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]

That would tend to further my suspicion that the carb isn't necessarily optimally set up for the engine in terms of performance and likely is a little on the lean side of ideal.  Hmm...

[LightBulbFun]

12 hours ago, Zelandeth said:

That would tend to further my suspicion that the carb isn't necessarily optimally set up for the engine in terms of performance and likely is a little on the lean side of ideal.  Hmm...

if only we knew someone who had an extensive advanced Automotive tuning computer and an exhaust gas Analyser, as well as owning a Model 70 I know the chances of that are like super slim

but if only someone did...

 

[Zelandeth]

A spare carb is probably useful too.  Wouldn't surprise me if a slight re-jet would make quite a difference.  One day I might actually need to try to get my brain around the numbering and see if I can get hold of a few and have a poke around.  Though equally I'd love to experiment with a little SU and see how that would behave.  Aside from anything else, I just like them.  Not least for their ability to be absolutely knackered, half full of sludge and still somehow run the engine absolutely fine.

Imagine something like the 35mm Mikuni on the Trabant would probably be pretty well suited as well.

Sadly I can't do any timing tweaks really as my distributor seems to be firmly welded in place - and having seen the results of trying to free it off using brute force I'm inclined to leave that well alone.

[LightBulbFun]

3 hours ago, Zelandeth said:

A spare carb is probably useful too.  Wouldn't surprise me if a slight re-jet would make quite a difference.  One day I might actually need to try to get my brain around the numbering and see if I can get hold of a few and have a poke around.  Though equally I'd love to experiment with a little SU and see how that would behave.  Aside from anything else, I just like them.  Not least for their ability to be absolutely knackered, half full of sludge and still somehow run the engine absolutely fine.

Imagine something like the 35mm Mikuni on the Trabant would probably be pretty well suited as well.

Sadly I can't do any timing tweaks really as my distributor seems to be firmly welded in place - and having seen the results of trying to free it off using brute force I'm inclined to leave that well alone.

along those lines, i'd love to see what one of the bigger capacity Steyr puch engines would be like, one of the 643cc or 660cc units or even the aftermarket 762cc option, i'd love to see what one of those would be like in a Model 70, not tuned for stupid screaming power, still just tuned for happy street use, but with the extra grunt of the added cylinder capacity, I bet that would make for quite a nice cruiser, be able to sit on 70 on the motorway nicely, especially if you swapped in a taller diff....

especially as there are other versions of the same Weber 32ICS carb, so you could go for a 32ICS9 for example (the carb from the 643cc version IIRC) and so everything would still look very stock

 

or you know, something like this!

https://www.ebay.co.uk/itm/298175073892

(I bet @AdgeCutler's Engine will be shinier still once he is done with it!

[Remspoor]

I was doing a reverse image search and this was thrown up as a result. It was nothing like what I was searching for.

It was from a film with the title The Girl from Starship Venus or in the USA The Sexplorer

 

[Yoss]

6 minutes ago, Remspoor said:

I was doing a reverse image search and this was thrown up as a result. It was nothing like what I was searching for.

It was from a film with the title The Girl from Starship Venus or in the USA The Sexplorer

 

Ooh! Austin 3 Litre! 

[Remspoor]

1 hour ago, Yoss said:

Ooh! Austin 3 Litre! 

Wrong thread🤣

[LightBulbFun]

popped down to REV this(?) morning

discovered her nearside wing mirror glass had gone AWOL

follow the clues...

on the pavement

a bit of tape later, like it never* happened...

(I had noticed the the black trim thingies, do like to work their way out of the mirror body and I usually pop them back in place ever other trip or so, I wonder if the nearside one finally worked its way all the way loose, if someone bumped into it or somehow the wind took it!)

the thing I popped down for, was to look at REV's CVT belt and ideally change it for one of the new HP2020 belts I have, but alas

