Zel's Motoring Adventures...Peugeot, Renault, Rover, Trabant, Invacar & A Sinclair C5 - 16/04 - Routine Consumables...

[Zelandeth]

Bloody editor. Let's try this again.

Not been much going on lately since the investigation of the V123 limo.  So no updates simply because there just hasn't been anything to update!

Better weather last couple of days has lifted the spirits a little and given me a little enthusiasm to get some work done.

Nothing major but I wanted to get this fitted.

This was in no way to be a full carb rebuild.  It was by and large behaving itself, so my only intent was to replace the top cover and accelerator pump housing gaskets.  These can both be done without having to remove the carb.

Plenty of access, all you need to do is unthread the choke to throttle linkage and disconnect the choke cable.  No point in messing with anything else.  All I really wanted to do was try to convince it to keep most of the fuel inside it rather than continually dribbling itself over the outer casing and inlet manifold.

I took the opportunity to blow the float bowl out with the air line and to clean the main jet while the float bowl was empty.  There was a fair bit of scaly residue on the jet which wouldn't have been helping anything.

Pretty obvious visually how much the original top cover gasket had shrunk and distorted with age.

The new one is about twice the thickness too.

The gasket on the accelerator pump housing definitely shows evidence of the fact that it's the one thing I didn't take apart when I cleaned the carb (as I didn't have a replacement gasket).  There was quite a bit of gunk in there.

That was blown out with substantial amounts of carb cleaner before I put the cover back on.

With it all back together it was immediately apparent that this had made a difference.  The engine started much more easily than usual from cold and the idle was more even.  My hunch is that there was an air leak around that tiny drilling near the centre.

A quick test run round the block showed we had definitely improved the fuel seepage issue.  The whole carb would have been wet before.

Still a little bit around the base of the carb which I think must be coming through the throttle shaft itself.

I decided this was a good time to bust out this bit of kit and to see if I could get the idle mixture set a bit more accurately.

Imagine this can only be slightly newer than the car.

I've found this is a tricky one to set up by ear.  There are two reasons for this: One is that there's about half a turn on the idle air screw between stinking rich and so lean it falls on its face and stalls if you so much as breathe on the throttle.  Secondly is that because of the length of the intake path for such a small engine (I'm sure the hard 90 degree bend right after the carb does wonders for gas flow...) means that there's quite a substantial delay between you making an adjustment and the engine reacting.  I also found that the idle tended to wander enough on its own to make it hard to judge.  So "good enough" was where I left it before.

The hope was that this would allow me to see better what I was actually doing.

Turns out that at idle she was waaaaaaaaay lean, at about 2% CO.  Which for an injected car wouldn't be far off, but for an old school engine like this is way off.

A bit of experimentation revealed that she seemed happiest with it set to around 5.5% - which if memory serves is about where my old Metros were happiest too (hence the ritual of having to back the mixture off a couple of turns before the MOT every year).

The emissions test for an engine of this age is simply a visual smoke check, the 4.5% limit not applying until a few years later.  Though I will need to check after a couple of hundred miles to make sure we're not risking fouling plugs.

Throttle response off idle seems to be a lot snappier now - though still a bit slow compared to most engines simply on account of the heavy flywheel.

Something this car has always had a substantial dislike for was driving on a very light throttle, for example at a steady 30-40mph.  This would tend to be interspersed now and then with a brief loss of power, a sneeze back through the carb then normal service being resumed.  Even though I'm used to it it's something which never stopped being unnerving.  It has tended to result in me using something of an "coast and burn" approach when driving at these speeds so as to avoid that behaviour.

Well I did upwards of 50 miles yesterday under various conditions and didn't have that happen once.  Not calling it fixed yet, but definitely improved.

I think mainly due to the better sealed carb than my twiddling of things (which shouldn't affect anything much once the engine is under enough load to be drawing from the main rather than idle circuit in the carb, though there is some interaction) it definitely *feels* like she is able to maintain 50-60mph more easily.  I guess the best test there will be to take a run up the hill towards Olney and see how far it drops.  Absolutely feels zippier up to 40 or so though, despite I'm absolutely sure the difference on paper being miniscule.

One thing that is visible is that trundling around town she is definitely running a touch cooler, which ties in with the indication from the exhaust gas analyser that the engine was running lean.

Reckon we've knocked maybe 20C or so off, haven't been out on a longer high speed run to see if that's carried over to that sort of situation too - though expecting less change there.

One of my main jobs for this weekend definitely needs to be sourcing the missing bits for my air cleaner.  I'm absolutely not proud of this bodge fest.

I've had two separate people who likely have one who have gone totally unresponsive for a couple of weeks now so I'm giving up and just going to pick one up from a commercial outfit.  Have to admit I'm curious to try one of the "normal" air cleaner housings anyway and see if they tame down the induction noise a bit.  It is quite obtrusive anywhere above 50 or so and is the sort of noise that gets quite tiresome after a while.  I figure the larger internal volume of the normal housing might act as a bit of a muffler.

Was really nice to get the car out again though, too long just sitting in the garage.

Couple of hundred miles off the 3000 mile mark now.  The current list of things to be included with the service that will come up at that point.

[] Resecure nearside rear wheel tub to the chassis.  I've noted that whole corner wobbles about a fair bit and I'm sure that's not helping with the amount of bodywork rattling going on.

[] Sort out the damage to the rear of said wheel tub to prevent the ignition coil getting drenched every time I hit a vaguely damp bit of road.  How it's not protested yet I have no idea.

[] Go over the car end to end checking basically every fastener I can find - if the air cleaner worked itself loose there's every chance other things may have too.  I'd rather not have mission critical things randomly falling off.

[] Adjust the valve clearances.  I put that off at the last service because the weather was horrible...no excuse there other than pure laziness.

[] End-to-end check of the brake lines.  I spotted one bit up front where one had been rubbing against the frame, I'd rather not have that going on.  Deploy additional clips as necessary.

[] Adjust brake free play.  

[] Order another indicator flasher unit.  The one I fitted recently had a really annoying "feature" in that there was a good 2 second delay between you turning the indicators on and them doing anything...this made signalling on roundabouts an exercise in forward planning.  So I nicked the one off the C5.  I need to replace it now of course.

[] Actually check to see what my ignition timing is set to (not that I can do anything about it), but it would just be nice to know what the initial and total timing I have is set to.  Really do wonder how much difference having vacuum advance available would make.  Know it's something that 2CV folks suggest makes quite a big difference there.  Moot point really given my distributor seems precisely as stuck in place as seems to be standard on these engines.

