Project 720z - 1982 Datsun 720 Sport Truck

[petercscherer]

In this thread, I'm going to simply share the process that I've recently gone through while taking my newly acquired 1982 720 from just being a beater pick-up to being what I consider to be an example of the sport-truck culture of the 70's & 80's. 

Here's the truck when I went to pick it up from the seller's house locally in Lubbock, Texas




I first started by removing those ugly dual exhaust pipes out the back; they weren't true duals, just a splitter behind the cab that ran into two obnoxiously loud resonators at the rear... Super annoying, so I stopped at my muffler shop on the way home and had them go back to a stock-style exhaust system. 

Step one for me was heading to the local Wrench-A-Part for some much needed pieces to get it on the road again. I found a nice 1983 King Cab and promptly robbed the the gauge-cluster, interior package tray, and a dealer-installed rear bumper from a dealership here in Lubbock, Texas.













I was able to combine the original gauge-cluster with the one from the parts truck to result in having the optional tach and clock. Of course, being 1980's electronics, neither one works, but at least the dash looks more "full" now.


Next, I needed wheels and tires; the old ones were badly weather-checked and out-of-round.

So, after locating a set of free rims from a Chevy guy upgrading to huge wheels, I had my local Firestone shop install a set of Firehawk tires. I combined this with a pair of 2" lowering blocks in the rear and releasing the front torsion bars a comparable amount. 

[petercscherer]

It was at this point that I really started driving the truck every single day and it started to come out of its slumber. It seemed to perform okay, but the original drivetrain seemed a tad anemic. One night, I was driving home and all of a sudden I hear a sound like metallic pop-corn coming from the motor; it subsequently started to misfire and stumble and I knew something was not okay. I pulled it into the shop the next day and began disassembling the top-end of the 2.2 Liter engine. 


Hmm, upper valve-train seems fine. No damage, sludge, or broken timing chain.... Let's pull the head off.





I don't believe that valve should be out that far, nor should there be a twisted spark-plug head in the number 2 cylinder. A quick inspection of the cylinder discovered this bugger:


Somehow, this piece of metal had gotten into the engine and had smashed my spark plugs and bent the valves in the #2 cylinder. No idea how it got in there since I'd only had the air cleaner off once for like 2 seconds while inspecting the filter condition when I bought it. I believe that whatever it was had fallen into the intake awhile ago and got stuck in the bottom of the intake manifold until it got sucked out while I was driving and wound up in the cylinder chamber. 

Luckily, no damage to the piston, but that old head/valve was shot. I was able to find a rebuild head on eBay for super cheap and had ordered one and we promptly installed it, as well as a complete upper gasket set. New oil pump and timing chain were also installed at this time.


I'd taken the opportunity to order a Weber carb kit as well as some Pacesetter headers so I installed those while I had the truck torn down this far:




While pulling all the emissions stuff off, I wondered how much of it was actually necessary for the truck to function... Some research online led me to some sources on how to de-smog my truck for a more powerful and impressive engine. Afterwards, it looks much cleaner under the hood and the vehicle now breathes very nicely thanks to the new carb and headers.


Back on the road again, the truck now performs even better and I've instantly seen a 4-5MPG increase in mileage as well as the added power available.

[petercscherer]

But, I couldn't leave it alone for long. The stock bench seat was far from comfortable or stylish, so I began researching around the internet for some replacement options. I read on several different bucket-seat installations, but I didn't like that most were junkyard quality cloth seats, so I went looking for some vinyl/leather buckets to install. That's when I found a 1976 Datsun 280Z in the Wrench-A-Part and I knew I'd found my next project. 


The old materials were super raunchy and worn-out so I took advantage of a clearance sale at The ZStore and picked up an uphostery & foam set and redid the seats over a weekend. The turned out super nice and mounted in with little modifications.


I also re-upholstered the hideous door panels that had previously been done in grey cloth, ugh.....


