Engine - removal, restoration & mechanics

Engine as it was when I got the van. 1600cc, Single Port - everything standard.

After 5 years without moving, it is time to get the van back on the road. Although I was confident that the engine would actually start with a bit of cleaning and a decent battery, it seemed a good time to take it out and give it a good service. To be honest, it would also make the van a little lighter and easier to move from the drive - assuming it wasn't likely to do so under its own steam. The intention is to remove all the tin shrouds, exhaust system and ancillaries and give everything a good clean, re-paint where required and then re-assemble - of course it might also be an opportunity for a few little upgrades :)

I have taken lots of pictures of the process (not like me!) in order to record the job, and also as a future reference tool. Always particularly useful to take pictures of something before you take it all apart, and with a small digital camera it is possible to take pictures of hard to reach areas. I took quite a few before starting the dissmantling process as a record of the condition, and to find areasthat might need attention later.

No bulkhead between the fuel tank and the engine on my van - I may change that in the future. This picture taken many years ago.

Slightly dirty but reliable, I took the engine out and gave it a good clean, and then painted it... well as the engine bay. Nothing fancy, but it actually brightens everything up a lot, and makes it far easier to see what one is doing when working in there.

Looking under the van at the underside of the (slightly rusty) vital tinware - note the greenary!

Back (or front?!) of the gearbox, where it meets the engine. A small oil leak here has kept everything a little oily, which has in turn helped prevent corrosion! I have never touched the gearbox, so may tale the opportunity to remove it and give it a bit of an overhaul. This view shows the oil drain plug.

An unusual view looking under one of the pushrod tubes to the 'inside' of the tinware that was pictured above. On the left is a heat exchanger, and on the right is the main engine block, with the engine number and place of manufacture - in this case Mexico - an 'AS' engine.

Normal rust on the steel cylinder barrels and pushrod tubes, and oxidisation on the alloy cylinder head!

A view taken 'blind' by holding the digi camera behind the cooling fan housing, looking down onto the joint between the engine (left) and gearbox (right, under the fuel tank) One of the main nuts that hold the 2 together can be seen near the bottom of the split line in this picture.

Same components taken from a different view and lower down. The fuel tank is top left (the first bay window vans did not have a firewall between fuel tank and engine bay) and the fan housing is on the right of this pucture. The slightly wavey rubber seal on the left seals the engine bay from the outside, and is a vital part of the engine cooling process - I shall replace this part as this looks a little perished.

The rusty rod across the middle is actually a tube that guides the accelerator cable through the tinware on the left and the fan housing on the right. Remember to remove this cable and the tube before trying to take the engine out! The spring on the right is part of the cooling vanes that are operated by the thermostat below the engine.

A few years ago the oil cooler which is mounted on top of the engine, and inside the fan housing, snapped off its mountings whilst touring in France. I managed to repair this on a campsite. After I had chiseled the floor above the engine to open a hole, I was able to lift the fan housing up and off the engine, allowing accesss to the oil cooler, which I could then get repaired - one of the tabs had split. I then made a wooden door to fill this gap, which is what you can see in the above shot.

This is what the hole looks like from inside the van. A bit messy for now - I intend to clean this up and source a proper hatch to close this hole - but it makes removing the engine much easier, as you have easy access to the 2 top engine/gearbox nuts and blots. Without this hole, you have to reach blind behind the the sides of the fan housing.



 Looking down onto the alternator connections Coil connections, for future reference!

Before starting to take the engine apart I tool lots of pictures so I could remember how it all looked - as an electrical numpty I always take pics of where each wire goes! These wires must all be disconnected in order to take the engine out, but compared to a modern engine loom this is remarkably simple!

Looking down through the hole, I have great access to the bolts that I need to undo to remove the engine - in this case the righthand side, top nut, as seen just to the right of the cable this is the accelarator cable with the guiding tube already removed. You can see how without that tube the cable will easily chaff and get damaged as it passes through the engine bay. On the right of the picture you can see the top of the tinware and the 'front' exhaust manifold as it exits the heat exchanger and bolts to the cylinder head.