[] Investigate an electronic voltage regulator for the charging system.  I know the system is never going to be great just given the limitations of the dynastart, but I've heard a few people say the modern regulators have vastly improved the behaviour of systems on cars with traditional generators, so seems worth a look.

[] She really could do with a wash...honestly can't remember when that last happened!  Hoping to get to at least one or two shows this year so would be nice to have the car clean at least.

[LightBulbFun]

29 minutes ago, Zelandeth said:

Bloody editor. Let's try this again.

Not been much going on lately since the investigation of the V123 limo.  So no updates simply because there just hasn't been anything to update!

Better weather last couple of days has lifted the spirits a little and given me a little enthusiasm to get some work done.

Nothing major but I wanted to get this fitted.

This was in no way to be a full carb rebuild.  It was by and large behaving itself, so my only intent was to replace the top cover and accelerator pump housing gaskets.  These can both be done without having to remove the carb.

Plenty of access, all you need to do is unthread the choke to throttle linkage and disconnect the choke cable.  No point in messing with anything else.  All I really wanted to do was try to convince it to keep most of the fuel inside it rather than continually dribbling itself over the outer casing and inlet manifold.

I took the opportunity to blow the float bowl out with the air line and to clean the main jet while the float bowl was empty.  There was a fair bit of scaly residue on the jet which wouldn't have been helping anything.

Pretty obvious visually how much the original top cover gasket had shrunk and distorted with age.

The new one is about twice the thickness too.

The gasket on the accelerator pump housing definitely shows evidence of the fact that it's the one thing I didn't take apart when I cleaned the carb (as I didn't have a replacement gasket).  There was quite a bit of gunk in there.

That was blown out with substantial amounts of carb cleaner before I put the cover back on.

With it all back together it was immediately apparent that this had made a difference.  The engine started much more easily than usual from cold and the idle was more even.  My hunch is that there was an air leak around that tiny drilling near the centre.

A quick test run round the block showed we had definitely improved the fuel seepage issue.  The whole carb would have been wet before.

Still a little bit around the base of the carb which I think must be coming through the throttle shaft itself.

I decided this was a good time to bust out this bit of kit and to see if I could get the idle mixture set a bit more accurately.

Imagine this can only be slightly newer than the car.

I've found this is a tricky one to set up by ear.  There are two reasons for this: One is that there's about half a turn on the idle air screw between stinking rich and so lean it falls on its face and stalls if you so much as breathe on the throttle.  Secondly is that because of the length of the intake path for such a small engine (I'm sure the hard 90 degree bend right after the carb does wonders for gas flow...) means that there's quite a substantial delay between you making an adjustment and the engine reacting.  I also found that the idle tended to wander enough on its own to make it hard to judge.  So "good enough" was where I left it before.

The hope was that this would allow me to see better what I was actually doing.

Turns out that at idle she was waaaaaaaaay lean, at about 2% CO.  Which for an injected car wouldn't be far off, but for an old school engine like this is way off.

A bit of experimentation revealed that she seemed happiest with it set to around 5.5% - which if memory serves is about where my old Metros were happiest too (hence the ritual of having to back the mixture off a couple of turns before the MOT every year).

The emissions test for an engine of this age is simply a visual smoke check, the 4.5% limit not applying until a few years later.  Though I will need to check after a couple of hundred miles to make sure we're not risking fouling plugs.

Throttle response off idle seems to be a lot snappier now - though still a bit slow compared to most engines simply on account of the heavy flywheel.

Something this car has always had a substantial dislike for was driving on a very light throttle, for example at a steady 30-40mph.  This would tend to be interspersed now and then with a brief loss of power, a sneeze back through the carb then normal service being resumed.  Even though I'm used to it it's something which never stopped being unnerving.  It has tended to result in me using something of an "coast and burn" approach when driving at these speeds so as to avoid that behaviour.

Well I did upwards of 50 miles yesterday under various conditions and didn't have that happen once.  Not calling it fixed yet, but definitely improved.

I think mainly due to the better sealed carb than my twiddling of things (which shouldn't affect anything much once the engine is under enough load to be drawing from the main rather than idle circuit in the carb, though there is some interaction) it definitely *feels* like she is able to maintain 50-60mph more easily.  I guess the best test there will be to take a run up the hill towards Olney and see how far it drops.  Absolutely feels zippier up to 40 or so though, despite I'm absolutely sure the difference on paper being miniscule.

One thing that is visible is that trundling around town she is definitely running a touch cooler, which ties in with the indication from the exhaust gas analyser that the engine was running lean.

Reckon we've knocked maybe 20C or so off, haven't been out on a longer high speed run to see if that's carried over to that sort of situation too - though expecting less change there.

One of my main jobs for this weekend definitely needs to be sourcing the missing bits for my air cleaner.  I'm absolutely not proud of this bodge fest.

I've had two separate people who likely have one who have gone totally unresponsive for a couple of weeks now so I'm giving up and just going to pick one up from a commercial outfit.  Have to admit I'm curious to try one of the "normal" air cleaner housings anyway and see if they tame down the induction noise a bit.  It is quite obtrusive anywhere above 50 or so and is the sort of noise that gets quite tiresome after a while.  I figure the larger internal volume of the normal housing might act as a bit of a muffler.

Was really nice to get the car put again though, too long just sitting in the garage.

Couple of hundred miles off the 3000 mile mark now.  The current list of things to be included with the service that will come up at that point.

[] Resecure nearside rear wheel tub to the chassis.  I've noted that whole corner wobbles about a fair bit and I'm sure that's not helping with the amount of bodywork rattling going on.

[] Sort out the damage to the rear of said wheel tub to prevent the ignition coil getting drenched every time I hit a vaguely damp bit of road.  How it's not protested yet I have no idea.

[] Go over the car end to end checking basically every fastener I can find - if the air cleaner worked itself loose there's every chance other things may have too.  I'd rather not have mission critical things randomly falling off.

[] Adjust the valve clearances.  I put that off at the last service because the weather was horrible...no excuse there other than pure laziness.

[] End-to-end check of the brake lines.  I spotted one bit up front where one had been rubbing against the frame, I'd rather not have that going on.  Deploy additional clips as necessary.

[] Adjust brake free play.  

[] Order another indicator flasher unit.  The one I fitted recently had a really annoying "feature" in that there was a good 2 second delay between you turning the indicators on and them doing anything...this made signalling on roundabouts an exercise in forward planning.  So I nicked the one off the C5.  I need to replace it now of course.