It was at this point that the truck became more than simply an everyday driver, and is now my baby. I feel the urge to make it the best possible Datsun that I can. So.... I decided to custom fabricate a set of panels to hide the rear of the cab in the interior. Usually, this wouldn't bother me, but I wanted to finish out the interior.
Some sheet metal got bent and molded to fit the cab:


I upholstered them to match the door panels



The end result was then attached to the rear of the cab with industrial Velcro to enable ease of removal if needed.




I also added a center console out of the aforementioned 1983 King Cab parts-truck at this time and I've now also added custom pedals and also some racing stripes. I ended up removing the rear bumper because it made the rear-end seem "heavy". 

[petercscherer]

I then installed a set of Stillen 2" Drop Spindles, 1985 Nissan hubs, rotors, & calipers. I also replaced the rear brake shoes, checked-out the entire braking system, replacing hoses and lines as needed to ensure the utmost safety and performance. 

After installing the drop spindles, I reset the torsion-bars to factory settings, so I once again have a lot of room to drop it more if I want(which I may do, it seems a tad high at the moment). 




I also installed a 1985-era full chrome bumper to replace the damaged rubber-tipped 1982 model. 




I also was dissatisfied with the stock exhaust look & sound. It would sound like your typical 80's import four cylinder at idle, with nothing impressive or distinctive to the exhaust note. It also had a boring tailpipe in the rear, that was stock, but it just killed the performance look I've been going for. So, after researching around for a muffler/tip that will give my system a throaty "rumble", I decided on the DC Sports Stainless Steel Muffler. After purchasing it online and having it shipped to me, I was very impressed with the finish and construction quality. After welding it onto my existing piping, I was totally impressed with the sound and look it brought. This is NOT a fart-can, instead it gives it a rumble similar to a stock Corvette or WRX. 






I have been trying to decide on new wheels for my truck as well, I considered various different Nismo and Jap rims, but they all were going to cost between $500-800. Then I was browsing around my neighborhood Advance Auto Parts and noticed some Duplicolor High-Performance Wheel Paint. I had to source the Bronze color online since local stores didn't have any. After wet-sanding my rims and multiple light coats of both the Bronze and Gloss Clear-Coat, I was left with the result that would've cost me about $700 if I'd bought different rims. I spent a total of $31 for a completely different look. I love it!





Overall, I'm satisfied with my recent updates. I have the look I want, and it didn't cost me a fortune. I recently picked up a 1979 Nissan 280zx with rust issues, but a cherry drivetrain and I'm considering swapping the engine and trans into my 720. I know the engine-bay will get cramped, but I think it would be sweet to have a 140HP 6 cylinder with gobs of torque and a close-ratio 5 speed trans. But that's probably going to come this spring. 

For now, I think I'll mess around with shocks and maybe get 3" or 4" blocks for the rear and maybe bring the front down some more. I really don't want to start bottoming out on speed bumps though... lol

Remember: No matter what you do, do it in a Datsun!

Cheers,
Peter

[flatcat19]

Needs more low. 

[Lockleaf]

Sweet truck. How long did it take you from picking it up to where the truck is now?

[wayno]

Your truck looks good, I would keep it the way it is, I have only seen one straight 6 cylinder build here ever, and the firewall had to be cut.

Here is a link to that 720ZX build, I am happy I was able to find it.

http://community.ratsun.net/topic/64040-720zx-time-to-finish-it/

If I were to do a 720ZX build like the guy in the above link, I would find another kingcab 720 and do it from scratch, but that is just me, I don't ever want to take a running Datsun off the road, especially a nice one like yours.

Here is a photo from that build.

[petercscherer]

Sweet truck. How long did it take you from picking it up to where the truck is now?

It's just about 9 months now. About 2 months of that was sitting in the shop at various stages of disassembly/repair. 

