This is the ongoing story of our MGB, following on from the restoration, and contains potted history of its mechanical maladies.
A number of local shakedown runs suggest that most things are working well, other than developing an occasional chronic misfire under acceleration when hot. Diagnosis is difficult, as the problem refuses to show itself on the driveway, with all sorts of theories being suggested and disproved. Finally, with time getting short, a wholesale replacement of ignition components – coil, leads, points and condenser – appears to do the job. The leads are a very nice set of Magnacore copper leads – none of this modern carbon based stuff to break up.
One other point was that the seal of the fuel filler cap had died. We found this out by seeing a pool of petrol on the floor after we had parked on a hill with what had been a fairly full tank!
Off to Le Mans and Magny-Cours via way of La Rochelle. On the way down, I notice the horn isn’t working and on entering a town to find lunch it looks like the fan isn’t playing either. Inspection shows the fuses are ok and we are getting volts, so the mystery deepens. Using some spare wire gets things going and it transpires that the contacts on the fusebox were, for some reason, not wanting to conduct much power. Cleaning them up with screwdriver blade and carefully tightening the spade connectors seems to do the trick, so we can settle down to a relaxed lunch.
Later in the trip our dreaded misfire returns, albeit in slightly different form. It will now miss during normal cruising, giving us and the car a good shake as it does so, but will then suddenly start working properly again. We make a couple of inspection stops, but with nothing visible and no more information to go on, we press on and hope for the best. To add to our woes, a short rainstorm shows we have leaks at the bottom and top of the windscreen.
It’s not looking good. Our misfire is now accompanied by load bangs as unburnt fuel meets a hot exhaust and we are notably down on power. On the final leg of the journey home we have a noisy and erratic full throttle maximum speed of initially 60mph on the flat. Hills are becoming a challenge and as we finally arrive home it needs a push to get us up the driveway.
More playing around is not solving the problem, but it’s becoming more than frustrating. Finally, inspiration strikes. I remember noticing at one of our unscheduled inspection stops in France the coil had felt hot. I wasn’t really sure how hot these things should run, but I would surely have noticed something that hot on other cars I’d worked on. Measuring the resistance of the low tension side of the coil showed 1.7Ohms, well below the 3.0 Ohm specification, but also higher than a ballasted coil should be. Checking the old coil showed this to be about the same.
Now suspecting this to be the root cause, I went armed with a multi-meter to Midland Sportscar and Classics, where they were good enough to let me check the resistance of a new coil in the shop. Sure enough, the DLB101 was below specification again at 1.9 Ohms, but the more expensive DLB105 sports coil clocked in at spot on 3 Ohms. It therefore seems as though there is a whole batch of incorrectly produced coils out there waiting to cause trouble.
On fitting the sports coil the engine fired up cleanly and now runs without backfire or hesitation – only 6 months frustration to find that one!!
During a garage clear up I find a couple of gaskets for the rear axle / hubs and realise I hadn’t fitted them. Obviously can’t be too much of a problem, but may as well get things set up properly. When doing the left side, I end up with some excess oil from the differentiation spilling out of the end which ends up on the brake drum and shoes. Hopefully though I’ve cleaned it all off.
Also decide to do the annual service although given the limited mileage I decide that in reality that comes down to a check over and an oil and filter change.
MoT time, although suitably delayed to find a day when I was home, Rick at the garage had time, and the weather was half decent – particularly bearing in mind we still have those leaks found last year. After a few months rest the battery has about had it but just manages to fire up the engine. That battery has done five or six years, so a replacement would be justified. I’ll probably get one at a show in springtime.
The MoT itself is a pass, although the left kingpin needs packing with grease to take some of the play out and there is are a couple of advisories on suspected leaks from the rear left shock and around the hub. The latter is most likely down to last month’s spillage, and on taking the drum off later at home it’s apparent that I hadn’t cleaned things up as well as I hoped. After cleaning everything up again, I go around all the dampers and top them up with jack oil as I hadn’t done this during the original rebuild. Getting the oil into the rear dampers is fiddly and needs a thin tube attached to a small plastic funnel, but we get there.
The clutch is making something of a squeal, which may be down to dryness having been rested for a while. I try to spray a little WD40 on to the legs of the release bearing by removing the clutch fork boot, but I don’t think it’s really been a success. Notice though that there seem to be some oily deposits and inspection of the gearbox oil level shows that has dropped below max so we may have a failing seal. Filling up the gearbox is another tube and funnel exercise, followed by another fight to persuade the rubber plug to go back in its hole.
Getting enthusiastic about the coming year, I see a pair of reconditions carburettors on ebay and decide to buy. I’ve never been 100% happy with the current ones and I know they leak air around the throttle spindles, so it will be interesting to see what difference the new ones will make. However, when they arrive the difference is that, other than being very nice and shiny, they don’t have ports for the crankcase breather pipes. To overcome this, I fit a neat breather filter on top of the metal breather pipe at the front of the engine.
Balancing and tuning the carbs is fairly easy, probably as a result of no longer having the air leaks, and we have a very good low speed idle for the first time in living memory.
It’s the 80th anniversary run down to Windsor Great Park. We have a good run along the A4 to meet up with Newbury MGOC at Chieveley Services and get our route instructions etc. On restarting though, there is a horrible metallic grating noise from the clutch, when the pedal is depressed. It doesn’t seem to affect progress, but each gearchange is a moment of trepidation until the coffee kicks in and I figure out that the release bearing must have collapsed leaving us with metal on metal contact. Not good long term, but should be ok for now – I hope!!
We have a good day out, meet up with some friends south of Bracknell and get back in one piece – this car does seem to have the habit of surviving!
Time is running out before this year’s Le Mans and I need to get the clutch done. As this is an engine out ( or at least half out ) job, it needs a good day with two of us and I fear that I’m not going to have the time. Hence a call to Rick at the local garage who is able to do the job and tells me afterwards there was no sign of the carbon release bearing, it must have completely broken up. He also said the bearing mounting was very stiff on the clutch fork, which may have been the problem so he’s released and greased it up.
