Homebrew Intercooler and Radiator re-builds - NOW WITH WORKING PICTURES!

[explosive-cabbage]

I had a little rant with my brother KruJoe this evening about the growing lack of resto/re-building/fabricating/creative threads on AS at the moment, especially with the growing numbers of keyboard warriors from Faceache.

Time to put things right.

205 TD radiators are like rocking horse shit.

You can get them brand new on eBay, though the cost is upwards of £200, and getting a specialist to recon one for you is no cheaper.



A little back story - I have had a fair few 205 TDs in my time, but when I was younger and stupider the radiator was the first thing that got damaged when you hit something hard, front on.
This was a frequent occurrence, especially when you live on a hill and are stupid enough to forget to put the handbrake on.



Many met their deaths.




Now I am older and more mechanically aware I know how to treat cars in a better manner. As the cars came and went I stripped parts and I have quite a haul of bits- along with half a dozen or so of these hard-to find radiators.

They are different from any other 205 radiators (or 306 or 405 ones) because they are so thick. The core is 56mm and the end tank has a take-off at a 45 degree angle - the extra cooling capacity is vital for hard-worked TD engines and especially tuned ones like I have.



My current radiator is a standard 205 diesel rad, similar to a GTi one and not really up to the job - so the question is, can I make one good radiator from 2 knackered ones?

The radiators I have are in various states of repair- most have core damage and good end tanks and some have damaged tanks and a good core.



This particular one had had light damage low down in the core and being 18 and daft I figured I could solve the problem by crimping the coolant tube with washers and a M6 bolt.



In all honesty I cannot remember whether this worked or not, though I suspect probably not.

So this brings me on to the construction of the radiators. They have a copper and steel core, with plastic end tanks crimped on, likely with a sealant or a gasket in between.





I figure that if I could properly un-crimp a good end tank from a damaged radiator I could transfer it to a good core and seal it up again. I have been thinking about this for a long time and I believe it can work.

This brings me onto the matter of intercoolers - by design very similar to radiators, and also a part of which I have loads of kicking around.



My engine, with intercooler on top.




I am burning a whole lot of veg in the 205 TD at the moment - partly because I thrash the hell out of it and partly because I turned the Bosch pump up more or less to the max. The acceleration is epic, as is the clouds of black smoke I am coaling.

This picture is of the road outside my house after caning it and coming on boost. The grey streak in the middle of the picture is a line of soot from my exhaust.



The problem is this - I am not getting enough cooling of the air before it goes into the engine, causing there to be a lower density of air in the cylinder, and therefore unburnt fuel being thrown out the back.

The problem gets much worse as the engine gets hotter.

I could easily rectify the problem by turning the fueling down, but that is no fun - what I can do instead is mount my intercooler in front of the engine in the cool air stream to get better cooling of the air between the turbo and the engine -
producing more power and better economy also.

Intercoolers have their drawbacks. They can be expensive new, difficult to shoe-horn in, and often too large for the application. A larger intercooler means more air in the intake system has to be compressed before effective boost is reached - meaning that the car is SLOWER because turbo lag slows the response of the engine.

This is just ridiculous for a 2 ish litre car like a tuned 205.



The 306 1.9 TD engine in my 205 was developed with an intercooler that was an appropriate size for the engine - even thought is wasn't mounted in its most effective position (as it was on top of the engine rather than infront)

I wish to move my standard intercooler in front of the radiator to get better cooling - and this means modifying it slightly.

See where I am going with this?

This is the intercooler in question, there is an up/down port at the top of the picture and a tubular port at the side.



The problem with mounting this intercooler at the front is that we would be using pipes to feed and return from it - so we need two tubular ports to put the pipes onto.

Skip forward a couple hours - this is what I am aiming for:



I have plenty of these intercoolers kicking around, so I have nothing to loose. As far as I am aware this has never been done to a 306 intercooler before!

So here is the build.

The intercoolers are similar design to the radiators- plastic end tanks and aluminiumn core, with a gasket in between.

Firstly I found a damaged intercooler with a good tubular tank - and started removing the crimped tabs with the grinder - every other one at a time to keep heat down and stop it melting the plastic.



Once the thin aluminium tabs had been weakend they could be prized up with a screwdriver.



Not long before I had the whole lot prized up, and then it was just a case of pulling the plastic tank off!



The rubber gasket was found to be in good nick.


The intercooler was chocked full of oil and debris that looked like it had come from a de-laminated pipe!





So at this point I had a scrap core, having removed a usable tank from it with the tubular fittings I needed.