[] Actually check to see what my ignition timing is set to (not that I can do anything about it), but it would just be nice to know what the initial and total timing I have is set to.  Really do wonder how much difference having vacuum advance available would make.  Know it's something that 2CV folks suggest makes quite a big difference there.  Moot point really given my distributor seems precisely as stuck in place as seems to be standard on these engines.

[] Investigate an electronic voltage regulator for the charging system.  I know the system is never going to be great just given the limitations of the dynastart, but I've heard a few people say the modern regulators have vastly improved the behaviour of systems on cars with traditional generators, so seems worth a look.

[] She really could do with a wash...honestly can't remember when that last happened!  Hoping to get to at least one or two shows this year so would be nice to have the car clean at least.

Oh look at you with your fancy working carburettor! LOL  

 

on a more serious note, given REV's carburettor woes I should probably fire off a link to that gasket set to Red5 just incase (although I imagine he has the facilities to make the gaskets and what have you himself if he needs to)

very awesome to see TPA get a some love and a fine tune! and that she is running better for it! and to see her out and about once more! and nearing the big 3000 too! your catching up quite quickly to @dollywobbler's total milage with TWC!  

(I think REV's carb could really do with this sort of TLC if its even salvageable, still scratching my head a little over how a carb can become supposedly so knackered after only 23K miles) 

 

sadly on the air cleaner front, that is my experience when trying to ask someone about anything Invacar related, it just either never happens or takes about 5 years to finally get a result and their communication standards just goes out the window

(most recently just when I thought I finally secured a replacement carb for REV, the person with it has now gone completely silent)

I dont know what it is about Invacars, but I have been waiting literal years for some people to get back to me on certain things...

its like trying to squeeze juice out of a rock...

 

I do wonder what can be done on the sized distributors these engines are seemingly becoming known for? it bugs me that I dont actually know if they can be freed off or not

 

 

[Zelandeth]

1 hour ago, LightBulbFun said:

Oh look at you with your fancy working carburettor! LOL  

 

on a more serious note, given REV's carburettor woes I should probably fire off a link to that gasket set to Red5 just incase (although I imagine he has the facilities to make the gaskets and what have you himself if he needs to)

very awesome to see TPA get a some love and a fine tune! and that she is running better for it! and to see her out and about once more! and nearing the big 3000 too! your catching up quite quickly to @dollywobbler's total milage with TWC!  

(I think REV's carb could really do with this sort of TLC if its even salvageable, still scratching my head a little over how a carb can become supposedly so knackered after only 23K miles) 

 

sadly on the air cleaner front, that is my experience when trying to ask someone about anything Invacar related, it just either never happens or takes about 5 years to finally get a result and their communication standards just goes out the window

(most recently just when I thought I finally secured a replacement carb for REV, the person with it has now gone completely silent)

I dont know what it is about Invacars, but I have been waiting literal years for some people to get back to me on certain things...

its like trying to squeeze juice out of a rock...

 

I do wonder what can be done on the sized distributors these engines are seemingly becoming known for? it bugs me that I dont actually know if they can be freed off or not

 

 

Manufacturing defect, bit of grit got into the throttle shaft, or the carb having been swapped at some point during the life of the car - potentially to try to fix another running issue due to carb issues which seems to be a running theme with these cars - I reckon just because the jets are so small and that there was never any meaningful fuel filtration setup on the cars in service.

A word of caution on the seller of that gasket set - while the actual item seems to be fine enough, just keep in mind that it took them nearly three weeks to actually dispatch it from the date of my order.

I do really wonder if this particular carb is just not well suited to the engine for whatever reason - I noted looking at the photo of the table full of them you posted a few days ago that they virtually all were significantly blackened inside which seems to be a result of the engine firing back through the carb.  I've never known another car do that other than when there was something actually wrong with the carb, either set up way lean or with a dodgy accelerator pump, or a mechanical issue like a sticky valve of course, but I think we can discount that here.  It'll be interesting to see if having fattened the idle mixture up quite a bit has really helped stop that. 

Breathing is always going to be a limiting factor in terms of the performance though I think - and the design of the inlet manifold is probably the biggest limiting factor there.  Which given how nicely designed the cylinder heads are is a shame.

I don't think there's really any easy solution to the stuck distributor problem.  I don't imagine it would have been an issue so much when the cars were in regular use as the oil film present would likely have done a lot to keep moisture out of the join between the block and distributor shaft, but once you've left something to rot for 20 or 30 years all bets are off.  It's also just a part of the fact that these cars are all heading on 50 years old at this point, things not wanting to move after that many years is just par for the course.

Periodically dousing it with penetrating fluid and checking when the engine is hot to see if it will entertain moving is the only real way forward I can think of, it will either start moving one day or it won't.

The other obvious solution would be to fit a fully electronic ignition system with some other means of adjustment - though the simplicity of the original setup has a lot going for it I reckon and it's not likely to be something I'll ever be bothering with.  The lack of vacuum advance is the only real gripe with the design of the system itself.

[LightBulbFun]

31 minutes ago, Zelandeth said:

I do really wonder if this particular carb is just not well suited to the engine for whatever reason - I noted looking at the photo of the table full of them you posted a few days ago that they virtually all were significantly blackened inside which seems to be a result of the engine firing back through the carb.  I've never known another car do that other than when there was something actually wrong with the carb, either set up way lean or with a dodgy accelerator pump, or a mechanical issue like a sticky valve of course, but I think we can discount that here.  It'll be interesting to see if having fattened the idle mixture up quite a bit has really helped stop that. 

interesting that you mention a dodgy accelerator pump as apparently the one in REV's carb has not worked for a long time

and she also fires back through the carb from time to time

and if you recall she quite clearly set her air cleaner on fire at some point in time LOL

 

could the spitting back issues you mentioned be caused by a failed or dodgy accelerator pump?

(I note that in the things you did above you cleaned out the accelerator pump section of TPA so I wonder if thats helped get rid of the coughing?)

I wonder if perhaps its leaning out on acceleration (due to the lack of a working accelerator pump) and back firing somehow? (I sadly dont know enough about carbs to make a proper informed theoretical conclusion here, or if what I have just said makes no sense at all LOL)

I know REV would only cough and splutter when trying to accelerate/rev the engine, as nicely demonstrated here 

 

I sadly dont have a very large sample size, but I noticed it seems to be our machines that exhibit it the worst and I know all our machines had previously been off the road for 20~ years

other Model 70's I have seen that where more continuously looked after (for example MHJ22P which lasted until 2003 in Ministry service and entered on road preservation in Late 2007) do not seem to exhibit such back firing

but again my sample size is not that large sadly, but perhaps the backfiring, is because something is actually wrong with our carburettors? 

