2CV wiring loom strip

I’ve got a salvage wiring loom that I’m going to work up ready to fit on the Burton.  The first step is to remove the wrapping to get to the wires.

This is best done with a seam ripper, it will cut the wrapping without damaging the wires themselves.

Removing tape from a 2CV wiring loom with a seam ripper

As the wrapping is removed re-usable cable ties are put at the junctions to keep the loom together whilst still allowing wires to be added and removed.

Wiring loom held with re-usable zip ties

2CV Cylinder Head Rebuild

After the port polish and lapping the new valves and cylinder barrels it was time to rebuild the cylinder head.  This is basically the reverse of removal.

The white exhaust valve stem oil seals are a tight fit on the valve guides, even without the securing collar.  They’re also a tight fit on the valve stems so it’s worth fitting the valves at this point before the springs.

2CV vale stem oil seal fitting

The springs have caps at either end so, with a generous covering of oil, these sit over the valve stems.

2CV valve spring

The valves are attached to the springs via the collets.  Like removal, this is a three handed job involving a heavy spring under compression so I didn’t take any photos.  Essentially, with the spring compressed and some grease on the valve stems to hold the collets in place the spring can be slowly and carefully uncompressed until the spring cap rides up on the taper of the collets until the whole assembly is secure.

The biggest departure from the removal was the replacement of the “special” bolts used to to hold the lower end of the rocker pivot.  As fitted by Citroën in their infinite wisdom the bolt has a strange head that has two flats.  Whilst this came off with the assistance of an adjustable spanner I didn’t want to put it back so I used a 35mm M8 threaded hex headed bolt.  This fits exactly as the original and uses a standard tool.

2CV rocker pivot bolts

2CV rocker pivot bolts

With the rockers fitted that’s the heads reassembled as far as possible.

2CV cylinder head

2CV Port Polish

Nothing too aggressive but whilst I had the heads off I got the Dremel out and softened the hard edges in the inlet and exhaust ports.

2CV combustion chamber showing inlet and exhaust ports

These edges seem to be where the cast inlet meets the machined area in the valve bowls..  With a finger it was possible to feel the lip but with a small amount of grinding and polishing it now feels smooth to the touch.

Other than removing a few minor casting marks I didn’t do much as the ports were already reasonably smooth.

I doubt it’s actually going to improve matters measurably but this was the only opportunity I’m likely to have to do it, it didn’t take long, and I can now say it’s been done.

2CV crank case build up

After removing everything from the crank case I cleaned it up with industrial strength degreaser and a pressure wash.

The dipstick guide had a bit of surface rust so that was cleaned up and painted with a couple of coats of black Hammerite.

The oil filler/ breather normally attaches with a pair of bolts but the V series engine had more practical studsSPOG sell a pair of studs for the A series engine which are easily fitted (with a bit of thread lock for good measure).

2CV engine breather studs prior to fitting

The longer stud with the thicker band goes on the off side as there is an alternator mounting plate on that side in addition to the breather.

2CV enginer breather studs in-situ

A new low oil pressure sender was fitted, complete with washer.

2CV low oil pressure sender fitting

This one needed a 22mm spanner.

2CV low oil pressure sender fitting with 22mm spanner

The oil pressure relief valve piston was liberally coated with fresh oil and inserted.

2Cv oil pressure relief plunger being inserted

When fully home the only the nose stands proud of the housing.

2CV oil pressure relief valve plunger in situ

The spring sits over the nose of the piston and, as I didn’t have a new copper washer, I annealed the old one by heating it until it was red hot and then letting it cool slowly.

2CV oil pressure relief valve fitting

The bolt is a 17mm and I don’t have a tightening torque for this so  I went with a good strong tweak with the breaker bar which should be enough to crush the washer slightly.

2CV oil pressure relief valve fitting

Another SPOG item is the 3/4″ thread oil filter spigot.  A bit of thread lock and this was firmly screwed into the oil filter mounting plate.

2CV oil filter adaptor prior to fitting

With a new o-ring and some sillyfoam sealant the mounting plate was re-attached to the crank case with the two alan bolts.