I took one look at the adjuster rod and realised, yeah thats not going to cooperate! (and for giggles I did try and get a spanner on it and it did not feel like budging) I was hoping to do it the @Zelandeth method, which is wind the adjuster all the way to minimum tension then you can walk the belt onto the pulleys without having to remove them and faff about with then compressing the secondary pulley to trap the belt in it (which is something I need a second person for as mentioned I am weary about how many more cycles the locking washer-tab thingies can take)

the other problem is to wind the adjuster off, theres 3 bolts in slotted holes you need to slacken off, but I could only find one, I could not find or see the other 2 at all,  I know they are there and I suspect if I got underneath I could probably find them, but fuck if I was going to faff about with that at this point in time LOL, you can see all 3 of the slotted bolt holes in the chain case drawing below

so I instead just made sure to inspect the belt, which looked in perfect condition for the most part, no missing bars or cracks (or even any cracks in between the bars)

the only thing I could find of any note was a section of the belt had a little bit of feathering to its edge as pictured above, but it seems to only be on the top very top surface layer,

so fingers crossed its nothing to worry about and can at least get me to the flower farm meet and back! ill still be looking to preemptively change the belt of course, but ill have to figure out another plan of attack for that 

I also had a bit of a silly run around in REV locally, to meet someone "half way" to pick up some tubes, but they ended up coming directly to my house anyways after they realised like I said, they would be coming right past my house anyhow! but I managed a trip to the chippy out of it anyhow  I had hoped but did not manage, to get a bit more high speed testing done in REV to see if the issue of spluttering to a halt at speed was still lingering about or not (the OG plan, had I been able to change the belt was to then run up and down the A12 a bit to do both medium-high speed testing and to run the new belt in at the same time) it was fine on my previous 14 mile run up n down my A12 test route I did a bit over a week ago, so fingers crossed it will be alright for the M25!

random aside in the random running about today in REV, I found this bit of graffiti art that I thought the fluorescent neon-tube effect was very well done, very much looked like an actual Neon sign at first blush

and then home once more!

[AdgeCutler]

Oilway caps have been refitted using a Loctite sealer, the type Dez’s earlier post mentioned is now obsolete but I had some sealer on the shelf which ticked all the boxes.

[AdgeCutler]

Attention then turned to the cam followers which a couple of were not making perfect even contact with the cams which would cause premature and uneven wear. They were “tweaked” by simply using brute force and a suitable lever to bend the metal until the faces mated perfectly. 

[AdgeCutler]

Conrods back together using feeler blades wedged between halves and web to ensure alignment. Then torqued up and peened for security.

[Noel Tidybeard]

iirc there should be a large diameter, fairly soft spring  that applies an amount of pressure on the mirror glass to hold everything in

[Snake Charmer]

9 hours ago, AdgeCutler said:

Oilway caps have been refitted using a Loctite sealer, the type Dez’s earlier post mentioned is now obsolete but I had some sealer on the shelf which ticked all the boxes.

601 retainer? Most excellent stuff.

[MrGTI6]

There was an Invacar on display at the Detling Bus Show today. 

I could have sworn I took a photo but can't seem to find it.

[Christine]

Bet that was fun going  down Detling hill in that !  Bum clincher..

[High Jetter]

4 hours ago, AdgeCutler said:

Conrods back together using feeler blades wedged between halves and web to ensure alignment. Then torqued up and peened for security.

Precision work!

[LightBulbFun]

10 hours ago, Snake Charmer said:

601 retainer? Most excellent stuff.

is that what they use to glue Trabants together with?  

[AdgeCutler]

The bottom end is back together, sealed with my old favourite stag Wellseal. Quite a fiddly little job trying to get the bearings to all line up with their respective locators while suspending the crankshaft while try to avoid redistributing the sealer. I could have used a third hand but got there in the end.

[Snake Charmer]

1 hour ago, LightBulbFun said:

is that what they use to glue Trabants together with?  

I tried a test on m8 bolts & nut left to set in the bench vice compared with 242. Tried undoing ttge 601 nut and sheared the  bolt, 242 came ubdone as expected.

[AdgeCutler]

Moving on to the top ends, I started by giving them a clean off. Cooling must have been somewhat impaired by all the crap in there including tarry oil deposits, Bird Cherry seeds ( left by Mr. Mousey and also a spark plug tit that somebody somewhere, somewhen was baffled as to where it had gone!