What I needed now was to remove and get rid of the plastic tank from the other side of a good intercooler, keeping the delicate aluminium tabs in good condition to in order to crimp my tubular tank onto it.

Removing the plastic tank, using the band-saw to cut flush with the tabs I wanted to keep.





So now I needed to remove all traces of the old plastic tank and at the same time keep the tabs in good nick. Out with the grinder - this time with an abrasive stone disk to melt and throw the plastic out of the way.



This is what I was left with



Now just a case of lifting up the tabs with the pliers to release the scrap plastic- gently gently!



Out she comes! I was well chuffed!



Nice and clean, and not one damaged tab!



Trial fitting of the new tank



Down to the pressure-washer with a bucket of washing powder mixed with water and the core was blasted clean - inside and out.





Gasket back in, and tank going on...



Held tight together in a Black and Decker workmate



Whilst I bent the tabs over gently with a small hammer and chisel



And crimped them tight with mole grips.



All finished!



I am well chuffed with that!

The question now is, is this possible with radiators?

What sealant would you use to seal the radiator back up if there is no gasket?

Sorry if this has been a bit in-depth, I hope you have enjoyed it and I hope this knowledge can help someone in the future.

All the best!

Will

[twosmoke300]

Good work will . Hope it works ok with no leaks . I expect you know this already but a push bike or c90 tube cut in half is good for testing inter coolers for leaks . Then some soapy water .

[Mr_Bo11ox]

My favourite radiator-repairing man in Stoke has swapped end tanks for me on radiators a few times so its defo possible. Great work will!!!! Know what you mean about the chit chat/ action ratio on here.

[Des]

I've repaired a radiator where the ally crimped bit for the end tank has corroded and crumbled away by sticking it back in with Sikaflex / Tiger Seal PU type snot and a brace of cable ties threaded through the core and round the tank.

[mat_the_cat]

I want to see more action too! But I'm guilty for not doing much on cars at the moment...hopefully that will change soon.

 

I'd check out the temperature rating on the various types of Sikaflex and see if there is one suitable for long term use; failing that silicone flue sealant will be fine at radiator temperatures - I've used it on exhausts before.

 

Regarding the intercooler - did a bonnet scoop cross your mind? Personally I wouldn't want one, but it might have been an easier option. Although where's the fun in that!?

[garethj]

I'm rubbish at doing multiple quotes so hopefully this will make sense.  I worked as a design engineer for a radiator manufacturer for several years, I think I can help.  Don't worry, you're definitely on the right track.

 

The core is 56mm

If you're searching around for a replacement core, it doesn't really matter if this is made of 3 rows of 18mm tubes or 2 rows of 27mm tubes (or whatever), the thickness is the important bit.  If you need more cooling capacity it's generally better to go for a bigger frontal area of radiator and keep the thickness the same, only for a thicker (more than 56mm) rad if you run out of space.  However the radiator fan might struggle and look carefully at the folded metal fins, some have a more open design than others which help airflow when the rad is really thick.

 

can I make one good radiator from 2 knackered ones?

Yes.  Easy peasy.

 

This particular one had had light damage low down in the core and being 18 and daft I figured I could solve the problem by crimping the coolant tube with washers and a M6 bolt.

The idea is fine but the application is a bit, errr, crude.  If you've got the odd leaking tube you can block that tube off with chemical metal at either end once you've got the tanks off.

 

So this brings me on to the construction of the radiators. They have a copper and steel core, with plastic end tanks crimped on, likely with a sealant or a gasket in between.

I don't think that's right; they're either copper tubes (coated with solder) and a folded brass fin, or aluminium tube & fin.  Steel is very unusual as it's a rubbish conductor of heat and very heavy.  Old school oil coolers sometimes, but not radiators.  You're right for the rest, the radiator tanks are 30% glass filled nylon (PA is the plastic's chemical name, Nylon is the trade name when it was made by GE plastics)

 

I figure that if I could properly un-crimp a good end tank from a damaged radiator I could transfer it to a good core and seal it up again. I have been thinking about this for a long time and I believe it can work.

You are bang on the money.

 

what I can do instead is mount my intercooler in front of the engine in the cool air stream to get better cooling of the air between the turbo and the engine - producing more power and better economy also.

Same as a radiator; avoid thicker intercoolers because they're harder to push the air through.  The preference for cooling should always be big frontal area and only thicker when you hit the inside of the bonnet.