One of the advantages of this period of Bay van is that the rear valance (bodywork) is easily removeable once the bumper has been removed. This means that once unbolted, the engine can simply be pulled out from the rear of the bus. Here, it has been removed to expose quite a lot of surface rust. Most of this is the twin quiet-pack exhaust system, which I will be dumping. You can also see the rear part of the chassis at the top-right of the picture, and the right hand engine mount nut. The beam it bolts through is attached to the front of the engine and runs full width.

The picture above, as well as showing me and my parents rather old dog Rosie, shows the bumper still in place on the van, with the tow bar also visible. Once this has been removed, the rear valance can be pulled off. Later models need to be jacked up quite high, and the engine lowered below this rear valance. To remove the engine all I have to do is unbolt it from the gearbox (4 bolts) and undo these 2 engine mounts, jack it up an inch or so, and pull back! (accepting that all the fuel lines, electrical wires and accelerator cable have also been detached)

TOP TIP  - don't do what I did at this point, and forget one crucial stage!! Once you undo the gearbox from the engine, the geabox is unsupported at that end!! You need to support it as you draw the engine out, otherwise it will drop as you pull the engine off the input shaft splines, and jam the removal process! Use a small trolley jack, or even a block of wood to keep it roughly level with the engine as you pull the engine out, allowing the engine to slide smoothly off the input shaft. The picture above shows the input shaft exiting the gearbox, on the right hand side. On the right of the empty engine bay you can see where the rubber engine mount was fixed. Once the engine has been removed you could strap the gearbox up in position so that you can push the van around more easily - if not, don't forget that wooden block under the van!

Looking up and under the right hand side where the exhaust enters the righthand side cylinder head. You can also see the heater hose snake its way around the manifold. The smaller pipe exiting up out of the exhaust manifold is the pre-heater pipe that connects with the inlet manifold above the tinware, and helps prevent icing (I think!) - incidently, the wetness you can see is just release spray.

I have decided to simply dump this rusty exhaust, and rather than take hours trying to unbolt rusty bits, I have simply cut it off. This makes access to the engine mount rubbers far easier from below (the quiet-pack boxes block the lower nut) and reduces the size of the engine 'block' to be removed considerably.

With the rear valance and bumper removed you can see how good access is to pull out the engine.

Heat exchangers and exhaust manifold removed. It is simply not worth using these again, rust makes any joints almost impossible to remove cleanly. I used a hacksaw to cut the thing off near the cylinder heads - I can then unbolt what is left on the engine more easily with the engine out of the van.

Engine out - dismantling

So - there we have it - engine out of the van and sitting inside! Note the cut-off exhaust manifolds ready to be unbolted, and the beam that supports the front of the engine and bolts to the van via 2 rubber engine mounts, left and right.

I don't know if the correct term for this is the 'front' of the engine (as it is facing the front of the van) or the 'back' of the engine - I shall call it the back from now on! Here you can see the clutch and flywheel, with the ring gear around the edge that the starter motor engages with. The starter motor itself is still attached to the gearbox, back in the van. You can also see the fan in the fan housing, where it draw cool air into the engine system from the engine bay itself. Also note the complete (and vital part of the cooling system) set of tinware that wrap around the cyclinder heads. The fan sends the cooling air into these shrouds to direct the air where it is needed, around the cylinder heads themselves - without them the engine will not receive the air it requires, in the right place, (it is an 'air-cooled' engine!) and will overheat! Mine are a bit rusty (particularly the more exposed lower ones) so I shall probably replace all of them. More exhaust manifold stubs to remove!

Back around the 'front' of the engine to begin removing all the bits. In the picture above you can see that I have already removed the coil and plug leads, the distributer cap and the single carburetor. You can now more clearly see the single port inlet manifold, with the smaller pre-heater pipe branching off to the exhaust (removed) - this is a one piece casting on my van - I believe later versions consist of seperate sections joined together. Some time ago I upgraded my dynamo to a more modern alternator, which you can still see on the engine.

