Jump to content

1980 Austin Princess


vulgalour

Recommended Posts

My Stellar has a similar type of joint i.e. ball ended downpipe and cupped manifold + a two hole loose clamp which is supposed to clamp the downpipe up tight on the fixed mating half on the manifold. Despite the fact that I have good access, a longitudinal engine and only one pipe, it has proved difficult to seal for long. The most successful attempt involved wrapping 1mm diameter copper wire around the downpipe so that the loose clamp graunched this up when tightened, assisted by gun gum.  After running the joint up to temperature and re-tightening a couple of times it has held for a few thousand miles, though I can still feel (but not hear) exhaust gas lightly puffing on one side.  The exhaust experts' efforts (I've had two new exhausts in ten years) remained leak tight for barely a week in each case.  It's not just BMC that can't design a reliable joint!

Link to comment
Share on other sites

I know I sound obsessed with it but that connection to the diff casing is mega crucial. If you get hold of the exhaust near the Flexi and waggle it side to side does it slip inside the collar at all? If so that needs looking at, maybe put a metal shim inside the collar so it nips up really tight. Another thing is, is the Flexi joint still flexing? The ones that are like a ball and socket seize solid all the time meaning the manifold joint ends up doing all the flexing instead.

Link to comment
Share on other sites

It's an absolute bastard rejoining those flangy buggers, I'm still angry about the last Metro dual one I encountered 20 odd years ago. I used to find the only hope was to start at the flange join and work back, get it lined up nice and square, maybe even forced up with a jack and tightened till you hear the squark of the threads galling, then hang the system and pry / bend / space / kick the steady brackets on. An old Citrotten sphere is handy for batting down the high spots of the downpipe flange. I wonder if a turn of fibreglass tape, exhaust wrap or tinfoil impregnated or slathered with the red silicon around the join before the clamp goes on would improve things.

If ever there was a need for proper hard crumbly asbestos.

Link to comment
Share on other sites

The thing that utterly dumbfounded me with mine was not just that it was still blowing, but it was still blowing so severely that the exhaust might as well not have been connected at all. And then on about the 19th attempt using the exact same method all of a sudden it just sealed. Obviously it must have lined up perfectly through sheer luck/balance of probability.

 

If it hadn’t been for my experience with that I’d probably be in the 'what are you fucking about at' camp too

Link to comment
Share on other sites

To expand on that and answer a few Qs...

 

Downpipe stay bracket - nice and solid.  You can't move the pipe in it and it doesn't wiggle.  It's tight enough that it doesn't come off the exhaust without a fight.

 

Flexi - it isn't seized but it doesn't have a lot of play.  It's the second weakest link in the system and it seems it should be a long wiggly one instead as standard.  I've had conflicted info on whether the ball or long-wiggle is the correct type so either BL used both (likely), or this is a bad aftermarket exhaust (also likely).

 

Jacking up - I've had the exhaust jacked up with the flange socket connected to the point that the exhaust is attempting to lift the whole car in the past.  If that can't seat it then I don't know what can, in all honesty.

 

Sealant/wraps - I've tried several, to no avail.

 

Honestly, fitting this exhaust is something that happens more by luck than anything else.  You either get it seated or you don't.   9 times out of 10 it isn't seated perfectly.  Of those 1 times it is, 9 times out of 10 it will work itself loose within a few thousand miles and start blowing again, no matter how tight you make the clamps, how much gunge you use or anything else.

 

 

If you genuinely think this job should be an easy one and you could do it and don't understand what the palaver is, please, be my guest and come and do it!  If you manage to get it to seal I'll even pay you because you're either some sort of wizard or have been blessed by the Machine God and I will be genuinely grateful for the intervention of the divine.

Link to comment
Share on other sites

I cannot add much more to the good advice given, which means everybody was in the same boat at some time or another. The Allegro does it but I have learnt to live with it by sorting it to such an extent that you can only hear it rasping on a cold start-up and it soon fades away once warmed up. The mating faces and the clamp must be scrupulously clean and free of all old sealant (though I suspect you already know that), and the best sealant I have used is CarPlan Fire Putty.