Afterwards, the clutch is great but it seems like he may have accidentally done something with the ignition or carburettors as the idle rpm is initially high and then gradually falls away. A quick run into town also shows that the fan has packed up working, so that also needs looking at prior to Le Mans. Checks show that the temperature operated switch has died, so I decide to replace it with a nicer set up involving an electrical sensor in a housing which is effectively cut into the middle of the top hose and therefore doesn’t have the copper wire poking out the end of the hose like the current set up, which always looks like a leak waiting to happen.
A timing check shows we are still at 12 degrees BTDC, so that’s all ok, but it looks like the carbs may be out of balance as a result of hastily increasing the idle speed to overcome the drag of the failed release bearing. Unbolting the linkages, rebalancing and then resetting the linkage clearance makes it all look better and the idle is certainly happy, but we will have to see what happens on a run.
We’ve also noted that the handbrake needs to be pulled up a long way to be effective and there’s no adjustment left on the cable. The brakes themselves are nearly at the point where I could turn in the adjusters by a notch, but not quite as there is still a bit of drag and I don’t want to cook them. Hence it looks like the cable may have stretched, or it could even be the wrong one as the records show I didn’t buy a new one.
It turns out that the new one is pretty much the same length as the old one, which must therefore have come with the axle and body shell. However, the old cable was quite sluggish to slide through the outer cover, so it still makes sense to fit the new one, which then does seem to adjust up a bit better. I do wonder though if I may have got the actuating arms on the shoes the wrong way round - I read that they are handed – as it still seems to need more adjustment than you might expect for a new part.
Off to Le Mans, and all is running well other than an early morning shower. I had slipped a bit of silicon sealant under the windscreen rubbers, in particular where they go over the joins to the wings, which has stemmed a couple of the leaks but we still have some water coming in around the corner of the screen and at the top where the retaining strip on the hood is just about shot. To add to the excitement, the wiper switch doesn’t want to allow us the fast speed and so there’s some trepidation over how long that will last. We survive, however, and once in France the hood comes down and we enjoy an apparently faultless drive down.
Once
arrived, and with beers in hand, we check on levels. Fuel consumption
has been a remarkable 35 mpg for a mostly 80 mph cruise, but the
coolant level has dropped significantly and needs a pint or so to
fill back up. A trip to St Saturnin is fun as always, in particular
being ushered into the main display area whilst much smarter
euro-boxes are pushed into the public parking area, much to the
irritation of their owners.
We have major rain on the way home through France, but no problems other than a steady drip of warm rain from the hood seal. Once back in the UK, the hood is down again and we make good progress until a couple of miles short of Chieveley services, at which point all power is suddenly lost and we coast to a halt. There is no interest from the starter, so I check under the bonnet and see what looks like a fair amount of coolant around the left side of the engine, which may be allowing the spark to track away from the distributor. Drying everything out allows the engine to start, but there is no power and after a couple of hundred yards we stop again and phone the man.
Sometime later we are recovered to the services, at which point we can verify we have spark but no fuel and there is a small puddle forming under the fuel pump and no tell tale clicks. Sharp taps with a hammer get some response, but it soon stops again so we are doomed to a ride home in the tow truck.
Our driveway is far too narrow and steep to be able to get either the tow truck in there or push the car up. However, we get lucky as a few more taps on the fuel pump gets enough life to fill the float chambers and get the engine running enough to make it into the garage before all is lost once again. So the final tally of the journey looks like fuel pump, coolant leak and rain leak – but still doing 35mpg so not bad overall??
Replacement electronic style fuel pump arrived and is duly fitted – bit of a fiddle underneath the car but no major drama. Check the timing after my fiddling about, which will also determine if I’ve messed the gap up. However, it’s still about 12 degrees BTDC which is where I wanted it, so all ok and it fires up straight away and runs cleanly.
There is evidence of escaping coolant underneath the heater valve and plug number 3. Hopefully this means our leak is just the gasket, but could it also be a head gasket problem as there does seem to be a small but steady amount of steam coming out of the oil filler cap. Not sure if this is just normal condensation or not, but I the plan is to start with the heater valve gasket and work from there!
To great relief, the new heater valve gasket fixes the coolant leak, so all is well. I also buy and fit a new piece of retaining channel for the front hood seal. The approved method is to remove the whole assembly so that the remnants of drilled out rivets can be removed from main hood structure, but with time short I figure that any rattling of surplus metal is likely to be lost in the overall cacophony of MG motoring so we will take the risk. Fixing the channel in place is simple enough, though I must buy a rivet gun with a thinner head for future jobs and inserting the rubber strip is easiest done by using screwdrivers to push it into place from the slide rather than trying to push it along the channel, even with the aid of lubricant.
We are enrolled in the MSA Classic, starting out from the Army Flying Museum in the Whallops, which we passed only a couple of weeks earlier on a trial run to check the fix to our coolant leak. In preparation for the run, the by now almost pure water in the cooling system is mixed with new antifreeze, by the simple expedient of removing the bottom hose to drain the hold and then pouring in the new. In addition, it seems like the rear nearside brake will take a notch of tightening and improve the feel of the brakes.
On arrival, however, the smell of burning brakes suggests otherwise and so urgent action is required prior to the start of the event. A handily placed RAC man offers me use of his soap and water; I don’t know what they use, but it definitely works well and my oily hands are quickly clean and soft. The work has, however, eaten the time available for breakfast so we grab a coffee and prepare to leave.
The route takes us on familiar roads up to Williams F1 in Grove, where we stop for a look around and another snack and coffee. Then on a less well known route to Prescott, where we are allow a run up the narrow, twisting road up the hill. The hairpin corners needed a fair amount of lock to get around, but at speed the most difficult challenge was turning into the sun and immediately losing sight of the lines of the road ahead.
