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  1. #111
    Metal-Glueing Idiot
    Join Date
    Jan 2014
    Location
    Bolton
    Posts
    105
    And the latest update video, wherein there is some weldening, I look like Darth Vader (black helmet, with a hideous blotchy pink thing inside ), and some painting.



    Yes, my shiny dome got sunburnt. Yes, it hurts. Yes, I should've worn a hat.

  2. #112
    Metal-Glueing Idiot
    Join Date
    Jan 2014
    Location
    Bolton
    Posts
    105
    Roight! As expected, I've been dismal at keeping this thread updated; since the last update:



    Some air tanks happened!

    All of the material, barring the tank straps themselves, was originally destined for scrap; so I think I've done quite nicely with it.

    The two tanks came off a pair of DAFs that were being chopped up by a local haulage firm (because it's apparently cheaper to buy a used truck, strip it down and sell/scrap what's left over, than to buy spare parts. Madness.) and are a bit overkill for the needs of the RL, but I'll certainly have no shortage of air! The channel was originally a single piece of box section out of the scrap skip that was just about the right length, then sliced longways; and the tanks are protected from rubbing on the edges of the bracket by short lengths of cut rubber air-hose left over from a job. Total cost to me: £5 for a tank drain valve that then got pinched for another job, so I'll have to buy another one.

    Anyway, the bracket:

    (Sack trolley not included.)

    It fits in this nice convenient space underneath the body...


    I said, It fits in this nice convenient space


    5 hours, a mild concussion, and lots of swearing later the truck has 60 litres of new air tank. The bracket is still a firm press-fit at the moment and I need to weld it in for peace of mind.


    Next on the list was to start putting a rear cab mount back in…



    This is a pair of universal engine/gearbox mounts and a bit of plate that bolts to the original cab mount; this was all going rather well, it was just the upper mount where it all fell to bits. Apparently my measurements weren't quite right, because...



    The holes are meant to line up with the studs from the top of the mounts, and the upright flange was intended to go up against the box section to spread the load a little bit. It does go on backwards just fine, so some trimming and go from there...



    I think my tape measure is out of calibration, that must be what it is! 

    Anyway, a week later...



    The back-side was only stitch-welded, to leave me room to tighten the nuts down (and it was tight even as it was; with the flange of the nut touching the box section the whole way down!)
    If I were smarter, I'dve started the leftmost stitch weld from where the tack was, so it'd consume that ugly blob. Nevermind, eh?

    Looks less bad with some paint on it, and it's not going anywhere.



    I'm not going to worry in the slightest about those welds. They only need to be stronger than the rubber of the mounts, or the two M10 bolts that hold it down to the chassis. And with that front edge fully welded -- a real pain, involving having to be curled up like a cat halfway across the engine cover and passenger's seat -- it should be plenty strong enough.

    Some gussets were considered, but I've since decided it'll be fine. I did find myself staring up at the cab roof and wondering what the hell I'd gotten myself into. 2 years and 10 months, now, and I've barely scratched the surface.

  3. #113
    Metal-Glueing Idiot
    Join Date
    Jan 2014
    Location
    Bolton
    Posts
    105
    (Now we're only up to last month's updates, so getting closer!)

    I went to go change the oil in the air compressor, and was scratching my head over the filler/dipstick.



    It's very definitely meant to be there in the top of that round bit that sticks up. But it looks like it's met with an unpleasant end. (Item No. 19 in the drawing.)



    Looks like it's been broken for quite some time, eh? Keep that in mind for later...

    -- SIDE NOTE RE: Unpleasant ends --

    And, on the note of unfortunate ends, the whole truck very nearly met one a couple of weeks back. I hooked up the battery as normal so that I could tinker some with the wiring (and make another attempt at getting the engine to fire, just to see if it's possible to limp it to the workshop & back.), I'd just gotten into the driver's seat and had my hand on the key when the oil pressure warning light started to glow dimly, getting brighter and brighter.

