Trevor's 1977 620 Project "KNGCAB"

[TrevDaddy]

Feel’s good to be back. 

 

First joined Ratsun in 2009 as an automotive tech school student with a really solid 73’ 620 that served as my very first project. I loved that truck, and got to enjoy it for about a year before I unfortunately crashed it and had to sell it off for parts. It was painful, I was young and naïve and didn’t truly appreciate what I had. Even though it didn’t work out with my first attempt, it solidified my love of old Japanese cars(especially Datsuns), and I’m thankful for that. 

 

After school I moved to Chicago for a couple years, then eventually back to Saint Louis where I landed at my current job. Girlfriends, a lack of a garage, and several life changes didn’t really encourage a project car throughout that time so most of my money went into my daily driver GTI which I autocrossed occasionally. 

 

Fast forward to 2020. I bought a house about a year ago with a tiny, yet usable garage. With COVID and the general shittiness of this year, I decided this was the best time to get a project and what else would be better than another Datsun?😁

 

This time around, remembering my 6’ 3” frame crammed into my old 73’ I decided I should probably look for a KingCab. I initially found a 77’ in Illinois at a classic car lot. It looked decent, but had a tired interior and a 4 speed, and they were asking a bit too much for it. I slept on it for a week, called before going to look at it, but it had sold. Finding another one in the Midwest was going to be tough, as decent ones just don’t show up too often in my area. Not getting discouraged, I remembered that most of the solid Datsuns were all up in the PNW so started looking more there. Luckily, I have friends in Bend, OR and it all fell into place. 

 

I found another 77’ KingCab on the Eugene, OR craigslist. It was the right price, had a bunch of choice upgrades, and wasn’t too far from my friends. I got in contact with the owner, agreed on a deal and started the process of buying the truck. It just so happened that my friends in Bend had to make a trip to Eugene to drop off a car anyway (stars aligned lol). They drove out, bought the truck, then drove it 3 hours back to Bend unscathed! 😄Awesome people, and the truck already had a cool story behind it. Shipping it back to Saint Louis wasn’t cheap or without some confusion, but was the best choice given my situation. Finally, after nearly a month since I found the listing, a Brick Orange 1977 Datsun 620 KingCab was sitting in my driveway. 

 

Here she is the day I brought her home! Banged up a bit, but absolutely solid body, no structural rust at all! Floors, rockers, bed, and frame have surface rust only. L20B, recently refreshed W58 head, Weber 32/36 DGEV, FS5W71B 5 speed, new carpets, Mini Cooper bucket seats, 4” lowering blocks/indexed torsion bars, 18” 6-spoke Titan wheels, KYB shocks, new back and side glass, and a bunch of other new parts. Oh yeah and the dash isn’t cracked to hell! 👍

 

The immediate plan is to refresh a few things, do some general maintenance, and just generally modernize the truck a bit. Down the road I’ll address all the bodywork and paint, and eventually convert to coils and either KA/SR or K-series Honda. Progress will be slow as I’m trying to budget, but I’m stoked to share my new project with you guys and hopefully learn a bunch moving forward. Onto the pictures!

[TrevDaddy]

Update 1

 

Since the truck was delivered, I've addressed a few things. I replaced a few bulbs and got it registered and insured. The fuel filter was pretty nasty, so I replaced it also noticing a few particulates in the new one after running the truck. I'll have to drop the tank and get it cleaned out and re-sealed in the future, but it’s fine for now. 

 

I did an oil change with 10w-40 Mobile 1 and a Napa Gold 1515 after hearing that recommended here. 

 

I won’t knock people for running the Titan wheels on their trucks, but they just aren’t my thing. Not only that, but they made the ride pretty harsh and I wanted more sidewall and a period-correct look. I settled for a set of U.S Wheel Modular 94. Bought them from Summit for around $400. Unfortunately one of them came with a hole in the barrel as if the machine weld was just missed in that spot. Got another one shipped to me for free, so I’ll keep the defective wheel and have it welded later and keep it as a spare.👍 Tire choices were limited, but settled on a set of 205/55/R15 Kumho Ecsta 4x II all-seasons. Kumhos have worked well for me in the past. 