Our
third stop was at the Gaydon Motor Heritage Museum, which is
predominantly contains cars from the ex-BL / BMC marques, including
some very interesting prototypes. MG representation is limited, and
there is even less Jaguar, and even the restaurant is down to a few
sad looking sandwiches and you get the feeling that the demise of BL
still hangs over the place.
Finally to Silverstone, where we are awarded medals for arriving (around 100 of the 800 odd starters didn’t!) and allowed out for a couple of laps on track. We have a lap each, and are able to stay with more exotic machinery through the corners but are shown-up as underpowered down the straights. Great fun though and definitely recommended.
The following weekend, we turn go to the Shalbourne Classic Car show. I had expected this to be a small event, but over 250 cars have turned out with everything from a vintage LaFrance to moderns such as DB7s and our own XKR also allowed in to play. A great way of spending time on a sunny Sunday, but one word of warning – leaving the event involves a track not suited to low-slung cars, and we had something of a Top Gear moment trying to get the XKR out without grounding out the front spoiler! MG was fine though – clearly the right choice!!
Starting to think of winter now, and what jobs will need doing. I’ve tightened the overdrive switch, which came loose during the MSA run, and also got a new wiper switch ready for fitting. The old fuel pump has been taken apart though I can’t see anything visibly wrong, so we’ll need some volts and water to try running it to see what the problem was. In addition, there will be a regular service and the battery is now 7 or 8 years old and must surely be on its last legs. We have tickets to Top Gear at the NEC in November, which also give us entry to the MPH show and Classic Car show, so that will be the time to look for parts.
After a long and cold winter it’s time to get ready for spring. I’ve tried a couple of times to charge the battery and start up, but although the engine turns over I don’t get much more than a cough and the battery quickly loses power. I obtain a new Bosch Silver battery for under £50 through the web, and fit this along with new plugs. It takes a few attempts, but the engine then splutters for a few seconds before roaring cleanly into life. I leave it a fast tickover to warm through, whilst conducting a pre-MoT check on lights etc. No problems there, so I then change the oil and filter, clean and re-oil the K&N air filters and take a look at the nearside rear brakes. There are some traces of oil and slight ridge on the drum and shoes, so something to keep an eye on. It also feels like we can take another notch on the brake adjuster, but bearing in mind the experience on the MSA run I’ll do a short test drive and check for excessive heat before I’m totally happy with it.
On the way back from taking the car on a long round trip to work, around 190 miles, the temperature gauge rises and although I slow down to reduce the heat output of the engine it continues to head for the end stop. It’s only a couple of downhill miles to the nearest garage where an inspection shows a lack of water. Once home, closer review shows a trail of water from the head gasket from between pots 2 and 3 – a common problem according to one or two websites, but the main problem here is that it’s only a couple of weeks until Le Mans.
The head gasket replacement is a reasonably quick job, although it would have been quicker if I’d remember to put the pushrods in place before dropping the head onto the studs, and it would have been easier on my back as well. To try to combat a repeat failure, I add a smear of blue haematite around the offending area, hoping that the overheating hasn’t caused any lasting damage. I also temporarily refill just with water, as there’s no anti-freeze to hand and in any case it would be a waste if we can’t get a good seal.
After
a short trial run, it’s time for Le Mans Classics, and we set off
with everything firmly crossed. All is well, however, and the car
performs brilliantly until we leave the motorway a couple of miles
from our destination, whereupon the overdrive refuses to kick in. I
wonder if it is simply low gearbox oil pressure given the high
ambient temperature and heat soak from a long, fast run. Tests the
following morning indicate this isn’t the case, and investigation
shows a lack of volts which is traced back to a failed switch. This
is temporarily swapped with the reversing light switch and normal
service is resumed.
Although the temperature gauge shows no ill effects, inspection of radiator levels on arrival home shows we have again lost coolant – hmm!
Later, after a shortish run close to home there seems to be a lot of steam coming from the engine breather, which doesn’t seem to bode well.
Various local runs haven’t seen any further drop in coolant levels, although other commitments have stopped us using the car for longer events. A sudden onset of cold weather and frosts reminds me I still have just water in the radiator so I take advantage of a period of jet lag following a business trip to the US to drain a couple of pints from the bottom hose and top up with some orange anti-freeze which I had in stock. I suspect the car won’t be going out again for a while, so it’s time to make a list of things to do over the winter:
Touch up some paintwork
Replace the failed overdrive switch, which is now in fact a failed reversing light switch
Fix the heater valve / Bowden cable / heater control which is slipping rather then changing the heat setting
Check rear nearside brake for oil
Investigate why handbrake is weak, even when fully adjusted up
Consider moving the engine breather, which is leaving a film of oil on the otherwise shiny carburettors
Think about a reconditioned rear differential to solve the clunk on setting off
Think about a new camshaft to get proper lift on pot number three again – but then the engine is generally quite old, and there’s still the worrisome head gasket, so should I bite the bullet and do a proper rebuild??
Recondition or replace sticking vacuum gauge
Routine service
Ok, so it's the end of winter and time to get ready for summer usage. The car has been started a couple of times to keep the battery charged but otherwise no activity for 6 months or so and, in particular, no action on the list of jobs above.
However, service parts have been bought at the February parts event in Stoneleigh, along with a new switch which is quickly fitted. By putting together parts from a couple of stalls I also end up with a 'mushroom' style engine breather, complete except for the plunger. Installation is easy, but running without this creates far too much vacuum and is pulling engine oil through the valve and into the engine. A temporary fix is to use a suitably sized bolt but it's less than ideal and a proper part is ordered and installed.
This still leaves the engine running very lean, with a significant volume of air being pulled in through the breather. Assuming that is normal, we obviously need to retune and balance the carbs.
Most of the routine service passes without incident. We've lost a bit of gearbox oil and there's still a bit of gunge getting into the rear brakes but nothing of concern. The points gap has widened and, after resetting to about 15 thousandths of an inch, a static timing check shows about 6 degrees BTDC. Whilst less than I'd be running before, this is close to the official specification of 7 degrees and arguably on the right side given use of standard unleaded petrol.
