I want or need to get one of my 521s running again.  I have two that were crashed, and one I quit driving sometime around y2k.  The one I want to get running again.  Unfortunetaly, I let it sit without antifreeze in it, and when I went to move it a few years ago, the expansion plugs were on the ground under the engine, hopefully that saved the block.  I have three mostly complete engines, two L-16's, and a L-18.  The 18 is the one currently in the truck.  The L-16's have not been run for 25? years, I think.  I hauled the two L-16 into the garage yesterday, and today, I got some bolts to hold them on my engine stand.  I put what looked like the best L-16 on the stand, and did some minor clean up on it.  It did not want to turn by hand, that was expected.  I cleaned up the area around the spark plugs, and drained the old oil.  I put a generous squirt of penetrating oil in each cylinder, and a few tablespoons of ATF, in each cylinder also.  I put some slightly used oil, still warm from a recent oil change in another car, in the L-16 engine.  The plan is to let it sit overnight, drain it and put some fresh oil in the engine.  If the engine regains compression, it will probably be put into the truck, for a test run.  Then I will do an extensive test of compression, vacuum, cylinder leak down, oil pressure, and any other thing I think of to evaulate the engine.  I will try to keep posted as I progress.

I had drained all the water out of one of my L16's for the winter and thought it was good enough...NOT!
there was still water in the block and front cover cracked when it froze...
good luck and keep us posted

    Do people want me to post where I got parts, and numbers of parts I used to get this project going? 
    Thanks for the info on the front cover.  I will be sure to do a close visual inspection of that area when I get to the L-18 engine. 

Sure! any info you can post will no doubt help someone sooner or later...

Too often people run into a problem and then come up with a solution and then not let anyone else know what they found out...

Take the disc brake issue....everyone wants them...someone figured it out several years ago but then didn't share the info....so for many years, people just kept asking and then someone who is a fabricator at heart decided to do something about it...

MKlotz figured it out and has posted what he did on NWDE...it took that posting for others to see, for other people to figure out other ways to do it...

now there are 4 different options for disc brakes on the front of a 521 and one option for the disc on the rear!

so, PLEASE post up what you find out...part numbers, what have you...it may help someone out and that is the whole purpose of this board!

Here is an update on the progress on My 521.  On Wednesday, two days after I started this project, I got the most promising L-16 free up and to turn, after letting it sit with penetreting oil, and ATF in the cylinders.   I sealed up the openings that do not normally have water in them, and pressure washed the engine, and occasionally myself.   I then bolted a transmission and starter to the engine, and hooked up a battery so I could do a compression test.  The compression test came out as follows: #1, 60 psi    #2, 75 psi    #3, 120 psi    #4, 60 psi.   I think I need a little more than that.  I put more penetrating oil, and ATF in the cylinders, and let it sit until Friday.
On Friday, did another compression test.  The compression test came out as follows: #1, 70 psi    #2, 77 psi    #3, 140 psi    #4, 132 psi.  There might be hope for this engine.  More penetrating oil, and more ATF.  I hope the reason for the low compression is that some pistion rings are stuck on cylinders #1, and #2, and the oil will loosten them up enough to maybe get the engine to start, and running the engine will finish the process of freeing the piston rings. 
     I have started exploring my other options for getting the truck running again.  I talked to a local Nissan dealer about parts availability, and pistons, rings, bearings, and other internal engine parts are listed in the parts information they have.  A local outlet of a national auto parts chain has remanufactured engines, and short blocks available.  The parts person at the local Nissan dealer also suggested the possibility of putting a more contempary engine, The KA engine used in the 1990 to 1997 hardbody pickups.
     Here is what I have found for parts, so far.  I live just south of Portland, Or, so some parts sources may apply only in my little world around Portland.
     For bolts and fastners, i have been going to a company called Oregon Bolt, INC.  They have had every fastner I have wanted so far, at prices well below what you would find at any "big box" home hardware store. 
    The local Nissan dealers  have oil filters,  current part number  15208-43G00, for $8.48
    I got an Engine overhaul gasket set from another local auto parts store, Clackamas Auto Parts in Oregon City.  The Gasket set was made by ROCK, the number is FGS6033, the price I paid was $58.00
    I have a lot of parts with rust on them, I am experimenting with a process of electrolytic rust removal, using a battery charger, and some reasonably common household cleaners.  I will let you all know how that turns out,  soon.
   

