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Reviving #5837.

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My 70' 240z is #5837. It was last registered in 1990.  I expect it's been at least since then that it's actually run.  Story was that they bought it, towed it home, pulled it apart and got in over their head, so they put most everything in side and parked it out in a field in rural NM.  I bought it about 3 years ago, or so and recently have found time to start working on it. 





What I've done so far: 

           I've looked over the engine and replaced obviously cracked hoses.  I found the engine, though it's an L24/e88, is not the original engine #. That's unfortunate, but not a show stopper.  It looks like the Motor was at least looked over because there's no oil leakage, or obvious damage.  The engine does have a plastic fan, and the Radiator shroud was in the back. So I'd guess it was rebuilt at one point.  Oil is still clear. 

          Months ago, I pulled the plugs and squirted 30weight oil into the cylinders. let it sit a month, then I came back with a battery pack and cranked it over with no fuel/spark  a few times. then I let it sit a while.  3 weeks ago I looked through the carbs and made sure they were hooked up correctly and sealed off anything that would be a vaccum leak. I put on new plug wires, adjusted the points, and noted the dist was loose, no biggie..  Then I got a jar and put about a pint of fuel in it with a new hose leading to the mechanical pump. Connected the battery pack and cranked it over (no water in the system)  it actually started with a cloud of sand and dust and noise since the exhaust header is held by one bolt and no gasket.  it ran fine for about 45 seconds, when I shut it off.  The oil pressure gauge read pressure. 

          I let it cool an hour or so while I went to lunch and to get parts, then came back and filled the Radiator, (Which leaks), filled the jar with another pint and started the engine again, just letting it idle.  The Dist is loose and for good reason, it's one tooth off, so I'll have to fix that, no big deal.  It idles about 3 minutes on a pint of fuel before it cycles that fuel back to the tank.  I don't want much in that tank since I've got to drop it an look.    The heat from the engine pushed water out the leak in the radiator. It's the drain plug, I tried to order a new petcock, but it showed up at 7/16" rather than the 5/16" that the plug looks like it should be. so if anyone knows the right part # for that, let me know.  I found one of the freeze plugs is seeping so I ordered a new kit for those, not too hard to put in.




On to the body.  It's pretty rough, the paint is so bad, and they'd sanded and primered about 1/2 of it before they parked it.  I'm going to need to patch a bit. pinholed floorpans.  I'm going to need a full rubber replacement kit. Does anyone know if those kit include the welting and rubber seals for the doors?   I ordered new  hatch struts. My Series one glass is good, but the defrost lines look like they've been scratched pretty bad.  I don't know if those are worth trying to repair.  

     I replaced the hood and left fender along with a new (used) fiberglass sugar scoop. since the hood had rust and had ben hit, and the left fender was sanded but not protected 27 years ago.  The car had a slight repair in the inner nose next to where the horns mount, so it was obvious this was hit at some point. The metal sugar scoop I replaced being another hint. 


I had tried the brake pedal and the clutch pedal, the clutch went right to the floor and the brake master was frozen, so replacing those was needed.   I replaced the clutch master and went to replace the slave, and found the slave was missing. Replaced it with new, and as expected, the rubber line leakes like a sieve, so I have that and all 4 wheel rubber lines on order.  I tried to find a replacement Brake MC for a 70' and no existy, unless I want to pay near $300 for a rebuilt.  I found the early S30 MC has the Front reservior at the back of the MC, while 71-73' MC ($50) has it in the middle of the MC. After some reading people have said you can just re-route the "front brake" line to the middle, and "rear brake" line to the end.  It should work fine. I did this and all it took was a couple slight bends to swap the hard lines from the manifold to the MC, front to back.  Both are 7/8" MC's.   I bled it and connected the hard lines, and sure enough the wheel hoses are leaking. (nevermind I'm expecting to have to replace/rebuild the wheel cylinders.)  So until parts are delivered I'm stuck on that part. 

