Dash The Automatic Express , 70 2 door auto

[Pjackb]

Good luck with the seats, I had my FJ55 seats done here in BC and for the money thought they could have been a bit better, but my first time with upholstery so maybe expecting too much.

The stock 510 texture was very similar to the Landcruiser’s.

Thanks , My guy is pretty good and I know him well

[Pjackb]

With the interior prepped and seats sent to get reupholstered it was time to focus on the mechanical.
List of key upgrades I wanted was; more power, better Brakes, and better suspension.

As I mentioned it was decided early on to keep the car automatic and make it a relaxed weekend cruiser so first order of the day was finding the right transmission , I wont bore you with all the details of my (long) search but there were a lot of evening reading up on the Internet, talking to people across the globe , and read almost every Datzenmike’s post on the matter lol. I will however share some of my key findings in case it can help someone in the future and save them some time.

Fist before any tranny swap(manual or Auto) you want to make you need to read up this issue of DQ (Vol11 Issue 4) , and it will save you a ton of time https://www.jdmjunkies.ch/wordpress/wp- ... cation.pdf. You can search for Datzenmikes post but since he wrote the article most of the info he will share is already there.

There are however a few nuances to some of the auto trannies that someone may find useful.

BW35 (Column Shift 3sp)
This is the tranny that came from the factory in my car and I hesitated a lot about keeping it and keep the original look, but my main concern was around its power handling capability however I now believe that the concern was unwarranted since this tranny is used in much more powerful cars with way more torque . I also found some compatible shift kits out of Australia but Since it would also have needed an adapter from 5 to 6 bolts we decided against it .

3N71B
This is the ubiquitous Nissan Jatco transmission that was in almost every Nissans and Mazda from 1970 to the mid-late 80s , One very important thing to note however on this one is that the 280ZX Turbo use a different yoke size and spline count than all the other Datsun including the NA ZX and you will need a driveshaft from the ZX Turbo or a new yoke (I found this the hard way). The turbo also has a larger Torque Converter.

4N71B (Maxima)
This would have been my transmission of choice with its lockable overdrive but they are impossible to find in Canada and Datzenmike had raised a concern that they might be too wide and would require tunnel modification. I had found a few in the US but since I did not want to modify the tunnel it was a no go for me as I didn’t want to ship one from Texas where I had found the one I wanted and find out that I could not use it. One thing to note on the Maxima 4N71B if you decide to go with that is that the Diesel is the one to get since it has the same ratios as the ZX Turbo version of the 3N71 with a lower 1st and 2nd gear.

In the end because I knew I would be putting some good amount torque with the engine and I had picked up earlier an R180 3.54 LSD from WRX STI I decided to go with a 280ZX Turbo 3N71. I figured the 3.54 would work well on the highway maintaining reasonable revs and the 2.842 1st gear would couple well with the diff for good launches, on the recommendation of my tranny guy I also picked up a torque converter from a regular ZX as he said the stall speed would better match the weight of the car.

This is the tranny when I picked it up.


Ok people lessons learned do not buy an automatic transmission that was stored in a shed for many years (lol), because it was on a shelf and not exposed to the elements I thought it would be ok but we basically had to replace everything internally. I’m very happy with the results and have essentially a brand-new transmission but the cost was quite a bit more than anticipated:

Transmission after full rebuilt








Diff had been checked looked great and was full of oil so we didn’t do anything to it



Time to get at the engine now ,

[Byron510]

You certainly have gone a different route than usual.
And you have a beautiful car, I look forward to reading up on the progress and your first hi-way drive impressions.
Thank you for posting your journey, it’s great to read about projects that go a different route.
Byron

[Pjackb]

Thanks Byron,
My wife gets a bit of motion sickness in vehicles but it's really less pronounced with an automatic so she asked me to keep this one automatic as she will be more likely to want come with me to events and drives. with 4 more manual Datsun to chose from when by myself it was a no brainer .

It's still quite a few months away but for highway drive According to my calculations at 70mph it should turn at around 3500 rpm which is not too bad as long as I'm careful with my exhaust choice and make sure it is not too loud and has no drone .