 

The fitment is almost perfect with just a rub here and there over bumps while turning. Not too shabby. I’ll keep this set on the truck for a while until I can get some real JDM 3-piece wheels in the future.

[klam07]

Awesome looking truck! Such a unique color.

And I'm a hard yes for replacing the titan wheels!

[Crashtd420]

Nice truck ...

One recommendation you said you used mobile 1 oil.... you need an an additive to go with that..... the newer oils can actually ruin and old flat tapet cam....

I think the mobile 1 is synthetic,  most dont like synthetic on these old truck because it can leak a little easier on an old motor....

I believe the recommendation is to use something like rotella oil for a diesel motor..... 

If you like synthetic go with the royal purple hps ... has extra zink and phosphate for flat tapet cams....

[Crashtd420]

Zinc additive 

https://shop.advanceautoparts.com/p/rislone-hy-per-lube-by-rislone-zinc-zddp-supplement-11-oz-4405/10380239-P

 

Royal purple, just to show the product, you can find it cheaper... 

https://www.walmart.com/ip/Royal-Purple-HPS-Synthetic-SAE-10W-40-High-Performance-Motor-Oil-with-Synerlec-1-Quart/126716088

 

Some one will chim in about the rotella , I use the royal purple myself

Edited October 25, 2020 by Crashtd420

[TrevDaddy]

3 hours ago, Crashtd420 said:

Nice truck ...

One recommendation you said you used mobile 1 oil.... you need an an additive to go with that..... the newer oils can actually ruin and old flat tapet cam....

I think the mobile 1 is synthetic,  most dont like synthetic on these old truck because it can leak a little easier on an old motor....

I believe the recommendation is to use something like rotella oil for a diesel motor..... 

If you like synthetic go with the royal purple hps ... has extra zink and phosphate for flat tapet cams....

 

Thanks @Crashtd420 for the recommendation of Royal Purple/Zinc additive. I'll be sure to pick some up soon. I've only driven it 50 miles or so on the Mobile 1 so I should be alright.

 

Update 2

 

Engine was running ok, but a noticeable ticking noise was coming from the valve cover. I found a few tutorials on valve adjustment for l-series motors (the best ones were for Z cars, same rules apply but with 2 less cylinders) and went by that. Ground down one of my 14mm wrench and used a skinny feeler gauge which helped a ton. 7 out of the 8 valves were out of spec! Some were several thousands out. The plugs passed visual inspection so I reassembled everything and took it for a drive. 

 

Engine runs so much smoother now. No more ticking noise and it seems to idle a little lower which was good. I still need to tune the Weber a bit as she runs a little rich at the moment.

 

I have access to a 2-post lift at work and noticed that my center support bearing rubber was crumbling apart. I thought this was the source of a metallic banging noise that I was hearing at lower speeds (turned out to be something else that will be fixed later). Regardless, it needed to be repaired. Shout out to @datzenmikefor the recommendation to just replace the rubber and not the entire bearing assembly, as the latter would require the driveshaft to come out and partially disassembled to replace the part. I found a 10ft section of 1/16” rubber strip on amazon and bought two of them. This ended up being the perfect solution as it took both lengths to finish the job. I cut away as much rubber as I could *see picture* then cleaned the bearing up and started wrapping. This was relatively tough at home in the garage as it was a balancing act to rotate the bearing while keeping tension on the rubber strip and lifting the driveshaft all at the same time. I also wire wheeled the bracket and gave it a coat of black paint while I had it apart. I’m happy with how it turned out. 

 

Also threw in some new hood rubber bumpers as the old ones were dried out and really crusty. 

 

Glad to be wrenching again!

 

 

[datzenmike]

Trev... if you would, don't use BOLD print. We're all equal here.  Font Arial and size 14 in black, thanks.

 

 

While synthetic oil is usable, it's overly expensive and gives protection you will never ever need. It's for use in newer engines that have tighter clearances, run close to boiling temperatures and even normally aspirated make twice the HP your L20B does. I found out the hard way that it will leak past older seals and gaskets.

