2CV cylinder head fitting

With the cylinder heads and the crank case done the next step was to put them together.

The old head studs were somewhat the worse for wear so I have got some high tensile stainless replacements.  Some blue thread lock on the crank case ends and the usual double nut technique and they were installed.  The two longer studs go on the top and the shorter one at the bottom.

Fitting 2CV cylinder head studs

Fitting 2CV cylinder head studs

Next the valve push rods go into the head through the push rod tubes.  The more domed end goes into the rocker end and the flatter end goes into the tappets.

2CV pushrod ends

The adjusters should be wound fully out at this stage to make assembly easier.  Some petroleum jelly will provide additional lubrication for the first run and the surface tension will hold the push rods into the cups on the actuators.

The push rod tube seals and springs need to go on – there is a right and a wrong way so check the manual to make sure you get the alignment right for the engine.

As they’re at different angles, fitting the head onto the studs and the push rods into the crank case is another three dimensional puzzle that requires some finagling before it all slots into place.

Fitting a 2CV cylinder head

Finally the head studs are done up the initial torque.  The final torquing is done once the manifolds are fitted.

2CV cylinder head fitted

With some spark plugs in turning the engine over there was a good amount of compression so that’s an encouraging sign.

Finally the rocker clearances can be set.

Fitting a 123 electronic ignition to a 2CV

I made a concious decision not to put an electronic ignition into Judith as I wanted to keep her as original as possible.  However, the majority of the hassle I’ve had with her has been caused by the ignition.  After my first shakedown run this year she was backfiring on the way home and my first thought was the ignition.

After checking the static timing, the dynamic timing (with a strobe gun) and the points gap I couldn’t find any obvious cause.  So then I started swapping out parts of the HT system to check if anything there was out but there was no change – she was still running lumpy and backfiring at about 3/4 throttle when accelerating.

As a final, last resort, check I ran the car with the points box cover off and could see that there was significant arcing over the contact breaker.  This is a problem as it means the contact isn’t being broken properly which will lead to miss-timing and a weak spark.  This is almost certainly due to a failed condenser – apparently a fairly common occurrence with newer condensers.

By this point it was well into the evening and I’d spent the rump of a day going nowhere (well, apart from 100 yards down the road and limping back on one of the shortest test drives I’ve ever done).  I put everything back together and had a think about what to do next with a club run coming up in a week’s time.

As the title of this post suggest, my conclusion was to fit an electronic ignition.  I had already purchased a 123\TUNE+ for the pile of parts I’m intending to turn into a Burton so, a few days later, that was pressed into service.

Fitting the ignition is refreshingly simple as it sits in place of the old points box and is a fully reversible figment.

2CV points box in-situ

The starting point is removal of the old points.  The box comes off with the removal of the two 11mm nuts on either side.  After that the thin metal shield comes out which exposes the timing cam and centrifugal advance weights.  Removing the circlip that holds the timing cam onto the cam shaft allows this whole assembly to come out.

This leaves the nose of the cam shaft showing and the two pins that attached the advance weights.  In the ignition kit there are a pair of sleeved magnets that slide onto these pins, the magnets being strong enough to hold them in place.

Sensor magnets on a 2CV camshaft

The ignition itself then fits on in the same way the points box did and is retained using the old 11mm bolts.

123 electronic ignition in place of a 2CV points box

The red wire is connected to what was the positive supply for the coil, this now gives the ignition a 12v power source.  The black (-ve) and yellow (+ve) wires will be connected to the coil terminals later.

With the ignition powered up the green timing LED on the front can now be employed.  This is identical to timing with a timing light – when the flywheel is at the timing mark, rotate the box until the light goes out then back until it just goes on again.

The black and yellow wires can now be connected to the coil terminals and we’re ready to go.  The difference it made was surprising, starting from cold it caught immediately – even when warm it used to cough once or twice.  The engine note was also noticeably smoother and it needed less choke.

But the fun didn’t stop there.  One of the benefits of the 123\TUNE+ is that it comes with an app that connects to the ignition via Bluetooth and shows a glass dash.

