Well after spending the past month in the "Help Me!" section, my 1975 280z lives! I figured it is a good time to start a build thread in the proper section to showcase my next steps.

Lets see, where do we start? The story goes that this 1975 280z was an Arizona car for the majority of its life. The owner parked it sometime around 1993 (last registered tags) due to an "ignition issue". It certainly looks the part for sitting nearly 30 years. Odometer says 80k miles, but maybe this is 180k? Looks like it was the silver blue originally then repainted, and finally the fading took over. The engine turned freely and nothing seemed to be seized. It was a clean title and only missing the key, an easy fix.

Towed it home:

And parked her to start tearing into it:

The interior was coated in a nice layer of dust, the window was cracked down a few inches...so the weather made its way inside. The ECU was indeed on the chair like that!

The speedometer was unreadable from the dust! But its all there which was nice.

These cards will need a full replacement:

 

Found some cool discount tire receipts from 1989 🙂 

 

And the color it was SUPPOSED to be!

 

 

Edited March 30, 20214 yr by Barefootdan

First order of business was to clean out the interior. I tore out all the panels and carpet to see what we were working with.

🤢

Drivers footwell has a few holes of rust:

 

But the passenger side got the metal cancer pretty badly:

This will be addressed at a later date, but its nice to see what I am working with.

The trunk wasnt too bad, just some surface rust and that original blue:

 

 

Some cleaning while I waited for parts:

Maybe the dust acted as a UV Barrier 😂

Dash is out, cracked and crusty. I'll be ordering a new cap soon:

 

But for now, some elbow grease is good enough:

 

Misc panels after a nice scrub:

 

 

 

You should just do a light sanding and a clear coat on the exterior.  It has character.

Next was to see this girl run! Even the engine bay has a nice coating of dust on everything! Luckily the previous owner capped the intake, I think they knew it wasnt going to run for a bit:

Here is the bay after sourcing an AFM, coil, plugs, wires, battery, starter, and some new fuel lines. The oil around the valve cover is from the missing 4 or 5 valve cover bolts! Started to seep as soon as I filled it. It didnt bother me as I knew we would be diving deeper soon.

 

This is when I joined the club and started to walk through all the electrical gremlins. @Zed Head was a huge help walking me through the FSM and EFI bible. We encountered numerous loose connections, all 6 injectors were bad, fuel pump needed replacing, redid the fusible links, etc. But we got it running! After nearly 30 years, its back to life:

 

 

Unfortunately cylinder #3 had 0 compression. a valve adjustment yielded no improvement. Maybe this had something to do with that? Found this guy in the trunk. I've never seen this before! 

 

 

 

So OFF WITH YER HEAD!

 

Check out that cam bolt. Probably torqued to 30ft-lbs only. Im glad I was able to get it off:

 

We can see #1 and #3 both had some run ins with their valves:

 

 

The rest of the pistons look...okay?

 

 

I did notice that the numbers on the pistons dont match up with the cylinder count (#3 is in cylinder #1) is that something to worry about?

The head had some gross coolant passages too:

 

The valves:

 

And of course the trouble makers of #1 and #3 could easily see a flashlight:

 

And well...that brings us to today. The head is off, and time to decide the build route. I am sticking with the oem efi system for now, so no crazy builds. My thoughts are a stage 1 cam, headers, exhaust, new valves, seals, etc all in the head. Thoughts? Maybe i just stick to a refresh for now?

Then I am debating pulling the pistons to do rings "while im in there". And of course a new timing chain and tensioner/guides to wrap it up.

 

Well there's your problem!!    Nice to find the smoking gun. Good luck with the project.

So you were talking about the condition of the rest of the pistons... Maybe it's just the camera or deposits on top of them, but I don't like the looks of them at all. Other than the dent, number 1 looks OK, but the rest of them worry me. Pitting on top? Detonation maybe?

Is it a trick of the camera? Are all the rest of them smooth metal underneath the crud?

Edited March 30, 20214 yr by Captain Obvious
typo

I bought a 78 parts car cheap mainly for the 5 speed.  I ended up using the engine in my 76, it was in much better shape.  Just planting a seed.  Your engine looks like somebody has spent too much time in there.  I don't think that Nissan numbered the pistons so the mismatch you saw might not be important.  I see some pretty deep scores in the cylinder you showed, so you might need new pistons anyway.  But then you're looking at pistons, a bore job, rings, all the extras...spendy.

Any L6 engine up to 1984 will drop right in.  A 280ZX parts car with a 5 speed would be a nice find.

 

Oh, and about the number stamped on the top of the pistons... The stock pistons should have a number on them, and there should be faint stampings on the block deck surface for each cylinder and the numbers should match. At least the first number. The stock stamping numbers represent "size", not "location".

That "3" stamped in your piston does not look like a stock stamping to me though.  Here's a couple pics from my engine:

 

 

12 hours ago, Captain Obvious said:

Well there's your problem!!    Nice to find the smoking gun. Good luck with the project.

So you were talking about the condition of the rest of the pistons... Maybe it's just the camera or deposits on top of them, but I don't like the looks of them at all. Other than the dent, number 1 looks OK, but the rest of them worry me. Pitting on top? Detonation maybe?

Is it a trick of the camera? Are all the rest of them smooth metal underneath the crud?

I'll be sure to give everything a good wipedown and check. Now that you pointed it out, I can totally see the difference between 1 and the rest.

11 hours ago, Zed Head said:

I bought a 78 parts car cheap mainly for the 5 speed.  I ended up using the engine in my 76, it was in much better shape.  Just planting a seed.  Your engine looks like somebody has spent too much time in there.  I don't think that Nissan numbered the pistons so the mismatch you saw might not be important.  I see some pretty deep scores in the cylinder you showed, so you might need new pistons anyway.  But then you're looking at pistons, a bore job, rings, all the extras...spendy.

Any L6 engine up to 1984 will drop right in.  A 280ZX parts car with a 5 speed would be a nice find.

 

Thats a good idea. There is a local 280z and tranny combo for $450. But its been sitting out of the car for a year or two. I'll probably pull the pistons first before jumping on another engine. I dont want to risk having two bum engines. 

Did a quick clean of the piston tops. @Captain Obvious thoughts? Im no expert on internals yet, but #6 definitely looks like something was flying around in there. The rest look okay for what they are. Looks like #5 and #6 also had a run in with a valve!

(Hopefully they upload in order starting with #6)

I take it back. Other than the valve dents and occasional other minor blemishes, those pistons don't look bad at all. If you don't have a really good condition other option, I'd run those. Must have been a trick of the camera. I was really expecting serious destruction.

And you can see the sizing numbers now. Not cylinder number. It was just luck that the only one you could see before was #3.     

One of your pictures, and the damage you've found, made me wonder about the camshaft.  Might be a performance, high lift cam.  A picture will tell, look for new stamps on the ends.  The lobes will have a smaller base circle if it's a regrind.

Detonation causes damage that looks like foreign object damage.  Might be that somebody built a "race" engine.  Check your head also  to see if it's been shaved.