 

I wonder if these Weber 32ICS's are known for developing dodgy accelerator pumps if not looked after or such, hence why all machines such equipped and neglected have the same back firing issue?

although this guy does not seem to mention any such issues apart from leaking floats after 50 years

(on the pile-o-carbs, I sadly dont know what their back story is all I know is they came from oddingley where KPL etc came from, so for all I know they could have been that garage's pile of duds waiting to go back for core exchange!)

[Zelandeth]

Wouldn't think they're any worse for it than any other carb.  Being plunger rather than diaphragm based I'd tend to think they're less prone to failure than a lot of others.  It's a pretty simple unit which doesn't have any glaring design deficiencies that leap out at me anyway.

Popping back through the carb is a classic sign of an overly lean mixture (any car with a manual choke may do it if you stomp on the throttle with the choke too far in when cold, my first Nova nearly took my eyebrows off more than once when I was working on the carb).  So a non-working or poorly performing accelerator pump is likely to cause it as a symptom, as that's a device that's purely there to compensate for the non linearity of the required fuelling curve Vs engine load/throttle position.  If the base mixture is on the lean side to start with it's obviously going to make it worse.  The accelerator pump on TPA does work fine and always has done since when the carb was first cleaned.  It doesn't seem that the gunk I flushed out during this job had really been hindering anything, I think it was pretty well just settled in a dead end behind that cover.  

I don't think TPA has ever been any worse for it than TWC based on what I've seen on video footage we've seen on the road, it's usually been something which would happen once or twice during a day's travels unless I really tried to provoke it.  Aside from when just pulling out the drive if I put the choke in too early - though it's only really needed for about a minute tops I find.  Disclaimer there is that she does live in a garage, so the block is never going to get as cold as would be the case for a car that's been outside overnight in winter.  Restarting during the day though she never needs choke unless she's been sitting for hours and hours though.

I'm sure I've heard more than one person saying that they just did do that from time to time even back when they were in regular service.

I just don't know enough about carb and fuelling theory to really make a judgement on how well matched things are, and whether there's maybe a shortcoming with the factory jetting of the carb, the engine timing or any one of a dozen other factors I'm probably not able to think of.

It's difficult to really tell what's going on without a rolling road and realtime data on what the AFR is up to at any given moment...a proper session like that would be something which would give a lot of insight into how things were set up at the factory.

[LightBulbFun]

31 minutes ago, Zelandeth said:

Wouldn't think they're any worse for it than any other carb.  Being plunger rather than diaphragm based I'd tend to think they're less prone to failure than a lot of others.  It's a pretty simple unit which doesn't have any glaring design deficiencies that leap out at me anyway.

Popping back through the carb is a classic sign of an overly lean mixture (any car with a manual choke may do it if you stomp on the throttle with the choke too far in when cold, my first Nova nearly took my eyebrows off more than once when I was working on the carb).  So a non-working or poorly performing accelerator pump is likely to cause it as a symptom, as that's a device that's purely there to compensate for the non linearity of the required fuelling curve Vs engine load/throttle position.  If the base mixture is on the lean side to start with it's obviously going to make it worse.  The accelerator pump on TPA does work fine and always has done since when the carb was first cleaned.  It doesn't seem that the gunk I flushed out during this job had really been hindering anything, I think it was pretty well just settled in a dead end behind that cover.  

I don't think TPA has ever been any worse for it than TWC based on what I've seen on video footage we've seen on the road, it's usually been something which would happen once or twice during a day's travels unless I really tried to provoke it.  Aside from when just pulling out the drive if I put the choke in too early - though it's only really needed for about a minute tops I find.  Disclaimer there is that she does live in a garage, so the block is never going to get as cold as would be the case for a car that's been outside overnight in winter.  Restarting during the day though she never needs choke unless she's been sitting for hours and hours though.

I'm sure I've heard more than one person saying that they just did do that from time to time even back when they were in regular service.

I just don't know enough about carb and fuelling theory to really make a judgement on how well matched things are, and whether there's maybe a shortcoming with the factory jetting of the carb, the engine timing or any one of a dozen other factors I'm probably not able to think of.

It's difficult to really tell what's going on without a rolling road and realtime data on what the AFR is up to at any given moment...a proper session like that would be something which would give a lot of insight into how things were set up at the factory.

interesting! thanks for taking time out to explain this stuff to me!

because as well being told "its broken" Im also one of those who like to try and understand why its broken and how its broken  (or if im told "it works in such and such way" I like to try and find out why it works in such and such way etc etc!)

 

on the whole how well does the carb match the engine, front,

Steyr puch, AC, Invacar and the Ministry obviously did care to some degree

because as you probably know by now given how often I mention it, but later Model 70's had their own dedicated version of the Weber 32ICS, the Weber 32ICS10T, it even says Invacar on Webers own documentation LOL

32ICS10T.pdf

earlier Model 70's has the Weber 32ICS3, which was the standard carb for all 493cc Steyr puch vehicles of the time period, but later Model 70's had the 32ICS10T which was used only on the Model 70

I sadly dont know exactly when the Model 70 changed from the 32ICS3 to the 32ICS10T, tis one of the things id like to nail down and Id also like to find out what the exact difference is between the 32ICS3 and the 32ICS10T

but they obviously must of cared about getting things matched up if they went out of their way to make a specific carb for what was a fairly niche low production volume vehicle!

its also interesting to note, that although the workshop manual makes mention of a Solex carb, I have never seen a Model 70 such equipped which makes me wonder if any where ever fitted with Solex carbs or not

 

and yeah from what I have seen TPA has been the most well behaved out of the 3 Model 70's in question here  

I know TWC was very bad for it back in her early days, and I think her carb could still do with a good ultrasonic wash  

[Zelandeth]

31 minutes ago, LightBulbFun said:

interesting! thanks for taking time out to explain this stuff to me!

because as well being told "its broken" Im also one of those who like to try and understand why its broken and how its broken  (or if im told "it works in such and such way" I like to try and find out why it works in such and such way etc etc!)

