Restoration of 1952 MG TD 2



Author: Bob McCluskey
First posted: 1 Sept 2000
Last amended: Nov 2009
Please email Bob McCluskey
Car No TD/11935
Engine No XPAG/TD2/12333
Body Type 22381
Body No 11301/78948






ngine Taking the engine out was a significant step just on its own account. It was like an irrevocable statement of intent: as though this was the step that finally committed us, even though in reality we'd already gone a long way beyond the stage where the only way out was to call the Council for their skip.

the engine comes out - first time in over 20 years

There really isn't much for me to say about the engine itself, since the machining tasks are well beyond me, and everyone already knows everything else there is to know.

I was inclined to put it into a corner of the garage and leave it till its time came in the normal sequence of events, but James was into Scouts at that time and wanted a major project for his technology badge. So here's a good idea: why don't we take the engine apart, have it machined as necessary, and reassemble it and get it running ourselves, with every stage carefully documented and recorded, so he can get his badge??

Well, the plan worked brilliantly at first.

I took the whole thing to the machine shop and they dismantled it, did what was necessary (which was almost everything), and gave it back to me in pieces. They advised not to put in valve seats to handle lead-free petrol, on the grounds that there was no demand yet for unleaded petrol, and the technology was unproven. Well, I suppose that gives you some idea how long this project has been running. Also they advised against the rear oil seal modification, this time on the much firmer grounds that the existing solution involved a lip-seal oil seal running on the edge of the flywheel mounting flange, and because of the large diameter and the limit on lip speed, engine revs would be limited to about 2000 rpm. There is a much better solution available now, based on the GM split seal, and no doubt if I ever want to do the modification, there will be a better solution yet.

The crankshaft had already been ground several times, and the journals were now at their limit. I was lucky, though, because the engineer said he might be able to source a replacement. And he did, and the price didn't seem too unreasonable. And when I told this to the President of the Car club, he laughed, and said the same man had lost his crankshaft, so he'd had to use his spare. So my car probably has the President's crankshsaft. And I wonder what happened to mine?

Anyway, we got the engine back, and I showed James how to
the engine goes back in
Well, as you can see from this picture of the engine going back in, I like polished aluminium, and I make no apologies for it, although some might turn their noses up. I am ashamed, though, of the colour I painted the timing chain cover bolts, and when I next take it apart, I will deal with that embarrassment.
reassemble the valve gear, using a spanner in lieu of a valve lifter, and I showed him how to fit the collets using a screwdriver, and how to watch where they went when the spanner slipped. I showed him how to fit the pistons using a piston ring compressor made from a baked bean tin and Jubilee clip, and I showed him how to take it apart again because you've got to fit the small ends before you fit the pistons. I showed him how to use the kitchen scales to calibrate Clive's torque wrench, which was so far out of calibration that its a wonder his cars didn't just fall apart, and we used the properly calibrated wrench to bolt up the big ends, the mains, and the head.

And for the record, the main bearing shells came from ACL Bearing Company, stamped M020 3109L 02Apr92, and were 20 thou under, and according to the data sheet that came with them, the flange width was 4 thou over, to allow correct crankshaft endfloat; the big ends were made in Israel, the box was marked RX3830 CB 383 030, and the shells themselves were stamped 030 REPL 383, and were 30 thou under. To the best of my memory, the pistons were 30 thou over.

I would have shown him how to set the camshaft timing by counting the links, because there were no bright links on the timing chain as the manual believes; but we didn't get that far. The problem was, James told Skip where we were up to, and Skip was so impressed he gave him the badge on the spot. From then on there was no more incentive for the boy, and because it was out of sequence there was very little for me; so the engine sat partly assembled for several years, wrapped in Gladwrap. Just to give you an idea of how long, when I finally came to finish putting it together, I couldn't find the sump. Now you can understand losing things like the castellated nuts off the steering column; but the sump is a seriously large bit of gear, and hard to overlook. I looked everywhere, before I gave up, and started to look for a replacement. I started with the machinist, because he was an MG specialist and knew where to source bits of gear like this. He took a bit of finding, because he'd moved, without leaving a forwarding number (or perhaps he had, but the notification had lapsed due to eflux of time). Anyway, he thought there might have been a sump, or at any rate something big, which they'd tripped over for several years and then used as a doorstop, but he didn't know where (or whether) it might be after the move; he'd phone me back. And to my surprise, he did: one of his guys had taken it with him and his wife was growing flowers in it. He thought it might be from an MG. And it was an MG sump, and it would fit my car, which was good enough for me, and in really very short time I got it back. I don't know what happened to the flowers. And who can tell: in view of the crankshaft, maybe he'd sold my sump to someone else, and what I'm using might be someone else's again.

There really is only one major caveat in reassembly, and that is that almost all the bolts and studs on the engine itself (but excluding ancillary parts like carburettors, starter motors, dynamos, etc) are metric: mostly 8 x 1 metric fine, but also a few 10 x 1.5. Mostly its not a problem, because things like rocker shaft bolts, for example, are specials, and if you have to replace one you'll probably have to source the correct part from a supplier. But things like sump bolts, and the many brackets, are also metric, but they're machined onto Whitworth/BSF hex stock, so they fit Whitworth/BSF spanners, not metric spanners. This probably accounts for the many stripped threads which have occurred as I've attempted to match 8 x 1 metric with BSF threads.

As you get ready to fit the water pump, don't forget the bracket for the engine steady rod, which bolts onto the front of the engine using two of the bolts for the water pump. Perhaps you can see, in this picture of the engine going in, that I hadn't fitted it yet. Not a major problem, it's not too hard to take the water pump off again, as long as you do it before you fit the fan and radiator. But if you wait till the car is almost assembled, you will find that you become seriously Pissed Off.

