Category Archives: Technical

Items of a technical nature relating to mechanical, electrical or bodywork issues

Metalworking – cutting bigger circles

Here is one that I did not know. I have drill bits that go from 1mm up to 10mm in 0.5mm increments. I needed to drill a 12mm hole in a panel that I had fabricated ready to take a grommet for a cable.

I checked in with a neighbour and he only had 10mm drill bit maximum as well, so I got online to order a 12mm and a 32mm one as well for another cable hole next to it.

Here is something called a hole cutter that comes as a pack of 3 allowing holes to be made in 2mm increments from 4mm up to 32mm. All 3 came in a little pouch for about £10.

And they worked so quickly I was rather surprised:

The 12mm hole on the right for the heater cable took about a second to cut from 10mm to 12mm. The one on the left needs the bigger cutter!

Inexpensive way of making lots of different sized holes!

Ageing your vehicle

If you have a Type Two, here is how to identify the age and type of your vehicle as it left the factory:

2 1 2 2 1 5 7 4 4

First digit – T2 (Bay window)

Second digit – Type of vehicle:

1 -Delivery / Panel van
2 – Microbus
3 – Kombi
4 – Microbus
5
6 – Pick up
7 – Crew cab

Third digit – The year (2 means 1972 and 9 means 1979 etc)

The rest is your individual serial number for the vehicle.

Replacing a sliding door seal without fully removing the door

by Mike Hobson

In October last year, I replaced the sliding-door seal, on my “crossover” 1972 VW Type 2. Despite being 71 years of age, I did it on my own, so younger members should find it a doddle! The tools needed, were a wooden spatula (as used by my wife in the kitchen), a selection of screwdrivers and an axle stand.
(1) Firstly, set the height of the axle stand, at as near as possible, to the height of the underside of the door. Pieces of wooden packing might be needed.
(2) Remove the cover plate from rear panel (covers sliding mechanism). This is where different types and lengths of screwdrivers are needed. You have to slacken the tightening bar (the screw can be difficult to get to). Once off, I drilled and tapped with the original thread right through, so can be filled with grease.
(3) You can now see the runner, about half way along is a cut-out. Line up with block on sliding mechanism and lift off rear of door and place on axle stands. Once done, presumably old seal will be out. Just hook new seal over projecting runner and then over door, move seal into position and door can be lifted back on to the runner.
(4) The wooden spatula is shaped as required and used to push the new rubber in. Adhesive can be used as required. It is a bit fiddly, but can be done. Adjustment to the door might be needed for it to shut, due to the thickness of the new rubber seal. It will eventually settle down. Job done.
P.S. I am no mechanic or engineer, just an old Joe Bloggs.

Experiences of overhauling a Volkswagen air-cooled engine

Compiled and written by Nigel A Skeet, previously published in the club magazine.

