1973 Hillman Imp 1.6 De Luxe...........wait, what??!
Discussion
So, update time for the Imp! And we start before the last one; At the end of August, last year. Location: Gosport:
That picture was taken last year, at the annual 'Gosporteers' classic car show. Aside from Goodwood, it's the only show the car went to. I don't seem to get as much enjoyment out of car shows as I used to. Sometimes it's good, but 9/10 times it's just a load of cars that never see the road in anything other than exceptional weather conditions (by the UK's standards, anyway) with a load of 'one-upmanship' thrown in, as everyone tries to out-polish everyone else. Gosport's not like that, thankfully. It's too quiet, to be honest! I did finish the show 'season' last year at Tangmere Air Museum though (not in the Imp - in one of the BXs), and that was a cracking event. Brilliant mix of cars on display. I think I'll try to hunt some more of those down this year in the Imp. I just don't use it enough!
But enough pictures of it sitting around doing nothing - you want to see something underneath, right?
OK. Last year, about the same sort of time I got it up and running again with the new clutch arrangement, I set about trying to improve the speedometer accuracy. Normally, an Imp has a mechanical setup, with a cable-driven speedo rotated by one of the front wheels (don't ask me which - this car never had one!) This Imp has an electronic speedo, which is driven by a sender unit which I (when I say 'I', I of course mean a man called Simon) fitted to the transaxle, so it reads the offside rear wheel (or more specifically, the offside rear output flange's rotational speed).
Originally, Simon (not I; I'm happy to accredit him with this particular detail, as it failed) set the unit up to read the three mounting bolts from the rubber driveshaft 'doughnut' to the flange, believing that - due to the style of sender unit - three pickups would be sufficient. Three pickups were not sufficient, and the speedo floated and bounced and generally did everything except the job is was designed to do; to accurately relay the current road speed to anyone who cast a glance at it.
So, a new system was devised (by me, I'm happy to report!) It had been suggested to me, that an old-style Transit fitted with a 2.3 petrol engine (well, that's what the part number I was given translated to), used a detachable type of toothed trigger wheel. This had 36 teeth (probably....I'm not totally sure, but it was more than three), which installed much more confidence!
The trigger wheel duly arrived:
Happily, it already had three mounting holes (the same number as the thing I intended to mount it to). Unhappily, it might has well have had twelve, as they weren't in the right place:
Even more unhappily, the holes I needed to make fell right on the inner edge of the wheel, which meant it wasn't going to be as simple as just drilling three holes (when I say 'simple', I of course mean drilling three holes on EXACTLY the right circumference, or have a trigger wheel that hopped up and down, and smashed up the sender unit). I had to 'relieve' some metal as per the pic above, and then sacrifice some washers to complete the holes all the way around.
I then welded the washers (or the remains of them, anyway) in, and ground it all down to try and make it look like it was meant to look like that from day one. Kinda:
Being that this was a trigger wheel for a crank pulley, it had one flaw in the design that would prove to be a big flaw. The crank sender on said Transit 2.3 petrol records all the teeth passing it, bar one. This is intentionally left out, so that each time it passes, the ECU knows the crank has made one complete rotation.
My sender don't work like that. Oh no. My sender wants to know how many teeth there are (more than three), and then just count how quickly they pass. It was no good. I had to conduct teeth......work.
Tooth fitted:
Tooth shaped:
New wheel offered up in place (before then being removed for painting):
The operation proved a success. The speedo now read smoothly, and resembled something like a speedo from a normal car. Only it still wasn't accurate! Not a problem, though, as with this speedo (as with all aftermarket electronic versions) it's possible to calibrate it. You simply press and hold the mode switch (I like the fact a Hillman Imp has a 'mode switch') until the speedo enters calibration mode:
Then, because you really can't be arst to read the instruction manual, you prick around pushing buttons and entering different number combinations until the speedo reads close to what it's supposed to. Besides being a tool for bringing emotional turmoil to numerous project car owner's lives, our rolling road has a speedometer test function, which is actually quite a handy thing. It allows you to bring the wheels up to a series of pre-determined speeds, whereby you pause at each one while as suggested by the car's speedo, before moving on to the next. Then, at the end of the test, the machine tells you just how inaccurate your speedo is:
As we can see, it's underreading a fair bit. It's normal for cars to underread, but that's a bit more than ideal. That graph was also taken after a fair bit of trail and error playing. I managed to get the higher speeds reading quite well, but around the 20-40mph mark, it's proving quite tricky. I did find out what the top speed of the Imp is though: 107.4mph. When you hit the limiter in top gear, that's how fast you're going. Out and about on the (private) road, it's very easy to hit the limiter in 4th, but there's normally a bit too much going on to cast a glance downwards at the speedo. Anyway, more work needed on the speedo front.