 

on the whole how well does the carb match the engine, front,

Steyr puch, AC, Invacar and the Ministry obviously did care to some degree

because as you probably know by now given how often I mention it, but later Model 70's had their own dedicated version of the Weber 32ICS, the Weber 32ICS10T, it even says Invacar on Webers own documentation LOL

32ICS10T.pdf 366.09 kB · 6 downloads

earlier Model 70's has the Weber 32ICS3, which was the standard carb for all 493cc Steyr puch vehicles of the time period, but later Model 70's had the 32ICS10T which was used only on the Model 70

I sadly dont know exactly when the Model 70 changed from the 32ICS3 to the 32ICS10T, tis one of the things id like to nail down and Id also like to find out what the exact difference is between the 32ICS3 and the 32ICS10T

but they obviously must of cared about getting things matched up if they went out of their way to make a specific carb for what was a fairly niche low production volume vehicle!

its also interesting to note, that although the workshop manual makes mention of a Solex carb, I have never seen a Model 70 such equipped which makes me wonder if any where ever fitted with Solex carbs or not

 

and yeah from what I have seen TPA has been the most well behaved out of the 3 Model 70's in question here  

I know TWC was very bad for it back in her early days, and I think her carb could still do with a good ultrasonic wash  

Wouldn't surprise me it it turned out to be zip difference between the two. 

If production of the ICS3 was winding down and Invacar/AC/Steyr then put in an order for "n" thousand carbs in a specific spec it wouldn't have surprised me if they slapped their own type number on them.

As my understanding of the nomenclature goes the 32ICS is the carb model - anything beyond that is simply essentially an option code.

Without actually comparing the two or having a Weber catalogue from the period though it's impossible to say.

[Zelandeth]

Fun fact, EGR systems on diesels are gross.

That's a throttle valve which sits between the intake manifold and airbox on the Caddy - presumably something to do with the EGR as I've no idea otherwise why you'd have a throttle on the air intake side on a diesel...unless someone knows more about the theory of operation of things on the SDI engine in which case I'm all ears.  No, seriously... I'm honestly curious about how this lot works.

Intake itself looks pretty grim too... though kinda hard to tell how bad it is given it's made of matt finish black plastic.

At some point I probably will pull it off for a thorough clean - not least because I'd like to clean the top of the engine properly and the intake is kinda in the way.

I wanted to clean this valve up a bit as a test.  We have one persistent fault code stored:

01283 - Motor for intake manifold flap (V157) - Sporadic - Open/short circuit to ground.

Also P1441 - EGR Valve (N18) Open circuit or short to ground...but that's because I have unplugged it as the system is plainly misbehaving at the moment.  So that code is expected.

Not expecting miracles, especially as there's something conspicuously rattling around in the actuator housing...but let's give it a bit of a scrub anyway.

Not going to call it clean but it's a lot better.  

Unsurprisingly absolutely no different.  The once-per-second engine speed "twitch" is back, a d huge clouds of unburned diesel out the back on light throttle.

Until I unplug the EGR solenoid, at which point it goes into whatever fallback mode it has, just leaves that intake throttle open and idles smoothly and stops smoking.

Given that we have a definite fault code stored for this assembly I think it's the first thing we need to try to sort.  One other reason I pulled it out was to find a part number, helpfully stamped on the front...but I completely missed and thought it was underneath.

Let's see what the internet has to offer.

Ow.

Maybe we'll have a look around tomorrow when I'm at an actual computer to see if I can find a used one first.  

Hopefully that will get us somewhere towards getting everything working properly without having half the emission control system unplugged which I'm obviously not a fan of.

Watch this space I guess!

[Zelandeth]

Two and a half months and going on 3000 miles after I bought it I finally gave the Caddy a halfway decent wash today.

Which is almost unheard-of for me as it's usually about the first thing that gets done.

Definitely wish I'd bought this about 15 years sooner.

Aside from the power available, just having a hose that's long enough so that you don't need to move the base unit at all once it's set up saves so much hassle.  Onboard detergent tank is a nice feature to have too.

I don't think the door shuts etc on the Caddy had ever been cleaned since it left the factory.  I'll still need to go over the areas like this better but it's an improvement.

I did find a used intake throttle assembly for £30 delivered, so we'll try that first.  If it doesn't change things at all we might need to do a bit more detective work.

Getting some paint on the front bumper and the wheels is high on the to do list too.

Fun fact: Yes, you absolutely do need a small step ladder or similar to reach the roof on the Caddy.  It's taller than it looks!

I am glad to report though that having blasted the substantial amounts of moss and general slime out of the seal between the windscreen pillar and the door closure that the annoying whistle from that corner at speed is now gone.

Wish I'd done that *before* driving to Glasgow and back...

[PhilA]

Re: Carburétor Al Carbon

The carb on my Pontiac is set up pretty damn good- the plugs tell me that. However, as a sidevalve it can afford the massive valve overlap it has, meaning that the intake valve is opening early compared to OHV engines. Modern fuels have a significantly longer burn than the fuel it was designed for, and that does make itself known in the form of carbon deposits, formed from the burn exiting both the intake and exhaust at low to medium RPM on light throttle, opening up when the mixture is rich.

You may just be suffering long intake tract plus heavy overlap.

Try running it on crappier fuel!

[Zelandeth]

A suggestion was made on another forum that the issue I was having with the Caddy could be down to that throttle unit having lost track of its home position so was closing too far, choking off too much of the air supply.  That fit pretty well with the symptoms I was seeing.  The tinge of blue to the smoke as well, as it's basically resulting in a shedload of vacuum being applied to both the EGR and PCV systems.

The suggestion to try in that case was to physically remove the throttle plate from the assembly...figured I'd nothing to lose really as it will be getting replaced anyway.

What do you know?  It only bloody worked.  We now have a non-surging, non-smoking engine even with this connected back up.

Which is nice as it means the engine is running the correct timing curve again.  It was really obvious that when it was disconnected that the injection timing was significantly altered, making the engine far more clattery at idle/light throttle.  When the new throttle assembly arrives we'll see if it behaves as the designer intended.  

As the weather was nice today I had TPA out again.  Probably the most unusual thing to pop up on the ANPR camera used for charging in the Brunel Centre car park today.

It really does seem that having tweaked the mixture more towards the rich side of things has got rid of the occasional tendency for the car to spit back through the carb.  That's two afternoons of use now without it happening once, and I'd usually have expected it to have done it at least once or twice in that time.  Throttle response under very light load feels far more predictable too (though the CVT always makes it feel a bit "strange" compared to a car with a conventional drive setup).  So I'm tentatively calling that a win I think.