I'm already getting good info from your posts, thank-you!

Especially looking forward to hearing about how the electrolytic rust removal is going and what kinda goop yer parts are soaking in.

[img]http://i76.photobucket.com/albums/j15/p ... 21phiz.jpg[/img]

Thanks for the kudos.  I am using Arm and Hammer Super washing soda, it is in a yellow box, I found it hidden in the aisle with laundry detergents at a larger store. It cost $2.39 USD.  I have an old, very rusted oil pump/distributer drive shaft gear that I am using for a test, in a 2 gallon plastic bucket   The sacrificial anode is a bundle of old steel wire.  I an using a 6-amp battery charger, with a 12v 6 amp setting, a 12v 2 amp rating, and a 6v rating.  I am using the 6v setting.  The information I found seemed to settle on using a fairly low setting, and take a longer time to clear the rust off parts.  It has been going about a day, now, I will keep people posted.

    More updates on my "get it...." The engine I chose to try to get running,  was slowly leaking oil.  The oil pan had some dents in it, so the decision was made to swap a good pan from another engine.  The other engine is probably going to be the one I put new pistons and rings in, if I need to.  (I have four mostly complete engines)  I pulled and cleaned the pan off the donor engine, and then pulled the pan off the engine I want to get running.  A lot of gunk was in that pan, and when I cleaned some of the gunk out,  I found several holes in that pan.  No wonder it leaked oil!  I also cleaned the oil strainer/pickup.  I installed the good pan on the engine.  I also removed the oil pump, cleaned it, and put a distributer drive shaft that I removed the gear from.  I gutted an old distributer, put that on the engine, and used an electric drill to turn the oil pump, to see how much oil pressure the engine would build.  After filling the oil filter, and the oil passages that have sat empty for years, the oil pressure quickly pegged the gauge I had put on the engine, over 50 psi.  Good news, the bearings are probably in good shape.  I also had the cam cover off the engine so I could watch oil come out of all the cam lobes.
    The electrolysis experinent turned out fairly successful.  The part I derusted was the distributer drive I used to turn the oil pump.  It seems you cannot restore a part to "like new" machined condition.  The red rust is removed, and there is a coating of a black substance that cleans off the part fairly easily, but when that is removed, there is still some pits in the base metal.  As the part had the rust removed from it, the current the derusting cell was using droped quite a bit.  After I was done derusting the distributer drive gear and shaft, I was easily able to press the gear off the shaft.
    The threads on the oil pressure switch are not a normal 1/8-28 NPT thread, they are a 1/8-27 ISO thread according to one auto parts store I went to, or a 1/8 BST (British Pipe Thread).  Anyway the adapter fitting I got that worked, was a Edelmann number 265220.  I also was able to get a new starter, I have not actually used it yet, but I will let people know when and if it fits, and works

Just a quick update.  I got the L-18 out of the truck, and the L-16 I want to check out to see if it is servicible into the truck.   I found a shop in the Portland Oregon area that said they would sell L-16 and L-18 useable short blocks for about $100.00.  I have not taken them up on the offer.  If I do get a truck or trucks running again, is there value in having the orginal serial numbered block in them?

L16 or L18 shortblock for 100? Rebuilt or used? If rebuilt, what's this shop name?

The name of the shop is Bill's Datsun Shoppe, in Clackamas, Or.  The $100.00 price was for a block that could be made running, if I rememner the exact quote.  The person I talked to said he had quite a few of the smaller blocks available, because a lot of people have swapped for a larger motor.  They are definately NOT rebuilt blocks.

