A cooked engine

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Post by Phil Bradshaw » Club admin » Wed Dec 11, 2013 11:27 am
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3818
Being a tale from 2009 of a disaster occurring to a CF350 coachbuilt camper with a 2279cc OHC (slant) engine running on LPG.

The cause: a split heater hose -

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The result: cracked cylinder head, here cleaned up enough to show the worst of the damage.

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Reason for cracks is that the engine was well and truly cooked when it ran out of coolant; pistons left smears of alloy on the bores along with some deep gouges.

Replacement cylinder head from engine donated by Skoota.

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Exhaust valve seats a bit peppered so it's getting inserts for LPG (installed already) & to keep standard tappet adjuster screws.
Last edited by Phil Bradshaw on Wed Dec 11, 2013 5:29 pm, edited 1 time in total.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: A cooked engine

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Post by Phil Bradshaw » Club admin » Wed Dec 11, 2013 11:34 am
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3818
This is while the short motor was on its way out of the van, with the gas regulator removed from the chassis next to the oil filter.
Rust on the bores is pretty much what appeared the day the head came off.

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Orange gas hose for petrol ... ye gods, the hose has softened so much it almost came off before the clips were released.

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There's a bit of tidying up of wiring & plumbing to do before the lump goes back in; the hose stub behind the plastic tee in the heater hose is where there was another tee, equally squashed, and the split moulded hose to the thermostat housing, here with the home brew replacement made up from 15mm copper (with a stub soldered in the elbow so that the hose clip won't crush it!) -

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The copper is over-long yet because there's a tee to fit once the engine is installed & then enough plain 5/8-inch hose to soak up engine movement; the elbow is for the thermostat housing end where plain hose would kink.

Cylinder head has gone in for exhaust valve seats for LPG, valves refacing & a skim. Before it went it got measured up because the exhaust valve clearances were minimal (0.010" or so) with the tappet adjuster screws out as far as they would go. This was with valve stem protrusion above the top face (H) of about 1.09"

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Alarm bells started ringing; this wasn't much a problem when CFs were in production because undersize tappet adjuster screws would compensate for up to 1.13" protrusion but they're not so easy to find (especially the ones I'm convinced I've got, somewhere...).

What this head needs on the exhaust valves is H = 1.07" to use the standard tappet adjuster screws it came with (same on the cooked engine) so that's what has been specified for the exhaust valves once the seats are done. (Removing material from the tops of valve stems isn't on; ~0.030" ground off is enough for the valve spring caps to foul the tappets with undersize adjuster screws in.)

Waiting for things to happen now so there's been some fettling so that when the engine goes back in there'll be no distractions.

Carburettor had b-all wrong with it that cleaning & adjusting wouldn't sort out but the idle shut-off solenoid was missing its lead.

New lead soldered to the remains of the old one, a blob of Araldite and the lead doubled, heat shrink sleeved then tied to the solenoid so hopefully it won't pull off again, for a while anyway -

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Distributor needed a new baseplate earth lead as well as contact breaker points and a new condenser but otherwise it's got no play where it matters and the vacuum unit is working -

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- and once it was back together the coil got tested with it because it has '12V' on the label...

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However, coil primary resistance is 1.7 Ohm, right enough for a ballast coil, & wired with the distributor to a battery through a 1.6 Ohm wire-in-ceramic ballast resistor it whacks out sparks a good 1cm long (so the new condenser is ok too).

The exhaust manifold was a pig, plain & simple: no studs for the exhaust front pipe & the hot air scoop almost broken off completely.
First off, the holes that had been drilled out when the original studs were shot weren't even straight; however, there was enough metal left to run a 10mm tap through to loosely fit cut-down 10mm cylinder head bolts that happened to be handy -

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- and a locknut on one with a dowel pin for the other will keep them in long enough to rust in. Brass nuts doubled up with locknuts to stop the threads from going too rusty too quickly (but being 'hard' steel they won't rust as quickly as original mild steel studs).

Hot air scoop took what seemed forever because the original bolts had to be drilled out starting with 3mm for pilot & working up gradually because they're hard enough to have to keep sharpening drill bits every 2-3mm (& much cussing when one bit broke); good job the original bolts were only about 10mm long.
New bolts are 5/16"UNC x 5/8" long with 1-1/4" mudguard washers underneath, 1" cup washers on top to make sure the scoop won't be rattling too soon. A set of new bolts for fitting the manifold just needs a set of lock tabs...

