Smithy77 Posted July 15, 2015 Share Posted July 15, 2015 I am picking up my new Caterham on Saturday (so I'm like a kid at Christmas right now!! 3 more sleeps!) but I have one job that I know will need doing fairly soon - a new radiator.The engine is an EU2 1.8 VVC which has had DVA work including new cams (VVC blanked off), Jenveys and emerald running at 180-185bhp. It is currently fitted with an R500 triple core all aluminium radiator (with what looks like the standard 9" fan) but it has been leaking both sides where the core joins the ali tanks. Looked after by Tech7, Andy Belcher added Radseal a month or so ago and it appears to have done a good job at sealing the leaks. I guess it is recommended to replace the radiator ASAP?I've done a wee bit of reading of the archives and I want to avoid the standard Caterham rads with plastic tanks as I hear these are more prone to leaking.The other alternative I read about was one from Radtech, who offer an option of a larger 11" fan upgrade - should I opt for the 11" fan or would I be OK re-using the current 9" fan?Radtech quoted me £336 delivered for new rad with 11" fan fitted, or £270 without fan.Any other (possibly cheaper) options out there that I've missed?Cheers Link to comment Share on other sites More sharing options...
Support Team Shaun_E Posted July 15, 2015 Support Team Share Posted July 15, 2015 I use the standard 9" fan on my 260bhp Duratec so you should be fine with it. I have a Radtec radiator. Link to comment Share on other sites More sharing options...
Area Representative Paul Richards Posted July 15, 2015 Area Representative Share Posted July 15, 2015 My engine is a similar spec to yours and I run a Radtec with standard fan. Link to comment Share on other sites More sharing options...
Smithy77 Posted July 15, 2015 Author Share Posted July 15, 2015 So the standard fan keeps everything cool anough and steady enough say in traffic on a hot day? Link to comment Share on other sites More sharing options...
revilla Posted July 15, 2015 Share Posted July 15, 2015 I would have thought your tuned engine and a standard engine produce about the same amount of heat when ticking over at idle in traffic and a standard radiator and fan should work as well on that engine as any other. Link to comment Share on other sites More sharing options...
Mankee Posted July 15, 2015 Share Posted July 15, 2015 CycleSi has a rad from a company in Nottingham (I think). You can see their rads on eBay and possibly their website. Here's his original thread:http://www.lotus7.club/forum/techtalk/radiator-availability-or-lack-itI'm about to send a damaged triple-pass rad from another club member to Allisport for them to take a look at it and possibly make an off-the-shelf rad for Caterhams:http://www.allisport.com/Finally, if you are after a Caterham triple-pass rad, a radiator company in Ipswich can actually supply/did supply that exact rad but at almost £100 off. I've not heard from them since I popped in to see them a few weeks back actually, so might give them a prod and see what availability is like. Link to comment Share on other sites More sharing options...
Smithy77 Posted July 15, 2015 Author Share Posted July 15, 2015 Shaun/Paul/Andrew - thanks for the advice. Looks like I'll stick with the standard fan.Mankee - cheers for your suggestions. Just dropped CycleSi a BM to see how he was getting on with the Coolex radiator. Assuming they perform as well as the Radtech item, it represents a decent saving of £30. I've also emailed Allisport to enquire about a Caterham radiator. What is this company in Ipswich called? Will be interested to hear the outcome of any prodding from yourself. Link to comment Share on other sites More sharing options...
Mankee Posted July 15, 2015 Share Posted July 15, 2015 Allisport will say something like they don't make any off-the-shelf Caterham rads but they've done modified ones. They are waiting on me to send them some rads to use as patterns. I just need to get my finger out and get them couriered!The company in Ipswich is a nice family-run business called Sheldrake and Wells:http://www.sheldrakeandwells.co.uk/If you do decide to get in touch with them, pick up the phone rather than email. He'll remember me asking about the Caterham triple-pass rads. I'm just not sure how far he has gotten with his investigations when a local club member bought a new rad from them in 2014. Link to comment Share on other sites More sharing options...