One of the other issues I had to sort after Goodwood, was the lack of rear brake lights. The Imp uses a pressure-operated brake light switch, rather than a pedal-mounted effort. This is mounted in the engine bay (which is at the back remember, sports fans). I've wondered in the past about the legitimacy of having it driven by the rear brakes, but then wondered if the balance is closer to 50/50 on the Imp, due to the backwards engine layout. Makes no odds - the switch is at the back, so I started there.
Took no pictures of the event, but one night I went to test the switch and found it unplugged. "A simple fix" thought I! Not so - there was nothing to plug the switch into. No wiring....nothing.
In the days to come, I found the wiring:
I do remember hearing a BANG once, while out in the car, but to be honest it's such an assault on the senses that the odd noises just pass me by these days! But it seems what happened was that my brake light switch wiring somehow picked a fight with the output flange on the transaxle (the opposite side to my new speedo sender, thankfully), and lost. Que an hour of phaffing around trying to extricate shards of copper wire from the output seal. Still, it answered my next question....what was causing the gearbox oil leak!
Since then I've just been driving the Imp around. Here it is, out and about in the salty roads last year:
There are still jobs to do, however. For this year, I want to get some of the tasks sorted before I go ragging around in it. So first up, I sourced some new doors:
The keener-eyed of you will notice that they are a slightly different shade of blue (and when I say 'slightly', I course mean, they're not blue at all). I've sent these away to be soda-blasted, and the only thing that's prevented me for picking them up again is that the van I was going to use ran out of MoT! But I'm hoping they haven't gone too rusty, as it was about 2-3weeks ago that they were done. My plan with these is to offer them up to the car, and see if the shutlines improve at all. You might remember I've had problems with the shutlines on the old ones, thanks to the complete cock-up the first bodyshop guy we enlisted to help made on the doors (one of which how has a big crack across it where the filler is breaking out) I'm hoping he didn't do too much work on the quarter panels either, otherwise I'll have problems there too. Plan is to offer the new doors up (which I know are pretty good) and then dress them to improve the panel gaps on the shell, before having them painted. I'll report back on this when I actually start it!
Lastly for today, I finally made a start on the new dashboard. I've never personally liked the layout it's currently got, so some time ago I sourced a (Chrysler-era) mk3 dashboard, which would look something like this (sans wood):
In place of the wood panelling, I plan to have real carbon fibre. And in place of the glovebox, I plan to have a steering wheel (because Britain).
My dashboard is looking a bit sad in places, and it's taken from a car that had no glovebox. That's proving a bit of a pain, because I want a glovebox (not just for practicality, but also because the dash looks like it's got a gaping hole in it with no glovebox!) The problem is that the end panel is different for a glovebox dash.
