Iíve owned Snappy† since August 2003 when it had a mere 19,000 miles on it and a good service history. Over that time it has provided a reliable old thing and has never let me down, however it had recently been very, very difficult to start from cold and despite replacing and adjusting several ignition and fuel parts the problem got worse. Once it was running and warmed up it would start first turn of the key. Very irritating.

The weakest link has always been the gearbox as it had a tendency to loose drive when going around corners or roundabouts at speed; kicking back in once the car had straightened up.† Constant checking of the fluid and regular fluid changes did little, if nothing, to improve it. I had to replace the selector cable several years ago as it had frayed, which meant I had to remove the access cover plate but ever since I refitted it kept leaking. Removing it again and fitting a thicker sealant did nothing to improve it and it leaked particularly badly when the gearbox was very hot after a motorway run. I always knew that one day it would have to come out and be overhauled properly.

A Sunday morning in late April I started up Snappy as usual and began my drive along the driveway when I realised that there was a very deathly rattling noise coming from the engine under load. I drove it up the road for a brief drive to see if I could confirm where the noise was coming from but it didnít sound good. Back in the driveway and with the bonnet up it was obvious that the serious rumblings were coming from the depths of the engine (or was it the transmission?) and it would almost certainly mean that it would all have to come out.†

Having resigned myself that this was going to happen I got on with the task of removing all of the parts I could to reduce the weight of the unit such as the starter motor, and alternator, removing the radiator, disconnecting the exhaust manifold and removing the driveshafts from the differential which is all very straight forward and can be done within 90 minutes.

I borrowed an engine hoist from work and my dad and I set about removing the engine from the car, made awkward by the fact that my driveway is all gravel. We decided the best way to do it would be to lift the engine clear of the car and then push the car back out of the way and lower the unit to the ground.

Once lowered we then set about separating the transmission from the engine which again is straight forward following the Haynes manual (though itís not always rightómore on this later)† though we did have difficulty accessing a bolt due to sealant completely covering the access hole for it. It wasnít until Martin arrived to give a bit of support we realised it had been there all along.

Three weeks later I had a call to say the engine and crankshaft were ready. They ground 010Ē from the journals, honed the cylinder bores and machine skimmed 0.002Ē from the face. The other job I needed to do on the crankshaft which Iíd forgotten about was to remove the spigot bush as the auto and manual bushes are different. According to the Haynes manual itís a matter of tapping a thread into the bush hole, winding a stud or bolt into it and easing it out using opposing force . We tried this and it would not budge so we tried using a slide hammer as explained in the official BL workshop manual. As we didnít have the official BL removal tool we made one using some stud bar, the head from a 4lb club hammer and a large socket.

After a few hours and a nasty cut to my hand we decided it would be best to give the crankshaft back to the engineering works and let them remove it.† Another two weeks went by.

The block was given a coat of black heat resistant paint and we then set about refitting the crank and pistons. I was going to refit the old piston rings but when I compared them to a new set I realised it would be a false economy not to do it whilst the opportunity was there.

Blown head gasket and damaged block surface between cylinders 1 and 2.

In any case it would mean that the block face would need skimming. We then get onto removing the rest of the block components to allow removal of the crankshaft and pistons. Surprisingly there seemed to be little or no wear on any of the bearing shells and in actual fact it all seemed in pretty good order. Could it have been that damn gearbox after all? The crankshaft and block were sent off to a local engineering works for the necessary work.

In the meantime I had decided that a manual gearbox we had acquired would be going into Snappy and this also had to be separated from its engine which again, was straight forward. I knew the gearbox was OK as a previous user had said so and I drove it a short distance also before it was removed from the donor car.

As the engine was out this gave me the opportunity to clean up the engine bay as it had been looking very tired. I did it in stages, painting the each inner wing individually and then painting the bulkhead area, made awkward by a plethora of brake pipes and suspension pipes in the way making everything that bit more difficult. All of the engine mounts also had a clean up.†



























Lifting out the complete unit. Gravel is not the ideal surface to work on!