    Another update.  In the last few days, I pulled the gas tank out of the truck, Cleaned it out, and put it back in.  On my tank, there is no fuel strainer in the tank, I must run a fuel filter to keep crud out of the carb.  I plan on replacing all the rubber fuel hose from the tank to the carb, some of it is 37 years old.  I also found and cleaned four fuel pumps, all the pumps draw a little vacuum, and build a little pressure when operated by hand.  I also have four carburetors, hopefully at least one is in good shape.
    I found that the bolts that hold the gas tank in the truck have American threads. (5/16 x 24)   I put penetrating oil on all the bolts a day before I took the tank out, and I did not strip or break anything.
   

On my 521 the SAE bolts holding the tank in were rusted so bad that the threads crumbled on one mounting point. I had to helicoil that one back in. The tank was in pretty bad shape inside, too. I used a POR-15 tank treatment that cured in a day or so, (using a heat lamp over the sending unit hole), and that came out pretty good.

After replacing the rubber lines, I was still getting rust chunks like a '49'er panning for gold, from one of the hard lines. I ran two filters back to back in the line ahead of the pump I replaced, till I could find a flare tool that would work right, (went through four of 'em...Murphy's Law), when I finally bent some new tubeage, everything was fine. Before rebuilding the carb, you wouldn't even have known there was a glass window in it.

~phiz

Actually, you should find that all the bolts on the 521's, except the motor, are SAE.  I might be wrong about the motor, but I'm pretty sure it's metric.  They went to all metric with the 620.

Oil Filter Supply is a Portland place where you can get any of the fuel tubing...even the large diameter stuff form the filler neck. 

Thanks for the heads up on Oil filter supply.  I have been there before, but now everyone who reads this knows about them.  I was thinking about getting a large fuel filter from them, to run for a while, until I know most of the crud is flushed out.

sounds like you Ore guys have a place like Williams oil up here...
they got tons of good stuff! they made my brake line for the rear with one part SAE and the other Metric...

    More updates on my project.  The L-16 engine I hoped to get running would not start, compression #1, 90, #2,60, #3, 30, #4, 150.  My service manual has a minimum pressure of 159 lbs.  On to the L-18, the one with the expansion plugs pushed our of the block.  It has no obvious cracks, so I did a compression test on it.  #1, 165, #2, 160, #3, 163, #4, 168.  I pulled the manifolda off to get access to the expansion plugs on the the left side, and had to repair a broken stud on the bottom on the exhaust manifold.  I was able to get the stud removed successfully.  I cleaned the intake manifold of dirt, and put it on.  I made a U shaped tube out of copper pipe, and put all the hoses on the engine, and then put a radiator on the two hoses just on the stand, and tried to pressurize the cooling system of the engine.  The thermostat housing leaked, so I pulled it off, cleaned both mating surfaces, and reinstalled it.   It appears my radiator might have a  leak in it, also.   Time to look for another radiator I think I have. 
    My brake master cylinder,  on the truck had no fluid in it.  I may need new wheel cylinders and a master cylinder.  The emergency brake cable that passes from the inside of the cab to the engine compartment is frayed, and stretches each time I pull on it.  It , and other brake cables probably need close attention.
    The clutch master cylinder had fluid, but did not operate the slave cylinder.  More attention needed there.
    I went to a meeting of DatsunsNW on Wednesday, to check out the club.  Good people.  They wanted only $24.00 to join, and club memberships are good for a discount on several businesses around town.  I needed a bunch of new hose clamps, to I went to Baxter Auto parts, and got two boxes of smaller clamps, 10 in a box.  I saved over 20 dollars on that one invoice!
    I replaced all the rubber fuel hose, I needed about 64 inches of hose to do that.
   

Glad to hear that you joined!!!  I'll definitely try to make the next meeting.   