      I cleaned out the car and I found a lot of EFI parts from S130's and most of the interior vinyl and some removed parts like the fan shroud.  I'll need a full set of emblems and the Series 1 hatch parts, but it's mostly complete.   I found the shift lever from a S130 and put that on (it was missing) and found this is a 4 speed, (possibly stock)  I have a driveshaft from a 280z that will hopefully fit. I need to find bolts though since the tranny is held to the engine by the starter bolts and 2 bolts on the top.  There's a lot of missing bolts. Does anyone have a good source for the M5, m8 and m12 bolts.  I'll put in a 5speed since the engine isn't original it won't make any value difference.   I'll post pictures shortly...





Edited by Pharaohabq
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Yeah I've been busy raising a daughter and changing jobs, it's been tough to get back to things.    I'll post up some pictures soon  I need to take some when I get back out there.


Not a Z note, but I have an 87 jeep wrangler that has a pinhole leak in the xfercase, any thoughts on how to patch that?  it was from rubbing on the belly pan.




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28 minutes ago, Matt 78Z said:

JB Weld, I've seen people do some serious patch work with it.

If it is not structurally damaged and just a pin hole, JB weld is really not a bad idea. Clean the area well, scuff it up, JB weld. Done. If it is on the bottom, you may have to drain to keep oil out of the epoxy. 



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Thanks, yeah I was thinking to JBweld it, but I might just drill that section and thread in a bolt since it's in an area where it was rubbing on the Belly pan.  I'm adding a rubber bumper to keep it from flopping around. the stock mount is 1/2 torn through. 


Anyhow that's here nor there, and not really related.  So back to what is.  (again Pictures are forthcoming. I am trying to locate the usb3.1 roundy cable for my camera. )


So I'd left off after swapping the Brake MC and Clutch MC,  The Clutch slave rubber line leaks, I just have to get back to that since I was waiting on parts.


I went to check the wheel cylinders since the Brake MC is just pushing fluid.  Looking under the car I can see fluid  running out of the  passenger side rear brake, so I jacked it up this past weekend, and  put it up on stands, and pulled the wheels off.  240Z's have rear drums as you know, and I could see fluid  dripping out of the drum.  it was stuck on hard, (this is common, you just need the BFH to get it off)  So a few whacks with the BFH and the drum comes loose. (oh another tech tip, a 4x4 block will allow you to use a claw hammer to lever the drum pressing against the strut. )  but suprise!  when I pulled the drum off, There was NO SHOES, no hardware, nothing,  they had sometime before yanked the shoes for some reason.  (note Ebrake cable rusted through)  so yeah,  it was leaking because the cylinder had nothing behind it.  No big deal, except the brake hardware kit is online order only, so that and new shoes will show up this week sometime. 




I pulled the wheel cylinder and the rubber line since I have a replacement. The hard line was frozen at the cylinder so I pulled it too.  I was supposed to remove the bleeder valve but it just snapped off when I tried to turn it. not good


With the cylinder out, I took a closer look. The rubber didn't "look" bad, but it was brittle. Fortunately I planned on rebuilding it.   The Cylinder itself was frozen in there with hardened fluid. Not a good thing. I'm going to need to flush all the hard lines.  I wedged the cylinder out and it didn't look too bad, but not too good either.  New 240z drum cylinders are out of stock everywhere you look so it's either fix these or find something newer. 


I inspected the cylinder and piston and fortunately it was just gunked up but not pitted. So I started with oil and 400 grit paper, then 600 grit paper and smoothed the inside of the cylinder out, visually there's some staining, but it's nice and smooth. I cleaned it with brake cleaner. rubber gloves were difficult with the sandpaper. 




once I was happy there it was time to look at the bleeder that snapped off. it looks like it was overtightened at one point.  Sucky part is it's two angles off from square. 