[petercscherer]

Your truck looks good, I would keep it the way it is, I have only seen one straight 6 cylinder build here ever, and the firewall had to be cut.

 

If I were to do a 720ZX build , I would find another kingcab 720 and do it from scratch, but that is just me, I don't ever want to take a running Datsun off the road, especially a nice one like yours.

 

 

I can definitely see where you are coming from, but I just can't justify the cost to purchase a KA24(D/E) and all that hassle when I already have a complete running/driving 280zx in my yard. I am not satisfied with the performance of the truck, it can pop around town just fine, but out here in West Texas, it's all about getting up to speed quickly and sustaining those high speeds on the freeways. So I'm looking for a drivetrain with 150+ hp, aftermarket potential (for turbo, supercharger, ECU, etc...), and it has to be a 5 speed. I'm sick of my current 4 speed and the stock Z22 engine only has about 90-105HP (at best). 

 

I frankly have more time & skills than money right now. However, I'd be open to ideas from the Ratsun community. I have spent countless hours researching 720 engine swaps and I just can't find one that fulfills my goals. :/

 

~Peter

[flatcat19]

The headache/cost of a KA will be saved vs. the headache/cost of trying to fit an L6. 

And you'll already have a more powerful base with cheaper/more reliable support to build upon. 

 

 

You could LZ your current motor for an increase in power too. 

 

Fuck it. VG30 is doable as well. 

[petercscherer]

Fuck it. VG30 is doable as well. 

Hell yeah, VG30DE is still one of the most eye-appealing motors Nissan ever made. I'm in love with it's symmetry! Unfortunately, the cheapest ones I can find are from JDM engine importers for like $1,200. I also have ZERO idea how to wire one of those. I can figure out 240-280z wiring, but the more modern systems are a bit baffling to me at the moment. Man, if I won the lottery though...

~Peter

[flatcat19]

DE would be unlikely. E is doable. 

 

 

 

 

Look into building LZ22/LZ23s. Cheaper than all, by far. Good power. 

 

Or, KA single cam head on your Z22 block. Easy to wire in with a can-am box. 

[Charlie69]

Buy a whole truck for the VG30 swap that way it cuts down on the extra parts you will end up needing.

[flatcat19]

^ That.

[petercscherer]

After tiring of having my original wheel falling apart from normal use, I bit the bullet and acquired a replacement. I'm super happy with the results!

 

The progress continues... Hopefully I'll have big news in the next few days. ;)

~Peter

[petercscherer]

Here we go!!! 

 

I wonder what could be inside????

 

Oh yeah!!!

 

I'm sure that's not what any of y'all was expecting. You're probably wondering why I'm not going KA, SR, or CA.... Well, let me explain:

1.) This is a 1.8L Mazda Miata 4 cylinder putting out 135hp stock with potential for much more.

2.) There's a huge aftermarket for the Miata drivetrain, which should make upgrades easier to plan-out.

3.) Miata engines are already rear-sump oil pans, so there's no need to modify it like a KA or SR requires.

4.) The Miata 1.8L is incredibly light and compact.

5.) I've spent the past 3 years driving NA Miatas and I've become accustomed with their mechanicals and aftermarket.

6.) The Miata transmission is one of the best in the industry and has perhaps the smoothest and shortest throw of any Japanese 5-speed.

7.) I'm the kind of guy who wants to be different. :)

 

 

So, plans from this point on is to tear the engine down to the basics, and replace the water pump, timing belt, etc... I'm not planning on adding a turbo or supercharger (yet), so I'll get it all re-assembled N/A with updated exhaust, clutch, and more.  

 

So far, the engine looks to be a real "low-mile" import from Japan. No signs of damage, wear, or misuse. Transmission shifts smoothly, and the clutch didn't seem abused at all. Compression is good in all cylinders and I'm going to soldier on with the build. I apologize for the blurry photos here, I promise the future images will be much sharper/cleaner.

 

~Peter

[flatcat19]