Also glad to hear that the L18 has such good compression. 

It is so nice to have the luxery of a parts truck.  The hydraulic brakes do not work on the truck I am working on.  I have been depending on the emergency brake to keep the truck from rolling.   I noticed that each time I pulled the handle, it came out farther.  The cable that goes from the cab to the bell crank on the frame was coming apart.  I will just grab the part from the parts truck.  That was the easy part.  After starting to reinstall the cable on the truck I want to run, I saw it would be a good idea to clean the rust and gunk off the linkage in the cab.  So I removed the whole E-brake linkage in the cab, it was only three bolts.  Then the fun began.  After dissassembling the pieces, I forgot exactly how it went together.  Back to the parts truck, and get the assembled linkage.  OK, back together now.  Lying on my back, under the dashboard, two of the bolts do not want to go back in, without cross threading.  Back under the dash, with a tap, to chase the threads in the cab.  Get an adjustable die, check the threads on the bolts, back under the dash, and finally the bolts go in.  Of course, I had to drop one of the lockwashers, and it went under me, where I had to crawl out, get the lockwasher, and yhen I had to crawl back in.  What I thought would be a 30 minute job ended up taking most of the day. Funny how these simple jobs take much longer then you would expect. 
   

I got the thermostat housing sealed up, and found another radiator, in better condition.  One of the expansion plugs was still leaking a little, so I pulled it out, and lightly polished the bore in the block, and put another new plug in with more gasket sealer on it.  I pressureized the cooling system, and it still is leaking air.  I heard air leaking into the block, from the oil filler hole.  I pulled the oil pan, and the front cover off the engine.  I have cleaned a bunch of parts as they came off the engine, but I still have not foung the source of the air leaking from the cooling system into the block.

    I have just been cleaning a bunch of parts, and the oil pan and front cover is still off the engine.  I plan on making a flat plate that will cover up the holes in the block where the water pump passages go into the block.  Hopefully, I will find no leaks.  But who knows, at this point.
    I took the best radiator I had to a local radiator shop, and got it cleaned out, and it has no leaks. so that part of the cooling system is done.

   

    I sealed off the water pump holes on the front of the  L-18 block, and made a plate to cover where the thermostat housing goes, and pulled the heater hose fitting on the back of the cylinder head, and plugged that hole.  That made a sealed chamber of the block, head, and intake manifold, I could put low pressure air into through the 10mm hose fitting on the intake manifold. 
    I pressurized the block to about 8 psi, and heard air leaking.  I pulled the cam cover off, and with a hose, found cracks in between #2, and #3 cylinders, that air was leaking from.  Time for a different head.

    I have removed the head off the L-18 block.  After dissassembling the head, and pulling the valves, and taking the spring seats out, I found a crack that went from #3 exhaust valve forward to between #1, and #2 cylinders.  I think this head is scrap.
    I pulled apart a L-16 head to see what the valves looked like, and the valves in this head did not look too good.  I was hoping I could use the valves from the L-18 head, but the intakes are larger than the L-16 intakes.
    One of my head bolts broke when I was removing the head from the L-18, but I got lucky, and after cleaning the rust away from the broken end, and a few raps with a hammer, the broken bolt came out with a pair of Vise Grip pliers.
   

    Another update.  I did order some valves, that I thought had oversized stems, to be able to hopefully not have to replace the valve guides in the L-16 head that I am working on, but when the valves got here, they had oversized heads, not stems.  I had to send them back.  I also used a hose from my compression tester to check for leakdown on the two L-16 engines I have that are still together, and both of them had air leaking past the valves on all four cylinders.  So, I have three cylinder heads that need valve jobs done to them.  The head that is off a motor, has the intake valves sunk into the head, that uses up clearance to adjust the valves, and with the valve sunk into the head, it does not flow as well.  To get this repaired, the head needs the valve seats replaced, and the guides are worn as well. 
   

