I'm not ready to do a proper test of the car as I still have a lot of work to do checking and fitting the hydraulic system. but I am ready (itching in fact) to do some prolonged testing of the engine now it's back in the chassis. Until this point, i'd only run the engine for a matter of seconds as I hadn't fitted the radiator and cooling system. Unfortunately, further testing means I need to fit the radiator and an exhaust.
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| Front silencer fitted |
The first problem was that i didn't have an exhaust system! The rear silencer had rusted away to a nothing and I'd had to hack it to off with a saw when the engine came out of my chassis about eight years ago. The front silencer was removed when i painted the underside of the car. it was in better shape but still on it's last legs.
Even before the engine went back in the car, I'd started to half-heartedly prepare the front silencer hangers. They were quite rusty but cleaned up well. I was able to reuse the square/ oblong rubber blocks that clamp the arm to the crescent-shaped brackets, but the pairs of bolts set into rubber blocks were worn, rusted and bent and so I used new ones.
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| Hanger for front exhaust box |
Oh. I also found a bit I'd been looking for for ages. it was driving me nuts.... see the little bracket arrowed in this photo?
That arrowed bit is one of the brackets that holds the long tube under the car. you know - the tube that holds the cable that is part of the light dipping mechanism. Anyway, that bracket fits right up by the front exhaust silencer. It doubles as a bolt to hold the exhaust hanger bracket on - which is why I'd squirrelled it away with the exhaust parts.
Maybe it's the shape it is to allow some flexing in the tube?? i'm not really sure about that.....
Back to my exhaust.....I gave Citroen Classics a call and they had exhaust systems in stock. I just went for a mild steel system. For a start it's cheaper, but i also heard that the stainless systems kind of sound 'different'......
I already had a spare flexi-pipe and as my car is a Pallas, I bought a front box, two straight pipes, a back box and a hanging kit. As well as the exhaust system (and with engine start-up in mind) I also decided to buy a 20 litre drum of Penrite premixed engine coolant. All together, these are big and heavy things. Rather than wait for them to be posted I decided to nip down the M1 and M25 and collect the bits from them that same day. 2 hours later I was standing in Citroen Classics new parts depot by the river. And 2 hours after that, the booty was back in my garage.
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| Booty! |
It was probably at about this point (or more likely the drive home) that I realised that before I could fit the exhaust, i needed to tidy up the front silencer hangers and polish the exhaust heat shields.....
The main shield is big. Very big. And took a lot of cleaning and polishing. It's large but lightweight (and dished) and proved very tricky to both hold down AND polish without bending it out of shape. While both sides got a clean, only the concave surfaces of the shields facing the exhaust were polished. I reasoned that they were the sides that did all the work - reflecting heat away from the car.
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| Exhaust heat shields polished. Awkward buggers..... |
Fitting the shields was tricky. for each of the bolts holding the shields in place there is, between the shield and the chassis is a fibre washer (if they haven't crumbled away to nothing). Crawling under the car, it proved very difficult to hold the shield up, slip a bolt through a hole, match a fibre washer to the blind side AND then locate the bolt in it's designated hole in the chassis: the fibre washers kept moving and not being bolted in place......In the end I decided to glue the washers in place on the back of the shields. That showed 'em.
At last it was time to fit the exhaust. I started at the front and worked back.
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| Front silencer parts - 1966 to 1969 |
First things first. The collar-like clamp that joins the front end of the flexi-pipe to the exhaust manifold downpipe attaches to the bracket on the sump. I guess it stops the downpipes vibrating. the thing to note is that there are at least two different kinds of those collars. On the collars for cars prior to September 1968 (so from the 10969 model year) the caged nut can move up and down the bracket.
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| Pre 1968: caged nut moves up and down |
On cars from September 1968 onwards, the caged nut is such that the nut can ACROSS the bracket......
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| From 1968: caged nut moves across bracket |
These differences might not seem very relevant - but they relate to changes to the support part on the sump/ block that the bracket attaches to. The pre 68 support (part 13 in the diagram earlier in this post) has a sideways slot. The post September 68 support (part 14 in the diagram) has an up and down slot.....The correct pairing of bracket and support gives both up, down and sideways adjustment.
