Well - never did get to the bottom of this one......
I can't remember quite when it was, but soon after I'd decided to get my car back on the road, I was doing some research. Given the crossover from DX to DX2 engines, any mention of 1968 was going to catch my attention and in manual 814 and I stumbled across something:
So with the introduction of the DX2 engine in September 1968, there was a change to the paper rings that sit on the bottom of the liners ('barrels') and a corresponding change to the head gasket? Whatever this change was and meant, it was significant enough to warrant mention in the workshop manual.
As I needed to buy a gasket set, I made a couple of enquiries with the usual sellers, but no one could offer me "joints with packing" or a head gasket with "circular seal". In fact they didn't know what I was on about!
Intrigued I searched through the earlier Manual 518 (published in 1966 and so before the gasket changes) for further information. It offered a tantalising clue in the form of a photo:
The photo showed a gasket on a liner. The gasket was printed with two parallel lines to enable the fitter to orientate it correctly as per the fitting instructions. So, before September 1968, the paper seals on the base of liners were padded (with brown paper?) - but they weren't just thicker, the padded parts were not around the whole circumference.
Questions, questions: Why on earth would Citroen do that? Why did they need to be aligned with the piston shoulders? Why were they needed? Why weren't they needed after September 1968? Since these are joint parts, what was different about the parts they joined? Did those parts change after September 1968? What was all the business with the 'oval' and 'circular' head gaskets all about?
However 518 had something else to say:
So even before the change in gaskets and paper seals, there were two different sizes (heights) of liners - identified by a colour mark. Presumably you used whichever colour (height) was needed to give the right height above the deck? At this time, BOTH would have been used with the padded liner seals and corresponding head gasket - as that was all that existed. The liners I puled from the car were so rusted that there was no hope of finding or identifying any paint marks.
518 still had more to offer:
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| Top Photo in the Picture Shows Location of Engine 'classe' Stamp |
So there are two different 'types' of liners and two different 'classes' (groups) of engines - and you need to use the right barrel with the right block? Now I was confused. How many variables were there! Were there two different heights of liners for 'classe 1' and two dfferent heights for 'classe 2'? There seemed to be lots of instructions telling you what you had to to do, but not necessarily how to do it! (Or why!!).
I searched for clues on my engine. The photo above from the manual is a bit hard to make out, but it shows an engine block marked as 'classes 1'. Here is the corresponding mark, under the oil banjo, on my block. Mine's a '2':
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| Engine 'classe' Stamp On My Block |
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| "Classe 2" DX Liner: Two Rings On The Upper Flange |
After much searching I found two very faint rings ('00') - corresponding to liners that match with a 'classe 2" engine. So that was good then. Unfortunately, I was planning to use the post-1969 liners that Peter ('Badabec') had given me: so I had a look at those too:
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| D Super 5 liners - Marked '2' on the Upper Flange |
They were marked with a '2'. Was that the later equivalent of the two rings on my earlier liners - meaning they were to be used with a 'classes 2' engine block? I couldn't be sure: other than mentioning the different gaskets prior to September 1968, manual 814 offered no special instructions/ requirements regarding liners matching to engine blocks.
I was way out of my depth now - just turning up questions and possible problems - not solutions. I'd found out too much! I knew things it wasn't healthy to know!
- Charles Vyse had also commented on the paint marks on liners in his recently published 'Goddess' book - finding an old address I tried to write to him to find out what he knew. No reply to date.
- Der Franzose sell two different gasket sets - in both cases these cover several engine variants. Their part number 30008 is suitable for DX2 engines, but their part number 30009 is said to be suitable for DX engines - but that might just be a typo and, anyway, the set also covered post 1969 engines. With only one head gasket in the set, it can't have been that the difference was that the set included a head gasket with 'oval seals'.
- I found a thread on the "Club DS Deutschland" forum where a DS owner had struggled to get a gas and water tight seal on the head of his DX engine after a rebuild. Was this perhaps down to using the wrong gaskets?
- At rallies I had checked the engines of some post 1968 cars and these continued to have a 'classe' number stamped under the oil pipe, so it MUST have continued to have had some kind of relevance to SOMETHING!!!!
This continuing uncertainty over gaskets and liners was now stopping me getting on with the rebuild......By the time of the DS rally in June 2017 - and with no clear answers on the horizon - I decided I'd had enough.
Since I couldn't satisfactory solve (understand?) the issues of the padded/ not padded gaskets, I decided to simply things by going back to first principles: when fitting the wet liners, the major consideration is for the liner to be proud of the deck by the correct height when fitted without, and then with the paper liner gaskets. The measurements are given in manual 518 and are in one of the photo's above. THAT'S what I would focus on.
As far back as June 2016 I'd bought a complete engine gasket set from Citroen Classics and at the 2017 DS rally I bought a second set of the paper seals for the base of the liners for ''extra padding' if needed. I would suck it and see.
Like I said I never DID get to the bottom of this one.......
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