After undoing the strap that holds the alternator to the alternaor stand, and removing the fixing screws from around the bottom, the fan housing can be lifted off whole. However, you must also remember to unscrew the connecting rod that screws into the thermostaic bellows below the right hand side cylinder head! It is then easier to get to the 4 screws that hold the fan and alternator to the fan housing itself, and simply lift them away. The two outlets that you can see on the fan housing above, direct air from the fan down and through tubes to the heat exchangers, where it is heated by the hot exhaust pipes before being directed up towards the front of the van.

Once the fan housing has been removed it is possible to see the vanes and flaps that control the flow of air around the engine, via the tinware. The fan drives the air down through these vanes and over the cylinder heads.

In the 2 pictures above the vanes are shown in their open position. This is controlled by the push-rod that you can see exiting the photo bottom right.

When this rod is pulled, the vanes close - as seen above. A series of linkages link the two sets of vanes on either side of the fan housing.

Ok - so how is this rod controlled? - by the thermostic bellows that you can see above. This picture is taken looking under the righthand side cylinder head. The rod in the pictures above screws into this bellows. As the engine gets hot, the bellows expand (upwards), and this pushes the rod up - as it moves up, it opens the vanes and flaps, thus allowing the fan to send cooler air down into the shrouds that cover the cylinder head, and cool the engine. When the engine is cold, the bellows are collapsed/closed, thus pulling the rod down, and closing the flaps. This allows the engine to warm up and reach operating temperature more quickly, or maintain it during cold weather. Incidently, the oily tube you can see in the picture above is the end of the breather tube that comes down out of the oil filling neck, allowing the crankcase to breath. It passes through the tinware and allows oily air to exit below the engine, coating everything with a fine oily mist!!

To undo the rod from the thermostatic bellows, undo the nut you can see underneath it, that bolts it to its bracket. You can then unscrew the bellows itself from the rod and remove it from the bracket.

With the fan housing removed, you can see the gap in the tinware where it once sat. This is where the air is sent into the shrouds and around the cylinder heads, after being directed by the vanes. The tall object bolted onto the top of the crankcase on the right of this picture is the oil cooler. This sits inside the fan housing and acts like a radiator for the oil. It was the tab at the bottom of this that snapped in France a number of years ago, necessitating the hole cutting in the boot floor to lift out the fan housing from above, whilst keeping the engine in the van!

All the tinware has now been removed, except the one piece under the blue front pulley - you need to get the pullley off in order to undo this piece. The oil cooler, fuel pump, distributer & shaft and the alternator pedestal have all been unbolted from the engine. Be careful not to allow anything to fall through any of the exposed holes and into the crankcase. You might want to use a better method than tissue paper stuffed in them, like I have above!

Now looking from the back of the engine. A pretty small and compact unit once everything has been removed. You can see where the oil cooler was mounted, on the 'clean' flat plate area on the right of the crankcase in this picture. The 2 reddish coloured discs are actually rubber gaskets that seal the cooler to the engine once it is bolted down.

While I was here, I unbolted the clutch plate to inspect the condition of the flywheel and clutch - both were fine and won't need replacing (unless I want a lightened flywheel!) I will try and source an old input shaft in order to centre the clutch properly when I come to bolt it back together again.

And that is it! I am left with the engine block itself, a box of tinware, carburetors, fuel pumps, fan housings and manifolds and a small tub of nust and screws!

I'll take the contents of this box and give everything a good clean and repaint where required. As for the engine itself, I'll probably just leave it as it is. Taking the crankcase apart is alot more involved than I need to get at this stage. The engine spins by hand freely, with no 'stiff spots' so I am hoping a good flush with cleaner and some fresh oil is all that is required to get it started again, once I have put all the stuff I have just taken off back on again. I don't think I need to buy much - I will need to replace most of the rusty tinware, and buy a new exhaust, but that should be it.

to be continued.......