    "Well, that's weird", thinks I, then I start to hear crackling and the cab fills up with smoke. The cab is covered with a tarpaulin, so I'm at this point inside a big plastic bag with the smoke from burning wiring being blown in from the open passenger's door.

    It's amazing just how long it feels like it takes to undo a battery terminal while the truck's trying to set itself on fire! Anyway, it turns out that the flexible metal conduit from around the battery positive cable had scooted up at some point until it was just barely touching the ring terminal and it was grounding out on the chassis. It wasn't making a good enough contact to cause noticeable sparks when I connected the negative lead to the battery, but enough that the conduit got pretty hot!

    Once it cooled down enough to touch, I pulled it out and the battery cable inside the conduit was looking pretty ugly.





    Thankfully, damage was fairly minimal. One length of battery cable needed to be replaced, and some other wires in the vicinity need(ed) to be repaired because the insulation had been burned off sections of them.

    -- END OF SIDE NOTE --

    So, while I pondered on the air compressor oil fill situation, I thought I'd spend a bit of time pulling apart the NOS front brake cylinders I got off the internet auction site that we all know and loathe...

    The first one I popped open looked to be the oldest, going off the appearance of the box, and all the innards are covered in a sticky substance that may at once point have been a lubricant or preservative. There's also something funny about one of those cup seals...



    Turned out, that cup-seal was harbouring a decades-old hitch-hiker!



    All the seals -- in both cylinders -- feel nearly brand new and look in fantastic condition. I still should pay the seals shop a visit, though, and get some new ones; it just makes sense, really...

    And now, the cylinder bore... This is the worst of the two, and the bulk of it is the slightly congealed sticky substance. There was some very slight discolouration of the bore in the middle where the seals would ride in use, but it disappeared after a quick brush through with the brake cylinder hone. There's no pitting or rust, so these have turned out fantastic.



    And then, because I needed to hear it spit and crackle, to get some enthusiasm back...




  4. #114
    Metal-Glueing Idiot
    Join Date
    Jan 2014
    Location
    Bolton
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    105
    So, back to the compressor...



    It's currently on my workbench, in about a thousand pieces. I washed the sump out with petrol to try break up the worst of the sludge, followed by filling it with new oil just to try flush out the remnants of petrol and water.
    Teardown followed a few days later:





    Not pretty, but cleaned up pretty easily and there's no scoring in the bores. The check-valves all seem to work quite nicely, and I cleaned out the passageways as best as I could. One of the bolts holding the inlet manifold down has a pretty gacked thread, so I've got a tap on order to chase the threads in the head just to make sure, and I'll get some new bolts on order. (1/4" UNF, so nothing particularly exotic.)

    I also had to break up the remains of the filler cap, since it seemed to have bonded itself into the threads and was stubbornly refusing to rotate. (I'd drilled two holes through it so that I could use circlip pliers to try unwind it. It bent the circlip pliers, then the edges of the holes started to break up.) Very careful -- almost surgical -- chipping with a thin chisel, and picks... 





    I've now got a tap for chasing the thread in that, and then I can have a new filler cap made, that I can fit the original dip-stick into.

    The wash-out with petrol, and following oil, helped dislodge the worst of the grot from where it was lurking, and down into the sump...



    (notice, also, the shards of plastic from the filler cap. It really did not want to come easily.)



    Sludge vs. Industrial Jetwash. Jetwash wins.

    Now that I could actually touch it without instantly becoming covered in slime, a closer inspection and some dismantling revealed that the oil pump was clogged; though it appeared to be with crumbs of plastic from the filler-cap, so that must've been after my precision extraction process.



    The relief valve, however, was stuck open by a much older looking deposit; which suggests that there's been no oil pressure at all? Uhoh.



    It's a pretty clever little mechanism, this oil pump. The shaft of the eccentric is the pump piston, and it's hollow -- with a little brass orifice in the end -- so that the pressurised oil squirts up it and is forced into the crankshaft; the pressure relief is a flat plate over a drilling, held down by two little screws with springs, such that once the pressure reaches its limit, it lifts the plate and squirts out. Nice piece of design and engineering.