This makes cold starting easier and has certainly cured the mild pinking under load in hot conditions, but the engine feels subjectively less willing at high rpm. I may play with that later in the summer, but given that the distributor doesn't want to turn even with the clamp bolt loosened then it can wait for now!
Whilst cleaning the brakes I also wanted to look into the issue with the weak handbrake. I had read somewhere that the actuating levers were handed and it was possible to install them the wrong way around, resulting in this problem. By swapping them over from side to side I've verified this is the case, but also that my original install was correct. Maybe I'm expecting too much of the mechanism, and it does pass the MoT, but not being able to reliably hold the car on a slope can cause inconvenience from time to time so a fix is needed. As shorter cables are available and I'm out of adjustment then we may need to get creative!
The heater valve problem is similarly reluctant, although improvement is made by clamping the sleeve of the bowden cable such that the outer is as close as possible to the operating lever when fully on, thus shortening the amount of exposed inner cable. However, it still sticks when going to/from full cold and its clear that it's caused by the profile of the slot in the valve itself. I will look out for a new valve of better quality manufacture and put in stock for when the cooling system next needs to be drained.
Our first major run out is the MGB Register Spring event, starting near Abingdon and ending up on the front lawn at Dhyram House near Bath. The sun is out and it's a fantastic day, made even better by the fact that we aren't losing any coolant or oil and the mechanical maladies are limited to a tweak on the carburettors, looking to get the tune just right after the installation of the breather system.
A visit to ebay results in a replacement vacuum gauge arriving in the post, but on connection it shows little sign of life. However, disconnection of the old one has allowed significant amounts of oily fluid to drain out and, with a spare available, I'm brave enough to dismantle the unit to see what might be happening. It turns out these are incredibly simple units, with a small piston driven by engine vacuum moving the pointer against spring pressure. The sticking needle is caused by wear and/or obstruction in movement of the piston but after a few end to end movements it seem better and, on reassembly, the gauge seems to work a little better – time will tell!
Next up is the Regency Run to Brighton. It looks like being a chilly and possibly damp morning, so we put the hood up the night before. It's a bit of a struggle, demonstrating that we are out of practice and also that the frame has got slightly bent during it's months in the down position. Having identified the problem it's easy to overcome but we'll have to keep a watch on future developments.
We meet everyone else at Epsom race course, drop the hood and have a pleasant run down to Brighton. A following car reports that our brakelights have failed, and inspection shows that the Lucar connector has parted company with the pressure switch, so there's not much to be done about that on the day! The run back is most enjoyable along the surprisingly unbusy A283 and A272 towards Winchester and finally home via Stockbridge. Other than a slight tendency to lose revs when idling for long periods ( still a tad rich? ) everything runs well.
Once home, a check on the plugs shows a healthy colour, though perhaps a tad on the brown side and certainly not lean so a quick tweak up on the SUs and we'll see what happens next time. A new pressure switch from the MGOC restores the brake lights and is an easy replacement, although you need to put a rag underneath to catch the trickle of brake fluid and be quick to not allow too much to get out. In theory, fluid being expelled means it shouldn't be necessary to bleed the system but we'll test that theory on a quick test run.
One other job is to – finally – fit proper fuel overflow pipes to the float chambers. A spare p-clip is attached to the engine mount to locate the pipes, which are then bent to suit. After bending the short length of rubber coupling pipe through ninety degrees, the front pipe can go more or less straight down with just a gentle initial bend and a further bend beneath the p-clip to follow the curve of the bodywork. The rear pipe is slightly more elaborate, needing a couple of ninety degree bends to follow the line of the manifold heatshield from front to rear.
After a mechanically uneventful summer, it is necessary to improve the efficacy of the handbrake prior to the stop go crawl up to the Shalborne car show. Having exhausted the official cable adjustment at the handbrake end, and verified the cable is the correct length, some improvision is called for.
The chosen solution is to back off the adjustment at the handbrake end and bolt a couple of metal plates together around the exposed end of the cable behind the rear axle. The end of the cable can't pass through the plates, which butt up to the outer sheath, effectively adding an inch or so of additional adjustment. Modest adjustment at the handbrake end now provides a fully functioning brake for the first time in a while.
After the annual service we head off for the New Forest run. It's an overcast day, but we mostly avoid the rain and keep the hood down. Pulling off road for an impromptu stop, we hit a pothole and everything dies.
Inspection with the voltage tester shows nothing wrong, but whilst fiddling things come back to life, so it looks like a simple bad connection which is solved by squeezing up the spade with pliers and we're on our way. Thanks to the kind gent who stopped just in time for everything to come back to life again!
Off to Le Mans Classic, fully loaded but everything running well until on the road to Rouen we pick up an occasional hesitation. Oscillation of the rev counter suggests electrics (again) so we stop at the next services to check the connections. All seems tight, however, and nothing appears amiss so we carry on.
Approaches the next services, the engine suddenly cuts completely. With 80mph showing, we are lucky to be able to coast along the hard shoulder and into the services for further inspection. At least we have a hard fault this time!
Finding nothing obvious, I chase the volts down to the distributor and see nothing obviously wrong. Closer inspection, however, shows that the plastic cam of the points has mostly broken off and is hanging by a thread, unable to open the points.
I've never come across that one before, but we have a spare set of points and, having set the gap with the british standard fingernail, we're off. Whilst all this was going on, another B pulled in and asked to borrow a spanner, so at least we weren't alone!
Shortly
after returning from Le Mans it's off to Silverstone for the
Classics. The campsite was nice and muddy, but we were able to get in
and out without drama and the weather over the weekend was hot and
sunny.
On Saturday evening we had a track run courtesy of the Silverstone Drivers Club. This contained a variety of cars, including some who wanted to make progress so we were able to get three laps in and test the strength of the door catches on some of the corners.