Area Representative Golf Juliet Tango Posted July 15, 2015 Area Representative Share Posted July 15, 2015 I put a high capacity 11" fan on the 21; it moves at least twice as much air as the standard item. My reasoning is this:- in cool weather the cooling is fine, when it is hot and the car stationary in traffic, the temperature rises rapidly (and alarmingly) and that is when you need the best possible cooling. Nothing is lost by this, you will not get too cool. Expenditure - small. Conversion - easy. Peace of mind - wonderful. Link to comment Share on other sites More sharing options...
Smithy77 Posted July 16, 2015 Author Share Posted July 16, 2015 Look like the Coolex rad is a front runner at the moment, and I will stick with the standard size fan I think. I will give Sheldrake and Wells a call at lunch to see what they can offer before ordering.Couple more questions:1) I can get it painted black for an additional £15 - is this worth doing from a technical/longevity point of view? Or is it just comsmetic?2) Am I right in thinking that generally it is one radiator/size fits all k-series models? Looking at the caterham parts website they only list two rads under Rover - a standard rad and a tripple core rad. At what point is a triple core rad necessary? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted July 16, 2015 Member Share Posted July 16, 2015 What's the finish if it isn't painted black?Radiation loss will be greater if it's black, but I'd guess the contribution that makes to total heat loss is trivial.Jonathan Link to comment Share on other sites More sharing options...
Smithy77 Posted July 16, 2015 Author Share Posted July 16, 2015 I called Sheldrake and Wells and it sounded like they hadn't got very far. They couldn't help without me first sending my radiator to them as a reference.Also just spoken to Andy Belcher and he advised that so long as the rad remains sealed, there should be no reason to change it. So I might just keep a close eye on it and replace as and when required. Saves a few pennies for now. Link to comment Share on other sites More sharing options...
Smithy77 Posted July 20, 2015 Author Share Posted July 20, 2015 So I've had the chance to do a couple hundred miles over the weekend with a good mix of driving in different temps and made some observations:1) Driving hard or at motorway speeds the temps look fine and settles at about 82c.2) Driving at night or cooler ambient temps (this was about 15c ambient) the temps really struggle to get above 80c and will actually hover around 70c3) As soon as driving at low rpm and slow speeds, say <40mph, the temps very quickly start to rise. After about 30sec being stationery the temp is up to 90c, fan kicks in around 92c and the temp will stabilise around 92-94c.I this a case of the triple pass rad being over specified for spec/use of engine, which struggles to get the flow of coolant at low rpm? Or could something be up with the thermostat? Not sure what stat is fitted but was told it had the drilled hole mod done. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted July 20, 2015 Member Share Posted July 20, 2015 Sounds as if the radiator is up to the job.What's the thermostat nominal rating?My 1800 K won't get warm on motorways on non-hot days. How many of use or should use blanking? Cardboard... or any interest in titanium?Jonathan Link to comment Share on other sites More sharing options...
Smithy77 Posted July 20, 2015 Author Share Posted July 20, 2015 I did try running with 3" blanking down each side of the rad yesterday...1) It still seemed just as effective at cooling at higher speeds/rpm.2) The temp seemed better at night at 80-82, but was a good 5c warmer ambient so not a fair comparison.3) Obviously at lower speed it had a tendency to heat up even quicker, and took a little longer to stabilise at 80-85 once moving again. While stationery there was obviously no effect to temps from the blanking.Found an interesting quote from SELOC (thanks Revilla!): The triple pass radiators are only intended for motorsports and are not recommended for road use. The reason being there is not enough coolant flow at idle (sitting in traffic) to force the coolant through three passes of the radiator. Road users who have fitted triple-pass radiators have resulted in increased engine temps. This advice holds for heavy trackday heros that drive their cars to/from circuit; the car is still liable to be stationary in traffic. Sounds like just what I'm experienceing to be honest Link to comment Share on other sites More sharing options...