Sometime in early 1983, our 1973 VW 1600 Type 2’s AD-series engine, developed a major oil leak, which we were unable to trace; leading us to completely dismantle the engine and renew every conceivable oil seal and gasket, plus the steel, pushrod tubes, which were noticeably rusty. Although by that time, I had quite a good selection of tools, including two click-stop torque wrenches, none of them were suitable for removing the 36 mm AF, flywheel gland bolt, which is tightened to a very large torque.
Fortunately, one of my engineering-student colleagues at Cranfield, named Jonathan Wells, loaned me his ¾ inch drive T-bar and 36 mm AF socket tool, which he used for the rear wheel hubs, of his VW based, autocross space frame buggies. Even with this tool, one needed to slide a long steel pipe (being several feet long, it is referred to in some quarters, as a scaffold pole), over the T-bar, in order to produce sufficient torque. When we later refitted the flywheel bolt, we were faced with the problem of how to obtain the correct tightening torque (which is critical for this engine); not having a torque wrench of sufficient capacity. This was finally resolved by weighing myself on the bathroom scales and then standing on the T-bar, pipe extension, the appropriate distance from the socket centre; ensuring that the pipe was horizontal.
Ten years later, in 1993, when we sold the 1600 engine, second-hand, in favour of a VW Type 4 style engine (the virtues of which, Jonathan Wells had extolled to me, in 1983), the buyer recounted a tale of woe, about his supposedly “reconditioned” 1600 exchange engine, whose flywheel bolt had not been adequately tightened. The flywheel subsequently came loose, resulting in a severely damaged engine, which was effectively written off.
On the whole, removing, dismantling, rebuilding and refitting the 1600 engine (my first ever attempt at such things) was child’s play (in many respects, simpler than doing a 200 piece jigsaw puzzle), but removing some of the cover-plates was a nightmare. Many of the cheese-head, slotted M6 screws had rusted in solid and needed to be drilled out very carefully. Noting that the screwdriver slots of conventional and Philips head screws were easily damaged, I later replaced them with 10 mm AF, hex-head M6 bolts, which would withstand higher torque. At a later date, I took the further precaution of coating the screw threads, with anti-seize copper grease. These days, I would also be inclined, to substitute stainless steel bolts and/or Allen socket-head screws, which are what I am using, on my transplanted VW Type 4 style engine.
Many of the cover-plates had corroded where they were exposed to the elements; having been given only a thin coat of paint at the factory. In some places, the steel had become wafer thin, necessitating repair. All the cover-plates were comprehensively treated with D-Rust (a phosphoric acid based rust treatment solution), to etch all the rust out of the pits, and repaired as necessary, by brazing on reinforcement sections, before repainting them with several coats of Finnigan’s Hammerite. When I sold the engine in 1993, these cover-plates were still in excellent overall condition, which I have since sold off piecemeal, during the following years; some as recently as 2010~12!
Removing the old exhaust silencer, proved to be no picnic either, and it was necessary to use a hacksaw and cold chisel, in order to disengage it from the heat exchangers. Had removal of the exhaust silencer not been necessary, it would probably have lasted a few more years. The original exhaust-manifold nuts, incorporated HeliCoil™ thread inserts, which did not rust, but the hexagonal outer portion had corroded badly and no spanner (neither metric nor imperial) would fit them snugly, so “copper exhaust-manifold-nuts”, were purchased as replacements.
We did initially obtain a stainless steel replacement silencer, from the local branch of Qwik Fit Euro, but this would not align correctly (may have been intended for a VW 1200 engine!?), with the cylinder head exhaust ports and/or the heat exchangers, so it was returned to the suppliers. Ultimately, we fitted a Scat ‘Monza’ style silencer, with two integral twin tail pipes, from the USA, purchased from the German Car Company, in Hadleigh, Essex. This lasted well, for nearly 8 years, until Easter 1991, when one of the twin tail pipes dropped off, somewhere on the M40 or M25 motorways. The so-called “copper exhaust-manifold-nuts”, which had been fitted nearly 8 years earlier, proved to be merely copper-plated steel nuts, and had rusted onto the screw studs; one of which sheared off and resulted in the need for an expensive repair to the cylinder head.
I had never been impressed with the standard, single-piece, exhaust-silencer clamps, intended for the VW 1600 Type 2, so instead I used a pair of two-piece, VW Beetle tailpipe clamps, which are more fiddly to fit (see Transporter Talk, Issue 27, February 1997, Pages 24~25), but provide a better seal between the heat exchangers and silencer. To be sure of a gas-tight seal, I also used a liberal quantity of Holts Firegum; a well-known brand of exhaust system sealant.
During the engine strip down, it was discovered that the valve guides were excessively worn, so the cylinder heads were taken to a local engine reconditioning workshop, in Basildon, Essex, for refurbishment. This proved to be yet another encounter with shoddy workmanship, resulting in one of our cylinder heads being consigned to the scrap bin. It was alleged that the damage had arisen, as the result of some earlier bodged attempt at replacing a single valve guide. The workshop manager disclaimed all responsibility, and showed us a cracked exhaust port, together with a rough-hewn valve guide, which had supposedly been removed from it. In our own minds, we were convinced that this was a deliberate falsehood, but could not prove it!
The cylinder head also exhibited deep bruising of the cooling fins, consistent with violent blows from a large ball-peen hammer; marks which we knew had not been present, when we submitted our cylinder heads for refurbishment. As a consequence of this episode, we were obliged to purchase a new, replacement cylinder head, from another supplier. Although this was for a VW 1600 engine, with the same sized valve heads as the original, the exhaust valve stem diameter was 9 mm, rather than 8 mm. I suspect there may have been other, more subtle differences, which were not apparent to my then untrained eye.
Such differences, may have contributed to cylinders 1 & 2, running hotter than cylinders 3 & 4, which I noticed some years later. Since then, I have learned that there are at least nine different VW 1600 ‘twin-port’ cylinder heads, with three different, standard combinations of valve head sizes, plus probably various differences in combustion chamber shape, volume and deck-height (i.e. squish or quench) clearance too. With hindsight, we should have noted the part number, cast into the rocker box of the defunct cylinder head (assuming it was originally ours!), but in those days, we believed there was only one type of VW 1600 cylinder head and were unacquainted with the significance of the suffix letters, in VW part numbers.
Whilst the engine was still out, it was a good opportunity to remove and inspect the petrol tank, which exhibited some corrosion around the fuel outlet, beneath the vehicle. Although there was slight pitting in places, the thickness of the steel had not been significantly compromised, so it was sufficient simply to etch out the rust pits, using D-Rust and repaint the refurbished surface. Other areas of the petrol tank were also showing signs of superficial rusting, which were similarly treated.
Having removed the bulkhead plate to gain access to the petrol tank, it was apparent that this too was rusting in places, so this was also refurbished before repainting. In common with the engine cover plates, the petrol tank and bulkhead plate, had received only a thin coat of paint at the factory, so all items received several coats of Hammerite; paying particular attention to those areas, which previously had rusted.
Prior to painting, I had twenty one, captive M6 nuts (with hindsight, M5 nuts might have been better!), welded onto the back of the bulkhead plate, coinciding with the top, middle and bottom, of the seven vertical ribs; anticipating that at some time in the future, I might wish to fit, electronic ignition and perhaps other accessories, which would need to be mounted in the engine compartment.