I pulled off the other rear wheel, and pulled off the Drum, Tada! brake shoes, no matter, it's getting replaced. New shoes are $20. so I took it all out and pulled the wheel cylinder. This one wasn't leaking, but also had no fluid in the line, so that's interesting.  It's a lot easier to pull it without brake fluid everywhere.  I took that one back to tthe bunch, and yup, frozen like the first. I wedged out the piston, same deal, cruddy put not pitted. so back with the oil and sandpaper. I wire brushed all the outside. The Ebrake adjuster was frozen in place too, but a couple taps popped that out. 




I put it in the vice and estimated the angles on the bleeder valve. Then I tried to match these up on the first cylinder on my drill press.  I slowly drilled out the snapped off bleeder valve then went in with the right thread tap, fortunately I was close enough that the old threads popped loose and pulled out.  A few times in and out, and I could knock the last of the old bleeder remains from the hole. I swapped over the good bleeder and it seemed to fit perfect. but that was a pucker moment since I don't know where I'd find another cylinder. 




I had to clean out solidified brake fluid from all the passages with a piece of wire, and I blew out all the crud.  The Ebrake adjusters were cleaned out, and greased, the little bolt has reversed threads, so don't lose that




I cleaned up the piston and with a little oil pushed on the new rubber. The new kit fit well. The little spring is important though I don't know exactly what it does.  I haven't put pressure in these yet, since I don't have the new shoes yet, but I'm looking forward to it. I'll put these back in, get them connected, then when the new hardware shows up I'll close both sides back up, put on a new Ebrake cable and then look into the front.  If the rears are this bad, I expect the front Calipers to be in not so good shape. Though Those are still availible so I'd just swap them out along with the rubber lines.


Look I added the pictures!







Edited by Pharaohabq
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  • 2 weeks later...

Well I got to work on things a bit more and unfortunately that brake bleeder is leaking which isn't so surprising.  I put in a solid 1/4in bolt in with a little gray rtv until I can source a replacement cylinder cheap. 


I resembled the rear brakes with new lines and shoes and bled them,  they do not seem to be leaking.  


While I had the rear up,  I dropped the fuel tank and cleaned it out.  There is no inside rust and I wire brushed and bedliner the outside.  I remounted the tank with new hoses. Though inside there's a air tank of sorts above the fuel filler that has a broken fitting I will need to repair.  I'm not sure if that's a canister of sorts. 


Next I'll work on the front brakes. There is no driveshaft, and a 280z shaft I have is an inch too long, I'm going to swap in a 82' 5 speed, so I'll wait till then to shorten the shaft.  The 4speed feels gummy when I was turning the driveshaft by hand. 27 years of sitting might have been bad for it. 



Look how bad this line was.


Edited by Pharaohabq
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I hope that wheel cylinder holds! I guess that’s on part I wouldn’t hope it works . I wouldn’t skimp when it comes to brake parts , and yes I know how expensive the early ones are- I own 4858. Looks like it had some decent pitting that would cause the cylinder to be oversized trying to clean it

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Yeah, it's actually stained, not pitted, but hey, I found this:  

Centric Parts 134.42606 Drum Brake Wheel Cylinder

It's almost the same, and only really really concours purists would know the difference.  It's not the exact one for the 70, but the cylinder is really similar.  So much so that the 70' rubber cover would fit the same.   The only difference is that they reworked the spot where the brake line attaches. (there's no bolt, and the line attached straight rather than at an angle. )  I've ordered these and will see how they work.



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  • 4 months later...

Sorry no updates in a while. It got stupid cold this winter and working in snow isn't any fun.  I did install the new rear cylinders and they fit just fine.  I need to install a used Ebrake cable  but that's pretty easy.  The MC I used has an issue tho, I think one of the seals went bad or flipped inside, because I can pump the brakes and they get pressure, no leaks anywhere, but after a short time they're worthless again.  This was a new MC.  I ordered another one after talking to the manufacturer. (they think I pusted the piston in too far when bench bleeding.  I'll pull it apart when it's out and see if anything's obvious. 