Sunday brought another lap, this time with the classic car clubs, for which it was Jo's turn to drive. Unfortunately this never seemed to get up to speed and so only one stop / start lap was possible. Doubly unfortunately, the main fuse appeared to be no longer making contact with its holder with the result that the electric fan was no longer working. This was confirmed by the temperature gauge reaching round to register around 80lbs of oil pressure!
I feared the worst, but apart from a small amount of steam from the vent pipe all was well and the return journey was faultless.
The only cloud on the horizon is that I've been able to pinpoint the clunking from the rear as worn splines, with the rear wheel able to rotate a little whilst the drums remain fixed. This will probably need new hubs and wheels, but hopefully we'll make it to the winter.
Time for the Pendine Dash. A bit of bad planning meant we had a party the night before, but in the morning the weather seemed warm enough for a hood down early start on the 3 hour trip to Carmarthenshire.
As this is England, it wasn't to be and we stopped at Chippenham to put the hood up as the rain began to fall! Once there, however, the sun was out again and we had a great day out around the countryside and along the beaches and coves.
Further complications on the way back, as the temperature gauge begins to vibrate strangely and then the overdrive cuts out. For a moment it seemed like the engine would too, but it recovered so we carried on slowly to the next services, which were handily placed a couple of miles down the road.
It was evident that the main fuse had blown, and whilst looking for a short I saw some melted connectors and, nearby, a damaged capillary tube from the temperature gauge. At a guess, some combination of vibration and the overheating from Silverstone had cause the capillary to chafe and melt through the plastic on the spade connector and cause the electrics to earth through the capillary tube. At least it was a fused circuit!
A replacement fuse and some tape around the electrics got us on the way again, with all apparently normal other than no reading on the temperature gauge, so we'll have to invest in a new one.
Not too much to report this month. The clunk from the back axle, which I feared was the differential, has now shown itself to be due to worn hub and wheel splines. The evidence was that with the wheel in the air to adjust the brakes, I could see it turn without any corresponding movement in the drum behind.
There's also some oil leaking onto the garage floor, which to look on the positive side is at least a good indication that there is some in there! From looking underneath, I guess it could be the sump but is more likely to be the rear oil seal. Hence the decision that this can wait until an engine out job is requried.
A lucky ebay find brings yet another vacuum gauge into stock and, somewhat to my surprise, this one at last appears to function correctly. Of course, this also points out that one cylinder isn't drawing air as much as it should, but we know that the inlet valve on number isn't opening properly due to a worn cam lobe, so at least that's not a surprise.
I have good fortune when the annual MoT picks up that the front left wheel has what appears to be a whole series of loose spokes. This probably means it is beyond easy salvation, but its inferior condition to the others makes me wonder if was an older wheel, which would explain the additional spare which came with the car. The short term issue is solved by using the spare wheel.
Other than that, there is a slightly weeping brake line which is easily solved by tweaking up the unions on the brass junction piece on the front wing. Perhaps I'd never tightened them enough in the first place. There's also the by now traditional excess play in the nearside kingpin, solved with an injection of grease.
The throttle is sticking open again slightly, and inspection shows that it is drag from the pedal pivot point which is at fault. It's easy to loosen the nut a fraction, but needs some further investigation to see if the bracket itself has bent at all.
We've decided we're going to do the Motoscape Rally in September – 10 countries in 7 days across Europe, finishing in Prague with then the drive home again. A friend did it last year and really enjoyed it, but the prospect of such a journey means that some issues will need to be sorted first. As a warm up, we also book a trip over to the Spa Classic at the end of May,
So task number one is to solve the rear clunk under drive by changing the rear wheels and hubs. On the Banjo axle these are an interference fit and need a press to remove from the half shaft. As I don't have the equipment, and the remainder of the job is in theory pretty quick, I entrust the task to Rick at my local garage.
He later reports that he had to get a friend with a commercial press to shift them, and then needed to slightly drill out the stud holes on the new hubs to make them fit. So much for a simple job, but I can now verify there are no more clunks and I'm hopeful that the new hub and associated gasket will solve the minor oil leak from the rear axle offside.
A set of parts is ready for the annual service, and I've also got some touch-up paint ready to tidy up some stone chips, but the weather is as yet too cold to go and play.
Off
to the Spa Classics. It's a largely uneventful run down, for which we
should always be thankful, and we arrive at the campsite in sunshine.
One consequence of this is that it gets cold at night, as evidenced
by the ice on the windscreen the following morning!
Finding our way to the allocated parking in the paddock is entertaining, and good natured confusion abounds. We've booked to do some track laps, which are nominally behind a pace car but it quickly becomes a fairly quick session with more than a hint of hot brakes after a couple of laps. No harm done though, and we also get back to Burbage in one piece.
July
2013
Jo is enroute to Silverstone Classics when a missed call tells me the car has overheated and she is stopped in a layby on the A34. It sounds like the connections to the fan (again) but she eventually makes it to the campsite and a quick tweak of the fuse box restores normal working operation, but it's clear the clips holding the fuses are past their best. Whilst there, we invest in a new fuse box, which grips the fuses much better and hopefully solves the problem for good. Definitely don't want problems on the Motoscape Rally!
The Motoscape Rally is an event for old or cheap cars, thus increasing the chances of mechanical mishap, taking in 14 countries across Europe in 10 days. On signing in at Calais, in turns out we are the oldest car there, though there is another MGB and an MGF for company.
The full story of the rally will be told elsewhere, but other than a few routine checks we make it through such challenges as the Stelvio Pass, the Vrisic Pass in Slovenia and some Hungarian back roads to make it to Prague without issue. The engine doesn't feel quite as perky as usual, so points gap etc is checked and readjusted though I think it may be more perception than reality One real issue is front wheel vibration at speed, which is thought to be a consequence of one of the many potholes on our route.
However, we make it back without any further concerns, covering a total of some 3300 miles and averaging around 35mpg, based on the car speedo which admittedly is something like 10% optimistic.
Service and MoT time again. Three out of four lever arm dampers are weeping, probably as a result of age and the pounding them got on the rally. Reconditioned replacements are sourced from Welsh MG for a miserly £18.50 each.