Screenshot 2023-03-12 135911.png (289.86 KiB) Viewed 265 times

[Pjackb]

Opening up the engine

The fun part of this build really started when we got to the engine as mentioned I had bought this engine sight unseen as the deal was just too good to pass up, it had a decent head, ZX 5speed and 240Z Sus so I figured even if it had issues it was complete and had some good parts so I couldn’t go wrong.

I had shipped it straight into storage for the past 12 months and finally got it out early this year, the first thing I noticed when I did was that the block was stamped Z22 which got me really excited since I had thought I had purchased a regular L20B and ended up with an hybrid engine.
the compression test provided by the seller looked good and we believed we had a regular L20B so we had originally planned to simply do a leak down test and install it as is if the test was good, but given that we now knew this was a more custom build and we didn’t have any history on the engine we decided to investigate a little further and figure out what we had before proceeding any further.

Right off the bat I was happy to see that the intake had been ported to match the larger SUs which is a good thing , and the head had been port matched to the manifold , my understanding is that there not much more you do



We then check the CAM and saw the B and M449 stamping, since I am not all too familiar with L series cams I had to do a little digging but came to find out it was a Shadbolt M449 street cam with a mild 256 duration and .491 valve lift





We decided to remove the head then to investigate further and got another surprise , we noticed the pistons had 4 valves reliefs so they were obviously not stock , we decided to remove one to figure out what they were and measured them to 89mm.



I’m sure some of you would have known right away but again I had to do some research to find out they were Z24 pistons.
We also had noticed some light scoring on the piston and piston walls.




This is where a decision was made to do a rebuild

[Pjackb]

In researching here I had found out that Shadbolt no longer existed but the knowledge lived on at Colt cams so the First thing I did was to get on the phone with Geoff at Colt to discuss the M449 and get his opinion , I explained to him what I was trying to achieve with the build and asked for his recommendation , I was very pleased to hear him say that the M449 and his C.540.S is the perfect cam for a street automatic and the one they actually recommend the most for force induction or automatic cars. He also recommended a static comp in the mid to high 9s
As I’ve mentioned before we knew nothing of the engine so before ordering parts, we started by figuring out what compression we had before dissembling the block ( we had measure the head at this point and had deemed it straight and uncut )









8.1 static comp was really not going to cut it lol, and probably why the previous owner wasn’t happy with the engine , I’ve also wondered if wasn’t turbo at some point but couldn’t find any evidence.

We did some calculations and figured KA24E pistons would bring the comp to somewhere around 9.4 so decided to go with that ,I wanted to have the pistons in hand when I sent the block for honing so I ordered both a set of 89mm and 89.25mm





The engine only needed a light honing to stay with the 89mm and be withing specs so we went with the ITM , one thing to note the pins where fairly hard to get in and the machinist said it was because they’re were slightly misaligned , he caution that he’ seen that often with ITM and recommended to always have them checked he did a slight honing to them and made them perfect , he also made sure all the rods were perfect and added an oil hole to each at the same time

[Pjackb]

The rest of the rebuild was pretty uneventful I got the block back and painted it , I like the Datsun blue but wanted something different so went with VHT Platinum Silver Blue




Everything moves smoothly

https://imgur.com/kK8Zsl6
https://imgur.com/CFRhuBx


And we made sure all holes were properly added to the gasket before closing it up


Since I wanted to make the engine pretty In the meantime I had the intake and exhaust manifolds ceramic coated and the VC powder coated



Final product assembled and ready to go back in

[Pjackb]

Lined up the transmission and engine


and decided to drop everything as one unit


That was very close lol ,


Nicely settled home

[Pjackb]

Alright let me take some time and talk ignition here, I’ve not seen much about the 123 Electronic Bluetooth distributor on this forum.