And when you fit the engine, this would be a good time to fit the clutch linkage, because if you wait till you've fitted the exhaust system, you'll have to take it off again. The clutch lever is symmetrical, and it doesn't matter which way round it goes; but front lever, which fits onto the side of the sump, is not. It must be fitted with the narrow side closest to the sump, because otherwise there isn't enough room to clear the exhaust system and you'll wear a hole into your expensive new downpipe.

It would also be a good time to fit the speedo cable at the gearbox end, because I found, when I had assembled almost the entire car, that it was very hard to fit it after the floorboards, which meant taking out the seats and floorboards, which in turn meant taking out the steering wheel, and the petrol pump, and diverse other bits. The cable is very flexible, and has a tendency to hang down below the car, which as you can imagine is a trap for bits of debris from the road. I stiffened mine with a bit of heat shrink plastic tube, which, as well as looking good, will, I hope, make it easy to keep bits of crap out of the corrugations in the outer sheath and prevent any further tendency to rust. I also made a little clamp to hold it in place on the firewall.

as it came offnew glands, new needles, new jets: as good as a new carby Fuel System Well I like SU carburretors - nice simple things, with only one huge jet that can never block (contrast this with say Webers, typical of fixed venturi carburretors used on most American and European cars. These have a main jet fitted into an emulsioning tube with an air corrector jet, an idling jet with two holes in an idling jet holder with four holes, an idling mixture adjustment screw and three progression jets, an appropriately named stuffing ball with its stuffing screw, an accelerator pump to cater for sudden demands for acceleration, and about a kilometre of ducts drilled into the body casting, any of which can and do get blocked with the result that the car doesn't work). In contrast this car was driven to its long rest with carburretors that looked like this. I really wouldn't have believed that a carburretor could be so glued up yet still have worked, and I'm sure that it would have worked still, except that the glands were all stiff and dry and the dashpot had no oil. Rebuilding them with new glands, jets and needles was really pretty straightforward, except that all the glands leaked. I had another go with new glands, soaking them in boiling water to soften them first, but the same result. Finally, with yet more new glands, I soaked them in hot oil which I warmed in the microwave, and they worked fine, and it's a good job the glands are so cheap. The big secrets are that the brass gland washers are concave towards the gland washers, top and bottom, and that the langite packing washer especially must be soft enough so that it compresses fully into the bevelled washer, allowing the jet screw to be fully tightened up, so that the copper washers between the jet screw and jet bearing, and between the jet bearing and carburretor body, are fully tightened and can make a good seal.

Before we started the engine, we towed the car around the block to get the oil pump primed and to get oil around the galleries. And having said there is only one caveat, I can now tell you there is at least one more. The oil pressure bypass port is closed by a metric 10 x 1.5 plug. When I put the engine together I didn't have a 10mm plug, so I covered the hole with masking tape, and when I painted the engine the tape got painted too, and forgotten. So now I am in a position to tell you that a piece of masking tape painted to match the engine colour is not an effective substitute for a 10mm metric plug when it comes to resisting the mighty pressure of an XPAG oil pump.

Having sorted out this minor problem, which dumped a gallon of running-in oil onto the road, finishing in a conspicuous puddle outside our house, we towed the car around the block again to make sure oil was circulating, and then we put the plugs in, turned on the ignition, let in the clutch, and it fired and started on the first compression stroke, and ran for the first time in thirty three years. I drove it back to its garage, and we cracked the champagne.

And although it wasn't registered because it still lacked bumper bars, we hired a trailer and took it to the concours which was celebrating 60 years since TDs were first introduced, where it attracted an appropriate amount of interest.

Oil Pressure Although the car was substantially finished - at least finished enough to drive it in good weather - the oil pressure was disappointingly low. I changed the oil pressure relief valve - no difference. I swapped the oil pressure gauge - no difference. I was puckering myself up for the first serious bit of maintenance - taking the oil pump apart and measuring/reconditioning it, followed by the oil filter bypass valve, and then even taking the sump off and checking the suction filter assembly and associated gasket which are located in the sump itself, which would have meant oil leaks ever after because I hadn't done the lip seal conversion and I don't believe it is possible to assemble the cork rear oil seal correctly without taking the whole engine out - when I thought to trace as far as possible oil pressures throughout the system. Now there is an external pipe supplying the rocker shaft from the lower oil gallery, and the feed to the oil gauge is taken off here. The diagram on Page A2 of the manual (Engine Components) shows the feed being taken off the top of this pipe, but Figure A1 on pA4 suggests that the feed is taken from the bottom of the pipe. All the cars I have seen have the feed coming from the bottom, with a union on the lower banjo, but I thought it made a much neater installation to take the feed from the top, so thats what I did. I inverted the pipe so that the banjo with the union was on the top, and took the feed to the oil pressure gauge from there. So the first step in my diagnostic procedure was easy - simply blank off the feed to the rocker shaft, and run the engine just long enough to check the pressure. Bingo: the gauge registered an acceptable pressure (still a bit lower than I would have wished, but acceptable). Evidently the rockers were taking enough oil flow to lead to a significant pressure drop along the external pipe. Solution: blow through the external pipe, replace it in its correct orientation, and take the oil pressure feed from the bottom. Now an acceptable pressure was registered: still a bit lower than when the rockers were blanked off, indicating a significant pressure drop even along the main gallery, and perhaps also indicating that the oil pump is not capable of supplying demand from the entire engine and therefore requires overhaul but good enough for me to put it off sine die.

more to come...

(Note to self: the new oil filter cartridge is RYCO R2001P (156x773x33)

Good luck, please send me an email
Bob.




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