 

That said don't use today's regular oils either as they have reduced ZDDP in them compared to the oils that were around over 50 years ago when your engine was first designed. You can safely run light diesel oils that are exempt from the decreasing ZDDP levels, such as Shell Rotella T4 10w30 or 14w40, Chevron Delo 400 is also good and there are others. All can be found universally and cheaply.

 

ZDDP is an anti scuff zinc additive used on flat tappet engines like diesels and offers proper protection on our rocker on cam engines. Today's designed engines don't need it and the zinc is harmful to the catalytic converters so oil makers are slowly phasing it out. Oil manufacturers say it's reverse compatible but it's up to you if you use it, but I wouldn't take the chance. Once your cam and/or rocker arms are damaged they are ruined.

[Crashtd420]

3 hours ago, TrevDaddy said:

 

Thanks @Crashtd420 for the recommendation of Royal Purple/Zinc additive. I'll be sure to pick some up soon. I've only driven it 50 miles or so on the Mobile 1 so I should be alright.

 

if you only drove 50 miles I wouldn't worry to much, but I would definitely go grab a bottle of the zinc additive and put that in before driving it more...

[RJRACIN240]

Cool looking truck and welcome back to Datsun's, couple of things, that was a lot of work for the center bearing. replaced mine and believe the bearing with center mounts was less than $40 from RockAuto.

Those rims look cool, but definitely would suggest some longer studs as in the picture they look like they do not engage the lug nots all the way, not sure but the Nissan quest ones work good on a 240Z, guessing they will work good on your truck as well

[TrevDaddy]

5 hours ago, datzenmike said:

Trev... if you would, don't use BOLD print. We're all equal here.  Font Arial and size 14 in black, thanks.

 

 

While synthetic oil is usable, it's overly expensive and gives protection you will never ever need. It's for use in newer engines that have tighter clearances, run close to boiling temperatures and even normally aspirated make twice the HP your L20B does. I found out the hard way that it will leak past older seals and gaskets.

 

That said don't use today's regular oils either as they have reduced ZDDP in them compared to the oils that were around over 50 years ago when your engine was first designed. You can safely run light diesel oils that are exempt from the decreasing ZDDP levels, such as Shell Rotella T4 10w30 or 14w40, Chevron Delo 400 is also good and there are others. All can be found universally and cheaply.

 

ZDDP is an anti scuff zinc additive used on flat tappet engines like diesels and offers proper protection on our rocker on cam engines. Today's designed engines don't need it and the zinc is harmful to the catalytic converters so oil makers are slowly phasing it out. Oil manufacturers say it's reverse compatible but it's up to you if you use it, but I wouldn't take the chance. Once your cam and/or rocker arms are damaged they are ruined.

 

Sorry about the bold, I was copy/pasting and it messed with the format. The truck was leaking a bit from the rear main when I got it, and I'm sure I'm not helping with the synthetic I went with. I realize now that the Rotella or Chevron route is more appropriate and I'll switch to that next time around. For now I'll put in some additive and keep the miles low (easy in the winter). I want this L20 to last so thanks for the info Mike. 

 

2 hours ago, RJRACIN240 said:

Cool looking truck and welcome back to Datsun's, couple of things, that was a lot of work for the center bearing. replaced mine and believe the bearing with center mounts was less than $40 from RockAuto.

Those rims look cool, but definitely would suggest some longer studs as in the picture they look like they do not engage the lug nots all the way, not sure but the Nissan quest ones work good on a 240Z, guessing they will work good on your truck as well

 

I definitely eyed the replacement from rock auto before doing the DIY version. The problem was that I was unsure about the diameter to go with as they had several options available for my model year truck. I'm happy with how snug everything is, and it should las a long time. Thanks for the suggestion on the lug studs. I was just working with what was on the truck when I bought it. I'll add that to the list. They all have a good amount of threads engaged and are torqued to spec.

[demo243]

Nice looking truck!

 

Dig the new wheels!

 

Everyone has their oil preferences... hahaha. I love mobil 1 but only in my Tacoma. For the dattos I use Valvoline VR1 racing oil- it has the extra zddp in it- just another option for you. The diesel oils might be cheaper. I don’t really need to use it anymore since I’m KA swapped in both... but probably still will.

Edited October 25, 2020 by demo243