invacar LightBulbFun's Invacar & general ramble thread, index on page 1, survivors lists on Pages 24/134 & AdgeCutler's Invacar Mk12 Restoration from Page 186 onwards, still harping on...

[Zelandeth]

So long as the manifold nuts come undone it should be an easy job to change the downpipes.

I doubt there would be much saving in getting multiples made given it's pretty entirely a manual task - so it's mainly the labour you're paying for.  I don't imagine they would be massively expensive to have made up either way.  Silencer itself on the other hand is a lot more involved and potentially expensive.

Interesting point about the tailpipe.  I don't remember seeing any welds on it, but I'll take a closer look tomorrow.  Surely this isn't going to be yet another variation on the silencer design we've found...

[lesapandre]

2 hours ago, LightBulbFun said:

489 miles or there abouts is how long the drive belt lasted from her first drive around the FoD to depositing itself all over the M25  (her Manifold is fine AFAIK?)

in REV's defence the drive-belt/pulleys has always since day 1 been something I have wanted to look at/change on precaution, its something I have mentioned a fair few times over the years, my folly was not pushing harder in getting something done about it, but its no different to buying a car with unknown cambelt history, (as I have no service history for REV prior to me getting her and I know that she had been off the road since 2002 otherwise) so I dont blame REV the failure, the system once fully serviced is generally pretty reliable on a whole, as evidenced by the 8000 miles or so Dollywobbler and Zel have done combined, without any major issue

I would love to know what the service interval was for the drive-belt, I have never actually been able to find any dedicated service information for the Model 70, although I know in general they where given minor services every 3000 miles and major services every 6000 miles, but what those services encompassed I am not sure, but I would not be surprised if the major one included a drive-belt change, I suppose you could look at what the belt service intervials where for ATV's or DAF's to get some idea? (although I recall reading that DAF's sometimes had special extra durable belts)

The drive belts will also just decay and get brittle with age - so depending how long they have been on - it does not make much difference between a few hundred and a few thousand miles if there has been years of storage.

[High Jetter]

I'm a bit surprised the belt hasn't been replaced before, considering it's condition and relative ease of improvement.

[lesapandre]

Life often gets in the way.

[dozeydustman]

Just a thought Dez, assuming you haven’t got one already, grab yourself a cordless impact gun and some sockets. The Parkside ones in Lidls are pretty good for a hobbyist and occasional use. Might save the hassle of a breaker bar, and you shouldn’t need to chock the pulleys.

Just make sure you can change the torque setting so you don’t over-tighten anything on reassembly, if you do decide to get one.

The Ryobi one I got 4 years ago has been a godsend for removing tight and stubborn nuts in that time, especially since I’ve had the Peugeot. Again not pro quality but certainly good enough for occasional hobbyists’ use.

[Zelandeth]

20 hours ago, LightBulbFun said:

offside rear right is the one thats mostly recently blown and then pasted, but the nearside left has been holed and then welded previously, so I think ideally they could both do with replacing in the long term, and while I do have a set of NOS downpipes in the 'Stash, I was wondering if I could get a set made up in stainless steel for longevity, and further to that, would having a whole batch of them made be worth it/drive the individual unit cost down? for example I would gladly pay to have 10 sets of downpipes made up in stainless steel, if the unit cost was much lower

of course if in the in-between someone would be willing to help me fit those used good ones, I would not complain, but I know exhaust work is generally a gruelling task, hence why I am thinking of going straight for some stainless ones if thats possible to do  

 

as an aside has that heat-exchanger been modified? the exhaust pipe on it looks longer then it should be, but not sure if its just the angle of the photo etc, heres my NOS example for comparison

 

glad to see you got the springs with the clutch shoes too  I have seen a case where the springs themselves had failed, so its good to have the complete package just incase

Exhaust comparison.

Definitely different to the one you've got there or on REV as there's a bend in the tailpipe (doesn't look to be a result of damage), in addition to being a bit longer.