revilla Posted July 20, 2015 Share Posted July 20, 2015 My thoughts, which you already know but I'll put down here for discussion; I agree with Jonathan that the radiator is at least up to the job, but it heats up rapdily when stationary, which suggests that the water pump isn't able to maintain a good flow rate of coolant at idle.For reference my VVC runs at just over 80 whatever I do with it, whatever the weather, fast blatting or idling. I know a lot of people find their temperatures rising alarmingly when stuck in traffic but for a road car I don't see why this should be accepted as normal.Quoting from SELOC (http://wiki.seloc.org/a/Radiator): "The triple pass radiators are only intended for motorsports and are not recommended for road use. The reason being there is not enough coolant flow at idle (sitting in traffic) to force the coolant through three passes of the radiator. Road users who have fitted triple-pass radiators have resulted in increased engine temps. This advice holds for heavy trackday heros that drive their cars to/from circuit; the car is still liable to be stationary in traffic."I think your radiator is fine for getting rid of the huge amounts of heat produced hanging the car off the rev limiter for mile after mile on track but I don't think it's right for road use and I just don't think the water pump is shifting enough water at idle when having to pass it through the resistance of the radiator three times. So you're left with a car that is happy being thrashed, overcools at speed on the road and overheats in traffic.Give how much the K Series likes nice steady stable temperatures I'd swap it out for a nice standard road-oriented radiator and I bet you find it's much happier. I don't see ahy reason why it shouldn't be like mine. Link to comment Share on other sites More sharing options...
revilla Posted July 20, 2015 Share Posted July 20, 2015 Haha well I did say you knew my thought already! Link to comment Share on other sites More sharing options...
Mankee Posted July 20, 2015 Share Posted July 20, 2015 Smiffy7, I reckon you and I need to swap rads, as I've got a road-oriented rad on my track-only car and I don't think it's man enough for the pasty-smashing I dish out on it! I've borrowed a triple-pass rad from another club member (thanks Gerry) and it's confirmed that I should have stuck with a triple-pass jobby. Link to comment Share on other sites More sharing options...
Smithy77 Posted July 20, 2015 Author Share Posted July 20, 2015 Mankee, was that a serious proposal or were you just "thinking out loud"? Andrew, thanks for adding your insight. I just wanted to see if there was anyone else who's had the same problem with similar set-up, if only to confirm our original thoughts. If/when I order a new rad from Coolex I was going to ask if they can fit a new rad thermo switch fitted for peice of mind. Can anyone confirm the spec/rating of this switch please? Link to comment Share on other sites More sharing options...
revilla Posted July 20, 2015 Share Posted July 20, 2015 Manufacturer: Bosch Typical Application: VW & Others Standard Part Number: 823-959-481F Other Part Numbers: 823-959-481D (77°C-82°C) 823-959-481E (70°C-75°C) 823-959-481F (87°C-92°C) 823-959-481A (87°C-92°C) Link to comment Share on other sites More sharing options...
Mankee Posted July 20, 2015 Share Posted July 20, 2015 Serious proposal! I was about to tape up the box tomorrow to send it to Allisport to use as a pattern, but if you want me to send it over to you to try out, then you are most welcome. And if it suits your needs and you decide to keep it, I do not want any £££ for it, as another kind club member helped me out with it last year. In my case, I should not have compromised cooling and coolant capacity in order to save a kg or two! Link to comment Share on other sites More sharing options...
Smithy77 Posted July 20, 2015 Author Share Posted July 20, 2015 Mankee, YHM! Andrew, Thanks for the part numbers. Is 87-92 the one to go for then? Link to comment Share on other sites More sharing options...
revilla Posted July 20, 2015 Share Posted July 20, 2015 I think that's the one that people usually go for. With an 82°C stat. Link to comment Share on other sites More sharing options...
Smithy77 Posted July 20, 2015 Author Share Posted July 20, 2015 All noted! The POBC shine through once again Thanks all Link to comment Share on other sites More sharing options...
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