A change of plan since the lump got taken out & stripped down: the crankshaft & bearings are perfect & although the pistons are ruined a 2nd ring off one of them gapped ok in the bores of the 'new' engine from Skoota that had well worn rings.
This prompted a closer look at the bores: wear ridges that can't be felt but show up with back light because the bores are glazed might disappear with honing.

So, once everything is all cleaned up & measured accurately there's a good chance that a hone and new rings might be all that's required. That said, a set of new rings isn't cheap (£100 or so) but neither is a set of pistons, £340 from Thorntons. We'll see; I've got places to visit yet to see whether the rings come cheaper matched by sample.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: A cooked engine

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Post by Phil Bradshaw » Club admin » Wed Dec 11, 2013 12:15 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3818
Inlet manifold: the donkey work

The inlet manifold has needed a fair amount of fettling: gasket faces weren't exactly flat and corrosion due to lack of inhibitor in the coolant has eaten away at the thermostat housing and cylinder head mounting flanges. Nowt new there then...

The (almost) finished article -

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Cylinder head gasket faces were the worst corroded with the unused rear port blending into the corrosion next to it where the gasket is open to a cylinder head channel.
On its own it wouldn't have been too hard to restore but both faces have to stay in-line & what came off one had to be taken off the other.

It took what seemed like forever but it's close enough now, 0.003" over the length of both faces using a straight edge - got that using a diamond 'stone' for finishing, £3.50 well spent I think.
Test will be dry fit to the head when it's done to see whether it needs any more fettling if the head faces are slightly out too.

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Carburettor flange was almost flat but needed pull-up around the studs taking out.
I didn't know carburettor nuts could be tightened so much ... all revealed when I plonked the carburettor on the manifold once that flange was flat: 0.018" gap in the middle.

Carburettor revisited, flange trued up & when it was being re-assembled with the return spring fitted now it's to hand I discovered that the throttle damper wasn't working.
A few sharp taps of the plunger on a hard surface seems to have convinced the valve inside to start sealing now; one to keep an eye on because although it won't affect driving the van it might be an issue at MoT test (emissions go high as the throttle is closed quickly if the damper isn't working).

Thermostat cover I think has been replaced not too long back with not being as rotten inside as the recess for the thermostat in the manifold; there's enough of an edge left to support a new thermostat though, a 92 degree one (QTH107) instead of the old 88 degree one (QTH102) that looks old enough to need replacing anyway before putting antifreeze in the cooling system although it test ok.

Flashlube adaptor -

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The Flashlube fitted to the van was piped to the air cleaner Air-Vac spigot on the servo adaptor.
Fine for cylinders 1 & 2 but 3 & 4 wouldn't get much of a look in.
Under the carburettor is what looks like a plug, in fact where the vacuum bleed that teed into the engine ventilation hose was fitted on early CF1s but is now part of the manifold casting.

Pilot drilling with a 3mm bit got the depth before drilling for 3/8" UNF (Q drill bit really but 21/64" is close enough with the alloy being relatively soft).
Shape & length of the brake tubing is a guess; likely it'll need shortening some when the Flashlube is re-instated, up front somewhere instead of under the cab engine cowl, next to the exhaust manifold.
Reservoir bottle hasn't melted but it doesn't look that old anyway.

Butyl O-ring is for a 'soft seat' that's easy to seal & avoid risk of bursting out the bottom of the drilling; countersink in the bottom of the tapped hole seals against the single flare well enough though.

Bits & pieces -

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and the details (dry fit less gaskets)-

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The 0.2" thick washer on the left side really makes a difference when getting at the nut: easier than with a plain flat washer because a spanner doesn't jam against the carburettor body so easily. The other nut is easy to get at anyway.

Coil bracket mounting -

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Without the 1/2" thick spacers the coil can overheat. With a slotted bracket it's easier to loosely fit the bolts then slip the bracket under the plain washers & then tighten up.

Incidentally, with flat gasket faces plain nuts with spring lock washers need only be tightened enough to fully compress the washers.
That's why I think it's worth the effort to get faces as flat as possible; even though Payen (Federal Mogul now) gaskets will accommodate a degree of distortion, each time alloy bits have to be tightened down a bit harder in order to seal properly the distortion gets worse.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: A cooked engine

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Post by Phil Bradshaw » Club admin » Wed Dec 11, 2013 2:35 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3818
Oil pump

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Pristine; almost as new apart from scuff marks on the bottom plate indicative more of slight machining misalignment of the rotor shaft with the end plate.

