Continued De-clarting of tinware

After the initial de-clarting of the tinware I now moved on to trying to clean them up further. However, after the best part of a day (or what passes for daylight hours at this time of year) with various abrasives and power tools I’d not made much more than an impact on the surface.

Dyanne tinware

As this has now sucked more than enough of my time I’ve opted to pay to have them sand blasted.

In the mean time I’ve picked up a new set of fixings to hold it all together when it’s done.

Burton 2CV tinware fixings

De-clarted tinware

I’ve got some Dyane tinware for the Burton engine, this has the “back end of a horse power” forced induction take off and the cylinder covers are metal rather than whatever it is the later 2CVs used. However, it’s seen better days so needs some renovation.

First off the engine mounts needed removing with the aid of heat, Super Crack Ultra, and an impact driver.  With that done I’ve declarted them using pound shop oven cleaner.

Dyane tinware being cleaned

Next step will be to give them a thorough going over with various grades of abrasive.

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.

2CV crank case rebuild

Assembly is – of course – the reverse of removal.

Note:  as there isn’t any oil circulation until the engine is running, lots and lots of oil is applied everywhere during re-assembly so that there won’t be un-lubricated metal-on-metal when it starts running.  Additional lubrication with petroleum jelly was applied to some virgin metal surfaces which need more lubrication, this has a higher viscosity so will adhere for a bit longer during first start-up.

Starting with the off side crank case shell (the one with the studs in it) the crank and cam shafts go in.  There are locating lugs in the bearing receivers and it’s important to line up the corresponding hole in the bearing shells when placing them.  If you don’t the crankcase won’t shut properly.

2CV crank case showing crank and cam

The timing marks on the crank and cam gears must be aligned.

2CV timing marks

The oil pickup is fitted and the retaining bolt is secured.

2CV sump oil pickup

The crank case halves are now ready to be joined, a thin bead of high temperature sealant was run round the mating surfaces.

2CV crank case before mating

Final check as the crank case halves are closed, the timing marks are still aligned.

2CV timing marks

The four 16mm crank case bolts can be put in finger tight at this point.

Next, the oil pump can be fitted to the end of the cam shaft.  Start with a new paper gasket, this is dry fitted with no sealant.

2CV oil pump gasket

The housing fits into the crank case first.  There is a flat that goes at the top, next to the crank shaft – this ensures the oil galleries line up correctly.

2CV oil pump without rotors

The the inner rotor goes on next, it has a flat that goes onto the flat at the end of the cam shaft.

2CV oil pump with inner rotor

The outer rotor goes on last as it can be easily rotated to the point where it fits with the inner rotor.

2CV fuel pump with both rotors

The oil pump cover receives a new o-ring and some sealant round the outer edge before it is bolted on.  In order to align these bolts with the oil pump and the crank case the pump housing may need to be rotated which is why the crank case bolts haven’t been tightened yet.

With the oil pump in place, the crank case bolts can now be tightened according to the sequence and torque settings in the manual.

2CV crank case without pistons

The two crank shaft oil seals can now be fitted.  The are a push fit but the tolerances are tight so use plenty of lubrication (also prevents them tearing when first running) and carefully drift them into place.

2CV front crank seal

2CV rear crank seal

Now’s a good time to put the tappets in – I’m using new tappets as I have a new cam shaft.  These are a tight fit and plenty of lubrication is necessary.

2CV tappet fitting

The cylinders had previously been lapped to the crank case so time to fit the pistons.  With some light persuasion the gudgeon pins slide through the pistons and the con-rod little end bearings.

2CV gudegon pin fitting

With the gudgeon pin mostly through the retaining circlip can be fitted.  The gudgeon pin can then be pushed through until it seats on the clirclip at which point the other circlip can be fitted.

2CV gundgeon pin circlips

Next step will be to fit the heads.

2CV engine without heads

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.

BMW 801D engine compared to 2CV engine

Visited the Museum of the air battle over the Ore Mountains fought over that area in September 1944 when 60 Luftwaffe fighters (Me 109s and Fw 190s) intercepted a formation of 36 USAF B-17s shortly before they rendezvoused with their P-51 Mustang fighter escort.

They had the wreckage of a BMW 801D engine from a Fw 190A-8/R2 Sturmbock of II.(Sturm)/Jagdgeschwader 4.  As this is an air/oil cooled engine of the same vintage as the 2CV the similarities are striking.

Whilst the size is significantly different (2.9l per cylinder as opposed to 0.3l) the cylinder and head assemblies are very similar with a ferrous cylinder and finned aluminium head:

Cylinder and head from a BMW 801 engine  2CV head and cylinder

Likewise, inside the head, the domed combustion chambers are very similar with one intake and one exhaust valve, hardened valve seats and the spark plug situated in the same place.

Cylinder head from a BMW 801 engine showing combustion chamber

2CV cylinder heads showing combustion chamber and push-rod tubes

Known as Black Monday, on 11th September 1944 the USAF launched a large number of bombing raids into the Reich.  The Luftwaffe put pretty much every available fighter into the air to intercept.

The FW190s involved in the action over the Ore mountains had extra armour and 30mm cannons.  They attacked the B-17 boxes in a tight formation known as Sturmbock (battering ram) opening fire at under 200m. The Me 109s were there to mop up any B-17s that were forced out of formation (Herausschuss) and to deal with the Mustang fighter cover which, in this case, arrived after the Surmbock attack.

The Museum is typical of a volunteer only effort:  there are a large number of items in very dense displays with very detailed and comprehensive notes.