1972 240Z Rebuild

[Strat067]

Getting closer to caught up on the build. Picked up a L28, F54 block. This will eventually will be built. Picked it up with a close-ratio five speed for a good price. The transmission I rebuilt, I will detail that later. The engine will sit for awhile, maybe next year. 

[Strat067]

Some great shots from two different cars and coffee events here in Minnesota. There are a total of 4 orange 240Zs (one not shown) in the twin cities that I know of, not sure if orange was just super popular locally, or globally, anyone know production numbers by color?

[Strat067]

The steering and suspension were pretty bad in the car, most notably the steering. Lot of play in the wheel and there was alot of drift driving straight. So i decided to rebuild the front steering rack:

Off the car, boots removed:

Tension busing (or whatever its called) out:

Steering shaft seal out, this grease was disgusting, and the bearing wasn't great.

Old and new seal I sized up at NAPA. It doesn't have the steel dust shield, but I don't think thats too much of a loss:

Everything removed:

Used my press to pop off the old steering gear bearing:

Sandblasted everything:

Primed and painted:

I don't have any reassembly pictures...so maybe this was a pointless post, sorry...just figured I would post all the pictures I had. The rack was put together with a new bearing and seal, new tie rods and boots. Also a new steering coupler bushing and the bushings that mount the rack to the cross-member. 

All of this is still a backlog, work done in the past, so I apologize for not having more pictures. 

 

Edited January 14, 2018 by Strat067

[Strat067]

As I continued to drive the car I fixed small issues as they came up. It was really great to slowly improve the car as I drove it more. I know if I had just stripped the car to a bare chassis in the beginning, there would have been a few things I just wouldn't have caught to fix during a restoration process. As I drove it I realized the brakes just were not cutting it. I was running the toyota 4 piston caliper setup with the stock 240z rotor in the front, with rebuilt rear drum brakes. The pedal feel was terrible and I wasn't even close to being able to lock up the tires under hard braking. I spent ALOT of time tweaking and slowly upgrading, but I will spare you from that whole process and just show what I ended up with:

I ended up going to a rear disk conversion kit to replace the rear drums. I went with Zcar Depot's kit, as it seemed the most resonable. You could do this cheaper by sourcing all the components individually, but it was really only about $50-$75 more I think to just get the kit delivered. 

Here is everything:

Drilled/slotted rotors, adapters, hardware, some good stoptech pads, SS hoses, and the maxima calipers. 

First Step was removing the old (new) drum brake kit:

In the bin

Parking brake cable removed, and its mount removed as it's placement will no longer work.

I also removed this brake line holder on the strut housing as the hard line from the hose to the brake cylinder is no longer needed

Unless you want to pull the stub axle then the dust shield needs to be cut off. My tools of choice were my angle grinder with a cutoff wheel, and a dremel for the tight spots:

The adapter plate gets bolted in where the dust shield was:

Did a quick test fit with my wheels, no issue:

The stock brake cable fitted up without any modification, just needed a new clip to lock it in (not shown):

Routed the new steel hose:

Loaded up the caliper:

And boom, rear disk swap completed. 

 

Repeated the same process on the otherside. To support the rear brake setup I installed this Willwood proportioning valve next to the master cylinder, and removed the stock proportioning valve that is near the gas tank in the rear. This gave me the ability to fine tune the brake bias to something that felt good.

In the picture above you will also see a set of Hawk HPS pads. The front brakes were not giving me enough bite in the least bit. The pads I got for the toyota calipers were garbage so I wanted to get a set of good pads for a track day event that was coming up. I got those Hawk pads hoping they would work. I did a bunch of searching for good pads for the Toyota calipers, but could not find good information on pads that would fit. I took a chance and ordered those, but they did not fit. If anyone is looking to upgrade to these toyota calipers, be aware that there are no good pad options for them. I decided to go to the track day with the pads I had on the front.