After replacing the rear hubs and wheels last year, it is now the turn of the front set of splines to be worn. New wheels, hubs and bearings are duly fitted, which also solves the high speed vibration issue we'd picked up. The old bearings where in good condition though, which was handy because the new inner bearing did not want to fit over the stub axle so the old one was cleaned up, re-greased and pressed back into service.
Fit new points etc at the service, which adjusts the timing a little to 9 degrees BTDC. This may be too much, but as we've got some 98 octane fuel in the tank let's try it.
After some initial use, a bit of play has crept into the front wheel bearings. It's only a small amount, but worth sorting out. One side has a thin shim which can just be removed, whilst the other side has a thicker shim replaced by the thin one. This removes the play whilst still allowing the wheel to turn freely. I also push some more grease into the inner bearing, just to be sure (the outer is largely inaccessible without removing and probably damaging the seal). The operation is done without disturbing the brakes by unbolting the hubs from the disc in situ. Replacement is a little fiddly, but so not sure whether I really saved any time, but you've got to try these things!
We take part in the Gloucester MG Cotswold run, which is an enjoyable event notable, amongst other things, for the quality of its bacon butties at the start! I do, however, notice a small amount of pinking with open throttle, low revs and high gear, so later put the timing back to 7 degrees BTDC to cope with regular UK fuel.
After a few local outings over the summer, it's off to Llandudno for the Snowdon run. As it's an early start and a long drive from home, we have a pleasant drive up the A49 and A5 before staying overnight in Llandudno before the event. The run itself takes in some stunning scenery around Snowdonia and Angelsey, and the weather manages to hold off until the finish at Penryhn Castle, whereupon visitors are treated to the sight of MG owners sprinting to their cars and a spot of synchronised hood raising. We stay over on Angelsey for the night, followed by another good drive south on the A470 and so back home.
Despite the constant rattle from the valve train, the car is running really well. Seems a shame to take it all apart, but inlet valve number three isn't getting full lift and I suspect the case hardening on the cam lobe has worn through so it's only going to get worse. Something will have to be done over the winter. I'm also told the brake lights don't work, although on test they operate when the pedal is pressed hard enough so unfortunately it appears down to premature wear of the actuating switch.
So
I've finally decided to fix the worn camshaft and its attendant
rattle. The engine also has a fair amount of blow-by so it's
obviously getting old so, given that the unleaded head was done
fairly recently, a bottom end swap-out is called for. Refurbished
units don't seem that common from the usual suppliers, but Welsh MG
provides an ex-Ivor Searle unit with apparently limited mileage. It
arrives as a fairly bare unit, so in addition to a full gasket set I
also source duplex timing gear and various other bits and pieces from
MGPartsUK.
Friend Tony is eager to help with the process and we devise a plan to do the work over the Christmas break. It looks like a four day job, roughly broken down into ancillary removal, engine removal and fitting of head/engine plates/timing gear, engine replacement and ancillary refitting. It didn't quite work out that way though........
Day 1 went smoothly enough. Removed the bonnet and then we each worked on one side of the car to remove carbs, manifolds, distributor, alternator and disconnect the various cables. The starter motor came out at the second attempt, having removed the oil filter housing. Drain radiator and sump and detach hoses, allowing me the discover that one of the downsides of being under the car whilst someone else is detaching hoses above is a tendency to get wet! Undaunted, fan, radiator and oil cooler are removed, along with thermostat housing and waterpump. So far so good.
Day
2 was engine out day. As it
would need to come off anyway, we decided to unbolt and remove the
cylinder head in-situ. The Payen gasket I had fitted a few years
looked good enough to reuse (I won't though!). It then occurred to me
that it would be a good ideal to remove the crank bolt, whilst the
engine was still in the car and attached tot the gearbox. With the
car in gear and being held on the footbrake, a 2 foot torque wrench
and then a 4 foot piece of box section steel as an extension both
failed to make any impression. Houston we have a problem!!
The decision is made to get the engine out and see if we can then shock the bolt into submission. Loosen the bell housing bolts, support the gearbox on a jack and the engine with straps, and separate the two pulling the engine forward. It separates without too much effort and by tightening the front straps to get the required angle we soon have the old block out and on the floor. Hammer and breaker bar don't touch the reluctant bolt, but fortunately it's Christmas and my mother is unknowingly about to buy me an impact wrench from Machine Mart. One shopping trip later, this 1KW beast takes a good few minutes of hammering away, but the bolt finally spins free.
Day
3. Only day 2½ really,
but we're a bit behind now
but a good run would see us back on schedule. We quickly complete
dismantling the old block, removing clutch, flywheel and backplate
together with crank pulley and timing cover. The back plate and cover
are cleaned up ready for renewed service and the clutch looks in
decent condition having been relatively recently replaced. However,
this reminds me that I still can't find my clutch alignment tool, so
it will need a trip to Moss.
Meanwhile, however, I've already cleaned the 'new' block so we can start putting back the various blanking plates and fittings, followed by the engine back plate, new oil seal, and gasket with some Loctite sealant. Our next task was fitting the new cogs and timing chain, but the crank gear would not fit over the already installed woodruff key. This required some careful and time consuming filing to allow it to slide on but yet maintain a snug fit. That done, and timing marks aligned, the tensioner was fitted and the internal allen bolt turned to release the internal spring. Front cover on, tappets in place and rocker covers in place, we finish for the day.
Day 4. Only day 3 really we tell ourselves. Flywheel bolted on, checking the alignment marks, followed by clutch, carefully aligned with new plastic tool. Looking at it though, I realise we've forgotten the spigot bearing. We need to have the special kind that mates a 5 bearing engine with a 3 synchro gearbox and, unsurprisingly, the old one doesn't want to come out. It's another trip to Moss, which also allows me the buy the right size clutch alignment tool this time!!