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| Post September 1968 support |
Another change from september 1968 is that cars have a small stabilising bracket.....for the bracket. It's part 12 in the diagram and looks like this.
My bracket had a stress fracture in its fold (and so did the second hand replacement I picked up). I welded that up and hope it will hold.
Now my car is pre-september 1968 so SHOULD have parts 11 and 13, but has somehow ended up with parts 12 and 14. Still with me? Suffice to say that I bought a clamp for a POST September 1968 car.... When fitted, it looked like this. You can just about make it out....
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| Downpipe to flexi-pipe join |
I used Holts exhaust assembly paste on all the joints - especially where the flexi-pipe fits onto the down pipe on the engine as that was quite pitted. I used a trolley jack to raise the front silencer into its approximate position and then loosely bolted the two side brackets to the chassis to hold it in place.
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| Mounting bracket for front silencer |
The two long pipes were clamped to the back end of the front silencer (more assembly paste). The front ends of the twin pipes are angled and have flanges welded to them.
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| Angled ends on long pipes |
Care is needed to fit them to the front silencer so that are parallel to each other AND provide a gas-tight seal.
With the long pipes fitted at one end, the rear silencer was fitted to the other ends and again i used a trolley jack to raise it so that i could fit its strap/ bracket in place on the chassis. and that is where I hit my snag......
The bracket/ strap needs to go over the mouths of the rear silencer holes to hold the long pipes in place. Except that if it was lined up in that way, it was out of alignment with the bolt holes on the chassis? I couldn't get both bolts to fit without potentially cross threading one of them and/ or putting excessive strain on the strap. The best i could manage was where the clamp covered the join of the pipes to the rear silencer. it didn't really seal and the silencer was touching the underside of the car - rather than hanging.
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| The hanging bracket was out of alignment and under strain |
If the bracket/ strap was lined up with the chassis bolt holes, then it only aligned to the two long pipes. it didn't clamp on the rear silencer at all. That wasn't enabling a gas-tight seal.
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| Bracket straight but not on the rear silencer |
The only way I could get the strap clamp to align with the chassis bolt holes AND to clamp around pipes and rear silencer was if the rear silencer was brought forward slightly..... To achieve this, I cut about an inch of each of the long pies at their rear ends.
It was very difficult trying to get a socket on the nuts of this bracket and a spanner on the bolt end. especially laying on my back under the car. And i had to put-on and remove that bracket several times....Anyway, this is what i ended up with.
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| End result |
The strap/ bracket thing is bolted in a straight line and is around the mouths of the rear silencer and the two long tubes.
That seems to have sorted that. However the other thing i'm not happy with is the final bracket/ strap that hangs down under the left rear wing and holds the angled and bevelled ends of the exhaust pies. The bracket didn't align laterally with the two pipes!
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| Another lack of alignment....... |
The angled pipes are part of the rear silencer. I need to get out a slide rule, protractor and compass to check, but I suspect the lack of alignment is at least partly because i shortened the twin pipes and brought the rear silencer (and it's tail pipe bend) forward so that the pipes kick out sooner. But what is one meant to do? Fit the back hanger correctly but not the middle hanger? Fit the middle hanger correctly but not the back? I'm too tired to worry about it now. i want to get on with some engine testing. I'll look at a few cars at the next d rally and see how everyone else has done it.
UPDATE (November 2023)
With my engine testing, i'm finding that I have a moisture drip at the front of the rear silencer - where I shortened the two long pipes. I don't think the pipe shortening has anything to do with it. That should have improved the pipe seal. I think things are going to have to come apart and see if more exhaust sealing paste is going to to get used. I may even decide I need to buy two new long pipes - but they are relatively cheap.
I'm also disappointed to say that I've discovered rust on my front silencer brackets already - and the car has only been sitting in the garage. This must surely say something about my preparation before painting - but i also have a vague memory of cutting a corner (in my haste to get the exhaust system fitted) and using a cheap can of of Halfraurds black rattle paint on those parts.
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| Rust already.... |
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