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Just checked the Sierra rad and it's 5 cm thick, 33 cm high (plus a 2,5 cm bracket) and 73,5 cm long/wide. Each end has a bracket protruding around 5 cm that needs to be cut off. And I'm fairly confident that it'll cope, since it's made for a uprated RS 500 and those turbo engines produce a lot of heat.

Best regards


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So time for a bit of an update. I bought a Sierra radiator, and the aircon condeser. Now to make that fit... A Sierra radiator: First to make the bolts that come out of the base of t

So it's been  a long time since an update on this.  There has been progress:       The radiator with the condenser sandwich and       fans fitted.  You can also see the bleeder hose in

Great timing John!    So another update   Trial fitted the compressor and alternator       Should clear the water pump outlet ok.    As I'm ending up with just two belts I was concerned

  • 2 months later...

So time for a bit of an update. I bought a Sierra radiator, and the aircon condeser. Now to make that fit...

A Sierra radiator:


First to make the bolts that come out of the base of the radiator (positions already marked)...

Take a pice of 6mm aluminium


Tap an M8 bolt hole, countersunk



then weld them to the base of the radiator...


Thanks to my expert welder mate, there you have it...

We also made up top brackets. these were a real head scratching exercise because the angles they both present to the underside of the boot are different. A bit of trial and error needed, I'll report on that soon...

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  • 1 month later...

Been a while test fitting the brackets we made up and adjusting them. The next thing to do was to fit the aircon condenser to the Sierra radiator to form a sandwich. If I could get photos off my iphone at the moment I'd show you what that looks like! We basically just welded small brackets onto the top and bottom of the Sierra radiator on one side and onto the end tank for the other side. Today I'll test fit the sandwich, I think there will be a bit of adjusting to do, nothing too drastic. Once that's in I can get the lines made up. In the overall project of getting the car back on the road I'm almost up to taking the motor out for cambelt changes etc so I can sort out that end of the lines and think about the compressor mount. Does anyone out there have a pic of the standard aircon compressor mount position and bracket?

I have another question for you all in the meantime. My friend that's been doing all the aluminium welding suggested that we install a bleeder to the top of one of the tanks. This could have a small hose on it with a valve at the end, coming up in to the front bonnet area. I know it's hard to get all the air out of these systems, what do you think? with a nice grommet to hold it in position and a rag around the valve it would be quite easy to get all the air out of the radiator when filling, and after running it for a while easy to check if any air has accumulated in the radiator.

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  • 1 year later...

So it's been  a long time since an update on this.  There has been progress:






The radiator with the condenser sandwich and






fans fitted.  You can also see the bleeder hose in position on the radiator.  This will go into the under bonnet area, to a ball valve and back out through one of the drain holes near the headlight pods. 


I spent quite a long time sorting the mounts and fibreglass parts to make sure it all fits ok.  I'm not sure what to do about the gaps around the shroud; I was going to make one or try to find one with better fit but ended up using the old original one.  Any thoughts? 



So the next bit that has taken a while to do has been sorting the compressor mount. 

As we all know there is original fitment AC on these cars, so my starting point was to try for OEM brackets.  Through the excellent services of LotusBits I got hold of an original rear mount, which bolts on to the oil pump/distributor feed housing.  I was not able to get the spacer, but more on that later. 


It turned out that to go with the original bracket arrangement needs the water pump housing to be changed (among a number of other parts).  I didn't want to go this way, so I was going to have to make the front bracket. 


The original manual cambelt tensioner has two 6mm spacers between the snubber and the tensionser.  So this was the obvious place to start, replacing the spacers with the bracket. 


I made a number of templates/trials to refine the bracket




From left to right, starting with cardboard to get a rough idea, then onto 6mm MDF.  As you can see there the bracket got progressively smaller, ending with the minimal version here




I will have to make up a range of spacers to link to the bottom mount point (an M8 tapped hole in the base of the crankcase), and to space out to the compressor and alternator.  I'll make a spacer for the rear compressor bracket at the same time. 

While the engine has been out with the gearbox I needed somewhere to work on it (and give it a good clean) so I made a stand for it. It has fence post uprights that the engine mounts and gearbox mounts sit on. 






It's not easy to make out on this picture but my engine had only one V belt, serving the water pump, alternator and crank pulley.  Obviously this won't do for the aircon compressor too, so I got hold of a double V pulley from LotusBits when I got the rear bracket. 


The plan is for the first groove to run the water pump, and the second to do the compressor and alternator. 


So a test fit of the finished bracket.  You can see the original rear bracket in position. 






As you can see I've run brackets down from the original alternator mount to the aircon compressor bracket.  This will be the new alternator mount point.  It's very tight to the air cleaner box but OK. 


No chance to use the normal brace for tensioning the belt, space is too tight.  Instead I got hold of a belt tensioner from the same donor car as the compressor (a 2003 Ford Courier Ute), and changed the pulley to a flat instead of V type.  This will push on the back of the V belt for tension, and will also address my concern of belt wrap on the compressor. 


Tomorrow I'll get the spacers made at a friends place... a friend with a lathe, handy. 

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I have a good working aircon pump and all the brackets if anyone is interested, only removed it yesterday and it was working fine, also have a spare power steering pump.



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  • 2 months later...

Great timing John! 


So another update


Trial fitted the compressor and alternator






Should clear the water pump outlet ok. 


As I'm ending up with just two belts I was concerned about the belt wrap on the compressor, so I put in a belt tensioner.  This also means I don't have to worry about a traditional tensioner for the alternator. 




As you can see there's no cambelt tensioner in at the moment.  I decided to change the threaded spring tensioner to the hex head version for aircon cars.  I've just got a couple of spacers in there instead so I could mount the bracket for testing purposes. 