 

Firstly I found a damaged intercooler with a good tubular tank - and started removing the crimped tabs with the grinder - every other one at a time to keep heat down and stop it melting the plastic.

This is the only bad bit I can find, you need all of those tabs to be full strength to cope with the pressures inside.  You remove a plastic tank by using a screwdriver to lever off every tab, one at a time.  If you can't get the tabs open, have a look at some devious method with a sharpened screwdriver or hammered to a rightangle or something.  When rads were repaired, it was done with the technician's favourite screwdriver.

 

Removing the plastic tank, using the band-saw to cut flush with the tabs I wanted to keep.

I think I see what's going on now, you didn't necessarily need to keep the old core from above?  But if you don't grind the tabs off you've got more of a useable core that you can repair individual tubes like I said earlier.  Keep all the spares you can, there shouldn't be any need to destroy anything.

 

Down to the pressure-washer with a bucket of washing powder mixed with water and the core was blasted clean - inside and out.

ORSUM!

 

Whilst I bent the tabs over gently with a small hammer and chisel

I think these are just done with a pair of particular pliers, they looked like the ones that the Bash Street Kids' dentist might use, but with slightly blunted ends.

 

And crimped them tight with mole grips.

Lovely

 

The question now is, is this possible with radiators?

Hell yeah!

 

What sealant would you use to seal the radiator back up if there is no gasket?

Get a sheet of gasket material of the right thickness, then trace around the old gasket and cut out a new one.  It looks like a sort of squeezable rubber and cork but goodness knows what it was made from.  Worth a google search to try and find the material, I'm not sure if neoprene will take the temperature and silicone won't take the oil contamination unless it's a special oil resistant grade.  But cutting it from a flat sheet of the right thickness is where it's at.

[skattrd]

Great work Will - if you do decide to stick with the top mount and want a bonnet scoop lmk, I may have a spare one from an Avanzato somewhere.

[explosive-cabbage]

Thanks for the encouragement guys!

 

I definitely don't want to go for a bonnet scoop - I would like to keep the car looking standard. This means not chopping the bumpers and valances up for an intercooler either, so it will have to be slim enough to fit between the bumper and radiator. I may have to get some slim line fans and mount them behind the radiator instead to give a bit more room.

 

I understand what was said about frontal area apposed to depth - Joe came up with a novel idea of doubling up these intercoolers by plastic welding them together - more to follow. Does this type of plastic take to the soldering method of plastic fixation? I think it is polypropylene or something similar.

 

I need to get the cooling system improved for summer - and therefore my next adventure will be playing with radiators themselves.

 

More to follow on this thread!

[sierraman]

I like the idea of reusing stuff, but with a radiator my cack handed work usually breaks something.

 

I did manage to salvage some bits from my knackered trolley jack, made a pair of drifts from the axles, made the steel brace into a handle for a box I made for a drill, used the various bits of tin to patch stuff up. I get a lot of enjoyment doing this sort of stuff.

[garethj]

I understand what was said about frontal area apposed to depth - Joe came up with a novel idea of doubling up these intercoolers by plastic welding them together - more to follow. Does this type of plastic take to the soldering method of plastic fixation? I think it is polypropylene or something similar.

The plastic always used to be 30% glass filled nylon, look for the recycle logo with PA inside the triangle.  Polypropylene is cheaper but I'd have thought it would struggle with the temperature, but if there's a recycle logo with PP in it, it is polypropylene.

 

Dunno about plastic welding, but armed with the exact material you can always enquire to the welding manufacturers.  Just be aware of the weight of a combined pair of intercoolers, I'd look at metal brackets to take the stress of all that weight.

[explosive-cabbage]

The plastic always used to be 30% glass filled nylon, look for the recycle logo with PA inside the triangle.  Polypropylene is cheaper but I'd have thought it would struggle with the temperature, but if there's a recycle logo with PP in it, it is polypropylene.

 

Dunno about plastic welding, but armed with the exact material you can always enquire to the welding manufacturers.  Just be aware of the weight of a combined pair of intercoolers, I'd look at metal brackets to take the stress of all that weight.

 

There did not seem to be any glass flying around when I was cutting it on the bandsaw and with the grinder, it just felt like ordinary plastic to me. I checked for codes PA and PP codes already but couldn't find anything. 

 

I have plastic welded before on a small scale and if you find the correct filler material it shouldn't be a problem I don't think. I have plenty of the tank left that I chopped up to could use that as 'solder' and it would be an exact match

[garethj]

The glass strands are very short in injection moulded plastic like that, it's not like fibreglass at all.  You're looking for a logo like this, with either PA or PP just below it or inside the triangle.  This one is for TPU but it's the best that google images could come up with...

