1973 Rebuild

[Matthew Abate]

Alright, the suspect carrier is in a vat of oil and the new one is in. This one has fewer miles on it anyway, so I’m looking at this as a glass half full situation.

Once I had everything ready to go back in I put fresh bearings on the new carrier and new seals in the case, which is what caused this most recent delay. 🙄

Figuring out how to torque the ring gear bolts without putting it in a vice was fun. The key ended up being an oil filter wrench with a reinforced rubber strap. Two people can do it, three would be better. They need 78 foot pounds on the Subaru diff (probably the same on all “K” r180s). They are only 50 to 58 on the Datsun (probably because they have lock washers).

Luckily I had the right mix of shims to get the backlash within tolerances (0.1mm to 0.2mm).

Major obstacle out of the way!

Edit: I forgot to mention the Ron Tyler style differential arrestor. Not much to say about it other than I was surprised how much of the bushing had to be removed to get the r180 to fit. I only had two notches to go before it was all the way to the hilt. I’ve seen these where there was a gap leftover but they must be using a different bushing. This one is pretty compressed. This isn’t going anywhere.

***

So now the differential is in. My 240z now has a limited slip… sort of. It’s a Torsen, so not a true LSD, but I’m thinking this is the most drivable option given it behaves like an LSD under power and like an open when you let off (open into the turn and closed out of the turn). 

***

This was perhaps unnecessary, but Nissan added this transmission mount shield when they designed the 280ZX/S130, so it is probably not a bad idea. It’s not like it weighs a ton.

[grannyknot]

I've never seen that transmission mount shield before, nice addition.

[Patcon]

I wonder what it's shielding from?

[Matthew Abate]

Couple of updates..

Other than the half shaft, the drive train is complete.

Restoring the driveshaft was simple. I had read somewhere that the u-joints are NLA, but I found them in two seconds at Z Car Depot, so I don’t know what that’s about.

 

***

I swapped the flange from my Datsun diff and put it on the Subaru way back, so it went right in.

Hanging the rest of the Spirit Garage exhaust system really felt like reaching a summit. Maybe it’s because now everything I need to do start the car is in the engine bay, which feels more doable conceptually.

The system went in really easily except for a few minor things:

The hanger tab in front of the muffler is about an inch too far forward, so I had to put a bolster on the bolt to take up the slack. I don’t love how it looks so I plan to get two that are half as long. That should clean it up a little.

The pipes hang a little low at the differential crossmember. I had expected them to tuck tight up into the relief on either side of the, but if I lift it any higher it hits the differential. That’s a little bit of a bummer, but it’s similar to what I’ve seen on some others.

Also, the exhaust tips are a little close to the rear valance. I could get different hangers, but I think it will be okay. Still plenty of time to think about that.

For hangers I opted for some universal pieces from Walker Emissions (36273 and 36274) that I just cut to an appropriate length.

So now I just need some stainless clamps and some acorn nuts to protect them from random debris.

Now back to the engine bay.

Edited January 7 by Matthew Abate

[Matthew Abate]

I took a break from the car to do some self care and get my mind in order by getting my tools in order. I bought myself a few packs of Toolbox Widget organizers, and so far they are doing the job. The box doesn’t hold quite as much now, but I also don’t have wrenches and sockets sliding around all over the place and piled up on top of each other.

Putting a layer of anti-slip foam on the bottom first really helps it feel slick. Not sure how I’m going to keep the dust out, though.

…

So you may remember that I was having a hard time adapting the 240z coolant routing to having Mikuni triples because that eliminates the carburetor warming channel that connects the bypass tube to the thermostat housing. I had experimented with just running a stainless steel tube in place of that system, but it fouled the manifold and front carburetor.

After much back and forth with various thermostat housings I found that the early ZX housing is the one I wanted. It has many extra ports, but these can be plugged with various fittings. The hardest one to find is the 1/4” BSPT, but McMastercarr had them.

Next I tried a few different Nissan fittings that are 1/4” BSPT male to a 3/8” hose barb. I found the 105° angled one to work best for clearing the distributor.