The 123Ignition system is a line of fully programable electronic distributors and they offer 3 types switch , PC and Bluetooth modes for many brands of car. For Datsun cars they only offer the Bluetooth version and its available for L4, L6 , R16 ,H20 and U20 engines ,
some of the key features of these distributor are :
- Fully programmable ignition curve via Bluetooth
- Programable vacuum advance via Bluetooth
- Rev Limiter
- Vehicle Immobilizer

You can read up more on them here https://123ignitionusa.com/about/

From a personal experience I have been using this distributor for over 3 years now and have one in 2 roadsters (R16, U20) and in my 260Z so it was a no brainer that the this engine was going to get one also. The flexibility and ease make tuning a breeze and the ability to adjust ignition on the fly saves you tons of time on the road or dyno.

Here a couple of examples of ignition curves from two of my engines



And a MAP curve


So as I said I got one for this car but we ran into a small issue , the PO who did the original modification did not use a front plate from an L20 but rather cut down the Z22 and welded it to fit with the L20 head now I don’t know if that created the issue but after finding a longer oil pump shaft and grabbing a distributor spacer we found that the engagement of the distributor to the shaft was minimal and could be of concern. The fix was simple but sharing it in case someone runs into the same thing.

We simply milled 3/16 from the base of the spacer , 1/8 would have been enough and what I would do if that comes up again on another car by the way



And voila perfect fit


Since the carbs had already been cleaned up and refreshed it was time to plug everything and give it a start

https://youtube.com/shorts/7ZEMNZw1zuw?feature=share

[RONSLYCHUK]

The engine sounds and looks great. I like the colour.

[Pjackb]

The engine sounds and looks great. I like the colour.

I'm really happy with how it turned out and the response ,
Keep in mind this video is first start not even tuned yet

[Pjackb]

Started working on my exhaust system , since the primary focus for this car is relaxed cruising I want to have a relatively quiet system without compromising too much on performance .

To that end I selected to go with a stock 4-2-1 Manifold , 2” pipes into a Vibrant resonator and Magnaflow Turbo muffler.
I have read multiple time that the stock manifold is good for up to 150hp only but to be honest I think it should be more than that when you consider that the primaries are at least 1.5” and the secondaries are 1 5/8” most exhaust shops I’ve talked to say they should support past 200hp with properly configured system and they all recommended longer than stock secondaries. This was ok with as the down pipe on the car was shot and needed replacing,

We started by taking some measurement and had 2 lengths of 36” pipe bent to the angles we needed, the originals are 1 5/8 but I bought 1.75” since 1 5/8 is almost impossible to find and the bends would crush the pipes some anyways



At first I had planed to use the flange from my originals but in speaking with a few people I found an already made flange that we used to mount them

Started by tacking one on to get our measures and final angles




Made some adjustment cut to the second tube.



Once the two tube were set to the right angles time to join them






And test fit everything.



We added a piece of 2” pipe to weld in the O2 bung and do final fit test.



I added a 2-bolt flange and sent everything to get ceramic coated.

[Pjackb]

As I mentioned earlier when it came time to install the driveshaft and diff I had a little surprise that the yoke on the ZX turbo was a different size and had to scramble around a bit to get things done
I located an auto ZX drive shaft and bought that hoping to use it but was surprise to find out they are very short an would need an extra 13.625” to fit , the original 510 shaft was around 6” too long.



So the easiest thing to do was to cut and machine the flange from the ZX and have it welded and balanced to the 510 shaft and we were good to go



Installing the Subaru LSD was a breeze as I had previously purchased one of the last set of CV Axles from Datsunrestomods

[Rush]

[Pjackb]

While I had the engine out I did take the opportunity to clean up the engine bay as well as steering and suspension components.
I think I mentioned that this car was regularly shot with rustproof during prior ownership it’s great as it preserved the car and made component very easy to remove but there was a ½” thick layer of semi hard crud everywhere lol.
The engine itself had the typical oil spills but really was not too bad and as I said I did plan on a repaint so we just made it clean

Started by cleaning as best we could with some paint stripper and degreaser






I had the local shop do a paint match and put on a few coats with 2K clear to make it nice and pretty , also painted the lines black


At the same time we had removed everything and sent the parts to get blasted and powdercoated satin black which we then installed with all new bushings






I’m quite pleased with the results