The Moo Engine Re-build

[OWmoo]

Part One. Up in smoke

A cloak of whitish-blue fog hangs over the once lovely town of Llangollen, Denbighshire. It was left there by my Morris last August on the homeward leg of our annual, ‘No kids, no dogs, no technology’ holiday touring Gods own. The Moo didn’t let us down throughout the 600 mile round trip but there was just one slight problem; she’d gulped over 5 pints of oil in the process and then on occasions, usually on prodding the accelerator after a period of over-run, a humungous great cloud of smoke came out the back and obliterated the queue of camper vans and 4x4’s in our wake. Mmm, worn valve guides I thought or maybe something else? There was another concern that made me wonder if something more than a few rattling valve guides needed attention. A couple of weeks before the tour, I thought it was high time to do an oil change. Imagine the shock-horror when I undid the oil filter bowl and found the filter lying uselessly in the bottom with no washer and spring. So far the un-answered question remained; if that’s what’s on the outside, what’s it like on the inside?

I took pity and bought the Moo eighteen months ago as a kind of rolling project. She’s a ’67 1098cc 4-door that’s had at least a dozen previous owners. The motor was a little grimy; some oil was leaking out of the forward tappet chest cover but not enough to leave a splodge on the drive. Despite that, the engine ran quite showed no loss of power, no rumblings or other nasty noises. By late October and with the nights pulling in, I decided to oik the motor out and prepare for a winter engine rebuild project and solve the mystery of the disappearing oil.

I suppose like any other Minor this one’s spent most of its life being passed around as a cheap old banger. FSH? Don’t all laugh. The engine has been painted in blue Hammerite, the rounded corners on bolt heads and great gobbits of gasket goo all tell a tale that this motor has been got at before – several times over. What lurks inside is about to be revealed. Well here goes….

Here’s your starter for 10. I’m suspicious that the tappet chest cover bolts are short and this might be why one of the covers is distorted. Does anyone know what length they should be?

Pictures;-
On the bench and ready for the autopsy.
Set of plugs. A bit black and a bit oily.


More to follow………[frame][/frame][frame][/frame]

[bmcecosse]

Plugs don't look too bad really... I would have run a compression test while it was still in the car - and lifted the head to inspect the guides. I have a head where the guides were allowing 1/16 movement AT THE GUIDE - and so that sort of thing will make a great cloud of smoke.... Strip the head before you go any further.

[OWmoo]

Ta muchly, the advice is sound. I was thinking about doing a bit of diagnostics whilst the motor was running, but it was coming out for a winter once-over anyway. Here's an update;

Part 2. Horrible History

Back in the days of long hair and loon pants I had a ’65 Austin Mini Countryman (the all steel version). I put in an 1100 engine complete with an aftermarket remote gear change. I later had a ’66 998cc Cooper and rebuild the engine for that so I’ve done some work in the past on A series motors. Getting an engine in and out of Mini was all grazed knuckles and swearing. Once you get one out you find that some clever-dick had put the gearbox in the sump – how silly can you get.

The Moo is another survivor. It’s been hacked about and out of fashion for most of its life. It’s survived countless transport ministers, scrappage schemes and probably a host of owners whose toolkit seemed to comprise a blunt wooden-handled screwdriver and a coal hammer. Quite simply the Moo shouldn’t be here but it is. With that you don’t want to be the gink who brings about the final demise. We’ve done the sills, floor-plan, wiring, brakes and got through an MOT. Now it‘s time for the engine.

A clear Saturday morning arrived. Out with the battery and radiator, off with the carb, and all the accoutrements. So far so good. I managed to get my hands on a gantry and made a couple of lifting brackets out of some 70 x 6 equal angle that I’d liberated from a scrap-bin at work. I put a block of wood under the motor and supported the deadweight on a bottle jack. All we had to do now was release the engine mounting bolts having given them a long overnight soaking with WD40. One or two of the crusty devils refused to budge, it was getting dark and needs must so I set to with a nut splitter but the ones near the roll-bar had to be sliced off with a small angle grinder…. They didn’t mention that in the famous do-it-yourself manual. I suppose it was a whole lot easier than the Mini’s I once had.