How many versions is that now?

[LightBulbFun]

so today my brother popped round for a few hours to help me chuck spanners at REV and hopefully get somewhere towards getting her moving under her own power again

getting the pulley nut itself undone was not too hard in the end with myself on the brakes and my brother on the breaker bar, the hardest part was actually knocking the locking tabs back

and then realising yes you will have to remove the pulley safety cage to actually be able to get the pulley out of there! thankfully we did not have to remove all the nuts holding it in place, just the one nut on the left, and then its flexible enough you can just lift it up out the way and withdraw the pulley

but getting that one nut-n-bolt out for the pulley cage was quite the PITA just because access to it was so awkward and the threads had years of gunk on them so the it was semi-sized the whole way out, in the end we got REV up in the air and my brother went underneath with the ratchet and an extension bar, while I held a spanner over the nut on the topside 

and then after fishing out all the string in the dome we could see, in rather amusing Terminator 2 esk "here let me try mine" scene, after my brother unsuccessfully tried to reset the pulley by hand, I with a bit of gentle persuasion with a big pry-bar managed to get it to reset back to its proper resting state and when it did slide back it was nice and smooth, so ill take that as a good sign that the internal gubbins of this pulley are still ok  

I then took the opportunity to check the distance between pulley centres and I was quite pleased to see it was pretty much spot on 10.25 inches, as well as one can check with a tape messure like this, so I am quite pleased about that, hopefully we can get the new pulley and belt on without having to disturb things here

and here is the rest of the gearbox linkage, thankfully its not as twisted as I first thought, at least not at the gearbox end of things, its just the fork on the end of the gear-selector rod thats twisted, not ideal but not a show stopper and not going to be putting too much undue stress on the gearbox internals itself at least.

the final thing for today was this issue with the seat base, I actually though this would need re-trimming, but it turns out after my brother had a look at it for himself, it just needed re-clipping around the seat frame (I thought the separate black bits where meant to be one bit of trim that had broken due to old age)

looks much nicer now, no longer scrunched up and coming away at one corner   and after my brother helped clean REV's windows, we then we wrapped things up and pushed REV back into her space, we had hoped to refit a new secondary pulley and drive-belt today also, but sadly Royal Mail has let us down

and the parcel containing the NOS pulley never actually showed up, hopefully it shows up tomorrow at least so we can get it fitted then  

all in all im pretty happy with the progress made so far, heres hoping we can wrangle things back together tomorrow!  

[Mrs6C]

Well done! That is good progress. If you haven't done so already, while you have easier access now, suggest you clear away the rest of the belt debris from around the place . You might like to clean and lubricate the gear lever linkage joints too, to give them an easier time of operation, before the new pulley goes on. A wire brush to clean and a dab of grease on the pivots ought to do it.

[LightBulbFun]

Just now, Mrs6C said:

Well done! That is good progress. If you haven't done so already, while you have easier access now, suggest you clear away the rest of the belt debris from around the place . You might like to clean and lubricate the gear lever linkage joints too, to give them an easier time of operation, before the new pulley goes on. A wire brush to clean and a dab of grease on the pivots ought to do it.

yeah we spent a while plucking all the fluff from everywhere, ended up with this rather dodgy looking bag full  

thats a good shout regarding the linkages I have some lithium grease I can try?  

[beko1987]

Nice!

Worth emptying 3 or 4 tins of brake clean and n old toothbrush over all that whilst it's nice and open and apart?

Or some nice satin black on that belt cage cover 😂

[Mrs6C]

9 minutes ago, LightBulbFun said:

yeah we spent a while plucking all the fluff from everywhere, ended up with this rather dodgy looking bag full  

It looks like you have sheared a sheep!

 

[lesapandre]

Errrr...in Lundun that looks like a bag of something else. 😂

[plasticvandan]

If you do manage to get to Kidderminster,which,aside from the steam railway and army surplus shop is definitely the toilet of the west midlands, you will not be far from worcs &district motor co in hartlebury,former Reliant and microcar specialists for over 50 years, and of course reliant spares in Cradley,worcestershire,both of whom would be able and likely willing to work on it,reliant spares had a crash damaged mk12 some years ago.