2CV oil filter adapter in situ

One of the advantages of the much more common 3/4″ thread is that a sandwich plate can be mounted.  In this case I’ve got oil temperature and pressure senders – important information to have available for an air/oil cooled engine.

Sandwich plate with oil pressure and temperature senders on a 2CV crank case

As I’m planning to fit an electric fuel pump I’ve got a stainless steel blanking plate for the standard, mechanical, fuel pump mounting point.  This is important as, without the actuator rod, omitting the fuel pump would leave a hole in the crank case.

2CV fuel pump mount with silicone sealent

After applying a generous amount of high temperature sillyfoam sealant the blanking plate was secured with stainless steel M7 nuts.

2CV fuel pump blanking plate

2CV Valve Removal

There are two steps to removing the valves from a 2CV’s cylinder head, you need to remove the rocker arms before you get access to the valves.

The rocker arms sit on pivots that are held in at the top by the cylinder head nuts and at the bottom by a bolt with a special head with two flats.  Fortunately an adjustable spanner provided enough purchase to free them off without needing to resort to “advanced” techniques.

2CV rocker arm lower boltNote that the head is upside down in this image.

With the bolts removed the rocker arms come free.

removing a 2CV rocker arm from the head

The rocker arms slide freely on the pivots and there are two sets of washers on them, a thick one one at the top and a spring washer and a thin washer at the bottom.

2CV rocker arm showing pivot and washers

Now to remove the valves themselves.  (Not too many pictures of this as it’s a job that requires three hands at the best of times…)

First a digression about how the valves are held in place.  At the top of the valve stem there are a set of circumferential grooves which match the ridges on the inside of the semi-circular collets.  The outside surface of the collets has a slight taper that seats them in the valve spring retainer plate that sits on top of the spring.

2CV valve showing spring and collets

As that taper is constantly under pressure from the spring and will be expanding and contracting as the engine heats up and cools down it’s going to stick so, before compressing the spring, give it a small percussive persuasion to free it.

With a valve spring compressor (effectively a large C clamp) in place and the percussive persuasion having been applied it’s time to wind in the threads.  When the collets are clear of the compressor collar you can go in with a magnet and extract them.

Using a magnet to remove valve collets on a 2CV

After fully unwinding the compressor to remove the tension, the valve springs lift off.

2CV valve stem in-situ

The valves then push though into the combustion chamber and can be removed.

Finally the valve stem oil seals can be removed.  With the valve spring seats removed the metal collar can be prised off which allows the seal to be pulled off the valve stem.

2CV valve stem oil seal

Other posts in this series:

  1. Engine tear down
  2. Crank case strip down
  3. Valve removal

2CV crank case strip down

With the crank case separated there were a few items that needed removing before they were ready to be cleaned.

First up, the oil pressure relief valve, this is a big 17mm nut on the off side

2CV oil pressure release valve

Inside there’s a spring and a plunger, which needed extracting with needle nose pliers.

2CV oil pressure release valve removal

2CV oil pressure release valve internals

On the other side is the low oil pressure sender.

2CV low oil pressure sender

2CV low oil pressure sender removal

In the front there’s some rubber seals for the oil cooler unions.

2CV oil cooler seal removal

The oil filter mounting plate is held on with two alan bolts, one inside the filter mating surface and one at the top of the plate.

2CV oil filter mounting plate

There is a rubber o-ring seal in the bottom of the plate where it mates with the crank case.

2CV oil filter mounting plate

The head studs are a bit awkward but the standard stud extraction technique of a pair of nuts clamped onto each other should provide enough purchase to get them moving.

2CV head stud removal

As part of the rebuild I’m fitting the SPOG oil filter adaptor, this allows the use of the more common 3/4″ 16 UNF threaded oil filters.  The kit comes with a a pair of nuts that fit the M16 thread on the old spigot and, using the same technique as for the head stud removal, it unscrews.

2CV oil filter spigot removal with SPOG nuts

2CV oil filter spigot removal with SPOG nuts

The new SPOG spigot has the smaller M16 thread on the lower half so it fits back into the mounting plate but the larger 3/4″ 16 UNF thread on the upper to attach the oil filter.

2CV oil filter spigot - SPOG replacement

Other posts in this series:

  1. Engine tear down
  2. Crank case strip down
  3. Valve removal