 

As to why this silly arrangement came about, I blame Austin penny-pinching. On the A30 and Austin-engined Minor the arrangement worked entirely satisfactorily, because of the traditional layout. The exhaust was free to move with the engine so you never had any trouble. But when the A-Series was mounted transversely, the torque reaction of the engine was enough to break this joint because there just wasn't the freedom of movement and in any case, a transverse layout put more strain on the downpipe. As it became so ubiquitous it was never thought of again, I suppose. Austin engineering really was miles behind their rivals Morris in the 1940's -1950's.

Link to comment
Share on other sites

Having had plenty of pfaff with those joints on an A series (longitudinal, really quite easy access) I have to say they're crap at best, and if the pipe has the remotest amount of spring to it in the position it's meant to actually sit and seal, it won't. Usually because the angle they want to spring to means the joint isn't aligned.

 

I've only ever had luck making them seal them the downpipe meets the ball of the manifold straight up when held up against it, held on with the rest of the bungies. If you have to fight it sideways, forget it.

 

My Renault has this type of join but has a proper spring loaded, bolt lengthways along the pipe design (with a collar around the lower pipe and bolts coming out of the manifold) and a big doughnut that sits between the two. It seals surprisingly well, so applying the clamping force sideways, a la BL is just generally a bad design, best left for old cast iron toilet pipes (which is where I think they got the design from).

 

Phil

Link to comment
Share on other sites

Exhaust then I suppose today.  Drive over in the Princess as normal, nothing amiss beyond the exhaust noise and I find the throttle getting gradually stiffer until I'm approaching lights and suddenly the throttle jams completely.  Fortunately I was next to a bus stop so could throw the car into neutral to stop it running away and turn it off to coast to a stop.  Hazards on, bonnet up, have a look.  Somehow, it was earthing through the throttle cable again even though all systems were normal.  I had noticed a dip in the ammeter with the headlights on, much the same as yesterday, but it was stable so just assumed the battery was a little low from lack of use.  I let everything cool down and the throttle returned to normal, I then carried on to the unit with the headlights off, which I don't like doing on a drizzly day, but it was less than a mile of the journey to go and nothing untoward happened.

 

Wasn't particularly thrilled about this so the first job was to investigate the earth issue and we thought we'd resolved it when we noticed the headlight earth point was a bit dirty.  Made a brand new earth point which improved matters, but after a while the throttle cable started to warm up again if the headlights were on (and only the headlights), so I need to find out what's going on with that.  At the moment the earth points check out fine and there's nothing obvious, all I can say for certain is that something on the headlight circuit isn't routing electricity as it should and further investigation is required.

 

Exhaust next then, since I didn't want to chase electricals until that was sorted. Air filter box, carburettor and heat shield off first for access.  I never disconnect the cables going to the carburettor because the end of the cables always fray and I can never get them back in again, so I always make use of the flat bits of the engine bay to keep the carburettor out of the way and still connected.  Unconventional, perhaps, but saves me the expense and hassle of fitting a new pair of cables every time the carburettor comes off... which has been a lot lately.

39653740934_5ddc832698_b.jpg20180219-01 by Angyl Roper, on Flickr

 

Mike and I wanted to make the exhaust components that were leaking as clean as possible so we opted to remove the manifold rather than dropping the exhaust this time.  This was also a consideration after folks on my various threads suggested the manifold casting can have flaws that cause issues with sealing, so we could deal with that too if it turned out to be the case.  The exhaust downpipe flanges didn't look too bad, with the exception of some exhaust paste to remove of course, so that was something.

39467546845_d56b9f1c1b_b.jpg20180219-02 by Angyl Roper, on Flickr

 

40319260762_4fe21c44d3_b.jpg20180219-03 by Angyl Roper, on Flickr

 

With everything cleaned up, which took forever, we  aligned the manifold to the downpipes and immediately a problem became apparent.  We moved things around a fair bit to double check and played with the clamps and dry fitting to be sure, but it looks like one of the downpipes is at the wrong angle and if you bent it to be at the correct angle, it wouldn't sit in the correct place to meet the manifold.  This is probably the root cause of the exhaust blow and only a replacement exhaust is going to solve that.  I was therefore okay to accept the exhaust will blow when reassembled, I cannot do anything about this at the moment.