    Unfortunately, a combination of that contaminated oil and a mostly-bypassing oil pump has not done the crankshaft or con-rods any good. I ran out of time today to investigate further, but there is discolouration on the crank and the big ends of both rods are pretty scored.



    No great surprises there, then. I also cracked open the Drawer of Excessive Precision* for my micrometers and did a quick bit of measuring. The rod journals seem to be within the realm of cleaning up sufficiently with a bit of polishing; the big end bearings having taken the brunt of the damage as expected, being white metal.

    The machinists precision G-clamps gave me some numbers (I'm majority metric, so bear with me! ) :

    №1 rod journal: 22.22mm, №1 big end (vertical, i.e. in line with the rod): 22.5mm. Clearance of 0.28mm, or ~11thou.

    №2 rod journal: 22.3mm, №2 big end: 22.45mm. Clearance of ~0.15mm, or a midges under 6thou.



    Big ends are just a touch out of spec. I'll double-check what the crankshaft mics out to after I've polished the journals, I can live with it being a hair undersized so long as I can get the rods to match it. I still need to finish tearing the compressor down fully, measuring the bores and whatnot, but so far it looks otherwise to be pretty good. I'll just keep on keeping on, for now.

    (* Above the Drawer of Insufficient Precision, which houses all my hammers and other tools of "Fit, damn you")
    Last edited by Tamber; 06-10-18 at 12:28 AM. Reason: forgot me footnote

  5. #115
    Metal-Glueing Idiot
    Join Date
    Jan 2014
    Location
    Bolton
    Posts
    105
    And on another sneaky side-note, I've gotten a little Megasquirt-compatible ECU all fitted up in an enclosure, and most (forgot the idle control valve wires. D'oh.) of the wires connected up to a plug, so that little side project is looking promising.

    Going to get some measurements of the inlet and exhaust manifold flanges, and have some of those laser cut so I can make up a fuel-injection manifold and a set of headers. Y'know, because this wasn't a big enough pain in the behind already!

    I know it's not ideal to be trying to figure out fuel injection on an already wounded engine, but I figure that if I can at least get all the supporting bits figured out and put together, then it should go quite nicely once the engine's eventually rebuilt.

  6. #116
    Might as well be part of the furniture.
    Join Date
    Jun 2013
    Location
    welwyn
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    1,677
    Love the write up's on this.

    Looking at the progress and thinking "not a lot has been done and there is loads to do" is my biggest issue and I then get put off doing stuff, so best I was given advice is take each item as a small project and eventually it will all come together.

  7. #117
    Metal-Glueing Idiot
    Join Date
    Jan 2014
    Location
    Bolton
    Posts
    105
    Oh, it'll all come together, slowly but surely. I've done a few other little bits and bats since the last update, mostly just putting wiring back together post-'fire' and connecting the beacons up so they now work on the switch. Oh, and some little brackets and whatnot so that can mount a second gauge along with a hazard switch; now the hazard lights work on a switch, rather than having to twist wires together.



    I still need to tweak the bracket for the indicator switch, because it doesn't fit where I first planned it, but that's not the end of the world. All the wiring will be tidied up when it's closer to being completed.

    The compressor's been broken down a bit further, and I've got a bearing separator on order so that I can pull the ball-bearings off the compressor crankshaft. And I've also gotten a little bit more welding done, mostly just adding some support to the battery tray to stiffen things up.



    The air-tank carrier was also tacked in place, so that it can be welded fully at a later date. It's not much fun working in a mud-pit, though.



    It's not the worst I've had to work in, but it's still distinctly less than pleasant when you're slopping and sliding around trying to move through the work area; it's too much like site-work at my day-job! Also, I keep catching myself on the legs of those metal screens all the time!

    Currently looking for another workshop nearby that I can rent, or something; because working out in the back of a car-park is no fun at all.

  8. #118
    Site Team
    Join Date
    Jun 2013
    Location
    United Kingdom Heathrowish.
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    3,328
    You have my total respect!

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