    I took one of my L-16 heads to a local machine shop today.  I plan on having the valve guides replaced, and the valves ground.  The machinist at the shop thinks my valves should clean up pretty well, and there is not a lot of wear on the stems.
    The head I took in has the old softer intake valve seats in it, and they were pounded down.  The intake seats are going to be replaced.  I am also going to try to see if the 35 MM exhaust valves from the L-18 head will fit in the L-16 head.    
    The head that has freeze cracks in it from the L-18 is a A-87 "peanut" head with 42 MM intake valves, 35 MM exhaust.   The intake ports are only about 1 1/4 inches.
     
   

    While waiting on a cylinder head to get done, I have been working on the lights.  When I started the light project, the high beam side of the high/low headlights did not work, the turn signals did not work, the four way flashers did not work, the reverse lights did not work, and all four side marker lights were off the truck. 
    A relay that was bad was the problem with the headlights.  The turn signals on the front were removed, cleaned, and rust removed from the sockets, and that got the four way flashers working.   A different flasher got the turn signals to work.  I was able to get one reverse lamp to light by changing the light harness on one rear tail light assembly, I need to change out the harness on the other side, I have some bad sockets for the other taillight assembly.
     The side marker have got very bad rust in them, I had to replace the socket on one of the side markers.  I used a socket for replaceing worn out sockets on domestic cars, and after taking off the parts I did not need,  I soldered a new socket on to the old marker light base.  It gets painted tomorrow.   Thats the end of todays update.

 

Hi Daniel,
We just met at the swap meet.....now I have a face to put with the screen name   If you would have mentioned the electrolytic rust removal, I would have remembered a lot more of your posts. 

I've been curious about how that has bee working.  Did you use it to remove the rust on the light assy's you've been working on?  I have the batt charger now, I just haven't fired it up yet.  oh....I still have to get the washing soda.

If I remember right, you don't have a way to get the pics on the forum.  We should set up a time.....I can come take some for you and you can do a rust removal thread

    I have been using the electrolytic process on some of the light parts.  Unfortunately, it is not a miracle process that will restore a part to like new condition, but it does help a lot, and does greatly reduce the time spent on physical cleaning methods. 
    After reading about hydrogen embrittlement, I do not think I will use the process on "critical" parts. (brake drums, suspension pieces, engine pieces)
    I tried the process on one side marker light that had a bulb rusted into the socket, but I still had to break the bulb, and with a pair of needle nose pliers, pry and pick out the lamp base, in pieces.  Maybe I did not leave the part in the process long enough, or did not have as good of a connection as I could of.
    I could get pictures up, but I just need to get the pictures developed conventionally, I just have a 35 mm film camera.  when I feel a little better about the whole process, I will post pictures.
    In the next few days, with good weather, and longer daylight hours, I think I might get two of my collection of PL-521's outside to take some pictures, and inventory what I got.   
    The machine shop called, and I might get my cylinder head back on Saturday, April 7, 2007 

I just saw something about the Hydrogen problem.....I thought they said that they cook the part to bake out the hydrogen.  Maybe I heard it wrong, but most of the parts are small enough to put in an oven....and I have an oven in the shop.  I'll have to check into it when I get some time.

My thought on the areas that aren't getting cleaned....the process is "line-of-sight"....so if those areas are ....around the corner...from the anode...you might try adding extra rods or change the position of the part you're cleaning.  Worth a try.

    I will try moving the electrodes, and part around, to see if that helps.  I got two parts cooking right now.
    My concept (and I could be wrong) on hydrogen embrittlement is this.  During the  electrolysis process, hydrogen is freed up from some water molecules, and actually seeps into the grain structure of the metal.  The hydrogen atoms then bond with the metal atoms in the crystalline structure, and the metal does not have as much flex as it did before.  The metal instead of bending, and bending back, then just starts to have microscopic fractures in its structure, and the fractures grow, join, and then the part breaks.