39467546655_ba225c08e1_b.jpg20180219-04 by Angyl Roper, on Flickr

 

After fiddling about with the clamps and the jack and the exhaust, we got a better fit than the above photograph by sort of wiggling the manifold down onto the pipe with me bracing various pieces while Mike got the clamp tightened up with a little exhaust paste.  Then the chore of refitting the manifold while it was attached to the exhaust, which is about as difficult as you can imagine since it goes on with bolts rather than sitting on studs and there's a gasket to fit at the same time, so you need about 6 hands attached to two arms.  It was like playing Twister, just a whole lot less fun.  With it all bolted up the extras were reattached so the car could be started and here's an idea of the access available to you if you don't remove everything first.

40319260772_6a42b7eb69_b.jpg20180219-05 by Angyl Roper, on Flickr

 

40319260562_40014a0aa0_b.jpg20180219-06 by Angyl Roper, on Flickr

 

The end result, on starting the car up, was that the driver's side clamp has sealed perfectly.  The passenger side one has a little bit of a blow, it's tolerable and should go through an MoT at least and will likely quieten down a bit once the car has been through a few hot/cold cycles.  Partial success at least.  Annoyingly the carburettor then decided it was just going to pour fuel out of the overflow while idling and didn't want to respond to any sort of attention and the headlights are still trying to earth through the throttle cable.

 

So the Princess has been left in the sin bin at the unit for a bit to think about what its done while I try and find the next bit of free time to go through the electrical issues with Mike.  Carburettor is probably just a stuck inside component, low oil in the dashpot or simply because SU.  I hate problems like these because they take ages to find and sometimes, even worse, mysteriously fix themselves.

Link to comment
Share on other sites

This is another thread which needs a "FOR FUCK'S SAKE" button.

 

I class myself fortunate to have never had to piss about with any Austin, apart from a Montego which was as leaky as a seive.

 

Good work Vulg, always good to see someone cracking into jobs when I really can't be arsed!

Link to comment
Share on other sites

Glad you've got the exhaust in a better, less noisy position. Bummer about the carb.

 

I've never worked on a princess, so I'm not sure how the wiring is routed, just wondering if the headlamp feed from the dash switch shares a bulkhead grommet with the throttle cable and it's chafed.

Link to comment
Share on other sites

Outlaw:  I threatened it with the scrapyard today.  We all know I don't mean it, but perhaps it'll get scared into working properly for a bit.

 

Dozey & 320: Unusually, BL went to the extravagance of making TWO holes!  No chafing to worry about.  I need to get the dash out anyway to resolve the mystery dead bulbs so the problem could be related.  Like the exhaust, the wiring would probably benefit from being thrown away and replaced with brand new.

 

The Five Stages of Princess Ownership

Denial

Anger

Bargaining

Depression 

Acceptance <- you are here

Link to comment
Share on other sites

my most memorable fuck happened just like your earth fault......

 

I left the bolt out of the body earth where the earth lead ones of the battery, bolts to the body and carries on to the engine. Result is the engine earth is ok but all body electrics struggle and use the throttle cable

 

The customer experienced throttle cable seizure on the A1.....he dipped the clutch and let it rev to destruction though. It became a very expensive come back job

Link to comment
Share on other sites

I’d be tapping up Basil Fawlty and getting him to come down with the largest, prickliest branch he could muster.

Alternatively, gently hook up some chains through the roof and windows, and try starting the car again.

Maybe, just maybe, it’ll get the message and start behaving.

Link to comment
Share on other sites

+1 for taking a big effing lever to the errant downpipe. I wish I knew what happened to my late Dad's crowbar when we emptied his house - at 5' long this solid iron bar (with a blunt end for lump hammers and a slightly less blunt end for breaking up stones when laying foundations; I digress, sorry) was just the right length, strength and weight for this job.

Tl;dr - if a scaffolding pole is too thick, try the longest chisel or wrecking bar you can get yer hands on...

 

Sent from my BV6000 using Tapatalk

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...