Then I found a 280zx bypass tube, which more or less mounts right up, but because it is meant for the fuel injection system I had to remove approx. 9” from the side that wraps around the thermostat and put a new bead at the point where I cut it. It also needed some spacers to change the geometry and allow it to clear the temperature sensor and point the tube at the 3/8” fitting mentioned above.

After that I needed a ZX water inlet with the 3/8” tube coming off the threaded adapter that connects to everything already discussed. That has a 5/8” tube pointing back to the heater hoses, so I had to replace all of my 3/4” hose. It also meant going full ZX with all of the fittings and getting rid of the 240z y-pipe. I had to find a coolant regulator/check valve, which is nearly a unicorn part. I know seller with some that are NOS in the box, and normally I wouldn’t go with used parts on a fresh engine build, but I’m not paying $175 plus shipping for something I can get for $30 in good used condition and is essentially just a 3/8” tee with a check valve.

The coolant system is now closed. After much trial and error and purchasing too much hose, I have the whole system plumbed and clamped.

I only used one of the OEM 240z hoses, and I cut it down significantly. They wouldn’t have worked at all with the Vintage Air system I have, so I put a pair of their bulkhead barb to threaded fittings coupled to their 90° barb fittings. I bought a pair of Continental hoses with a bunch of turns from Summit Racing, which allowed me to keep everything under the dash pretty snug. I was worried I would need to make a bracket for the heater control valve, but it’s floating pretty far from everything so it should touch anything even with a huge amount of vibration.

So now I just need to check all my fasteners and get a radiator overflow tank. Next is decide whether to move on to the fuel system or put the AC lines in.

Edited February 4 by Matthew Abate

[Matthew Abate]

Okay. Time for an update. I’ve done a bunch of random stuff, mostly on the dash wiring, but here and there with other stuff…

First, I e been working on the AC lines. I went around and around in this one, looking into making stainless line, then buying the Godzilla kit, and then buying Vintage Air hard lines. I ended up settling on a mix of hardlines and Aeroquip E-Z Clip hoses.

”Prototypes (i.e. failed attempts):

AC hard lines for inside the cabin are in, but ugly. This one was a pain. I went through several pieces until I got the lengths and bends right, and even these aren’t wonderful, so I’ll redo them one more time.

I opted for Vintage Air U-Bend-Em aluminum hard lines because stainless was going to be far too expensive and the hose options I investigated didn’t quite cut it. These fit okay, but you can see the -06 line is too long and I had to cram it in. I got another so I could make them fit better. It’s important because right now they are pulling on the lines they connect to in the engine bay.

The firewall insulator is OEM from eBay. It’s in pretty good shape considering its age.

• • •

I’ve also been scrounging up my relays, which I talk about in my wiring thread.

The fun one to find was the seatbelt warning buzzer and the three wire door switch, but I was able to find them after a lot of direct messaging.

I’m not 100% certain all of these relays are good (still testing), but I cleaned up the best looking pieces from my pile and assembled them a few weeks ago.

• • •

The wires for the dash harnesses are all cut, spliced, and zip tied, so the next step is test fitting them in the dashboard and marking where they will get cut for the terminals. I won’t be wrapping these until I know everything works, so that’s a ways off.

They look like a mess here, but they’re simpler than they could have been. They’re pretty heavily modified, with the stereo and antenna deleted and add provisions for various new components like footwell lights and USB-C plugs. All of the splicing and positioning has been checked and verified against the diagram I made as well as the original harnesses. The wire is heavier gauge and marine insulation (yes, overkill). Will it fit? We will find out.

Why? Burnt wires, the PO used a harness for an automatic in a manual car, I wanted to incorporate the fuel harnesses into the dash harness, and to make it fresh.

That right there is over a year in the making. Glad it’s over.

• • •

Now on to the engine bay.

Carb-side AC lines are done! The hose for the other side is in the mail, so I’ll knock that out soon.

You can see the prototype of the hard line in the photo above. There are two problems with it: the max length is 72 inches, which is about two inches too short to get a nice clean routing, and about six inches too short to tuck it away and make it discreet; and the end is just slightly wrong for the R32 Skyline AC drier/receiver in the last photo in this sequence.

I like that drier too much to switch it out and I’m uneasy about modifying the end of the line and potentially not getting a tight seal, so hoses it is!