 I was a bit apprehensive about what splitting the head from the barrel would hold in store but with some prying at the strongest points of the castings and avoiding damage to the fragile fins, they parted without too much effort.

[Andrew353w]

Away in France for a few weeks and suffering a “deja vu” moment: is the contributor to this feed following me….?

Picture taken in Courdebec A Cour on the Seine!

[AdgeCutler]

A protracted blasting with the pressure washer, a cycle through the dishwasher and some scotchbright later and the barrel and head were looking good enough to start work.  I have to say, the castings are lovely, in particular the head is a work of art! However , I was not happy with a previous repair to the rocker cover stud, it has been sheared, threaded and sleeved to accept an Allen cap head bolt which just doesn’t look right.

[AdgeCutler]

I did try to remove the stud on a couple of the knackered heads from the scrap engines to no avail, even after a lot of heat was invested. I came to the conclusion that these studs may even be cast into the head? 
It was decided to weld a new end onto the existing stud, so a suitable brace was made to ensure alignment when setting up the weld. I also ensured it would end up at exactly the length of the original, which I didn’t realise at the time but this actually works to stand the head at the correct angle to work on valve seats when inverted.

[AdgeCutler]

So then onto valve grinding, the faces did have quite a step in them so I pulled out the lovely old Wolf valve grinder that I saved from a skip some years back. A lovely piece of kit it is too. 
the seats were actually pretty good and I decided not to cut them. I stopped in at friends to see if I could borrow a suction cup as mine is AWOL and being Sunday I couldn’t buy one. Anyhow, he did one better and produced an “Easy Lap”. I’ve never seen one before but now want one, it fits in a drill chuck and has a suction cup the other end which rotates small increments back and forth exactly as you would when manual lapping. It was then when the head was placed upon the table that I realised that the rocker cover stud length brings the valve seats parallel to the chuck!

[AdgeCutler]

I forgot to mention that using a conventional valve spring compressor doesn’t work due to the angles and recesses, a little open sided bucket was made to work with the compressor. It did the job and just allowed enough access to remove/refit the collets

[AdgeCutler]

Using a barrel from a scrap engine that already had broken fins, I knocked the rest of the fins off and used it to lap the head (metal on metal seal, no gasket). One top end nearly ready, next to its partner that awaits the same attention.

[AdgeCutler]

On 11/04/2026 at 03:21, LightBulbFun said:

popped down to REV this(?) morning

discovered her nearside wing mirror glass had gone AWOL

follow the clues...

on the pavement

a bit of tape later, like it never* happened...

(I had noticed the the black trim thingies, do like to work their way out of the mirror body and I usually pop them back in place ever other trip or so, I wonder if the nearside one finally worked its way all the way loose, if someone bumped into it or somehow the wind took it!)

the thing I popped down for, was to look at REV's CVT belt and ideally change it for one of the new HP2020 belts I have, but alas

I took one look at the adjuster rod and realised, yeah thats not going to cooperate! (and for giggles I did try and get a spanner on it and it did not feel like budging) I was hoping to do it the @Zelandeth method, which is wind the adjuster all the way to minimum tension then you can walk the belt onto the pulleys without having to remove them and faff about with then compressing the secondary pulley to trap the belt in it (which is something I need a second person for as mentioned I am weary about how many more cycles the locking washer-tab thingies can take)

the other problem is to wind the adjuster off, theres 3 bolts in slotted holes you need to slacken off, but I could only find one, I could not find or see the other 2 at all,  I know they are there and I suspect if I got underneath I could probably find them, but fuck if I was going to faff about with that at this point in time LOL, you can see all 3 of the slotted bolt holes in the chain case drawing below

so I instead just made sure to inspect the belt, which looked in perfect condition for the most part, no missing bars or cracks (or even any cracks in between the bars)

the only thing I could find of any note was a section of the belt had a little bit of feathering to its edge as pictured above, but it seems to only be on the top very top surface layer,

so fingers crossed its nothing to worry about and can at least get me to the flower farm meet and back! ill still be looking to preemptively change the belt of course, but ill have to figure out another plan of attack for that 