 

[lesapandre]

Super casting with the AC logo on there.

[lesapandre]

 A distant relative - a 1958 AC railcar. Five built and one survives preserved at Colne Valley Railway.

[LightBulbFun]

5 minutes ago, lesapandre said:

Super casting with the AC logo on there.

aye the Model 70 gearbox was a bespoke item made by AC, so regardless of if you have/had an AC Model 70 or Invacar Model 70, you had an AC logo somewhere on/in the car! I have always thought the logo on the lid was a nice touch indeed  (I keep meaning to grab a close up photo of it for @Snake Charmer but I always keep getting distracted by the task at hand!)

[Snake Charmer]

16 minutes ago, LightBulbFun said:

aye the Model 70 gearbox was a bespoke item made by AC, so regardless of if you have/had an AC Model 70 or Invacar Model 70, you had an AC logo somewhere on/in the car! I have always thought the logo on the lid was a nice touch indeed  (I keep meaning to grab a close up photo of it for @Snake Charmer but I always keep getting distracted by the task at hand!)

Ooh, real AC parts! 😎  🤣

[LightBulbFun]

alright new pulley has shown up and my brother is on his way to help me fit it  

looks like there will be a little bit of mounting of hardware to transfer over, but hopefully that wont be too much finagling, at least with the pulley off the vehicle it can be attacked much more directly! 

[plasticvandan]

Can tell you don't have girls over often😅

[LightBulbFun]

so with the new pulley in hand and my brother round, we transferred the lock washer-tab-thing and spacer to the new pulley and then popped down to REV once more  

and after *much* faffing about trying to get the new belt suitably trapped inside the number 2 pulley, we got the pulley with its locking key and belt in place! 

torqued the bolt up to 32 ft/lb using the Norbar @Joey spud very kindly sent me a couple years back, moved REV back n forwards to reset the belt-gearing, staked the locking tabs in place  

`

then went for a very short drive up n down the road, to which im pleased to report everything seemed to have worked!

so bolted the belt cage/guard back in place, along with the bathtub and seat-back

then went for a drive round the block!

to which im pleased to report REV performed without any issues, and the bad shunting is completely gone now, so I think we can safely say that if your experiencing bad shunting in a Model 70, check/change your drive-belt before it goes pop/lets go!

thats about 1.5 miles covered since the old belt let go on the M25! did notice on the return trip that a fuel pipe to fuel tank connection was leaking a bit, and I was able to move the pipe about but a few turns on the hose clip sorted it  

and then I parked REV up under her own tractive effort this time!

 

all In all I am very pleased of course! I am very pleased to have REV back ,and to have gotten rid of the shunting, as well as having the reassurance a new drive belt is fitted  I just hope that it doesn't go pop again! safe to say im probably going to be a bit paranoid of any noises for a while (I did notice that on the reverse-overrun there is a bit of a fast ticking noise, but it only happens in that specfic reverse-overrun, under power in reverse its not there, and going forward both under power and on the overrun its not there, so im going to chalk that up just a noise the driveline makes!)

I am also quite egier to find out if this has improved REV's top end performance, but I think its advised to be gental and break the drive-belt in over the first 20 miles or so, so might be a little while before I can give performance figures, although again the shunting/hoping is gone, so that immediately has improved things there  (and many thanks to @st185cs who sent me a NOS pulley in double-quick time, as due to logistical reasons my own personal spare sets are not accessible atm)

[beko1987]

Awesome, well done!

Now you know how it comes apart and what tools you need periodic maintenance will be a lot easier! 

[High Jetter]

Worth having another new belt to carry on the longer trips just in case? Glad it was a fairly easy fix.