I didn't think it was too bad though when it was still in the engine; the drive shaft peg took some turning with the fingers & once it turned it felt really smooth. A big relief considering the prices new oil pumps fetch.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: A cooked engine

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Post by Phil Bradshaw » Club admin » Wed Dec 11, 2013 2:37 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3818
Engine mounting

I can get Quinton Hazell EM1448 for £6.90 next day direct from QH but these days they come minus the locating peg near the threaded stud each side.

For about 10p the fix is 1/4" Sellock (roll spring) pins -

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The mounting plate that fits to the engine makes a reasonable template but the round plate from the well squished original mounting turned out better once what was still stuck on got attacked with a boning knife (deeply curved cutting edge - ideal for slicing thick rubber).

The stud punches out as does the peg and the plate dropped onto a mounting provides a better guide for a 7/32" drill bit (peg hole isn't quite 1/4"). Dowels pressed in to leave 3/16-1/4" protrusion; I used 5/8" long dowels, drilling 7/32" diameter into the rubber then opening out only the hole in the steel plate to 1/4".

Dunno why Quinton Hazell have chosen to delete the pegs; once the mounting nuts are tight the pegs are redundant but without them the mountings can't be aligned properly until the gearbox is refitted & the engine lifted so that any twist in the mountings is released.

Sod that: once the short motor is in I want to hear the mountings click in so that they can be tightened up there & then. Too easy to forget to go back after an hour or three...
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: A cooked engine

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Post by Phil Bradshaw » Club admin » Wed Dec 11, 2013 2:40 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3818
Water pump

Another almost pristine bit -

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Bearing is smooth and tight and there's not even any distortion on the gasket face. Cast impeller too: has a flywheel effect that balances any fan imbalance; them as fit pressed steel impellers probably aren't too bothered if you need another pump sooner because the bearing has given up because you've got a steel fan still or a plastic one that's seen better days...

Hose to replace the very soft old one for the pump to elbow connection is 2" length cut from 32mm inside diameter Mafco hose 451-5670 with bonded fabric outer layer: a whole 50p for the 2 inches and plenty left if anyone else wants a piece.

EDIT. 4 years on and Mafco 451-5670 hose is nearly twice the price. :(
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: A cooked engine

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Post by Phil Bradshaw » Club admin » Wed Dec 11, 2013 2:45 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3818
Alternator

The Delco alternator came off as a black oily mess inside as well as outside with bearings dry (what lubricant was left was well congealed). However, once the bearings were cleaned out they were fine -

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Rotor slip rings are good too: 0.864" diameter & not scored.

Front bearing as good as new once cleaned; bearing housing bore in end bracket and retainer plate undamaged too -

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Front bearing packed with grease & pressed back into casing -

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and the seal in the retainer plate checked out ok on the ring on the rotor (below); retainer fitted with a wipe of grease on the seal & a dab of Loctite 243 threadlocker on each screw -

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then rotor fitted -

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Now the other end: bearing pressed in & greased (bearing has an integral seal) -

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Bits sorted out after rectifier & diode trio checked with an Ohm-meter -

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Rectifier & regulator fitted, regulator loosely at this stage -

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Brushes & their springs fitted to brush holder & held in place with a piece of stiff wire (single strand earth from some 4mm twin & earth mains cable in this case) -

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Brush holder assembly fitted with wire passing through the drilling in the casing provided, then diode trio fitted -

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Stator tested with an Ohm-meter & fitted; wire holding brushes adjusted so that about 3mm protruded above the brush holder in order to clear rotor -

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Last chance to check all fixings are tight. Regulator screws with insulators have 1/4" AF heads; rectifier connection nuts are 9/32" AF.

Final assembly -

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when the wire holding the brushes in can be withdrawn. Casing screws have 5/16" AF heads.

All that's left to check is the regulator (can't be done with a meter alone). Without a test rig handy (in progress - found an old spin drier already to rob the motor from & bits & pieces to replicate the one I had umpteen years back but it's f-f-f-ing freezing in the shed) this will have to wait until the engine is in & running to check the output.

Very much a stitch in time: if the bearings had been left dry then the rotor could clobber the stator & write off both if either bearing gave up.

It would have been nice to fit new brushes too (old ones 12mm long, minimum length is 10mm) but it looks like it's going to be a while before I can lay my hands on some at a reasonable price; still, it'll be a while before the old brushes wear down (unlike Lucas ACR units...) & it's not much of a job to change them.