I also had a bit of a silly run around in REV locally, to meet someone "half way" to pick up some tubes, but they ended up coming directly to my house anyways after they realised like I said, they would be coming right past my house anyhow! but I managed a trip to the chippy out of it anyhow  I had hoped but did not manage, to get a bit more high speed testing done in REV to see if the issue of spluttering to a halt at speed was still lingering about or not (the OG plan, had I been able to change the belt was to then run up and down the A12 a bit to do both medium-high speed testing and to run the new belt in at the same time) it was fine on my previous 14 mile run up n down my A12 test route I did a bit over a week ago, so fingers crossed it will be alright for the M25!

random aside in the random running about today in REV, I found this bit of graffiti art that I thought the fluorescent neon-tube effect was very well done, very much looked like an actual Neon sign at first blush

and then home once more!

That adjuster looks fine, you shouldn’t have much worry with it, stick some decent penetrating fluid on it a day or two prior( not crap like WD40). It’s actually very good looking. The three bolts though, one is a little elusive (up underneath) but will be fine with your brothers help and diagram to hand. Personally, I’d be happy with the belt you have.
Back to your points, they don’t look pristine but also have a spark erosion pock mark centrally. Either a proper points file, nail file or even wet or dry will address this with a little time. The pock mark was probably formed by a weak condenser causing sparks at the points, whether it be a condenser past or present.

[High Jetter]

2 hours ago, AdgeCutler said:

Using a barrel from a scrap engine that already had broken fins, I knocked the rest of the fins off and used it to lap the head (metal on metal seal, no gasket). One top end nearly ready, next to its partner that awaits the same attention.

 

 

Y, tho? 😀

[LightBulbFun]

as likely seen elsewhere on the forum, I had good ol jaunt in REV today, up the Flower Farm shop just off Junction 6 of the M25 to attend the gathering of fellow shitters arranged by @inconsistant  

warming up!

soon up to temp and then on my way, first stop, some petrol, was feeling flush, brimmed the tank, all £18 of it! only 38Mpg this time, but I think there was a bit more City driving and less cruising then on the last couple fill-up's

then hit the road, A12-black-wall tunnel-A2-M25, and got to flower farm right on time without any issues  

Datman off Retro-Rides (the Chap I got the 1951 Throlux trough reflector fixture from) popped over with his Electric Berlingo and kindly dropped this off for the VDP

then eventually I headed home, the M25, got buggered *just* before my exit,not without reason tho, a 3 car smash, I could not help but notice, that as I drove past the scene of the accident, everyone sitting on the crash barrier, looked up at and towards REV as I pottered on past, I hope I gave them something to smile about in an otherwise distressful moment in time! (or hopefully I did not cause someone to think they had a concussion and where now seeing things!)

but 85 miles where covered without a problem! cruised at about 50-55 on the way there and at about 55-60 on the way back, thankfully touch wood it seems the stumbling issues that where present in the last 2 lightbulb collection capers have resolved themselves  (perhaps the old hand on the carburettor trick managed to do something this time!) 

very pleased REV is back to performing as she should, and I actually managed to get to the Flower Farm gathering unlike last time

there a few rattlings and squeaks that have developed over the last few months, that I probably should try and figure out whats what! theres a squeak in particular that happens when I go over bumps, coming from the front, I cant tell if its the front suspension itself squeaking or something in the bodywork squeaking LOL, ill have to try and record it and see what the Autoshite hive-mind makes of it, I tried a few times to just bounce the nose of REV when stationary and it does not do it then, its only when on the move and you go over a bump, and of course I need to do something to fix that wing mirror properly! I might take the opportunity to get a Convex Mirror for it, REV has a Convex Mirror on the offside and a flat mirror on the nearside, interestingly the VDP has the same arrangement, a Convex Mirror on the offside and a flat mirror on the nearside

I wonder why that is? why not just have convex on both sides for the wider field of view? figured I should ask incase theres a good reason I am missing before I do fit a convex mirror in place of REV's nearside flat mirror (I Much prefer the convex mirror as you get a wider FOV)

[High Jetter]

Flat glass gives a more accurate and less-distorted judgement of distance.