn't yet hooked up.


Edited by ECS620
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