The track day was a blast. I new going into it that I still had a lot of unknowns with the car, and that the suspension was still utter crap. It was a track day at a local college, Dakota County Tech if anyone is Minnesotan. Its a very small track that was built as a training ground for police and tractor trailers, top speed was probably 70mph. It was perfect to get to know the car. y a few bad things happened. The front brake pads, as I suspected, were not up to the task. The brake fade from the front, even when I was only pushing the car to about 60%, was horrendous. I was maybe driving spirited for about 20-30 minutes throughout the day and I almost went through the entire pads, and the rotors were grimed up really badly.

The second bad thing to happen was a small fire on my exhaust. The one fuel line I didn't replace, because I thought it was good, had a pin hole leak that spilled fuel on the exhaust- igniting it. 

So we got trailered home. I was pretty down on myself for not catching this issue, and for taking the car to a track day when I new something like this would happen. It took me a few weeks to even get back into the garage to clean it up and start fixing. But I eventually came around:

The culprit was the hose that goes to the vent shown in the picture above. The picture below shows the issue. The hose portion on the right, that looks new, was what I could see under the car. I saw the new hose and figured that was all good. The portion on the left was the old hose. The previous owner had replaced the hose up to the point it went inside the car. The new hose was spliced in using a heater hose union. The old hose was dry rotted and as I was cornering the car the fuel went up the vent and spilled out the cracks onto the exhaust. I should have caught this, I didn't take the time to take the interior panel out to look at the vent hoses, which was stupid. But at least this happened at the track where i could pull to a corner worker that had a fire extinguisher, and it didnt instead happen on the road. 

Learned my lesson with old cars I guess. Here is the extent of the damage:

Pretty minimal all-in-all. Could have been a whole lot worse...I could have lost my car. 

I don't have pictures, but I replaced the line and double checked all other lines and got it back on the road. 

 

I never said I was smart.

 

 

Edited January 15, 2018 by Strat067

[Strat067]

With that behind me I wanted to get the brakes solid before winter hit, and I moved to the next stage with this project. So I bit the bullet and went to the S12-W toyota caliper, as this did have good options for pads - and would allow me to use the Hawk HPS pads I had already purchased. This caliper also allows the use of the 300zx vented rotor, only helping to make sure I never have a brake fade issue again. 

The Calipers:

One was zinc plated, and that annoyed me...so I painted both:

Loaded with the pads:

The 300zx rotors bolt on with a 20mm (if I remember) thick spacer I got from Silvermine Motors. 

You need longer hardware to bolt the rotor to the hub. I think the spacer was 20mm, and I got bolts that were 20mm longer than stock so I had the same thread engagement into the hub. 

With these on the car the brakes were suddenly amazing. I didn't realize how bad the pads I had previously really were I guess, because the car stopped SO much harder with this setup. 

The last thing I did, that I don't have any pictures of, is installed a 10" brake booster from a 280z. I had to do some enlarging of holes in the fire wall to get it to fit, but it made the pedal feel much nicer. That was the last item in the brakes, I now have a really strong brake setup that I hopefully never have to change again. A lot of these changes came a step at a time. I kept upgrading and changing until I found a pedal feel an stopping power that I wanted. 

[Strat067]

That was the last big work on the car for the summer, so I spent the end of the summer and a good bit of fall just enjoying the car before the winter. Big plans were being made for the winter, so I got as much driving in as I could.

 

Edited January 15, 2018 by Strat067

[grannyknot]

@Strat067 You might think about replacing the rear wheel studs with longer studs now that the brake rotors taking up a good portion of the threads.  You might get away with it if you are just doing cars shows and highway, but if you're going to start pushing it at the track it's good to have a few more threads holding the wheels on.

[Strat067]

6 minutes ago, grannyknot said:

@Strat067 You might think about replacing the rear wheel studs with longer studs now that the brake rotors taking up a good portion of the threads.  You might get away with it if you are just doing cars shows and highway, but if you're going to start pushing it at the track it's good to have a few more threads holding the wheels on.

Not a bad idear, thank you!

[v12horse]

It sure looks like you're having a lot of fun with your Z. I have enjoyed reading about your progress as well as the show and track day. Keep it all up!?

Your car has the look too.?

Ben