Puma / Dorman 6LE / MacFarlane B46B / 110 kVA Generator Resurrection

[awemawson]

Thanks chaps 

Today's objectives:

A/ Remove and identify battery charging alternator

B/ Strip out the old relay controller and it's wiring.

Now this charging alternator has a pressed plate on the rear secured by three slotted head screws, but in such a position that you can't easily get a screw driver at them due to the oil filter housing, and they were VERY tight. They'd been soaking in 'Plusgas' over night but even so I ended up having to use my impact driver - anyway eventually they unscrewed revealing a mess and a bodge. The main output 'faston' terminal has obviously grossly over heated and is corroded and slack, and one of the other terminals has been bodged with ty-wraps and what looks like a bolt 

Now previously I'd mentioned a mystery wire from a water temperature sensor that went into the alternator - no, the cable just passes through and behind the rear plate so at least that mystery is solved.

Try as I might I could not shift the through pivot mounting bolt, again it's not in the easiest of places but never the less it's 'spanner bending tight' and has been given another anointment of Plusgas.

It seems that the engine has  'pad mount' provision for an alternator, but has a bracket attached to the pad converting it to a more conventional 'J180' mounting but the spacing of the pivot 'ears' is rather short at  about 75 mm. It may be that I end up removing the pad mount adaptor and alternator as one and attack it on the bench.

The external charging alternator controller is a CAV 440A so I suppose it is probable that the alternator itself is a CAV - if anyone recognises it please shout. I think I'd prefer to replace it with one with an integral regulator but if I can get  it off I'll take it to my local 'auto electrician' who rebuilds starters and alternators and see what he has to say about it.

[awemawson]

So on to today's 'objective B' - removal of the old relay controller and associated wiring.

This went rather better, and after all it was just aggressive pruning ! Many of the smaller nuts and bolts resisted unscrewing, but a cold chisel made short work of them. All the relays and wiring have been removed (So no going back now!) with the exception of wires entering the rear of the controller box who's conduit from the engine actually comes in behind the 'false panel' so cannot be got at. When I re-wire, the new conduit will emerge in a more user friendly place.

I was horrified to discover that the voltage monitoring connections are made directly to the heavy wires from the main alternator and didn't pass through ANY form of fusing or isolation to the front panel mounted monitoring meters and switches They will when re-wired - I have temporarily terminated them safely to save having to re-make those humongous crimped terminals that they are jockeyed onto.

So boats now burnt - it HAS to have a new controller, and I've not tested that the Deep Sea 3110 that I have works - fingers crossed !

[hermetic]

LIKE!! The engine sounds sweet enough too! Always a relief when it's running and produce a steady 415V.
Phil
East Yorkshire.

[awemawson]

I've decided to retain the upper indicator panel that caries a Volt Meter, a Frequency Indicator, a Current Meter, a Running Hours Clock, and the switching to switch the meters from phase to phase. Apart from the current meter this will duplicate things that the Deep Sea controller can display, but I want the current meter and it's easier to keep the lot !

The  Right Hand 'mode' panel I will replace with one just containing the Deep Sea 3110 controller and an Emergency Stop button

The three phase supply to the meter panel I will route via a small 3 phase 30 mA RCD  and 6 amp trip just to add a modicum of safety

[awemawson]

So having taken the decision - better  implement it !

Old panel removed leaving space for Deep Sea 3110 and eStop button

[Sea.dog]

H,M,L on the schematic - High, Medium and Low charge rate perhaps?

[awemawson]

That was my assumption, but I'm hardly an expert on these things. But looking at the schematic it would have that effect 

Does anyone recognise the make of that charging alternator?

Slight 'undoing' progress in that the bolt that passes though the tubular bit of the alternator and acts as a pivot for belt tightening moves a  bit (maybe 10 degrees) in the threaded hole that it screws into, but is firmly jammed in the tube itself. More Plusgas added and I may be able to tickle it with a propane flame tomorrow - needs care not to fry things !

[awemawson]

 Sea.Dog I found this image on a Rolls Royce forum where someone has opened up one of these regulators - but if you look at the die cast lettering on the case it confirms our assumption 

[Sea.dog]

We can feel a little smug then 

[awemawson]

Today I was determined to get the charging alternator off and identify it. The pivot bolt would unscrew from it's bracket but was stuck absolutely solid in the bore in the alternator itself.