After a grand old clean down with paraffin it was time to face the music and get the head off. Rocker cover; no probs. Rocker shaft; looking fine and no play, so too the tappets and push rods. A set of cam followers looked like new and there was no signs of any wear on the cam lobes. Things were looking up. I’d already prepared by collecting cardboard boxes and bought a roll of sandwich/food bags to place each set of parts in a numbered bag. With Christmas approaching I treated the Missus to a new baking tray and nicked the old one for use as a de-greasing tank. I’m very generous when it comes to kitchen hardware.

With a deep draw of breath the head was lifted. What a wondrous site to behold. +.030” pistons, decent looking bores, maybe a bit of scouring from enthusiastic hand-honing but no step at the tops. The measuring stick placed about a third of the way down each cylinder - spot on, no re-bore required here, though I’ll probably do a light hone. So far, I’m a happy bunny.

More to follow

Pictures;-
Years of gunge build up inside the bell housing. It can wait another day
+.030” bore’s OK. No axial scores, no step at the top.[frame][/frame][frame][/frame]

[OWmoo]

Part 3. The Good, the Bad and the Stuck.

I’ve placed the cylinder head to one side even though I think this might be the culprit. I then set to work on the main lump to have it stripped, cleaned, inspected and re-build first. In taking out all the peripherals I hit a couple of snags. Firstly, the oil-pressure release valve was stuck on its seat. No amount of squirting WD40 made any difference. I stuck my little finger down the hole and you could just feel the thimble move but it wouldn’t budge. Time to build the ‘Mk I OW patent oil-pressure thimble extractor’ made from a length of 12mm dia bar bored out to make a body tube. The end was knurled so it was a close fit in the thimble. The knurled end was slotted with a small hacksaw and then a tapered collar screwed onto a M6 bolt so that the extractor body would expand outwards and grip the thimble. Result. One and a half hours work at the lathe and vice to remove a sticking thimble in 2 seconds flat.

Next up, a stubborn cam nut. It’s 7/8” with an incredibly fine thread. I found an old BSA M20 clutch spanner would fit but not enough to get adequate grip so yours truly had to bite his bottom lip and shell out £7.31 for a 1 5/16” A/F socket with ½” drive. It still didn’t undo. A long soaking in my favourite substance. No good. A bit of heat. Null point. A good thrashing with a birch twig a’la John Cleese, well it cowered but still no movement. That’s it, out with a Dremmel and some key-hole surgery to slit the thing in half without touching the camshaft. Out came the cam and what a beauty, practically brand new. I’m now concluding that not many miles have gone since this motor was last put together.

More to follow.

Pictures;-
Special tool for removing a stuck oil pressure relief valve. Unlikely to be ever used again.

It took just a few seconds to dig it out. Can anyone tell me; What happens if the relief valve is permanently stuck?

It’s out. No damage, it was stuck to the seat with old gum and gunge.[frame][frame][/frame][frame][/frame]

[bmcecosse]

Enterprising..... but I've always found the dowel handle of the valve grinding tool fits nicely - and with a wee wiggle - out it pops........ Can't understand the cam nut being so tight - there's no need for that. You write a good blog though - keep it up !

[OWmoo]

Part 4. Deeper and Down

I hadn’t done an awful lot this week other than clean up and bag everything that had been stripped so far. I flipped the lump over and took the sump off half expecting to find the gurgling bowels of the Moo knee-deep in sludge but nope, not a smidgeon, clean as the proverbial whistle so it came as no surprise to find the big-ends and mains were also in pretty decent nick. Nothing to worry about here except for the tab-washers – they’d been re-used and the bent up bits on one or two bolts were either missing or were about to part company. Judging by the state of the gaskets, I think they’d been re-used as well. At least this justified the strip down. I now have a really decent engine but so far I’ve found no reason why it smoked and supped oil so much.
Maybe the piston rings could provide a clue. I took them off piston No 1 and set them down about a third of the way down the bore. According the good book the gap should be 0.007”/0.012” I’ve got about twice that so it’s a new set of rings to add to the list.

Pictures;-
Sump off, despite running for umknown miles without an effective oil filter things weren’t so bad.

All big-ends and mains in good condition.

More to follow…..[/frame][frame][/frame]
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[bmcecosse]

Hmmm - these big ends are showing the effect of the unfiltered oil. What do the shells look like ? And the centre main - can we see it, and the shell ?

[les]

If you want a guide as to the competence of a mechanic ----check out his lock washers!!