Here's hoping the regulator tests ok...
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: A cooked engine

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Post by Phil Bradshaw » Club admin » Wed Dec 11, 2013 2:47 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3818
Fuel pump

There's not much can be done with the later fuel pump except clean the screen under the cap -

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The seals were fine (the one under the screw head is best left alone unless it's bad enough to need renewing). Locating pips of the screen are to centre it in the cap; easily missed...

Vacuum & pressure checked out ok when reassembled -

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This had to go -

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I hate this stuff being used on engines because it can look fine but once it goes hard & can be twisted with the clips tight it will leak. This bit, for between the pump & carburettor, was so hard that it twisted off the pump spigot without slackening the clip. Bin.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: A cooked engine

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Post by Phil Bradshaw » Club admin » Wed Dec 11, 2013 2:54 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3818
Starter Motor

Lucas M35J PE unit had the usual worn bits - brushes & bushes - and also a faulty solenoid end cap. Like the alternator is was oily messy inside, so first some notes on cleaning of starters (applicable also to alternators re: windings insulation, brush gear).

Armature can be ruined by immersion degreasing that can soften insulation on the windings & is best cleaned using a 'vapour degreaser'. In th'owden days Trike (trichloroethylene) did the job but it's a CFC so as a general rule it's best to just clean up the commutator segments unless what's being used won't soften shellac or modern substitutes (polyurethanes etc.)

Field coils are insulated using resin-impregnated paper & are best left alone unless soaked already. However, like the brush end plate they can be cleaned by immersion using a water-miscible degreaser (e.g. paint brush cleaner) provided rinse water is allowed to dry off completely; insulation must be bone dry & springy before re-assembly.

Brush gear should never be cleaned with anything that can leave oily residue in sintered brushes; this will lead to poor contact & can cause arcing severe enough to scrap the armature.

(And yes, I've ruined a few starters & alternators over the years with not bothering what I used for cleaning...)

Drive end plate.

Bush renewal -

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Best guide to wear of bushes is to compare play on armature shaft of old & new bushes, dry.

New bush soaked in warm engine oil overnight & pressed in flush with outer face of housing.

Brush end plate.

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Old brushes getting close to their limit, after which arcing can destroy the armature commutator segments (below). Field coil brushes wear at a slower rate but brushes are best renewed as a full set.

The shouldered rivets securing the plastic brush holder were loose (not unusual); place to peen them down is from the side shown while supporting the other ends on something substantial. Gently does it though; peen rivets to stop the holder from moving but don't bust it.

Top hat bush soaked in engine oil overnight before fitting. End plate must be supported on its boss inside the brush holder, NEVER on the brush holder, or it will break.

Brass nuts are 7/16" AF.

Assembly -

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Brushes wires deliberately are too thick to pass through the narrow tops of the brush holder slots; tease wires through so that they can be re-formed once through to hold the brushes against the holder springs.

Field coil.

Waxed paper insulation should be intact.

Brushes renewal requires a fairly hefty soldering iron -

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Enough of the original spot welded brush leads needs to be left intact to solder to (field coil windings are aluminium). 1/4" both sides can be a little too much sometimes especially if solder is allowed to wick along the new brush leads. Braided leads like the ones used are better than twisted leads at resisting wicking. Make sure the connection holds itself in place as tightly as possible before soldering.

Assemble brush end plate to field coil casing -

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Patience required ... to hook longer lead under the lug of the brush holder and work the brush leads through the narrow tops of the slots & against pressure of the brush holder springs until they stay in place.

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Screw heads are 7/32" AF.

Solenoid.

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Solenoid end cap -

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Old type with 1/4" (6mm) studs and IGN tap for 'cold start' wiring (slant engine with Delco ignition system) is hard to find (NOS only); new cap is Ford pattern with 8mm studs.

Cargo make comes with a blade terminal kit to fit the Ford pattern 5mm stud IGN terminal -

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Original solenoid terminal nuts are 7/16" AF; new ones are 1/2" AF. Blade terminal nut is 5/16" AF.

Assembly -

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Fit insulators flush with body face after wires passed through slots, fit O-ring seal in cap recess & place contact plate assembly in position -

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Loosely fit cap ensuring that wires will pass through holes in solder tags.

Assembly -

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Screw heads are 5/16" AF.

Armature

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Pinion assembly has a one-way clutch; pinion can be turned one way but not the other when it should lock; any slip when the body is securely held in a vice will cause the starter to squeal or squawk & sometimes fail to turn the engine at all.