Here's my current dash:
And here's the offside end panel (made of tin, incidentally) on my current dash (looking a bit sad):
Now for the nearside end panel, I should have a mirror image of that (I'm assuming), but I don't. I have this:
Ordinarily, you would approach the owner's club and ask for assistance in finding a spare. Sadly, it's quite an odd request for most, as it's not the sort of part you keep laying around (and if you have one, you probably need it). Also, I keep falling out with members of the Imp club (the younger ones mostly, but sometimes the older ones can be so far up their own arses they refer to their garage as a 'studio') on account of my ridicule of their 'sick stance' and various other assorted ways they've ruined their cars. I'm not very popular in Imp circles these days, but happily it doesn't really bother me too much. By the way, here's my prediction for the future: The Imp, as a classic, will get rarer and rarer. You'd assume they've already made the transition into bone-fide classic status, but the original cars are owned by all the older people. When they pass away, the cars get will bought by the 'yoof' (I'm 34, FFS) and then get slammed until the tyres make contact with the road via about 20mm of rubber collectively, and have stickers all over the windscreen, and skulls for gearknobs, and generally have so many pictures taken in that bloody awful vignette effect for their Insta-friends that the paint actually starts to go blue. As a result, the Imp in its pure form will continue to get rarer and rarer, rather than being firmly in the safe-zone like you'd expect. You want to make money on a classic? Buy an Imp, thats my opinion! I'm aware of the irony that I'm saying all this with that whacking great iron lump in the back of mine....
Anywhoo, my backup plan is to remove this similar looking panel from inside the glovebox aperture, and cut bits of tin out of it until it sort-of fits the existing nearside mount, before welding it all together and painting it. It won't be identical to the driver's side, but it will kind of resemble what it should be. Kinda.
I continued to dismantle the dash ready for refurb. It's a metal frame design, and comes apart quite easily. This unless some Scotsman made a hash of pulling through a pop-rivet in 1973...
From there I kept going until all the bits were split down. Next step is to make that nearside end panel, before shot blasting everything and painting it all up, either gloss black or, if I'm feeling lucky, crinkle-coat black.
That's as far as I've got currently. Plan is to finish the dashboard (along with some new gauges), install some kind of heater-demister system, beef up the front suspension mountings and renew the fuel lines. I might also fit an oil cooler, but haven't done enough testing yet to determine whether I need one or not. Oh and of course, the doors.
Plan for next year? In reality, to sell it. As things stand, 2019 will be the year I part ways with it. I want to 'finish' it first, which includes finally getting it into the mag feature it had to pull out of last minute a while ago. Not so much for the attention, or 'credit' of the thing, but because in a weird way, the feature would feel like the seal of approval. The stamp of completion. That's one of the reasons I took the car on - because I wanted to see it finished. I don't use it enough otherwise, and have many other cars that need my attention. That's why this year, I need to get out and about in it as much as I can
That picture was taken last year, at the annual 'Gosporteers' classic car show. Aside from Goodwood, it's the only show the car went to. I don't seem to get as much enjoyment out of car shows as I used to. Sometimes it's good, but 9/10 times it's just a load of cars that never see the road in anything other than exceptional weather conditions (by the UK's standards, anyway) with a load of 'one-upmanship' thrown in, as everyone tries to out-polish everyone else. Gosport's not like that, thankfully. It's too quiet, to be honest! I did finish the show 'season' last year at Tangmere Air Museum though (not in the Imp - in one of the BXs), and that was a cracking event. Brilliant mix of cars on display. I think I'll try to hunt some more of those down this year in the Imp. I just don't use it enough!
But enough pictures of it sitting around doing nothing - you want to see something underneath, right?
OK. Last year, about the same sort of time I got it up and running again with the new clutch arrangement, I set about trying to improve the speedometer accuracy. Normally, an Imp has a mechanical setup, with a cable-driven speedo rotated by one of the front wheels (don't ask me which - this car never had one!) This Imp has an electronic speedo, which is driven by a sender unit which I (when I say 'I', I of course mean a man called Simon) fitted to the transaxle, so it reads the offside rear wheel (or more specifically, the offside rear output flange's rotational speed).
Originally, Simon (not I; I'm happy to accredit him with this particular detail, as it failed) set the unit up to read the three mounting bolts from the rubber driveshaft 'doughnut' to the flange, believing that - due to the style of sender unit - three pickups would be sufficient. Three pickups were not sufficient, and the speedo floated and bounced and generally did everything except the job is was designed to do; to accurately relay the current road speed to anyone who cast a glance at it.
So, a new system was devised (by me, I'm happy to report!) It had been suggested to me, that an old-style Transit fitted with a 2.3 petrol engine (well, that's what the part number I was given translated to), used a detachable type of toothed trigger wheel. This had 36 teeth (probably....I'm not totally sure, but it was more than three), which installed much more confidence!