The hose for the E-Z Clip system bends tighter than regular AC hose, but it doesn’t bend quite as tightly as I had hoped (it’s rated at a 2” radius for the -08 hose) so it gets weird in a couple of places, and I’m still unsure if these Danfoss E-Z Clip fittings are going to be air tight. We will find out when I try to charge the system.

You can barely make out where I sleeved the hose at points where it might rub on something. I used three layers of heavy duty shrink wrap for this and I think it looks almost like it’s supposed to be there. All I need to do with these, though, is add a hose separator that is the right size to keep that -08 hose from flexing too much. I have two of them in the mail to me now.

• • •

I installed the fuel rail for the triples the other day. This was surprisingly involved. I thought I would just slap it on and call it done, but there were several barriers; nothing crazy, but time consuming and requiring thinking it through.

I had intended to use the empty M10x1.0 holes that are next to the M8 manifold mounting holes, but the rail brackets aren’t drilled for that, and the manifold nuts are too close. I tried a bunch of different workarounds but in the end it was easier to use the manifold studs as the mounting points.

To do that I had to use longer studs, which meant grinding some relief into the manifold. I REALLY didn’t want to do that, but I caved and broke out the Dremel tool.

Was I paranoid I was going to pierce the runners? 100%

But I didn’t. I switched to hand files after a while just to make sure I wasn’t going through it too fast. All those years of model making have paid off in writes on this car.

So once that was done I put the thing together and realized these rails are meant to go with electric fuel pumps. I have a NOS mechanical pump on this car and I worked too damned hard to find it to go dumping it for this, so the rail got a trim and beads rolled on the end. Looks like it’s supposed to be like that now.

After that I just had to tweak the bends to make sure it cleared everything and it’s good to go. Now to figure out the fuel hoses and find a fuel filter bracket.

• • •

So the big question now is…

HOW TO ROUTE THE FUEL LINES?

I would like to use the return line, so I would need to send the fuel back to the other side somehow. Right now I am leaning toward installing my Mikuni cooling bodies and running a line across the front of the engine under the coolant line, but I’m trying to think of something more elegant.

Edited May 13 by Matthew Abate

[Matthew Abate]

Some progress:

Reboxed all my parts. It really drove home how much work I still have in front of me.

•••

Wrapped up the remaining AC lines. Pretty pleased with how these turned out. Hopefully they don’t have any leaks! 

•••

Refinished and rebuilt my gauges. I matched the green to the inside of my clock rather than the blue from the gauges because the clock was in the best shape. Is it correct? ¯\_(ツ)_/¯

I used warm LEDs, which helped to knock back the intensity of the color. I’m still investigating PWM options to control their brightness.

•••

 

Added some filter screens and cooling bodies to my carburetors.

•••

Made some hose retainers for the fuel lines with a friend’s CNC machine.

•••

Wrapped up the fuel lines. I may make a rail to clean up some of those cooling body hoses, but it will work for now.

Edited June 30 by Matthew Abate

[Patcon]

That's good progress! How close are you to being ready for startup?

[Matthew Abate]

2 hours ago, Patcon said:

That's good progress! How close are you to being ready for startup?

Thanks!

It depends on whether or not I make the dashboard wiring harness a blocker. If I don’t then I only need to jump some wires in the engine harness, make battery cables, fill the radiator, and bypass the heater. I have everything necessary to do those things, so I could theoretically finish all of that in a week.

I also need to decide if I am going to fill the gas tank now or have the supply come from an external tank.

Oh, and I need to get the transmission into neutral without having a shift stick, clutch cylinder, or clutch pedal in the car.

Edited June 30 by Matthew Abate

[Patcon]

I would start with the external tank, I believe. One less variable.  Once it runs properly add the main fuel system and pray you get the same result

[Captain Obvious]

What he said. In fact, I wouldn't even deal with a tank... I'd just fill up the float bowls with a piece of tubing and a funnel.

Round tops will run the engine for 30-60 seconds before the bowls get sucked empty. I would hope that your carbs would be in the same ballpark.

[Patcon]

My thought process was a temp tank close by, especially if it's close to fender level, makes it easy to prime the fuel pump and verify it's functioning