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Insulation between each segment and armature shaft should have high resistance.

Commutator segments can be dressed with fine emery to clean them up; all dust must be removed afterwards. Skimming more than 1mm from the face isn't on; there's precious little copper to start with. Wood Auto armatures come with thicker commutator, worth ~£30 they cost I think; recon starters usually have Lucas original, skimmed...

EDIT. Wood Auto armature now about £50. :(

Lightly grease scroll on armature that the pinion rides on before fitting pinion.

Locking the snap ring -

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A stretched snap ring can be closed up with pliers until the collar can be started over the ring.

(To unlock snap ring, drive collar towards pinion using a tube or socket that clears the snap ring; snap ring then can be levered out but it can be a tricky little blighter sometimes.)

Starter assembly

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Retainer can be pressed onto armature shaft end with a suitably sized socket to obtain about 0.010" (0.25mm) end float maximum (gap between retainer & bush when armature pushed against brush springs).

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Starter operation can be checked at this stage by holding it securely, connecting starter body to one side of a battery and touching brushes terminal with a suitably thick wire connected to the other battery terminal. Armature should run free with a whizzing sound with only the pinion lever rattling, if at all.

Solenoid plunger -

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A smear of grease on the retainer helps to get it in the right way round & also provide lubrication for where the plunger engages the pinion lever.

Final assembly

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Fit & stake lever fulcrum pin-

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Pin is mild steel & can be staked with a cross-point screwdriver bit -

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With pinion held fully forwards, engage solenoid plunger with top of lever (push against rebound spring retainer), fit main spring & foam rubber seal -

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Almost there -

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Altering brushes lead to fit solenoid terminal -

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Correct terminal is for 16 sq mm cable; shank is approx. 5mm internal diameter. Cable insulation usually suffers when un-soldering the old flag eyelet terminal (terminal needs cutting first to break crimp grip): heat shrink tubing fixes it.

When attaching cable to brushes terminal the first of the 2 nuts must be held with a spanner to prevent the brushes stud from turning when tightening the second nut.

Fit IGN blade -

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IGN terminal nut is 5/16" AF.

Extra 8mm eyelet terminals will be needed to replace 6mm eyelets on van wiring.

Check starter operation by connecting body to one side of a battery and solenoid terminal with large blade connector to the other side; from the solenoid connection bridge to the soldered blade terminal (not the IGN terminal - nothing will happen), when solenoid will throw the pinion forwards and the armature will spin almost at the same time.

It turned out that the wiring terminals on the van are 8mm already. Saved some crimping & soldering on the van wiring.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: A cooked engine

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Post by Phil Bradshaw » Club admin » Wed Dec 11, 2013 3:00 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3818
Flywheel & clutch

Flywheel was worn on the clutch face -

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The gap under a straight edge measured with feeler gauges was 0.018" after the face was wire brushed; not too bad as clutch faces go but the CF slant 9.5" clutch mechanism needs all the help it can get to release the clutch as it wears and the diaphragm spring starts to 'cone' or the operation will get too heavy long before the linings wear down to the rivets.

Skimmed flywheel -

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The clutch cover (pressure plate) locating dowels have to be removed before the clutch face is remachined; they're in tight though. Quickest way I've found to remove them is to bash the claw of a claw hammer onto each dowel close to the flywheel face then insert a rod under the claw so that the dowel can be drawn out in one go. This nicks the dowels but with being relatively soft they re-form well enough to fit the clutch cover locating holes if refitted upside-down to how they came out.

If the dowels have to be drilled out then they can be replaced with 1/4" Sellock (roll spring) pins 5/8" long (& they're easier to remove next time by squeezing them with vice grips so that they close up a little.

Clutch -

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Rusty clutch face on the cover is where the centre plate can stick when a van sits for long enough, usually resulting in the clutch not releasing; sometimes this can happen on the flywheel face as well just to add to the problem. The centre plate unsticks readily enough when the clutch is removed ... somewhat more easily than trying to shock it free by starting the engine in gear.

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Once the cover was cleaned up the lack of wear on the ends of the diaphragm spring fingers & no wear lip on the clutch face boded well. The rivet depth below the linings faces both sides of the centre plate is only about 0.020" less than new (& that's including the surface 'furring' on the ground faces of the linings than soon rubs off when the clutch is used.)

Release bearing has nothing wrong with it so all it's needed is a wipe to be ready to be refitted (immersion cleaning can wash out bearing lubricant).

Another box ticked - 9.5" clutch isn't cheap.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

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