[Andrew353w]

Is there a figure quoted for the minimum gap between the secondary pulley when it's at rest? Dafs much have a gap of at least 1mm so that the belt's  always under tension. New belts will stretch a little, so check the gap after 500 miles or so. 

[LightBulbFun]

13 minutes ago, High Jetter said:

Worth having another new belt to carry on the longer trips just in case? Glad it was a fairly easy fix.

yeah I always carry a spare drive-belt with me  , however I think the side of the M25 was not the best place to try and fit it LOL

12 minutes ago, Andrew353w said:

Is there a figure quoted for the minimum gap between the secondary pulley when it's at rest? Dafs much have a gap of at least 1mm so that the belt's  always under tension. New belts will stretch a little, so check the gap after 500 miles or so. 

not sure I follow on what you mean by gap between the secondary pulley? the workshop manual gives a distance between the centre of pulley 1 and pulley 2, this is what sets the belt-tension and is explicitly meant to be set to 10.25 inches (which it is on REV  ) your not meant to try and tension it by feel, just by explicitly setting the distance correctly 

this in itself was a bit of a problem in the early days of the Model 70, where workshops/mechanics were messing up the CVT system, so the DHSS had to send a letter out which was basically "RTFM!"

 

[Andrew353w]

8 minutes ago, LightBulbFun said:

not sure I follow on what you mean by gap between the secondary pulley? the workshop manual gives a distance between the centre of pulley 1 and pulley 2, this is what sets the belt-tension and is explicitly meant to be set to 10.25 inches (which it is on REV  ) your not meant to try and tension it by feel, just by explicitly setting the distance correctly 

On the Daf system there has to be a gap between the two halves of the secondary (driven) pulley when the car's at rest. This means the belt is always under tension, so there's no slippage.  I gather there's no way to move the driven pulley away from the primary (driving) pulley in an Invacar, so the 10 1/4 inch measurement must be the way it's done. I assume the belt is under tension when the car's at rest, like a Daf is.

[LightBulbFun]

37 minutes ago, Andrew353w said:

On the Daf system there has to be a gap between the two halves of the secondary (driven) pulley when the car's at rest. This means the belt is always under tension, so there's no slippage. 

oh you mean between the pulley sheaves of the secondary pulley I see , I dont know if there is a gap or not at rest, never actually checked for one, and theres no mention of either way in the workshop manual, but the belt is always under tension even at rest, thats pretty self evident when yah look at things

 

this is while we where installing it and it was still slack as the belt was still trapped in the secondary pulley (you trap it in there so you have enough slack to be able to slide both pulleys onto the shafts, or in my case. hook the belt over the primary pulley and slide the secondary pulley on the shaft)

and after it was installed and all procedures done, rocking the car back-n-forth to release the belt from the secondary pulley, note the difference in tension  

37 minutes ago, Andrew353w said:

I gather there's no way to move the driven pulley away from the primary (driving) pulley in an Invacar, so the 10 1/4 inch measurement must be the way it's done. I assume the belt is under tension when the car's at rest, like a Daf is.

the distance between the primary and secondary pulleys is adjustable (hence the RTFM note above because people where messing with it), but its meant to be used to explicitly set the distance of the 2 pulley shaft centres 10.25 inches apart, and its at this explicit distance that the belt is properly tensioned 

[Andrew353w]

Yes, the rolling back and forward allows the belt to settle and yours looks suitable tensioned. 

[Pieman]

On 10/04/2025 at 21:13, plasticvandan said:

If you do manage to get to Kidderminster,which,aside from the steam railway and army surplus shop is definitely the toilet of the west midlands

Clearly you've never been to Walsall.

[plasticvandan]

6 minutes ago, Pieman said:

Clearly you've never been to Walsall.

I bought a Reliant Fox from bilston,which is hands down the worst place I've ever been.the sellers directions were " mine is the house that isn't boarded up"

[lesapandre]

16 minutes ago, Pieman said:

Clearly you've never been to Walsall.

It does have a new art gallery.