Day 4 – again. Getting the old spigot bush out of the new engine requires removal of clutch and flywheel (been here before!) and use of a dremel to cut through the bronze. Having done this it can be tapped backwards to loosen it and then easily pulls forward and out, to be replaced by the new item with smaller internal diameter matching the 3 synchro gearbox input shaft. Flywheel back on, new locktab (I did think ahead this time!) followed by newly aligned clutch.
Now time to lift the engine and move it round to be re-introduced to the gearbox. After a few adjustments we think we have the angle right on the straps and it feels like the input shaft is engaging with the spigot, but it doesn't want to go it. The engine turns so the splines are not engaged. A bit of push me, pull you is followed by getting a couple of bolts into the bell housing and various adjustments to angle of gearbox and engine, but to no avail. Looking back, I suspect our issue was not being able to hold the engine and gearbox steady enough to be able to wiggle it together with confidence.
However, the decision was taken to remove the gearbox. Off with the gearlever, followed by the supporting cross member. The nuts here are a real fiddle to access but come off in the end. The prop shaft is also difficult to access above the rear cross member, so is detached at the much more accessible rear. The whole lot is then moved forward and, after detaching the overdrive electrical connection, lifted out of the engine bay. The propshaft was the detached from the gearbox to make the whole assembly more manageable when putting it back.
After doing all this, reattaching gearbox and engine took about 5 minutes tops. Do up the bellhousing bolts and retreat for a cup of something strong.
Day
5. Not quite the home straight,
but perhaps on the last corner? Time will tell. Engine and gearbox
are lifted into the engine bay and overdrive wire attached as the
gearbox disappears into the tunnel. Propshaft is fed over the rear
crossmember and attached to the gearbox, followed by another game of
to-me, to-you to get the rear of the gearbox above the cross member
whilst lowering the engine sufficiently to allow the front of the
gearbox to clear the transmission tunnel.
Bolt the engine to its mounts and then underneath again to reattach the gearbox cross member and propshaft. During this process, it becomes evident that the crank pulley, which we didn't initially fit to avoid it fouling on anything as we installed the engine, can't now be fitted as the steering rack is in the way by about a quarter of an inch. Oh well, it's only four more bolts, plus one for the clamp on the steering column. Finally, refit gearlever but can't find securing circlip so promise to be careful for now!
However it feels like we're making progress again, and a good day should see us done.
Day 6. Not a bit of it! All starts well though, as the cylinder head studs and fitted and the gasket placed over the block, with a little Blue Hylomar around the coolant and oil passages on each side. Pushrods inserted and then lower the head, fiddling with the pushrods to allow the head to move down. Torque up gradually, following the approved pattern, and then let it settle whilst turning to other matters.
The starter motor refuses to go back in the hole, despite having come out that way. All sorts of angles and permutations tried but nothing doing so, as we're in practice, the steering rack is unbolted again allowing the steering column to be moved that extra fraction to allow the motor to slide home. Manifolds, carbs, alternator, distributor etc all follow, but the choke cable is fraying and really doesn't want to play ball. We get it more or less there in the end, but one or two mangled strands impede the action so it will probably have to be replaced – job for another day though. We are reminded that the world awaits our presence elsewhere and activity is curtailed for the day.
Day 7.
The oil pump is primed by pouring what oil would pass very slowly down a tube into the oil pipe fitting at the back of the engine. Torque on the cylinder head bolts is checked and then the valve clearances set using the rule of 9, plus another rule that says 13 thou is a tight 14 and loose 12 when you don't have that combination available on the aged feeler gauge.
A new radiator is offered up to the mounting points and doesn't fit, requiring some unsubtle use of molegrips to bend it's mounting brackets back towards the 90 degree mark. A short battle has radiator in place and pipes attached, quickly followed by oil cooler and it's pipework. Top cover on, heater pipes, throttle and distributor vacuum attached, fluids added and we're ready to fire up.
To begin with, the plugs are removed and the engine spun on the starter for three or four 30 second bursts. No untoward mechanical noises is a good sign, as is the drop in engine oil level in the sump and finally the pressure gauge coming up to about 50 psi. Reinsert plugs and the engine turns over slowly now, so at least we have compression. After some churning there's a cough and the starter drops out of engagement. On the next go, however, it starts and settles down to a steady 1500rpm.
There's some smoke coming from the manifold area as it warms up, but hopefully it's just something burning off and indeed it lessens after a while. The engine is warmed through thoroughly, with a couple of cycles of the electric fan cutting in, and the carburettors are given an initial tune. Five flats richer sees a decent idle around 900 rpm, with no excessive valve noise, so that's looking like a job well done.
So it's time for the New Years List:
Fit new brake light switch – check. Replaced quickly to avoid having to drain and bleed the system.
Fit new choke cable – check. Need small hands to get behind the dash, and the body of the new unit needs a bit of grinding down with the Dremel to allow the nut to slide easily back into place, which is essential when working with very limited space.
Fit new earthing wire in distributor (noticed this was hanging by a thread during inspection last month) – check. Didn't even have to remove the distributor, though I did drop one of the screws and needed to reset the points gap. Noticed that the mounting plate wasn't able to move, which turned out to be the points screw locking against the base plate and was resolved with an additional washer.
Fit new circlip to secure gearlever (never did find the original one) – check. In the absence of a helping hand, molegrips gripped on the gearlever can be used to compress and hold the spring in place.
Recheck cylinder head torque, valve clearances and ignition timing before tuning carburettors – tuned carbs anyway after refitting choke cable and all nicely set. Will need to recheck later.
Probably need to fit new ignition barrel as one set of keys now seems to work and that doesn't feel particularly convincing – solved by putting WD40 on the key, inserting on twisting a few times.
Oh, and refit the bonnet – not got around to that yet! - check. Fit looks better than it did before!
So now we are ready to go, just as snow is forecast and the roads are covered in salt!!
MoT
time, and there's an advisory on front kingpin play but that's the
same as it's always been and essentially the way they are made. I can
tighten it, but that results in excessively heavy steering which is
more of an issue itself. The new bottom end has clearly brought and
improvement with better starting and more power throughout the rev
range.