[OWmoo]

Here's some dirty pix;
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Timing end main bearing[frame][/frame]

Centre main[frame][/frame]

Drive end main[frame][/frame]

Big-end, cylinder No 1[frame][/frame]

[bmcecosse]

I've seen much worse...... the crank should be ok with new shells .

[OWmoo]

Part 5. Off my Head

I’m getting to the point now where I could really do with finding a problem to my smoking habit otherwise it’s all down to a leaky tappet cover. Time to dismantle the head.

How do you like my valve spring compressor? I made it! I got the ‘C’ plasma cut in 12mm thk MS plate, made the fork and the threaded boss and got a bloke at work to weld it up for me. The rest is a M10 x 140mm long bolt threaded up to near the head and ball formed on the end.

The valves are a bit crusty and a couple of ‘O’ rings were missing (if this is significant). The remaining ‘O’ rings were on the stems and not on the neck beneath the split collets. The stems are scuffed and definitely show a fair bit of wear. There is most certainly a sloppy rattle fit in the guide, I’d guess there is about .007/.010” s-rock. I went and got a second opinion from a time-served, A-Series engine expert and he says, “They’re crap”. So there you have it, a full technical analysis resulting in new valves, guides and springs added to my ever growing list of things to buy. To get things ready, I then went off and made a punch and guide setting collar following the good book advice that the top of the guide should be 19/32” above the machined surface (spring seating face). Here I discovered that the existing guides were set a bit lower, probably been set from the cast surface in the recess.

I’ve had a think about going for hardened seats for running on unleaded. You can get a complete exchange cylinder head assembly with hard seats for about £220 but the seats in my head look fine so I’m going to do the re-build myself and grind in new valves in the time-honoured fashion and then carry on sticking the odd spot of fuel additive in when I’ve got some pocket money. The reasons? A. I’ll be lucky to do no more than 3 – 4K a year at the most. B. The Moo will not be storming up and motorways all day. C. My old cast-iron head BSA’ motorbikes ran OK without any valve seat regression. D. I’m skint and working to a tight budget.

More to follow…..

The head untouched[frame][/frame]

The OW patent MkI valve spring compressor[frame][/frame]

[bmcecosse]

WOW! That's some spring compressor! The valve stems are unlikely to be significantly worn - as long as the seating faces are ok - I would reuse them... maybe just new exhausts? Valves don't come cheap! New guides though - get the ones with a wee groove to hold the top hat type oil seal - but only put seals on the inlets. Forget about O rings.....and don't waste money on additives.

[OWmoo]

Part 6 Sticking it back

An A-Series block stripped down, cleaned and painted is an object of great beauty, the crankshaft is wonderful sculpture and a camshaft is pure art in its highest form. They should bury a Mog engine in Westminster Abbey or mount one on a pedestal outside the National theatre; it’s got to be up there with the unmade bed and the half a cow in aspic. Oh well, I can’t spend the rest of eternity gazing at these amazing objects. I need to get a move on, there’s a hint of spring in the air and I’m missing going out in the Moo and getting lost in the country. The plan was to get it back in and running by mid February to give me a few weeks before the next MOT.

The last couple of weeks have been spent cleaning parts and painting. As for paint I was going to do the Moo motor gold but in the end I bought a tin of Bronze Green quick dry synthetic enamel and gave the block, head, sump and other bits a couple of coats. I’d also got some Daffodil yellow left over from a previous project to do the fan pulley and blade.

When shopping for parts I couldn’t resist a duplex timing chain kit as both of the old pulleys were looking a bit frayed. The chain is endless so there’s no split link to worry about. I did a dry run to check alignment, in my case I didn’t have to remove or add any shims. Shoving all the bits back in has so far gone with little drama. I made a piston ring compressor, a clutch alignment shaft, a punch for knocking out the old guides and a setting collar for putting them back in the right amount.

I forgot to mention in the previous episodes that I measured the crankshaft journals and found both the mains and big-ends are on minus 0.010” so there’s a lot of life left before the crank is retired, chromium plated and stuck in a display cabinet at the V & A.

More to follow…

Paint. We've gone for green
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A makeshift spray booth. All the bolt heads and nuts get a coat of aluminium paint[frame][/frame]

Clutch alignment tool
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[PaulTubby]

Nice work! Be nice to see how you fitted the new guides.. I can knock them out but getting the new ones drifted in can be very hard without damaging them as ive found the new ones can be very tight to knock in!