[LightBulbFun]

35 minutes ago, Zelandeth said:

As the weather was nice today I had TPA out again.  Probably the most unusual thing to pop up on the ANPR camera used for charging in the Brunel Centre car park today.

 

hah very cool! it reminds me of, in one of Police Camera action videos they do a segment on bus lane cameras and have the camera focused on the output of one, and this drives past  

its a shame the registration is blurred out, id of loved to have known which it was, especially being from July 2002 it would of been one of the last few in ministry Service! (and also the chance of encountering one then would been quite slim!)

35 minutes ago, Zelandeth said:

It really does seem that having tweaked the mixture more towards the rich side of things has got rid of the occasional tendency for the car to spit back through the carb.  That's two afternoons of use now without it happening once, and I'd usually have expected it to have done it at least once or twice in that time.  Throttle response under very light load feels far more predictable too (though the CVT always makes it feel a bit "strange" compared to a car with a conventional drive setup).  So I'm tentatively calling that a win I think.

very pleased to hear the carb tuning is having a positive effect on things! hopefully the spark plugs behave themselves still with the richer mixture  

[Zelandeth]

Decided to pop out and check the timing when I was putting her back into the garage.  Really no excuse for me not having done so before given the time it takes.

Dab of paint marker to make the marks easier to see.

Then out with the timing light.

Our results show that at idle we have 15° advance...

By sheer fluke I managed to catch the marks aligned in that photo if you look closely.

This rises to 43° at...quite a lot of rpm.

Didn't have the tach hooked up, but it seemed reasonable to my ear.  I didn't recall the manual giving a total timing measurement anyway, just at idle...so it was more just to confirm the centrifugal mech was working smoothly.

That 15° is rather a lot more advanced than the manual calls for...

Especially as the amendment there seems to suggest they were basically setting things up for zero advance...I know they were running on two star fuel, but even so...

15° sounds a reasonable number to me, though I've not a huge amount of experience messing with this sort of thing.  Definitely sounds better than zero!

For comparison, did we ever get a note of what TWC has her timing set to, either on the current or original engines?

[Zelandeth]

Can you spot what's different in this picture?

Probably not...I finally went and got the tracking reset so the steering wheel is now straight.  This also means I'm not fighting continually with the indicator self cancelling mechanism every time I'm trying to turn right at a roundabout.

Thanks to VW's genius decision to position all the warning lights along the very bottom edge of the instrument panel that also meant I couldn't see any of them to the left of the brake warning light before when travelling straight ahead.  Given that included things like the oil pressure and coolant temperature warnings I was somewhat enthusiastic to sort that.  While I hope I never see those while driving, if they ever were to pop up I'd far rather see them than miss them.

This also gave me my first chance to get a proper look at the underside of the van.  It's actually astonishingly fresh under there for the most part.  The only area that's crusty unsurprisingly for a wheelchair conversion is the dropped floor section which needs some TLC.

Those rear axle brake hoses are looking quite crusty on the ferrules as well, kind of surprised they didn't get at least a mention on the last MOT.  

Definitely need to get that rear area cleaned back and protected, but overall I'm quite happy with how she looked underneath.

The design of the modified exhaust is daft though.  All of the hangers are just of the straight bar type rather than hooks, so there's nothing to stop it from sliding left to right - which is why it does clank against the floor sometimes, especially turning sharp left.  Have to have a think about that somewhere down the line (as I'll probably want to drop the tailpipe at least to deal with the rust around it), just heating up and bending the hangers a little to put a bit of preload on it should do it I think.

[Zelandeth]

Had a very brief look at the Cavalier today.  

The bulge in the nearside front tyre has evidently gone "pop" at some point over the winter so that wasn't holding air.  Other three seem fine.

We dug the spare out and it seems to be holding air just fine, so will get that swapped over shortly.

In retrieving it I had to retract my comment about the interior having stayed surprisingly dry as the boot was a different story!

Well at least we know there aren't holes in the boot floor!  It had been draining via the bung for the fuel line.

With bungs pushed out on both sides the water was removed.

Took an impressively long time to drain through two 1" holes.

With a bit of fresh fuel she started right up just fine, though we did find a fuel leak on the line from the tank to the plastic (nylon?) line under the car.  Cutting back the end and stuffing it back on didn't sort it as the line has had it - attempting to do that resulted in me ending up wearing probably about a gallon of fuel.  It tastes precisely as unpleasant as I remembered.

Will just need to replace that bit of flexible hose.

Didn't stop us being able to let the engine run for a bit though, just long enough for the thermostat to start opening - at which point I noted the (automatic) choke was still on a bit so blipped the throttle...and the engine cut out and refused to restart.

A little detective work quickly revealed (thanks to folks who had brought things like a multimeter, unlike me) we'd quickly enough diagnosed that we had lost spark because the points were stuck open.  Sadly I was out of time then so had to head for home.  Not sure if I'll have the opportunity to head back over tomorrow or not.  If not I'll make time later in the week.  Should be the car pretty much ready for transportation then I think.

I mean it could be moved now, but having four inflated tyres and being actually running always makes things easier.

[Andyrew]

When father rew owned one of these around 1985 the boot was always filling with water.  He hated the car and used to leave the door  just on the latch, and keys in the ignition in the hope it would be stolen. 

Water in the boot wise He was told back then it was more an issue with luton cars and not with beligian(?) Cars as the rear window glass were cut short on radius of the lower the corners. 

Maybe @4wheeledstool can shed any light on this

This may have been complete bollocks tho! 

[Zelandeth]

This one I *think* I remember someone commenting on there being a tag under the bonnet somewhere mentioning Belgian manufacture... looking forward to having it home so I can start unearthing these mysteries. 

Put together a bit of a to do/shopping list.  Very high level really at this point.

[] Sort brakes - unless they're hard to find figuring on just replacing both front calipers as at least one of them is thoroughly seized.  Discs are shot too.  I'll measure them, but there's a substantial lip so I'm guessing they're beyond refacing.

Rears I'll wait and see.  Personally I've had pretty good luck so far with drums surviving disuse, but they'll need to come apart for inspection anyway.  

All flexible lines will be changed.

[] Replace all rubber and plastic fuel lines.  No idea if the plastic section is ethanol safe, so it'll have to go.

[] Carb *at least* given a thorough clean.

