After using the van for a while and going on a few camping trips, it became apparent that the engine needed some work. Although it was probably possible to repair the existing engine, we happened to get into a situation where we could get a recon engine for a reasonable price, so I decided to swap it.
Old Engine
As the engine is aircooled, this makes the process of removal a lot simpler – there are no water channels to worry about or a radiator. In fact, there are only a couple of engine mounts and 4 bolts holding the engine to the gearbox. There is a lot of tinware that has to be removed. This is essential for the cooling of the engine and separates the hot half of the engine from the cool half.
Probably the most difficult part is getting the engine out of the engine bay. Some people remove the back valance from the van in order to get the engine out – this can then be replaced with a removable one.
After thinking about this for a while, I decided to try the technique of lifting the van over the engine instead. The method requires three trolley jacks – two to lift up the van and one to lower and drag out the engine.
In order to get the two jacks high enough, I had to stack them on a load of wood but the technique works fine.
Here is the engine out, you wil see one of the jacks in the background:
Once the engine was out, it was pretty easy to strip the ancillaries. The fan tinware is pretty big and the fan is driven by the back end of the alternator shaft. There are temperature control flaps that are meant to regulate the temperature that you can see in the picture below. Clearly a lot of oil had been leaking from the engine as the shroud was covered in it. Although this engine is called aircooled, technically it is oil cooled. The engine oil gets pumped through a heat exchanger that sits at the back of the fan shroud next to the fan when the engine is assembled.
There was also a lot of oil sitting in the bell housing of the gearbox but the thrust bearing and drive shaft were fine.
I had also noticed when driving the van that there was often a smell of petrol when turning corners. So, while the engine was out, I decided to remove the firewall and check the petrol tank.
After digging around for a while it became pretty apparent that some of the small rubber hoses were pretty perished, including this one which I think was the worst (and causing most of the smell):
Okay, back to the engine, but first a quick coffee break.
After removing the ancillaries the engine looks like this:
This is called a flat four twin port engine. Flat because that is the arrangement of the cylinders and twin port because of the two holes in the cylinder heads. It is a pretty simple design and there is no head gasket as there is no water. In order to maximise the cooling, the push rods run along thin tubes that are just squashed in between the head and the block (see picture below). The mount for the oil cooler can be seen on the left hand side of the engine. The mechanical fuel pump is driven off the shaft for the distributor.
The cylinders were in pretty good condition but there was some oil in there. It was either coming through the rings or the valve guides and it was only in one of the cylinders.
Anyway, we have a new engine so we don’t need to worry about it. The old engine will be sent back for reconditioning as part of the deal.
New Engine
The new engine is just the block and heads, so I had to transfer all the items off the old engine onto the new one (after a bit of a clean up of course).
Maybe, I’ll use new studs for the manifolds though.
One of the items I wanted to change during the engine swap was the heat exchangers. One of the problems with the aircooled engine (particularly the bus) is the lack of heating in the cab. Basically the cooling fan blows air over the exhaust pipes and then this are is very weakly blown all the way to the front of the van. By the time is comes out of the vents it is luke warm at best. One of the other issues is that if there are any leaks you end up with exhaust fumes being pumped straight into the cab. So it is worth spending some time to try to get this to work properly – just remember to take a coat.
I had some other new parts to fit. In the end, I replaced the alternator with a high current version, the fan shroud with a chromed version, the single carb with a set of twin webers, pulleys, belts, pipes, fuel lines, caps, distributor and added a temperature sender in the oil drain plug.
As it says in the Haynes manual – refitting is the reverse of removal… (some steps omitted) 🙂
Eventually I also replaced the exhaust with a decent one.
Ignore the wiring, I did eventually tidy this up!
I did try an electronic ignition but I found it was worse starting in the cold than the points so I just put that back in the end.
This engine lasted until I got rid of the van years later, so it was worth spending the time to sort it out.
Bits and Bobs
Of course, over the years of owning there were many parts replaced and maintained but there are just the initial faults with the van.
There was an issue with the steering, mainly due to the state of these track rods (notice the bend):
There were also a few issues with the brakes. In fact, one of the few times the van left me stranded was because of a broken brake pipe in the first few months of ownership. See below for the state of one of the brake pipes after removal. I also replaced all cylinders, pads and even the backplates for the brake assembly. While I was in there I also did all the wheel bearings.
The brakes on one of these old vans are probably the weakest point (well maybe behind the heating). The drum brakes require adjusting every 3000 miles or so because they don’t self tighten. This van also had no servo assist, so it took a good leg muscle to get it to stop. Still, when it is all adjusted they aren’t bad.