[don58van]

ive found the new ones can be very tight to knock in

Did you have them in the fridge for a few hours before knocking them in?

Don

[OWmoo]

Since you asked……

Part 7. The Daily Grind

It’s been like Vladivostok in my work-shop. I’ve had to don my thermal long-johns under so many layers of knitted woollies so I can have a session refurbishing the cylinder head. First off, knocking out the old guides and banging new ones in. The surface of the workbench was probably colder than the fridge so I could just lay the new guides out ready. I needed to get the cylinder head fairly warm so I stuck it in the oven. On the lowest setting and gave it about quarter of an hour if that. The idea was to get it somewhere between very warm and hot so when I took it out I could hold it with my bare hands. Beyond that it would be up to something like 85 degrees C which is about as far as you’d want to go. Once on the bench I gave each guide a skirt of cold water followed by a short-sharp tap with a punch to get them moving. They came out fairly easily. The head was still holding enough heat to enable the new ones to go in so, again, a short tap to engage the new guide into the head by about 1/8”, then checked with a square and then a series of further taps to get the guide well on the way. I made a 19/32” long collar to sit on the spring seat and then placing a cap onto the guide I could set the guide to the right distance without it going too far in.

Apart from a cursory comment made by my good lady. “Why does the kitchen smell like the garage?” I think I got away with it. Mind you, when we sat down for a lasagne later on I thought it tasted a bit like the, err, the Morris.

The next session of the week was to grind in new valves. A laborious process with a suction stick maybe but helped with occasional breaks for tea. Once I was satisfied with that constant grey ring on valve and seat everything was given a wash down to remove any grinding paste. The only difficulty when assembling new valves was getting each ‘O’ ring over the valve stem. I found a pair of small long-nose pliers that help to expand the O ring a little. Mindful that it could ping off into orbit and never been seen again I kind of worked it on under a piece of old rag and made sure my thumb was held firmly over it.

Finally, the kerosene test. Assembled head now placed on its side, ports up. Paraffin poured into the ports and left for 10 minutes to check for any seepage past the valves. Nothing, it’s passed.

More to follow…..

My head in the oven. Who needs the Great British Bake-Off.
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Grinding and more grinding...
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The kerosene test
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[bmcecosse]

Well done - yes the answer is - hot head and cold guides.... They slide in easily. The O rings are useless - far better with the later guides with a location groove and the much better 'top hat' oil seals - but only on the inlets.

[OWmoo]

Part 8…Back in the fold

My prayers for a sunny Saturday were verily answered. I needed a good day to re-install the motor and that included a keen morning’s work to clean up the engine bay and remove over four decades of accumulated gunge from inside the bell housing. In the end there was even time to slosh some paint around the radiator mountings. Apart from taking off the fan the engine install went without too much drama the whole thing slipped back in surprisingly easy. A couple of things amiss though. I marked the position of the distributor before dismantling but then went and cleaned off the mark. We have electronic ignition planted in the dizzy so I might end up having some fun and games getting that set up. I’ve also put the engine steady bracket on upside down…. Oh hum.

Going back over the project I could have got away with re-doing the cylinder head and leaving the block alone but who was to know anyway, at least I now know what’s under the bonnet. I’ve had the dynamo apart, good commutator and fairly new brushes were in place. So too the starter, a clean up, bit of paint and all should be well.

As an aside my curiosity about a defunct heater valve got the better of me and despite being warned about not being able to do anything about the said device I took it apart…. I’ll post a separate topic on this saga at a later date.

When I bought the Moo it had 72K on the clock. With the purchase came a big fat file of bills, old MOT‘s (mostly refusals) going back to 1977. I sifted through the whole lot and entered it onto a spread sheet listing events by date, mileage if known and the gory details of what was replaced, fixed, welded, repaired or bodged. It was then that I discovered that the Moo had gone around the clock in 1982! But the big stand out bill was dated from March 1984…. The listing seemed endless and the bill came to a staggering £960…. New wings front and rear, £60 pr; bootlid £110; a re-spray £150; this that and t'other and at the bottom of the pile ‘Recon engine £215…..

Now I need another weekend to finish off and get it running

More to follow……

One recon engine on it's way back to the mothership
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And back in the bay[frame][/frame]

[bmcecosse]

Nicely done - keep the reports coming!

[les]

Bit late now but the photo seems to show a couple of damaged teeth on the ring gear,or is this an illusion?