Here are the compressor fittings in the engine bay waiting for the re fit




Aircon hoses run across the subframe then in to the condenser




I found some high temperature foam to seal up the ducting.




The aircon hoses I had planned to run through the tunnel, and I think that there is enough space to do that but I was worried about fouling the gearchange. 


Instead I ran them alongside the backbone box frame.  One on each side, they ride up over the body/chassis mounts, then through convenient holes in the front and rear subframes. 


The front end is now all put together, including the new hoses to the radiator. 


The sierra radiator has the inlet/outlet the other way up to the orignal radiator.  It made sense to run the hoses in the original orientation at the front, and I'll cross them over at the engine end. 


It has taken a while digging through some radiator hose bins to find the correct angles.  As you can see in the pictures above I've used a small length of alloy pipe on the drivers side. 


A couple of weekends and the motor will go back in.






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Hi Simon..... :clap: ... Well thought out and nicely executed...


Curious why you did not install the a/c compressor, brackets,

belts, pulleys and tensioners off the later model Esprits. All Bolt 

on bits.. It could have saved a lot of time and hassle...You may

also be asking a lot of that one belt , it is not an area you want

to revisit when fitted into the body.!!!


Still great work and inspiration for those who like to do ''Changes''



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There are a few bits that are very hard to get hold of; the water pump housing and alternator brace from memory being particularly hard to find.  The future holds a different motor gearbox combo so this is a short term option, and has been put together (at the compressor end) for not much money... just sore knuckles etc.


Otherwise yes, that would have been an easier process. 



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  • 8 months later...

A big day yesterday.  The aircon was gassed and checked over fully; the only issue that needs attention now is the grub screw on the fan control knob came loose, always two forward one back with the esprit!  I'm really happy with the result so far, the vintage air unit is good providing plenty of cold air and good hot air too.  I'll take a load of pics on the weekend of the finished project. 

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So I thought I'd put up some pics of the works mostly finished... been a bit untidy this as I started threads for each bit I did rather than one project thread. 


Also please note that I have made changes from 'standard' and 'original'.  Feel free to let me know you wouldn't have done it like that...




One of the big projects was to fit the electric column from a Corsa.  This was done similarly to the one done by Hilly on his Audi conversion, but being almost 2 metres tall I chose the tilt adjustable column, giving a bit more leg room.  In this pic it's tilted up a bit. 




The power assistance gave me the ability to fit a small diameter wheel.  I also canted the column a bit away from the centerline, as I had issues changing gear, the space between the 'tunnel' and the wheel was very tight.  Much more comfortable now. 




Keen eyed observers will note the Elise seats too.  I also replaced the seatbelts as the buckle/sockets were too long being designed for the original seats.  It's quite neat now, I have lost the seatbelt light but I'm not too worried by that.


I currently don't have speed control going to the column, and have yet to drive much on the road (just been going up and down the driveway so far...) so I don't know how much 'feel' I will have lost.  A future mod is to add cruise control so the speed signal that provides may be useful. 






I went through changing pretty much all the bulbs with LED units.  The door warning lights are really bright as they are red LEDS so very little light is stopped by the red lens.  You can see the puddle lights I fitted to the bottoms of the doors too.  They are encased in resin, little 4 LED blocks. 






I fitted front and rear parking sensors.  The front sensors are on the now defunct fan switch on the dash (fan control is part of the aircon fitment below), the rear sensors are on the reverse light circuit as you'd expect.  Gives good control down to about 10 cm, will make manoeuvering much easier. 


For those that wonder the bumpers were colour coded when I bought the car, I don't hate them. 




I took the heater unit out of the car and replaced it with a vintage air heater/ac unit.  I have much more detail in the thread about fitting it, including fitting the condenser and compressor etc.  This shows the control panel, not too bad a unit.  I had to make smaller vents (came from a Ford Laser) to fit the control panel and a full height stereo head unit. 


It's a bit fiddly twiddling the knobs, but the unit works beautifully.  Plenty cold, servo control of vent direction, nice thermostatic AC control. 




It's possible I went overboard on the LEDs... Red for the heater controls, and blue tucked away into the door handles




The head unit is a Parrot Asteroid, a mechless unit with pretty much anything able to plug into it.  It also has a GPS transponder, seen here fitted in the acres of space availble after removing the giant fan unit. This meant I could blank off the original panel with this lightweight replacement.




The Parrot runs a cut down version of Android, with integrated hands free.  The little colour screen can show the maps etc.  There are steering wheel controls available, the Corsa column has the clockspring fitted so future fitting of extra controls is possible. 




I also fitted remote central locking, as well as the new leather interior.  I chose the colours, and I like them too.  The binnacle is covered in alcantara to limit glare. 


I modified the drivers door lock to fit the barrel from a Corsa so there's only one key... and since I have central locking I changed the passenger handle to one without a key, both sourced from a landrover supplier. 


As part of the job it's had a new cambelt, other drive belts, and a full stainless system from SJ.  That was quite reasonably priced but does need modification, it goes too close to one of the frame tubes and needed bending away.  I went without the resonator, hopefully it won't be too loud to get registration. 

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did you do a thread on the steering conversion? love the air con mod will be looking into doing mine for sure. Wish I had known about the sierra rad before putting mine back in. Still thats a job for another day!


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Yes there is a thread in here somewhere about the conversion.  I have to say it's great so far, nice easy pressure to turn the wheels and still good feel. 


The great news today is that I passed the first inspection OK, a couple of things to do (upper ball joint rubbers replacement and he picked the ancient rubber which I will change anyway) so I'm close to getting it on the road properly. 

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