With the engine and transmission separated and the cylinder head removed an inspection revealed a major problem. The head gasket had blown across cylinders 1 and 2 and there was a light indentation in the block to match it. Could this have been the cause of the poor cold starting issues?

Painting the engine bay was awkward but worth it. I even gave the suspension pipes a coat of silver.

Despite our best efforts the bush wasnít having any of it.

Nicely machined parts back from the engineering works.

I suggest that when fitting new piston rings change them one at a time as they have to be fitted the right way up in their correct grooves, so make sure you have at least one original complete piston for reference. The manual isnít much good in this instance! Fitting the crank and pistons is again straight forward, following the procedures in the Haynes manual and using loads of oil, but make sure the piston is facing the right way around. It has FRONT stamped on the side that should be facing the timing belt end.

The Haynes manual states that when fitting the connecting rod caps the side with the numbers stamped on them should be adjacent to each other. I thought this was odd as when I removed the caps at least one of them had the numbers on opposite sides, but weíd number punched each cap and rod upon removal to ensure they went back on the way they came off. So, taking the Haynes manual as being right I reassembled the rods and caps with their numbers adjacent to each other, ignoring my original stamps and tightened them all to the correct torque.

All well and good but now I couldnít turn the crankshaft! I put the longest bar I could find onto the end of the shaft and it would not rotate. It simply lifted the block off the bench!† I decided to refer to the official BL repair operations manual and it makes no mention of the bearing cap and rods having numbers on them or even that they should be adjacent to each other! So I removed the cap that was upside down, as it were, and fitted it how I removed it. Now the crank turned easily with a very small amount of resistance, just as it did before I removed it. Mark everything as you dismantle it and take photos if you can. It will save you a lot of grief!

So, with the block now reassembled it was time to attach it to the transmission. This was all done in dadís garage as the gearbox was in there from when we removed it from the donor.

Engine mated to manual transmission. New gaskets all round as the clutch housing is fitted.

I bought a NOS clutch kit from ebay as well as all the gaskets and seals I would need for the rebuild. I also fitted new differential oil seals for the driveshafts and the gear selector rod. With it† now ready to go back into the car I borrowed the works van to transport it to my house for the refitting. I had acquired some marine ply in the meantime to put over the gravel so that we had some manoeuvrability with the hoist to aid refitting.

I cleaned up the clutch housing with the wire wheel on an angle grinder to give it a nice bright finish and refitted the oil pump and timing gear assemblies. At last we could put the engine back where it belonged.

Block and transmission back in the engine bay

With the engine back in position I then realised that two of the four mounting brackets from the automatic are not the same on the manual! This was a bit annoying as I had all of them powder coated, as well as a few other pulleys and parts. This meant I had to clean up one of the rear brackets and give it a coat of black paint. It hardly notices. The front bracket is the same shape but the two holes for the bolts that pass through to the clutch housing are in a different position. We couldnít remember what weíd done with the one from the donor car so I had to get two new holes drilled into the bracket.† A silly oversight that I should have checked up on.

Now, you may well be asking but ah, what about the clutch system, pedals and gear change selector? Surely they need to be fitted.

Well, in the times between the various components being away for work I had already fitted most of them. I got the clutch master and slave cylinder from a Princess that was being broken at a breakerís yard in Shepton Mallet. This donor car also yielded a gear stick, a selector gaiter† and a few other parts required for the transmission swap. I already had a three pedal box and remote gear selector unit.† Due to its position in the car swapping over the pedal box is very awkward but undoing the bolts and nuts that secure it is fairly easy.†

Swapping two pedals for three.