The MG now has a friend in the garage, in the shape of a 1960 Daimler Dart, but the unfortunate consequence of this is that the MG has to stay at home for Dtive It Day. It does, however, get used for Jo to go to work on sunny days over the spring and summer and is on show for our regular jaunt to Silverstone Classics. It has also been requested to be the brides transport at the wedding of a friend's daughter and seems to have won a few friends during the day.
September brings an MG club run starting at Millets Farm, followed by another annual fixture at the Shalbourne village car show. Friend and supporting mechanic Tony drives the car and is surprised by the cars nimble handing and mid range performance.
I’ve
been remiss in keeping records this year. The MoT came and went
without much drama, although it was noted again that there is some
play in the nearside kingpin which will need attention. Perhaps after
all these years it’s time to get around to it.
We took part in the annual MGB Register Spring run, but the B was left to sulk whilst we used the Daimler for Drive-It-Day in April. Other events included the Stockfest show, where we took both cars with offspring as navigators and had a thoroughly good day out.
We planned to go on the Snowdrop run up in Cambridge, which would provide an opportunity to visit the club shop and buy a few bits for the annual service. However, after limited use last year the B took umbrage and decided the week before to dump the end washer, spring and other sundries from the inertia starter motor onto the floor when we went to pick up the Mundane after it had new boots fitted at the local garage. The guys push started the car to get it home, but as this was Thursday and we were due to leave for Cambridge on Friday there was no time to source replacement parts.
I assumed the retaining clip had simply given up after fifty odd years of service, so was hopeful of simply obtaining a replacement. However, it seems they can’t easily be sourced for these old motors, and then it turned out that obtaining an exchange unit wasn’t possible without these parts. Looking at the cost of either a non-exchange refurbished item, or a modern style replacement, I came across Phoenix Marine Services who provided a very reasonably price non-exchange, original specification unit.
These starters are big and heavy, carefully designed such that as you pull them forward to clear the bell housing they don’t fit between engine and bodywork to allow removal from below. Removal and refitting from above means removing the distributor and oil filter housing, a lot of jiggling around and a firm push of the unit between body and oil filter housing to get it through.
Having the distributor out encouraged me to look at the Magnetronic ignition kit I had been donated by friend. Fitting to the 45D distributor should be straightforward, but the supplied countersunk screw for the Magnetronic base plate was of larger diameter than the hole in the distributor plate. The solution was to use the original screw from the points set up with the head carefully filed to allow it to sit in the countersunk hole. It also also necessary to shorted the fixing screw as it otherwise had the effect of locking the moving plate of the distributor, thus preventing any movement for dynamic timing.
The plastic rotor was also very tight and needed a little judicious filing to achieve a good fit. This achieved it was then a matter of connecting the wiring, with one connection on either side of the coil. Static timing can be set using a voltmeter across the coil terminals, and I’ve set it so that the voltage rises (the equivalent of the points opening on the old system) at 8 degrees BTDC.
In theory, the Magnetronic is just a more efficient switch than traditional points and hence should be compatible with the B’s current based tachometer (RVI type, as indicated on the face plate). I was pleased to see it working, and in particular a bit more stable, which is a benefit of not having the points ‘bounce’ of the traditional set up. The starter sounded a bit slow to turn, but the engine fired and ran cleanly so all appears well in this area.
Next job was the play around the nearside kingpin, which you may recall has attracted the attention of the MoT man for a number of years. Closer examination showed that with the car jacked up and levering the tyre up and down with a crowbar, the movement was the stub axle assembly relative to the kingpin rather than the kingpin itself against the suspension arm or bushes. This pointed to the shims which fit on the kingpin between the stubaxle and upper trunnion.
In the previous rebuild I had just used the existing shims. Not sure if I lost one, or there was play there already which I hadn’t noticed. Access involved supporting the front of the car on axle stands and then using a bottle jack under the lower suspension arm to control the downward force of the spring and prevent it escaping. With the arm supported, the anti-roll bar link can be unbolted to allow greater movement of the lower arm. Undo the bolt at the mid point of the damper lever arm, then remove the cotter pin and loosen the nut on the upper trunnion securing bolt.
A few taps of a hammer will determine if the bolt is to come out easily or put up a fight. In this case, having been relatively recently rebuilt, the pin moved and I was able to drive it out using a flat ended punch. Before final removal, I used a long tie wrap as a check strap around the brake caliper to avoid the weight of the hub being taken on the brake house. Then lever out the trunnion from the damper arm.
At this stage, lever out the bushes to enable removal of the trunnion. Finally, ensuring the lower suspension arm is supported, undo the nut at the top of the kingpin and remove the trunnion. I used a mixture of hammer taps and a large screwdriver through the trunnion to get some leverage.
In theory, there should be enough shims to leave just a fraction of movement for the stub axle, ensuring it is free to turn. I found two large shim washers already in place either side of the thrust washer, so had little option but to experimentally add another. After re-torquing the king pin nut, there was no play, but the steering was still free although admittedly a little less so than before. Reassembly is straightforward, ensuring plenty of copper grease on the upper trunnion pin.
During all this I had also noticed what appeared to be weeps from the front brake house and clutch slave cylinder. The brake hose was easily replaced, doing it quickly to minimise spillage and taking care to adjust the alignment so it doesn’t bind with steering movement. The brake fluid had been in there for a number of years and needed changing anyway, so with easybleed kit fitted I went around both front and rear cylinders, allowing plenty of fluid through and stopping when the easybleed bottle was empty to avoid introducing air back into the top of the system.
The pedal firmed up nicely – maybe even better than before. The clutch, as is well written elsewhere, was a bit more problematic. The trick, it seems, is in conjunction with the easybleed to push the operating rod back into the slave cylinder, producing a flow of bubbles, then close the bleed valve before releasing the rod and drawing more fluid into the cylinder.
The MoT passed without incident so now we’re ready for the year ahead!