In the end I had to remove the adaptor bracket from the side of the engine and with it in the vice apply rather a lot of violence before in the end it yielded.

Having removed the bracket and got the alternator out a plate was uncovered revealing that it is a CAV AC5A24-3 - now these are still available as they are used on Rolls Royce's and Bentley's but for rather a lot of beer tokens

So I visited SAE services in Ore where Steve runs a one man band auto electrics shop out of a double garage behind the shops. Having gone through his stock of new alternators trying to find something physically  compatible he then remembered that he actually had an old AC5A24-3 tucked away that worked but had knackered bearings - pictures of the Queen changed hands and my task this afternoon is to dismantle it and identify the bearings and order them up.

[awemawson]

So an early lunch then start pulling the alternator apart. I've changed many but never dismantled one before - how hard can it be 

Not too bad really - I hadn't realised I'd have to un-solder and remove the slip ring assembly, but using 'chuck wedges' pulled it off it's spline eventually. I'll put a bit of Loctite on it on re-assembly.

Bearings came out without too much drama - whole thing would have been very quick if I hadn't been distracted by an urgent call to fix a cattle crush as the Vet was waiting to do a TB test - no pressure 

Bearings measure out at 20 x 52 x 15 mm and 15 x 35 x 11 mm both being double rubber sealed. £11.28 produced a pair for delivery later in the week which isn't too bad at all 

Now I need to measure up some anti-vibration mounts that hold the oil pressure and charging gauges and the big electrics box as the originals have perished not surprisingly after 47 years !

[hermetic]

So why was there no oil pressure showing on the guage Andrew? Faulty electric sender?

[AdeV]

...urgent call to fix a cattle crush...

I could ask my sister (who is a vet), or you, what a "cattle crush" is, but I prefer to imagine it's a crushed ice-based drink, either grass or beefburger flavoured, served in a black-and-white mug with a large stem of hay, a pair of Christmas cracker fake cow horns, and drunk through an udder......

 

In all seriousness, it sounds rather nasty, and I hope all concerned emerged unharmed.

[awemawson]

So why was there no oil pressure showing on the guage Andrew? Faulty electric sender?

Puzzled 

Oil pressure is showing in excess of 60 psi whenever the engine is running - there was no pressure showing at initial cranking but that's not really surprising.

Ordered some light blue hammer finish paint and some anti-vibration mounts today. Lets see if the weather lets me trot outside with it and attack it with the steam cleaner in the next day or two

[awemawson]

...urgent call to fix a cattle crush...

I could ask my sister (who is a vet), or you, what a "cattle crush" is, but I prefer to imagine it's a crushed ice-based drink, either grass or beefburger flavoured, served in a black-and-white mug with a large stem of hay, a pair of Christmas cracker fake cow horns, and drunk through an udder......

 

In all seriousness, it sounds rather nasty, and I hope all concerned emerged unharmed.

A cattle crush is a sort of tight pen holding a cow (or bull) tightly so that various things can be done to it, such as administering various veterinary products, or for instance artificial insemination. In this case it was a TB test:

"The TB skin test is the common name for the Single Intradermal Comparative Cervical Tuberculin (SICCT) test. This skin test is regarded as the definitive indicator of infection by the bacterium that causes TB in cattle - Mycobacterium bovis. It is the required test in the EU and has proved to be a reliable tool worldwide. In Northern Ireland, all herds are tested annually, as a minimum requirement, but some are tested more frequently if they are considered at increased risk.

On Day 1 of the test, two sites are clipped on the neck of the animal. The skin thicknesses at both sites are measured and recorded. Two types of tuberculin, one made from killed Mycobacterium bovis and the other from killed Mycobacterium avium, are injected under the outer layer of the skin of the neck (i.e. into the dermis) at the ‘bovine site’ and the ‘avian site’ respectively. On Day 4 of the test, the skin reactions to the two types of tuberculin are measured and compared. When the bovine site reaction exceeds the avian site reaction by more than 4 mm, the animal is declared a reactor under standard interpretation. When the bovine site reaction measures 1-4 mm more than the avian site reaction, the animal is declared an inconclusive under standard interpretation."