The remote gear change unit was one I took from a 2200 Princess many years ago but I wasnít sure if it would be the same on the O-series. I could have taken the one that was on the Princess at Shepton Mallet but scrabbling under that, stacked on old wheels in amongst stinging nettles did not really appeal to me. According to the parts listing there are two part numbers for the selector but we deduced that this was probably due to the 1978 driveshaft issues where the engine was moved back and so later ones may be shorter. As it turns out the one I fitted is right. Another job was to join the now redundant inhibitor switch connection.

As I have mentioned before, I had a some components powder coated and one of the major ones was the exhaust/inlet manifold. I had this painted a in high temperature silver coating and very smart it looked, too but there was a problem...

On closer inspection I discovered two cracks in separate places, meaning it would either have to be welded, replaced or remade. I made enquiries and the engineering works I had used said they knew someone who could repair it so I gave it to them. I was quoted £280, which I thought was way too expensive., but I was chatting to a friend who supplies the company I work for with various fork lift truck† parts and repairs and he told me he knows a chap who works a couple of industrial units down from him who specialises in this kind of welding work and could do it a hell of a lot cheaper. His workshop is near Worthing so I would have to wait a week or so for it to be done. One week later I had it back, beautifully welded and all for £60!

With the engine mountings tightened we could get the cylinder head back onto the block. I fitted the smart, newly painted manifold and carburettors onto the head and we lowered it onto the block as a complete unit (itís heavy and awkward but manageable) onto a genuine Unipart cylinder head gasket I sourced from ebay.† With the head correctly torqued down the timing was set and then water pump, pulleys, alternator, starter motor, wiring† and cooling system were all reassembled in position and fresh oil was filled to the level.

So at last it was finally time for the start up.

Having rotated the engine several times on the crank pulley I connected up the battery and removed the HT king lead and turned it over with the key. With all seeming well I refitted the king lead and pulled out the choke. Nothing. This went on for several hours but still it wouldnít fire. After lots of head scratching we deduced that it was obviously fuel related so I† removed the carburettors and took them apart wher it became clear what the problem was. The person who took the carbs apart to overhaul them (who shall remain nameless) didnít refit the jets properly and so they were not doing anything useful. I installed them correctly and then refitted the carbs to the manifold.

Reconnecting the cables and opening the choke I tried again. Vroom! Success! A bit lumpy but it was running although the blow from the exhaust manifold was a disappointment. Anyway I ran the engine up to temperature until the fan cut in. Next job was to get the clutch working.

With a new clutch hose fitted it took quite a while to bleed the clutch but eventually we got a working system and so Snappy would now move for the first time in almost three months.

Time for a drive up the road.

Easing out onto the road from the driveway was a bit nerve-wracking but I managed to get through all the gears without much fuss, the clutch seemed to work quite well and the engine was pulling well enough, though the exhaust blow was a big distraction.

Having got it back home I was feeling quite pleased with myself as it all seemed to work but I knew I would have to find out why the exhaust manifold was blowing, thinking perhaps the welding I had done on the manifold wasnít up to scratch. The following Saturday I again removed the carbs and unbolted the manifold and it wasnít long before I discovered the source of the blow.

†††††††††† The manifold gasket had blown almost immediately the car was started.

The gasket I used came from a cylinder head overhaul kit I had, used mainly because it was the first one that came to hand. Delving through my parts I found a genuine Unipart gasket which was at least three times thicker than the one I used. It was duly fitted along with the manifold and carbs. That was much better; I should have fitted it in the first place!

So, with all of the issues addressed I could get on with giving the car a proper shakedown. So far I have covered almost 400 miles and as confidence has grown I have pushed it a little more each time, managing to get to the heady heights of 70 mph, though I have to remind myself I need to change gear now.

Iíve never undertaken a rebuild like this before but it has turned out to be very satisfying and I now have the car I have always envisaged and one that would be more in keeping with the ST badge bestowed upon it.

Complete installation with all ancilliaries connected.

Block separated from transmission

Epic O-Series engine rebuild and gearbox swap

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