In the moulding it sometimes looks like there's a silvery appearance to the plastic, especially close to the injection feed gate.

[fordperv]

My favourite radiator-repairing man in Stoke has swapped end tanks for me on radiators a few times so its defo possible. Great work will!!!! Know what you mean about the chit chat/ action ratio on here.

Pete at pk?

[Tayne]

[explosive-cabbage]

Stinking hot day yesterday wasn't it?

 

With cooling man and machine at the forefront of my mind I thought I would produce some more pictures for your delectation.

 

This a rare-as rocking horse shit 205 1.7TD radiator I picked up from a scrapyard recently for £10. It is in bad condition, with one of the coolant 'bars' on the front having been damaged then soldered up.

 

In this picture I am pressure testing by filling it with water and using a bicycle inner tube and a compressor to provide pressure.

 

 

From this picture you can see a small streak of water pissing from the centre of the core. This can be fixed reasonably easily using solder.

 

Firstly I cleaned up the area with a wire wheel. I wasn't bothered about damaging the vanes between the coolant bars too much as it was a pretty battered radiator anyway. The important thing was to get the damaged bar good and clean so solder would stick.

 

Next I pre-heated the area with a camping stove (I had run out of gas for the blowtorch!) And this worked very well, luckily the damage was far enough away from the plastic end tanks to risk melting them with the stove.

 

 

Whilst I had the radiator steaming itself dry and heating up the core to accept solder, I prepared the soldering iron and flux, and as soon as It got hot hot hot I flipped the radiator over and dabbed on the solder. It worked brilliantly!

 

 

 

I pressure tested my work to 35ish PSI (well above operating pressure) with my home-brew bicycle tube technique showed no other leaks so it was a successful job!

 

The next job I spent the rest of the afternoon doing was building 1 radiator from 2 damaged ones... More to follow!

 

[explosive-cabbage]

So as you all know I now from the post above I have a good radiator from a 205 TD, though not one I would bet my life on as it is pretty battered.

 

I also have 2 more radiators to make a good one from, both similar but made by different companies so slight differences in how the end tanks are held on. Here they are. The one on the right has a damaged core and the one on the left has a damaged end tank, the union broke off it.

 

 

The plan is to take the end tank off the radiator on the right and put it onto the radiator on the left. First I started by removing both end tanks -

 

 

 

I noticed that the end tanks and the design by which they were held on was slightly different, this one, the good end tank, had plastic 'crenelations' which held into holes pressed into the metal flange on the core -

 

 

And this one, from the radiator with the good core, had a metal strip with tabs to crimp the end tank and the core together -

 

 

The problem was I had to remove the plastic crenelations so that the metal strip with the tabs in the picture above could be used to hold the end tanks on.

 

Here are the 2 end tanks together -

 

 

And here it is after 10 mins on the bench grinder....

The top one is the good replacement end tank without the broken union.

 

 

I then noticed that the replacement end tank (on the right) had a deeper lip and therefore the metal strip with the tabs would not reach over the lip...

 

 

Out with the power tools!

 

 

After an hour of sanding and flattening down with sandpaper and a wooden block I had a shallower lip:

 

 

Ready to go back together

 

 

The metal plates at the top and bottom of the core are really bad water traps, and one was damaged so I replaced it and sprayed them both with underseal.

 

 

 

 

 

I used ratchet straps to hold the whole lot together and crimped the tabs on the top and bottom of the core onto crenelations I had left to accept them.

 

 

 

To prevent rust I sprayed up the metal strips with the tabs (top) and also the 6 metal strips used to hold the top and bottom plates I had just replaced together.

 

 

Replacing the strips to hold the top and bottom metal plates together.

 

 

Metals strip with tabs ready to go back on.

 

 

I used the ratchet strap to hold the end tank in place under tension, whilst I used mole grips to crimp the tabs down; in a similar fashion I had used to on the intercooler previously.

 

Unfortunately I seem to be missing a picture of this stage, sorry.

 

I then stood the radiator up in the Black & Decker Workmate, holding the metal strips, whilst I tightened the tabs down further with a light hammer and a blunt screwdriver.

 

 

 

Job done!

 

 

Or so I thought.

 

Under my home-brew bicycle tube pressure test the end tank leaked from one end, possibly from an area where I went hard with the sander. I had to seal it up, but the only sealant we had was some glue/sealant stuff and I wasn't convinced.