The trigger wheel duly arrived:
Happily, it already had three mounting holes (the same number as the thing I intended to mount it to). Unhappily, it might has well have had twelve, as they weren't in the right place:
Even more unhappily, the holes I needed to make fell right on the inner edge of the wheel, which meant it wasn't going to be as simple as just drilling three holes (when I say 'simple', I of course mean drilling three holes on EXACTLY the right circumference, or have a trigger wheel that hopped up and down, and smashed up the sender unit). I had to 'relieve' some metal as per the pic above, and then sacrifice some washers to complete the holes all the way around.
I then welded the washers (or the remains of them, anyway) in, and ground it all down to try and make it look like it was meant to look like that from day one. Kinda:
Being that this was a trigger wheel for a crank pulley, it had one flaw in the design that would prove to be a big flaw. The crank sender on said Transit 2.3 petrol records all the teeth passing it, bar one. This is intentionally left out, so that each time it passes, the ECU knows the crank has made one complete rotation.
My sender don't work like that. Oh no. My sender wants to know how many teeth there are (more than three), and then just count how quickly they pass. It was no good. I had to conduct teeth......work.
Tooth fitted:
Tooth shaped:
New wheel offered up in place (before then being removed for painting):
The operation proved a success. The speedo now read smoothly, and resembled something like a speedo from a normal car. Only it still wasn't accurate! Not a problem, though, as with this speedo (as with all aftermarket electronic versions) it's possible to calibrate it. You simply press and hold the mode switch (I like the fact a Hillman Imp has a 'mode switch') until the speedo enters calibration mode:
Then, because you really can't be arst to read the instruction manual, you prick around pushing buttons and entering different number combinations until the speedo reads close to what it's supposed to. Besides being a tool for bringing emotional turmoil to numerous project car owner's lives, our rolling road has a speedometer test function, which is actually quite a handy thing. It allows you to bring the wheels up to a series of pre-determined speeds, whereby you pause at each one while as suggested by the car's speedo, before moving on to the next. Then, at the end of the test, the machine tells you just how inaccurate your speedo is:
As we can see, it's underreading a fair bit. It's normal for cars to underread, but that's a bit more than ideal. That graph was also taken after a fair bit of trail and error playing. I managed to get the higher speeds reading quite well, but around the 20-40mph mark, it's proving quite tricky. I did find out what the top speed of the Imp is though: 107.4mph. When you hit the limiter in top gear, that's how fast you're going. Out and about on the (private) road, it's very easy to hit the limiter in 4th, but there's normally a bit too much going on to cast a glance downwards at the speedo. Anyway, more work needed on the speedo front.
One of the other issues I had to sort after Goodwood, was the lack of rear brake lights. The Imp uses a pressure-operated brake light switch, rather than a pedal-mounted effort. This is mounted in the engine bay (which is at the back remember, sports fans). I've wondered in the past about the legitimacy of having it driven by the rear brakes, but then wondered if the balance is closer to 50/50 on the Imp, due to the backwards engine layout. Makes no odds - the switch is at the back, so I started there.
Took no pictures of the event, but one night I went to test the switch and found it unplugged. "A simple fix" thought I! Not so - there was nothing to plug the switch into. No wiring....nothing.
In the days to come, I found the wiring:
I do remember hearing a BANG once, while out in the car, but to be honest it's such an assault on the senses that the odd noises just pass me by these days! But it seems what happened was that my brake light switch wiring somehow picked a fight with the output flange on the transaxle (the opposite side to my new speedo sender, thankfully), and lost. Que an hour of phaffing around trying to extricate shards of copper wire from the output seal. Still, it answered my next question....what was causing the gearbox oil leak!