[] Ignition system full service.  We know the points are finicky as they caused headaches when it was being revived in the summer and have just dropped out on me again.  It'll get an externally mounted polypropylene film condenser fitted like I did on the Invacar so I don't need to faff about with the modern automotive ones which last about five minutes.

[] Figure out where the ten gallons of so of water I just drained out of the boot got in and convince it to cut it out.

[] Try to come up with a more period correct looking solution for the centre console/gear lever as the bits of 80s Manta just look ridiculous.

[] Install a stereo.  There's already been holes cut in the parcel shelf so I've no reason not to use them.  Won't be anything daft don't worry.

[] Weld up the hole in the front chassis rail.

[] Replace missing exhaust tailpipe.

[] Try to get the worst dents out of the nearside doors.  For the benefit of our neighbours that'll probably be one of the first things done.

[] Four new tyres (the spare actually looks fine, and having been stored in the boot hasn't been exposed to UV etc, so it will probably be left alone) as even though they generally look fine aside from the NSF they're 15 years old.  Being probably the single most safety critical part of the car, just doesn't make sense to take chances.

[] Road test, see what that adds to the snagging list.

-- Borrow (or buy) a car roller so I can get at the underside better

[] Weld up the hole on the inner sill.

[] Thoroughly rust proof the underbody.

[] MOT.

... Hopefully enjoy driving it!

 

Got the new intake throttle body installed on the Caddy today.

This is behaving very differently to the one I took off, so there was definitely something amiss with it.  This sharply flips open/closed precisely in time with the EGR solenoid cycling - though you can only tell it's doing this if the intake hose is off.  So the old one was definitely acting up.  It used to close fully and then just twitch open very slightly (which was the surging you could hear).  That's why it was smoking, as the air intake was basically cut off!

With everything assembled as the factory intended we had a smooth idle and no smoke.

For reference, this part number looks to be used on a plethora of models in 1.9SDI, 1.9TDi and 2.0TDi versions.

Everything was then put back together properly and we went out for a longer test drive.

I did manage to launch the intake hose clip for the air filter end a good twenty or thirty feet straight up in the air while trying to compress it.  I still hate those bloody spring clips.  Thankfully this one just went vertically up so I caught it.  I did have a moment of panic where I thought it was going to land on the company car parked next to me.

That throttle plate sitting on the battery is definitely from the old throttle body.

Be interesting to see with it running the correct timing map without logging sporadic error codes etc if the economy changes at all, though it's managing mid 40s already which around here I consider to be pretty good anyway.

[Zelandeth]

You all know me well enough to know the old throttle body wasn't going to get chucked in the recycling pile without some degree of post mortem, don't you?

No obvious smoking gun really.

The carbon traces on the position feedback potentiometer look fine, no missing or chipped teeth and no obviously fried electronic components (on this side of the board anyway).  The rusty residue though does suggest to me it's got damp at some point.  There was actual surface rust on the inside of the cover.  So my money is that has got into the brains of the operation or has resulted in contamination of the carbon tracks.

Nothing definite though which is a shame, but it was interesting to pull the cover off for a look at what makes it go.

[mat_the_cat]

6 hours ago, Zelandeth said:

You all know me well enough to know the old throttle body wasn't going to get chucked in the recycling pile without some degree of post mortem, don't you?

Oh, I knew you'd open it up. My only surprise is that you weren't able to fix it and keep as a spare!

[Zelandeth]

3 hours ago, mat_the_cat said:

Oh, I knew you'd open it up. My only surprise is that you weren't able to fix it and keep as a spare!

If there had been anything obvious I'd have had a shot, but the issue here seems to be something to do with the electronic side.  Given it's a double sided board of surface mount components which has obviously been damp at some point (and doesn't seem to have any form of conformal coating) I suspect a lot of tail chasing would get me nowhere.  Especially as there doesn't seem to be any direct connection between the pins and components inside, it's designed to talk to the ECM handling the emission control system digitally so I can't just hang a meter off a couple of pins and experiment.

[Zelandeth]

Caddy is booked in to Six-Cylinder's usual trusted garage for the end of next week to have the aux belt tensioner, idler and belt swapped out.  I've had a look at it and quickly came to the conclusion that it's an awkward enough job someone else can do it. 

This is *precisely* the sort of task I rapidly run out of patience with very rapidly, when it's something dear simple but made fifty times harder because of stupid spring loaded tensioners and the engine being 2.3 nanometres from the chassis rail for absolutely no good reason.  So I'm happy to pay someone else to do it.

Plus I'd really like to start building a bit of a rapport with that garage as my usual one are so swamped these days that it's just impractical to really use them for much beyond MOTs.  They couldn't fit me in for a full month.  

Annoyed at the weather.  Made the stupid mistake of saying that things looked to have dried up nicely so we could look at moving the Cavalier soon...then it goes and sets up to rain for a week.  Arse.

Still going to try to head over that way later in the week to swap wheels, change the knackered fuel line and hopefully sort spark so collection will be simpler when the ground has dried out again.

[Six-cylinder]

9 hours ago, Zelandeth said:

Caddy is booked in to Six-Cylinder's usual trusted garage for the end of next week to have the aux belt tensioner, idler and belt swapped out.  I've had a look at it and quickly came to the conclusion that it's an awkward enough job someone else can do it. 

This is *precisely* the sort of task I rapidly run out of patience with very rapidly, when it's something dear simple but made fifty times harder because of stupid spring loaded tensioners and the engine being 2.3 nanometres from the chassis rail for absolutely no good reason.  So I'm happy to pay someone else to do it.

Plus I'd really like to start building a bit of a rapport with that garage as my usual one are so swamped these days that it's just impractical to really use them for much beyond MOTs.  They couldn't fit me in for a full month.  

Annoyed at the weather.  Made the stupid mistake of saying that things looked to have dried up nicely so we could look at moving the Cavalier soon...then it goes and sets up to rain for a week.  Arse.

Still going to try to head over that way later in the week to swap wheels, change the knackered fuel line and hopefully sort spark so collection will be simpler when the ground has dried out again.

Why would you want to take your car there, you will have to listen to them moan about the cars I bring them!

[Zelandeth]

4 hours ago, Six-cylinder said:

Why would you want to take your car there, you will have to listen to them moan about the cars I bring them!

Because the last garage other than Two Wrestlers I used handed me the van back with a £600 bill for about £300 of work, overfilled to the extend of overflowing brake fluid, a misadjusted handbrake, interior and exterior covered in greasy hand prints and two road wheels that were less than finger tight.