Other things:   I went and picked up a 5 speed out of I think an 81, S130. The guys let me take the L28 too for $50 so I'm going to check compression on it and see if it's worth swapping in with the carbs in place of my L24. (it's not the original L24, so it doesn't really matter for any real worth)  I may stil look at EFI if the wife complains too much about gas fumes. 


I bought a 2+2 clutch which will fit fine and clamp just a little better. (bigger diameter) so that'll go in along with the 5 speed.



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So I started looking into the L28 I got. It's a 42/n47 engine. I think that cooresponds to a 79-80zx.  Anyway as with any engine, one of the first things I figure to check is compression.   (Do you like my engine stand?  This is temporary, I couldn't rotate it on the real safe engine stand. ) 




I put a pair of bolts in the flexplate and then bolted in the starter with a pair of 14mm m8 bolts.  




I pulled the plugs and though it's an older engine, the plugs are bosch platinum and look almost new, so I figure someone was working on the engine before the donor was junked. 




I put on the compression gauge and pulled compression readings first dry then with ~ a capfull of oil in each cylinder starting from #6 the closest to the flywheel.  I used a jump box and a wire to the starter.  it turned evenly and at a good speed. 


Cyl/Dry PSI/WetPSI


#6, 90, 170

#5, 100,150

#4, 105, 170

#3, 105, 155

#2, 105, 180

#1, 35, 70 !!! 


Well crap. I was pretty happy till I hit cylinder 1.  Yeah 90 on #6 wasn't so good, but it came right up with oil, so it's okay.  #1 though dang 70 at the most.  


I'm reading that as probably a head/valve issue since the compression did come up a  bit. it sucks though, it means I get to tear into the engine.  I just bought rings and a seal kit so it'll all go in.  I'm going to pull the cover and check the rocker gaps for #1 and see if maybe they're just too tight, but I bet something got burnt or something. If adjusting the valve clearance doesn't fix it, I'll pull the head and see what's what.   I doubt there's a cracked cylinder, I'd really suspect a valve.  Maybe a broken ring, but you'd figure the oil would not have made as much difference. 


Yay Rebuild fun. 


I did find that the 2+0 flywheel and the 2+2 flywheels are different, I've ordered a 2+2 flywheel to match the 2+2 pressure plate and clutch disk I bought.  Larger clutch should last longer.  Cheaper parts too. 


Sooo Anyone got any ideas before I tear into this engine?  parts should be here Friday...  





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Well So far as I know the L24 may have been rebuilt prior to 90' when the car was parked. It's not the original engine.  It appears to be stock. It does run, albeit badly, but it's connected to the 4sp that it turns out has sand in it.  It's fine, I hate 4speeds anyway.  When I got the car the Tranny had 2 bolts in holding it together.  Nothing on the engine was connected except the radiator hoses. The story was that it was a project car that they never got back to then it was lost in the weeds.  Who knows what they did. If it was the original engine I'd be much more interested in keeping it stock. 


I have the 5 Speed that  I was originally going to swap in and use with the L24, but this L28 was $50 so I figured I'd check it out.  If I were to use the E88 instead of the N47  Would I be looking at much of a difference?   I'm going to have to look up that combination.  Whichever head I end up using I'm going to have to go through.  If the N47 head has a bad valve and the E88 is all good, then that would save some work.   


I only have the stock headers for both the L24 and the L28,  is there any advantage to going with the ZX manifold over the 240z? at least until I get real pipes. 




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So, I got a chance to tear into the L28 to try to see what was going on with the low compression on cylinder one.  I took off the Intake and the Exhaust header and the valve cover. I think I have a good idea what's going on  


I found with Cylinder 1 that the metal shield for the exhaust had cracked and was half missing. 




These are here to protect the aluminum head from overheating, which this one has done. You can also see that the aluminum had lightly melted patterning, to the gasket.  Does anyone know if that liner is actually replaceable?  How are these held in?  Pressure fit?