[awemawson]

So today's job was to steam clean the engine and chassis, but first a bit of preparation was needed.

A/ Remove exhaust flexy and silencer and blank off the exhaust manifold.

B/ Remove starter motor (the terminal post for the solenoid needs drilling out and re-threading) and blank off it's mounting hole

C/ Wrap the outer end of the main alternator in plastic and tape to stop splashes getting in

D/ Remove the rest of the wiring and associated trunking from the engine.

(The blanking pieces were made from 6 mm steel only because there happened to be an off cut on the plasma table)

Then it was a case of fork lifting it into the rear farm yard, putting it on blocks and dowsing it in 'Gunk'. While the gunk was soaking into the muck I dug out the big steam cleaner and set it up. Then set too with extremely hot water.

Once steam cleaned it didn't look too bad - still loads of flaking paint to deal with but less than before. It then got a second 'Gunking' and steam cleaning to get any bits that I had previously missed.

[awemawson]

The removable covers for things like the air intake filters I will sand blast in the cabinet blaster and paint as separate items.

Next I removed the remnants of the canvas 'air duct' that had lead hot air from the radiator and fan to the outside world. The canvas had just been cut off and what remained was trapped by 1" wide steel strips retained by self tapping screws that were the devil of a job to remove.

Once that was off I then removed the fan & fan belt mesh cover - I needed to be able to remove the fan belts to measure up for replacements. Again the mesh will be painted as a separate item. The three fan belts are surprisingly narrow - probably originally 3/8" 58.25 " long from the 1972 build date. They are being replaced by 9.7 mm x  1483 mm modern ones - I think that there is enough adjustment to accommodate the slight variance.

While this was going on, the new paint arrived.

I had a go with wire brushes to start the task of getting rid of the rest of the flaking paint. It's not going to be a 'back to bare metal job' as that would take far too long, just get rid of the loose stuff. It's an immensely tiring job and I'm now whacked 

[awemawson]

I thought that I'd have one last try with the starter motor terminal with the seized grub screw. It was at the point that the D shapes either side of the screwdriver slot were shearing off. I was sure that if I could heat it up it would unscrew - but it's mounted on (inflammable) paxolin and is adjacent to the main terminals that are also mounted in a plastic insulation.

So how to heat it safely.? I hit on the idea of drilling a shallow hole in a rod such that it would just fit onto the body of the terminal post. I then heated the end of this rod to red heat and pressed it briefly onto the post. Rapid application of a screw driver and out she came - success    So that's one more job off the list.

One oddity that I noticed when steam cleaning: Each cylinder head stud has a cross drilling in the head such that the stud can be seen from the outside world. I can only conjecture that this would allow you to cross drill a seized stud allowing the head to come off, and leave enough stud in the block to weld onto and unscrew. It may be for some other totally different reason, but it's the first time I've seen it on a cylinder head, in fact the only time I've seen this sort of thing was on a wooden boat with a timber keel with a  lead ballast keel bolted  on, and cross drillings were used to put the nuts on the bolts !

[awemawson]

The charge alternator bearings arrived yesterday so today I re-assembled the alternator - all went well until I realised that I'd left a spacer off - Plonker ! - didn't take too long to take it apart and put the spacer in, and now it spins beautifully on its new bearings. The rear cover was pretty knocked about so it got grit blasted and given a coat of zinc rich primer.

Having got that pesky grub screw out from the starter motor terminal block I wanted to replace it, but what thread? Almost 2 BA but bigger than 4 BA and not metric - what the heck is it? Turns out that it's 8-32 UNC that nice common size! However the gods were smiling on me as it turned out that I have a whole box of them - OK they are Hex socket ones but that's OK. So starter motor cover replaced and it's ready for a lick of paint before re-installing.

Today electrical parts have started arriving. I've sourced an old style Contactum metal single phase consumer unit. I've previously used an identical one with it's innards stripped out, to house 3 phase MCB's and an Isolator so I know that it will take Wylex 3 phase MCBs and I also have a Contactum 30 mA RCD on order so this box will take the low current 3 phase from the main alternator via the RCB and a 6 amp MCB to feed the front panel metering, so at least it is a bit safer than the previous unfused and non RCD'd arrangement.