1973 VW 1600 Type 2, removeable fuel-tank compartment bulkhead, with nineteen M6 nuts, welded onto the back of the seven vertical ribs.
Note also, the additional holes in the bodywork, on either side of the bulkhead, for supplementary electrical cables, pipes or hoses, to enter the engine compartment.
Any accessories could then be fitted, using custom made mounting brackets; avoiding any later haphazard drilling of holes in the bulkhead (which might penetrate the petrol tank), to accommodate self-tapping screws. About ten years later, a local VW Type 2 owner of my acquaintance, who sadly lacked this kind of foresight, somehow managed to drill three holes in the forward face of his petrol tank, when fitting secondhand motorcaravan furniture, in his Microbus. Fortunately for him, I had a secondhand petrol tank for sale!

Fitting a Voltmeter

In many campervan conversions, keeping an eye on battery voltage can be a very handy feature, especially if you are camping without electric hook-up and have an electric fridge, lighting etc.

You can connect the voltmeter to either the main vehicle battery, used for starting the engine and supplying the vehicle’s 12v electric systems. Connecting the voltmeter to a leisure battery will enable you to see the voltage remaining in your battery for auxiliary accessories such as lighting and fridges. Or you can purchase a switchable voltmeter that enables you to see both battery voltages at the flick of a switch, like the one sold by Just Kampers (J11477).

• Before installing the gauge, disconnect the earth terminal from the main battery in your vehicle and from the leisure battery, so that you do not create any short-circuits which may result in damage or fire.

• Choose a location to mount your gauge, allowing enough room at the rear of the gauge.

• Connect the negative/earth wire on the back of the gauge to an earthed part of your vehicle, such as a bare metal part of the chassis.

• Run a fused wire from one of the positive terminals on the voltmeter to your vehicle’s main battery live terminal or a live terminal on your main fuse box.

• Run a fused wire from the other positive terminal on the voltmeter to your leisure battery live terminal, or to a live terminal on an auxiliary fuse box connected to your leisure battery.

• Reconnect the earth connections on your two batteries that you removed earlier.

• When you have selected either switch position, the gauge should now read the correct battery voltage for that battery.

• Sit back and enjoy the luxury of being able to monitor your batteries voltage levels.

Aircooled engine cooling

When summer is here that hopefully means that we are experiencing warmer air temperatures. With warmer air temperatures, comes warmer engines. Those using aircooled engines will find it even harder to keep the engine cool during the summer months and we have all seen the odd VW at the side of the motorway! Don’t let that be you (not through overheating anyway!)

The tinware on a 1.6 Type 1 engine

Although it may seem like a small detail, to ensure cooler engine temperatures, it is absolutely vital that the tinware and engine compartment rubber seals are all present and intact. This ensures that there is cool air above the engine and hot air below it. These are known as the cool and warm zones. If tinware parts are missing, or the seals around the front and back of the engine are torn or broken, hot air will be drawn from the cylinder heads and exhaust back into the cool zone around the top of the engine and then sucked in by the cooling fan and re-circulated over the cylinders and heads, causing the engine temperature to rise, potentially to a critical level. This can cause all kinds of problems over time, some of which may not be immediately obvious, from hot starting troubles, to cracked cylinder heads, up to and including a seized engine.

If you’ve just bought a car/bus, it is well worth checking the condition of the tinware and seals and also making sure that there are no foreign bodies stuck in the cooling fan (remember to do this with the engine turned off!)

If you are fitting a reconditioned or new engine, don’t just rely on refitting the parts that were on the old engine, as they may not be correct either.

The thermostat is another vital piece in the cooling system. There is a set of flaps inside the fan shroud, that actually block cooling air when the engine is cold, in order to warm up the engine more quickly. These are opened by the thermostat, located between the cylinder barrels and if this part is defective your engine will very quickly overheat. Check the function of the thermostat and flaps and if required, replace. The alternative is to completely remove the thermostat and flaps, which while it certainly simplifies matters, is not ideal. It means that your engine may never reach the correct operating temperature in cold weather conditions.

The last few points to consider are your ignition timing, air leaks and fueling. Poor ignition timing can cause your engine to run too hot, it’s unlikely to be visible if it’s wrong but you should hear it. Fuel mixture is equally important, so ensure the carburettor jetting is correct for the size of the engine, fuel starvation will raise the
engine temperature internally. Your fuel system could be setup perfectly, but if your engine is sucking air in elsewhere through a split hose or a broken gasket, then the whole fuel/air mixture is compromised and the chances of running lean and therefore hot, are increased too. Spraying the intake system with Wd40 whilst running will help to detect this, an air leak will suck the spray in, using it as fuel and changing the engine note at the same time.