I checked the Valves and they look like they are set properly.


The gap was fine on the valves and the cam looks fine. but I don't know how hard or worth it it would be to try to repair that head. The Valve is likely burnt bent or melted.  I'm doubtful at this point.  I might go ahead and swap in the E88 head, but that would make the L24 worthless.  If I can find another L28 head I might do that. 



I was going to pull off the Thermostat housing, but the bolts seem seized, likely from the overtemp on the Cyl one port right below it.  If I get another head I'll just snap the bolts if they don't break loose.





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9 hours ago, Pharaohabq said:

I found with Cylinder 1 that the metal shield for the exhaust had cracked and was half missing. 


These are here to protect the aluminum head from overheating, which this one has done. You can also see that the aluminum had lightly melted patterning, to the gasket.  Does anyone know if that liner is actually replaceable?  How are these held in?  Pressure fit?


I was going to pull off the Thermostat housing, but the bolts seem seized, likely from the overtemp on the Cyl one port right below it.  If I get another head I'll just snap the bolts if they don't break loose.


That's not what the liners are there for.  They are emissions devices, meant to get very hot to help complete combustion of unburned fuel.  So that cylinder didn't "overtemp" because the liner came loose.  Still not clear why you have low pressure.


I think that they are cast-in, and start in two pieces, maybe tack-welded together.  So yours might not have cracked, one piece just came loose.  You'll probably find that some of the others are a little loose also.


The thermostat housing bolts are almost always tight, even on engines that run perfectly.  If the gaskets leak just a little bit the coolant gets in to the bolt hole and causes the bolt to rust.  

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Yeah this one definitely snapped off. it was likely lodged in there causing the head to heat up a lot.


   I'm going to the junkyard this weekend to pull another head.  I was reading the n47 or P79 might not be bad choices.  I'm not going to turbo this.  none of the others were loose.  I have been soaking the water bolts in liquid wrench, hopefully they'll come loose, but if not, no big deal  The P79 is supposed to have a really good quench pattern.  They said they might have a p90, not a p90a, I'm not sure the difference there.


I'm pretty sure the low pressure in that cyl is from the way over temp,  it might just be a bent valve from the busted tube, or it could be something worse.  I'll know more when I pull the old head.




Edited by Pharaohabq
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 yeah I've actually got a spare block, so that's not really an issue.  I did pull more of it apart this afternoon and oddly the valves on cyl one actually does't look that bad with just the head off. 



I haven't pulled the old valves out to check the seats so that may not be the issue.   If that cyl one got too hot maybe the rings are toasted. The cylinder walls don't look bad, no scoring or anything.  I'm going to pull the bottom apart tomorrow so we'll see what it looks like.  I've got new rings and bearings already, so might as well hone and replace.  I have to do all the seals anyway. 



What's the best way to clean rust out of the water jacket?  There's a goodly amount showing.  I could flush most of it out then hit it with an acid like muriatic, then flush it again.  I don't know how well that would work.

Edited by Pharaohabq
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I went out yesterday to look at some parts.  This buy out here has parts from probably 30 S30's.   If you need parts, PM me and I'll get you his Email.. 


Anyhow I looked at maybe 10 heads he had, mostly N47's but a few P90's and a few E88's and E30's.  He had one P79 which I liked because it had actually looked really good.



it hardly looked used at all in the cylinder heads and valves.


But the issue is that it's sat up on a shelf for who knows how many years, so the top is a bit dirty and missing the cam etc, But those are good on my N47.


Not to mention the Cam towers have a little scoring. I'll need to take this all apart to clean it and replace the seals, but the head looks really good to me, at least once it's cleaned.  All the springs, pads rockers and keepers are the same between the N47 and the P79 right?  I couldn't find anything that says differently. 


One nice thing about the P79, is that they fixed where the Exhaust tubes could get loose by adding bolsters.






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