Since then I've just been driving the Imp around. Here it is, out and about in the salty roads last year:
There are still jobs to do, however. For this year, I want to get some of the tasks sorted before I go ragging around in it. So first up, I sourced some new doors:
The keener-eyed of you will notice that they are a slightly different shade of blue (and when I say 'slightly', I course mean, they're not blue at all). I've sent these away to be soda-blasted, and the only thing that's prevented me for picking them up again is that the van I was going to use ran out of MoT! But I'm hoping they haven't gone too rusty, as it was about 2-3weeks ago that they were done. My plan with these is to offer them up to the car, and see if the shutlines improve at all. You might remember I've had problems with the shutlines on the old ones, thanks to the complete cock-up the first bodyshop guy we enlisted to help made on the doors (one of which how has a big crack across it where the filler is breaking out) I'm hoping he didn't do too much work on the quarter panels either, otherwise I'll have problems there too. Plan is to offer the new doors up (which I know are pretty good) and then dress them to improve the panel gaps on the shell, before having them painted. I'll report back on this when I actually start it!
Lastly for today, I finally made a start on the new dashboard. I've never personally liked the layout it's currently got, so some time ago I sourced a (Chrysler-era) mk3 dashboard, which would look something like this (sans wood):
In place of the wood panelling, I plan to have real carbon fibre. And in place of the glovebox, I plan to have a steering wheel (because Britain).
My dashboard is looking a bit sad in places, and it's taken from a car that had no glovebox. That's proving a bit of a pain, because I want a glovebox (not just for practicality, but also because the dash looks like it's got a gaping hole in it with no glovebox!) The problem is that the end panel is different for a glovebox dash.
Here's my current dash:
And here's the offside end panel (made of tin, incidentally) on my current dash (looking a bit sad):
Now for the nearside end panel, I should have a mirror image of that (I'm assuming), but I don't. I have this:
Ordinarily, you would approach the owner's club and ask for assistance in finding a spare. Sadly, it's quite an odd request for most, as it's not the sort of part you keep laying around (and if you have one, you probably need it). Also, I keep falling out with members of the Imp club (the younger ones mostly, but sometimes the older ones can be so far up their own arses they refer to their garage as a 'studio') on account of my ridicule of their 'sick stance' and various other assorted ways they've ruined their cars. I'm not very popular in Imp circles these days, but happily it doesn't really bother me too much. By the way, here's my prediction for the future: The Imp, as a classic, will get rarer and rarer. You'd assume they've already made the transition into bone-fide classic status, but the original cars are owned by all the older people. When they pass away, the cars get will bought by the 'yoof' (I'm 34, FFS) and then get slammed until the tyres make contact with the road via about 20mm of rubber collectively, and have stickers all over the windscreen, and skulls for gearknobs, and generally have so many pictures taken in that bloody awful vignette effect for their Insta-friends that the paint actually starts to go blue. As a result, the Imp in its pure form will continue to get rarer and rarer, rather than being firmly in the safe-zone like you'd expect. You want to make money on a classic? Buy an Imp, thats my opinion! I'm aware of the irony that I'm saying all this with that whacking great iron lump in the back of mine....
Anywhoo, my backup plan is to remove this similar looking panel from inside the glovebox aperture, and cut bits of tin out of it until it sort-of fits the existing nearside mount, before welding it all together and painting it. It won't be identical to the driver's side, but it will kind of resemble what it should be. Kinda.
I continued to dismantle the dash ready for refurb. It's a metal frame design, and comes apart quite easily. This unless some Scotsman made a hash of pulling through a pop-rivet in 1973...
From there I kept going until all the bits were split down. Next step is to make that nearside end panel, before shot blasting everything and painting it all up, either gloss black or, if I'm feeling lucky, crinkle-coat black.
That's as far as I've got currently. Plan is to finish the dashboard (along with some new gauges), install some kind of heater-demister system, beef up the front suspension mountings and renew the fuel lines. I might also fit an oil cooler, but haven't done enough testing yet to determine whether I need one or not. Oh and of course, the doors.
Plan for next year? In reality, to sell it. As things stand, 2019 will be the year I part ways with it. I want to 'finish' it first, which includes finally getting it into the mag feature it had to pull out of last minute a while ago. Not so much for the attention, or 'credit' of the thing, but because in a weird way, the feature would feel like the seal of approval. The stamp of completion. That's one of the reasons I took the car on - because I wanted to see it finished. I don't use it enough otherwise, and have many other cars that need my attention. That's why this year, I need to get out and about in it as much as I can
Evangelion said:
And if you looked at the driveshafts themselves (which were the thicker ones from the Commer Imp van, 1 inch thick instead of 7/8ths) you could see they were twisting because the seams were no longer straight.