 

 

So this morning I went to town and bought myself a small tube of white silicone sealant which stated that it could be used for ''industrial uses and in gaskets' - Perfect.

 

This afternoon I pulled the radiator apart again in order to apply the sealant - it was a messy job because of all the waterproofing underseal I had used!

 

 

 

I cleaned the area up well with petrol, washed it down with warm water and detergent, then blew it over for 10 mins with a hot hair dryer until perfectly dry.

 

Applying the sealant, used in conjunction with the original rubber O-ring seal.

 

 

Strapping it back together.

 

 

After leaving it to cure for half an hour I tested it.

 

 

 

Check out this reading - and no leaks whatsover!

 

 

That's around 30 PSI, much higher than operating pressure! I am well impressed.

 

Job jobbed!

 

 

Till next time, Will

[Christine]

This rad i bought as " biggest rad you've got that you'll never find a buyer for , as its obsolete.. there

for CHEAP !" I was told it was a "Peugeot dodah da ", but i wanted it for a solar hot water project ,so didn't listen .. Is it the £200 one ?? core is 21" x12"

 

 

 

 

 

[explosive-cabbage]

That radiator looks like a 205 GTI / 205 1.7 non-turbo deisel one, like the one I have fitted currently but am looking to replace. Value is about £30 on eBay.

[garethj]

IMG_1748.jpg

 

I worked at Serck Marston for a few years designing radiators, pretty sure that's not one of mine but you can see the blanked off ports around the header tank so they could get more radiator variants from one mould tool using inserts.

[the judge]

So,if its surface area and not thickness that is required for efficient cooling,what about air con rads? Fast and efficient cooling is what they are for shirley?

[Mr_Bo11ox]

'Fast and efficient cooling' is what all heat exchangers are about innit. cooling of what though, how much of it, in what environment, and to what extent.

[garethj]

Yes, but don't call me Shirley.

 

What was the question?

[explosive-cabbage]

I have just sorted the pictures not working in previous posts, so I'll bump it for those interested!

 

[forddeliveryboy]

Pix of rad repair not working here...

 

Your car probably needs something like autospeed has touched on, to keep the power up on hotter days.. http://www.autospeed.com/cms/article.html?&title=Worlds-Best-Intercooler-Water-Spray-Part-1&A=113191

 

Have you thought about water injection? - ie into the inlet air itself as well as over an intercooler? Evaporation of the water cools the charge well, plus it keeps the insides of your engine proper-clean. People have de-gummed rings having driven like grannies on veg, it's very effective.

[KruJoe]

That's an exciting article FDB!

The pump they mention can be had off ebay here for £12.75 delivered, search "Ulka Ex5 pump", not the code they give.

They say that once it's up and running, with about a five litre water tank "refills should only be needed every two or three tanks of fuel".

Very impressive.

 

The pics in posts 15 and 16 are now not working again Will. That photo hosting system you use is proper pants.

[M'coli]

None of the images work for me, even when I cut the link out manually and pasted it into a browser window.  It displayed this message:

 

The image “https://41u0ta-sn3302.files.1drv.com/y3pjDQ-_mE242SvWuPk79IC0VgTyCukyfZ9aGSl78s0jBsUglCHJYVpzPilw1VwfBX3gQwuIFWMmZWe_w7WN3BLy12sKfi_1sttdOGvQxTE8L7L2lhd6TO8sGYH1gR8vghqrpcxAVfbuPTjUqrwkIeZGY0as0aJun7tJnp-I_PSZeo/WP_004651.jpg?psid=1â€Âcannot be displayed, because it contains errors.

 

Excellent stuff though, I like the link to the pump ad stuff as that might also give more cooling capacity for other vehicles too...

[forddeliveryboy]

Will, if you get greedy for even more power, add methanol to the water if you start doing what the WW2 Spitfire engineers did. Works well.

 

Why not add some lpg to your intake air, while you're at it? The more you use, the colder it gets -  adiabatic expansion and all that - so the denser the charge. Virtuous circles. A little valve on the accelerator pedal should do the job nicely.

[Richard]

There, I fixed it.

 

 

Glass clamp from a Polo window regulator.

[KruJoe]

Chompy, have you ever tried emptying a bag of ice onto your engine-top intercooler and going for a spin? Just for lols, give it a go... I've heard the results are entertaining

[stuboy]

Chompy, have you ever tried emptying a bag of ice onto your engine-top intercooler and going for a spin? Just for lols, give it a go... I've heard the results are entertaining

or rig up nos to spray on the cooler