420R (S3) Radiator design issue, regular failures???

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ScottR400D
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SLR is right, it shouldn't be possible to over tighten and clamp up the rubber bit. 

L7C
Blue7
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Well I think you are taking the best course of action by contacting and complaining to Caterham.  Personally, I don't like their fix and like other comments, I don't like the look of that radiator, which looks cheap and nasty, probably made in Shenzhen and fixings and outlet may not be in the correct positions.  That weld is a disgrace, even a first year apprentice would not produce something as ugly as that, which does not inspire confidence.

Given that you have now had two or three radiator failures, you would probably have a good case to take to the Small Claims Court because they have not been satisfactory quality or fit for purpose but you would need supporting written evidence from someone with expert opinion.  The trouble is that at the end of the day you still have to replace the radiator and all that seems to be available are more crap radiators / or crap brackets.  

IMO Caterham should supply you with a new radiator FOC plus a fix for the problem but I wouldn't hold my breath and the easiest answer at the end of the day is your own fix.  What about making a couple of new brackets or suggesting to CC that they supply modified brackets that would increase the radiator height by say 10mm.  I don't think the bobbin torque would be a problem, the only problem may be clearance with the nose cone.

CtrMint
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If you take a look at the first post, second image you'll see the bobbin is trapped between the ali bracket and hanger, so has no capacity to flex, and certainly wouldn't if I torqued it up so much that it held the radiator in position should I open up the ali mounts to increase the mounting height.

 

Caterham 420R S3 Lotus Toxic Green,  Caterham 620R S3 Exocet Red. Blog: https://www.caterham7diaries.com
CtrMint
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honestly, I just can't be arsed.  I've had the patience of a saint while 59K depreciates in the garage tied up in an unused 620R, now need to go through more cr@p.  It's just a joke, one which keeps my peers very much amused.

Caterham 420R S3 Lotus Toxic Green,  Caterham 620R S3 Exocet Red. Blog: https://www.caterham7diaries.com
SLR No.77
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Mark, regarding the bobbin, I've done some rough mods on your photo below, bare with me, I'm better with engines than I am with techie stuff!

Where I've drawn the red circle you absolutely must have some clearance, this must remain the case when the bobbin is tightened fully which it must be.  If there is not sufficient clearance then maybe add a suitable washer where I've drawn the blue circle?  If fitted correctly the bobbin should appear to be trapped between the ally radiator bracket and chassis hanger.

As far as the chassis bracket is concerned the 90 deg upward bend on the end is the same as has been in place for a lot of years, the small additional bracket is obviously for the fitment of this particular radiator.  The bracket placing upwards pressure and vibration on the hose or radiator entry pipe is likely to be the cause of a radiator failure.  It shouldn't be necessary but as already stated, removing a little material at the contact point might possibly solve the problem.

Stu.

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CtrMint
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Hi Stu,

There's no contact where you marked in red, i.e. the rear of the bolt head.  The contact occurs at the top of the bracket, it hits the inlet pipe on the rad.  There's also contact between the hose and top of the hanger.

Based on the number of people that have messaged me over Instagram, either we're all doing something wrong, or there is a real quality issue here.   Either the design or the rads. 

Caterham 420R S3 Lotus Toxic Green,  Caterham 620R S3 Exocet Red. Blog: https://www.caterham7diaries.com
TomB
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Wouldn’t a couple of minutes with a grinder and touch up paint on the bracket relieve any pressure on the inlet? 

ScottR400D
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I wouldn't bet on that being the problem. My money would be on a poorly made radiator from the start. A glance at the welding is a clue. 

Yes, it's a lousy piece of design and engineering but a decent radiator could withstand the bracket touching the hose, IMO. 

L7C
Geoff Brown
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Do we have something occurring of epic proportions that mirrors the TITAN fiasco ?

There may be the need to start a dedicated thread 'viability of the latest aluminium radiators post (insert date here)' then sit back & watch the sh1t hit the fan.........

But it is unlikely that CC will take a jot of notice unless 'politely' threatened by group litigation which I think those with carbon plated Titans should have done. But that is another story.

When the Sigma engined Seven was introduced there was a a big problem with the radiator plastic header & footers leaking/bursting. It took a lot to convince CC that there was indeed a problem to the point that a face to face meet between certain members of the MT at the time & CC finally got the message over.

That was when we had club technical liaison & I was it ! Sadly that post did not last very long as it was deemed to be too much of a hot potato.

ChrisC
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My only wish would be for CC to not treat road going 420 owners as second class citizens.  Race spec 420 owners get the significantly cheaper option to replace just the coolant radiator, but road spec requires oil and coolant radiator to be replaced at the same time.  The oil cooler is only held onto the coolant radiator with two bolts.