Not to mention having failed the MOT on it for "missing rear reflectors" TWICE when they're built into the bloody tail light lenses, and having fixed the solution by sticking on trailer ones (squint) precisely 2" away from the stock ones, and charging me for the privilege.

I'll take tales of doom and gloom about the nonsense they have thrown their way by you over that any day!

[bobdisk]

On 3/10/2022 at 9:24 PM, Andyrew said:

I Have roll over jig your welcome to borrow if im more local than the other chap. It belonged to Ian who used to own your cav.  Ive never used it bit it looks complete.

This type i belive. 

 

How big a car will this do?  BMW E46??

[Andyrew]

4 hours ago, bobdisk said:

How big a car will this do?  BMW E46??

Can see why not. Ive never used it but i know its had a carlton gsi on it. 

[beko1987]

21 hours ago, Six-cylinder said:

Why would you want to take your car there, you will have to listen to them moan about the cars I bring them!

If you took them simple jobs like an aux belt and pulley change every once in a while rather than massive projects they might like you a bit more 😂

How's the trevi getting on? If it's back at the FoD for the Easter Saturday it's carpets could do with a vacuum or 25...

[Marm Toastsmith]

On 3/30/2022 at 12:53 AM, Zelandeth said:

Caddy is booked in to Six-Cylinder's usual trusted garage for the end of next week to have the aux belt tensioner, idler and belt swapped out. 

Just thought I'd mention that the belt was replaced roughly a year ago. I'm fairly sure the VW specialist that did it would have replaced the pulley too if he thought it worthwhile - job came as part of a thorough service including cam belt, water pump etc... you should have the bill!

[Zelandeth]

8 hours ago, Marm Toastsmith said:

Just thought I'd mention that the belt was replaced roughly a year ago. I'm fairly sure the VW specialist that did it would have replaced the pulley too if he thought it worthwhile - job came as part of a thorough service including cam belt, water pump etc... you should have the bill!

I do, but one of the pulleys is definitely noisy, especially when cold.  The surface of the tensioner pulley is badly rust pitted throughout so is the main suspect.

The belt has worn a groove in the surface that's the best part of a millimetre deep, which just doesn't seem right to me.

Shouldn't be that bad a job, just fiddly.  Which is why someone else can have it to do.

[Zelandeth]

Finally getting around to addressing one of the things which has been bugging the hell out of me in the Caddy since day 1.

The gear lever gaiter has had it.  It's shrunk so there's no way to get it to stay on the clip at the top and there are two holes in it anyway.  It's just past it.

Used ones are generally all just as bad, yet eBay sellers still want £30-50 for for some reason.

So we've gone for a third party one priced at a more reasonable £15.  We'll see how crap it is or isn't when it gets here.  If it's hopeless we'll probably just end up making a new one, it's hardly a complicated bit of construction.  Basically just four triangular pieces of fake leather stitched together.

This is the other issue I need to look into in more depth is shown below (the editor is being an arse and refusing to let me insert the cursor anywhere below the video).  

There's a bit of free play in the steering.  This feels like in the column rather than rack or track rod ends.  So I need to get the trim out so I can see the UJs down there while I get a helper to move the wheel.

I will do that checking the track rod ends first though as they're easier to get to!

I do need to check it's not something dead simple like the steering wheel being slightly loose on the splines too as there is a little fore and aft play in it...

[Zelandeth]

This arrived this morning in the post.

Given the state of the fasteners I opted to leave it soaking in penetrating oil for a few hours while I got on with other things.

After a few hours I returned to it.  After a lot of very careful backwards and forwards spinning of the nut to clean the threads out I got it apart.  

A huge amount of shaking and blowing through the housing with the air line then followed.  There was a lot of crud floating around inside it and there's no way to dismantle it to really gain access.  Eventually it stopped rattling or producing clouds of rust and was in a state I was happy enough to fit it.

Will want a bit of paint at some point but that's hardly a priority.  

One last detail I needed to deal with was the support rod which should sit between a tab on the filter housing and an eye on the inlet manifold below it.  My original filter didn't have this and it had rusted away to nothing on the replacement.

This doesn't need to be massively strong, it's mainly there I think to discourage the filter assembly from vibrating too much.  After a bit of a rummage round the garage I opted for a bit of 10mm microbore copper pipe.

Couple of holes drilled to match the mounting points and that's a job done.

Engine bay looking a bit more like most people expect now.

Obviously the support will get a coat of paint as well when I give the air cleaner housing a going over.  I don't actually have any suitable paint in stock just now, so it'll just have to wait.

The end result though is the air cleaner assembly being robustly held in place, which is what we were after.

It was interesting to compare the original air cleaner to the "normal" Steyr Puch/Invacar one.

Well, nearly normal Steyr Puch one.  In pretty much all other applications the filter seems to face to the right rather than left.  My guess as to why this was done is for packaging reasons.  If it faced to the left it would make installation of the engine as a pre-assembled unit more difficult.  The proximity of that brace I've got my fuel filter attached to would make changing the filter a real faff too.

The "stubby" filter I have does seem to be something of an anomaly though.

My gut feeling is that someone modified this housing sometime goodness only knows how many years ago.  Possibly in the search for more power, given how much smaller the intake port on the original style housing is.

A lot of work to go to though...and if you're doing that why would you leave a ridge round the edge still shading half the filter element surface?

Quite possibly effort in vain too...Steyr-Puch seemed to have their heads screwed on pretty well and did quite a lot to make sure that the heads on this engine flowed well, it wouldn't surprise me in the slightest if the design of that air cleaner has more science behind it than it looks like.  There's no practical reason for it to be that big - the one TPA had does just fine, unless that cavity is intended to act as a resonator or something like that and aid in getting the air into the engine where it's needed.  Or it might just be to silence the intake a bit...though refinement never really seems to have been a priority...I just don't know!

There is definitely at least one sign of differences to the standard filter assembly too, in the form of the filter retaining plate.

The original one I had (which made the successful break for freedom a few weeks ago) just sat in the centre of the air cleaner element, the outer edges were left exposed.

Whereas the one I just fitted completely covers the outer face of the filter element.

Would be really interesting to know if someone had altered the old filter housing, and if so to what end.

Suffice to say I *have* now fitted a jam-nut on the cleaner retaining bolt!  Ensuring it isn't winding itself off will become part of the regular checks.

I will be curious to see if this makes any difference to behaviour when driving.  Both in terms of power delivery and in helping calm the intake noise a bit as at speed that could be really quite obtrusive.

Time will tell I suppose!