Ha- this ^ I have spotted the same issue on my new Imp project that I have recently taken on. It has a Datsun A12 engine fitted with only about 70bhp. But obviously enough torque to wind up the shafts under hard driving (its a race car that has been rallied so lots of shock loads run through the transmission ).jpg)
.jpg)
Anyway- your 1.6 Imp is fantastic and I'm glad someone from retro rides had linked me to the thread! I have 2 more Imps on the way and plan to do some sort of interesting engine swap in the future into one of the shells. Always great to see other ideas. Luckily it seems that Imps lend themselves to being modified :-) I'm loving the simple clean engine on yours.
Alex
Edited by yoeddynz on Thursday 22 March 07:52
Moderator edit to comply with Rules of Posting
Edited by Scrump on Tuesday 2nd April 20:35
Well I have very much enjoyed reading this. Quite the journey, both technical and emotional, it would be extremely gratifying if it was to go back to its original owner when you do decide to sell, however unrealistic that may seem.
I actually googled southways automotive as I have a mk2 (headache) Golf that needs putting back together and would quite happily send it to you to be worked on given the skill and passion that has been conveyed in this thread, however when I discovered you were based near Portsmouth (I'm in Wigan) ahhhh welll.
I actually googled southways automotive as I have a mk2 (headache) Golf that needs putting back together and would quite happily send it to you to be worked on given the skill and passion that has been conveyed in this thread, however when I discovered you were based near Portsmouth (I'm in Wigan) ahhhh welll.
yoeddynz said:
Evangelion said:
And if you looked at the driveshafts themselves (which were the thicker ones from the Commer Imp van, 1 inch thick instead of 7/8ths) you could see they were twisting because the seams were no longer straight.
Ha- this ^ I have spotted the same issue on my new Imp project that I have recently taken on. It has a Datsun A12 engine fitted with only about 70bhp. But obviously enough torque to wind up the shafts under hard driving (its a race car that has been rallied so lots of shock loads run through the transmission )Anyway- your 1.6 Imp is fantastic and I'm glad someone from retro rides had linked me to the thread! I have 2 more Imps on the way and plan to do some sort of interesting engine swap in the future into one of the shells. Always great to see other ideas. Luckily it seems that Imps lend themselves to being modified :-) I'm loving the simple clean engine on yours.
Alex
Interested to learn more about the Datsun setup! Will read your thread later
Thanks for the kind words!
Coakers said:
Well I have very much enjoyed reading this. Quite the journey, both technical and emotional, it would be extremely gratifying if it was to go back to its original owner when you do decide to sell, however unrealistic that may seem.
I actually googled southways automotive as I have a mk2 (headache) Golf that needs putting back together and would quite happily send it to you to be worked on given the skill and passion that has been conveyed in this thread, however when I discovered you were based near Portsmouth (I'm in Wigan) ahhhh welll.
Thanks. Yes, certainly been a journey. There have been many points where morale just dissipates completely, but at the moment it's enjoyable. That's all part of trying to build something rather than buy something though, I guess.I actually googled southways automotive as I have a mk2 (headache) Golf that needs putting back together and would quite happily send it to you to be worked on given the skill and passion that has been conveyed in this thread, however when I discovered you were based near Portsmouth (I'm in Wigan) ahhhh welll.
Ah yes, Wigan's a bit of a trek. OH has family up there. Mind you, we get cars from France, Spain etc. Got one from Luxembourg at the moment!
Kitchski said:
.... Mind you, we get cars from France, Spain etc. Got one from Luxembourg at the moment!
We *do* have cars in Luxembourg, an amazing number of vehicles are registered here considering the ~600k population. 
Been watching this thread with interest. Always has a thing about Imps, but my Dad told me stay away from them when I was a teen.
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