123\TUNE+ app dasboard

This is all well and good for a cold engine idling with a bit of choke.  The problem came with any more revs than this:  the voltmeter pinned itself to the top of the dial (15v).  (Curiously, the voltmeter in the dash that uses the factory connection in the wiring loom was reading about 14-15v – a bit high but not indicative of an issue.)

This lead me to conclude that the voltage regulator was goosed.  From what I can tell, it’s the original Paris-Rhone item that was fitted to the car at the factory.  The somewhat steampunk appearance didn’t add to my confidence in it’s continued ability to function in an efficacious manner.

Steampunk appearance of an original 2CV Paris-Rhone voltage regulator

The replacement item is a fraction of the size of the old one and is a simple swap.

2CV voltage regulator

The ignition now reads a consistent 13-14v confirming that the old unit was indeed past it.*

With everything in place and a shakedown run up and down the road – more than I’d managed last time – it was time for a longer run.  When fully up to temperature and with some fresh dinosaur juice she was running really smoothly.   The accelerator response is right there (although with 29 horses it still takes a while to have an effect on the road) and, most noticeably, she’s significantly happier when coming off the throttle.

For all the trouble it has caused, I’m glad I persisted with the original system – not only do I now have a good working knowledge of how it operates but I fully appreciate the benefits provided by a modern electronic ignition!

* I think that the failed regulator was a significant contributing factor in the previous ignition issues – it will have been over loading the system and may well have over stressed the condenser, especially if it wasn’t the best quality anyway.


Liked on YouTube: EDEN Mehari Electric Car

EDEN Mehari Electric Car
We are just a few years away from the 50th anniversary of the Méhari, and the 2CV Méhari Club Cassis got to thinking of a concept car to glorify this model symbolises the leisure car of excellence.

This model had to respect the tradition of the Méhari and be recognisable at first glance, and therefore there was no question of changing the form. You will notice in the concept car, the only exception to change is for security, because we have installed a rear roll bar and 3-point seat belts.

We wanted this vehicle to be elegant, the French elegance. This can be seen in the detail and quality of the upholstery entirely made in are workshop at Carnoux, and in the paintwork realised at our workshop at Cassis.

The third point is the modernity, because we want the Méhari to continue into the future. The Méhari will soon be 50 years old, for us 50 years old is the age of reason. We implanted an electric heart because pollution and consumption are subjects that concern the consumers and our society in general. We wanted to increase the longevity of the Méhari.

There is still a great demand for the Méhari. A problem which limits us in the construction of the Méhari, is that to build a Méhari we need a base to build from, this means finding a wreck with registration papers and building around that. This is no longer the case. The Méhari Club has become a car constructor. We will now be able to create our own chassis numbers and issue our own registration papers.

When we started this adventure we entered into contact with our clients and Méhari enthusiasts, and they encouraged us to think about commercialising this type of vehicle. The vehicle has recently passed shock and electromagnetic tests and it could be commercialised. Of course we will need to do some optimising and on road tests to ensure as always the high standards of quality and security that our clients have come to expect of our products.

To respect the tradition of the Méhari we decided to keep the original gearbox and a maximum of other parts made by us using the original Citroën moulds and tools. Of course there are some parts made specifically for the electrical motorisation. We kept the gearbox so that Méhari enthusiasts would have that gear lever and find the same unique sensation of driving a Méhari. Also the ability to change gear helps the vehicle to advance more efficiently on a slope.

We decided to use tried and tested technology. The batteries are Lithium iron phosphate. We chose a technical solution that provides a good balance between performance, reliability and longevity of batteries. We have two difference battery packs. The standard battery pack which provides a range of around 80Km (50 miles), and we have an extended pack with a range of 120Km (75 miles). This of course depends on the style and manner in which the car is driven. Given that most users do not drive more than 50Km (30 miles) a day we are sure the range is secondary for this type of vehicle. It is about the pleasure of driving wind in the hair and in almost complete silence.

We have a short charge time of 30Km (20 miles) per hour. In less than 3 hours the batteries are fully charged.

With the Eden we consider we have the project that bears the closest resemblance in look and feel of the original Méhari.

An advantage for us which is an element essential for our clients, is the experience and expertise of our upholstery and mechanical workshops. They have used the maximum of original Méhari parts to create this unique model.