Also the three new fan belts have arrived and seem to be correct I won't know for sure until the charge alternator is re-fitted.

I spent some time investigating the various sensors and switches on the engine. On the oil feed there is what I presume to be a simple pressure switch, it's open circuit - OK it may well close on pressure but if it doesn't it's a commodity item and easily changed. On the housing for the spigot for the water hose leading to the top of the radiator there is what may be either a temperature switch or possibly an analogue sender - I can't unscrew it yet as it's below the water line, but I will when I drain and fill with anti-freeze (memo to self - order some!). Then on the water / oil heat exchanger that is bolted to the engine there is a tubular heater element  marked 220-250 Volt which is obviously a 'winter warmer' to aid starting, however it is currently open circuit. Its fixing flange nut measures 42.82 mm AF and try as I might I cannot get it unscrewed using large adjustables, and I don't want to ruin the rather thin flange. I may end up cutting a ring spanner on the plasma table, but of course until the engine is drained I can't completely remove it anyway.

The mounting plate for the fuel solenoid must have taken a knock at some time in it's life as it was bent rather Z shaped. I removed it, squashed it flat on the 60 ton press, grit blasted it and gave it a coat of zinc rich paint.

After that it was a case of more paint scraping to try and remove the flaking bits - I can see this could go on for days, but I have to be realistic and say enough is enough and hope the new paint glues down what I've missed 

[awemawson]

I have to go visit a friend in his nursing home this afternoon so I was packing up early, but as I was washing my hands it dawned on me - I've drawn up a hexagonal spanner in Autocad before for some project - it just needs the right scale applying and I don't have to start from scratch 

Turns out that is was a 55.5 mm spanner, so applying a scale factor of 0.77477 gave me a 43 mm spanner that fits nicely. A quick trial and I've undone it one 'flat' - daren't go further or I'll let the water out!

Did I ever say that I LOVE my plasma table 

[John Rudd]

Is it possible to be toooooo envious of someone? 

I do miss working.....we had 3 3.6mw turbine gensets with deutz diesel hydro starters........

[awemawson]

John, I don't miss work at all, but I do intend to enjoy my play time 

Today's Progress:

I decided certain things needed removing as they would be far easier to clean up off the engine and actually will get in the way when it comes to spraying. So I removed the Purolator air filter housings, the instrument panel, all the contents of the relay box (fuel solenoid and starter relays) and also the top of the terminal box for the main alternator - this later item wasn't in anythings way but was difficult to clean being under the diesel tank.

I tested the ammeter and the oil pressure switch which both worked OK 

Then I went into an intensive cabinet blaster blasting session, emerging over two hours later with some cleaned up parts ready for their zinc primer.

Prior to this I made a new window for the cabinet blaster - surprising how a gradual blast etching creeps up on you and you think it's misting - what a difference, I can actually see what I'm blasting !

[John Rudd]

Looking good so far...

I guess by the time you have finished, it'll be worth twice what you paid for it.....

[awemawson]

Well John, at least hopefully I'd be able to offer to demonstrate it working were I to put it up for sale, but that's not the intention. As you know I bought it as 'spares or repairs' as a bit of a pig in a poke, as I'd not even seen it in the flesh - sometimes you just have to take the risk and this time it paid off 

[awemawson]

After supper I removed the metering panel from the main 'box' reasoning that it is easier to remove it than mask it up for spraying. Anyway I need to sort out it's wiring. Essentially it is driven by the three phases and neutral for voltage selection and the hours meter, and the leads from three current transformers for the amps meter, so theoretically it shouldn't be too bad, but those stacked selector switches always confuse me as to what is connected to what and when 

The drive cables had to be cut to remove the relay logic board, but anyway the three phases and neutral need feeding through the 30 mA RCD for a bit more safety. The RCD arrived in the post this morning so I can press on and build the sub board.

The panels were retained by self tapping screws - I don't like self tapping screws in this situation, anyway they were quite rusty. I'll probably replace them with nuts and bolts as hand access to the rear is fairly good. I contemplated putting in 'hank bushes' and may still. At least there is no marking out to do, all the 'pilot holes' being there already !