Catch Can Questions

[CtrMint]

A quick update, I'm posting to seek continued advice, mainly due to lack of confidence in CC.
Numerous emails have been exchanged with CC over the matter.

CC have suggested that a number of actions may need to happen for the radiator fitment issue to be resolved.  CC do maintain they need to see the car at PBS to determine which combination needs to be used for final fitment.  I've also explained to CC that I need to get the car as close to perfection prior to PBS so that I can minimize it's time in the UK, given the complexities of using a UK IVA from the IOM.  This continues to be a sticking point and challenge between us.

At present CC suggested a combination of actions may be required at PBS;
1) Modifying the mounting tabs on the chassis.
2) Fitting a new nose cone, although this now raises concerns over body fitment.
3) Modifying the radiator.

I have to say the suggestion of modifying my chassis was not met well. 

I've continued to try and get the nose on, and after significant persuasion did manage it, however it is clearly against the radiator, I've yet to remove it again.  I took the following picture and sent to CC, in response CC accept the fitment is wrong, and it should not be touching the radiator in the manner shown.  

see top left of radiator, same on the right too.  You can just about get you hand down and feel the contact, but the backlight helps shown the contact area.

The last communication I received was an offer of sending an alternate race radiator which has been tested fitted to another car.  I've requested they do that, but wasn't quick enough before the Xmas break.  CC seem less inclined to allow me to swap back to the old design once I requested it.

With regards a new nose, CC stated the following;
"However, the nose is matched to the chassis and bonnet, the latter’s position also being relative to the scuttle which is turn is dependent on its shape (hand-built – they vary) and relation to the upper dash tube."

Now you'll have to excuse my ignorance here, but does that mean a replacement nose will be a nightmare for the rest of the body parts even though it fits the radiator?  I thought the paint was the biggest concern with a replacement nose.

On the plus side, I missed a call from Mr McDonald, he left a VM, he's due to call me back on the 2nd Jan.

[John Vine]

CC accept the fitment is wrong, and it should not be touching the radiator in the manner shown.  

Well, that’s something (and they’re right, of course).  I’m assuming that the race nosecone has slightly different (that is, larger) internal dimensions and would fit.  Have CC ever confirmed this?

CC do maintain they need to see the car at PBS to determine which combination needs to be used for final fitment

Given that you’re in the IoM and are planning a mainland IVA test, that’s not a very helpful suggestion.  I don’t really understand their stance given that they could resolve the issue by either (a) sending you a race nosecone, or (b) exchanging your rad for the older style.

(Btw, is “PBS” CC’s new term for what used to be called PBC – post-build check?)

Modifying the mounting tabs on the chassis.

It depends what they have in mind, but my take would be to refuse this entirely.  It amounts to bodging the chassis to accommodate ill-fitting parts.  That's the sort of thing Ford Special builders did in the '60s!

Fitting a new nose cone, although this now raises concerns over body fitment

That’s the best option if you’re to keep the race rad.  IMO CC’s concerns over “fitment” are simply a smokescreen.  I suspect they are simply reluctant to consider offering you a replacement race (double-aperture) nosecone due to the extra costs involved: painting to match exactly, shipping etc. I’m sure we all have a nosecone that doesn’t really fit the bonnet very well, and a bonnet that doesn’t really fit the scuttle very well.  That’s the nature of the car.  After all, nobody expects CC to match the shut lines of a Mercedes*.

Modifying the radiator.

What do they mean exactly?  Altering the mounts to improve fit, perhaps?  From what you’ve said, the rad is a poor fit at the top on both sides, so I doubt there’s much scope for altering the mounts (unless, of course, they propose to set the rad further back in the chassis?).  And I can’t believe they’re proposing to reshape the actual metalwork, as you’d have the same problem later on should you need to replace the rad.

an offer of sending an alternate race radiator which has been tested fitted to another car

That could be the best solution rad-wise.  But what alternative race rad do they have in mind?  The 620 rad won’t fit as the inlet and outlet spigots are different.  Is there another 420 race rad we don’t know about?  I would ask CC to send you a photo similar to yours to demonstrate that this alternative rad does indeed fit the standard nosecone.  And if they’re willing to send you a different race rad, why not send you an older-style one instead?

does that mean a replacement nose will be a nightmare for the rest of the body parts even though it fits the radiator?

I very much doubt it.  As I pointed out above, there’s already a lot of variation in fit. 

I thought the paint was the biggest concern with a replacement nose

Well, it shouldn’t be, provided they use the same paint shop (TSK?) and the same paint code.

 

As has been said before by others, I still think the best overall option is for CC to exchange your race rad for the older design (plus oil cooler), as those parts are not only tried and tested, they would fit properly too.  Of course, you’d need the oil cooler mounting brackets as well.  Also, your oil hoses might not fit, and the fan would need to be mounted behind the rad rather than in front (so maybe you’d need a different fan too).  I’m still curious, however, as to why CC don’t want to go down this route. 

(* Other makes available)

JV

[Jim 123]

That point touch condition will stress and damage the fibreglass. Although an alternative race rad may very well do the trick.  

Have you got good clearance between the rad lower and the nose cone? Elongation by 5mm of the chassis mount holes, or the rad bracket holes where the bolts sit, would eliminate the touch on the top corners. You will need to think about the LH upper chassis bracket top radius for hose fit as you would be lowering the rad. 

Also what if you loosen off the lower bobbins  and remove the top bobbins, would the cone fit OK if you wire  back the top of the rad by say  8 to 10 mils to bring the rad top further rearwards.  That would suggest a thinner depth full set of bobbins could do the trick and might also improve top hose fit.

[John Vine]

The new CC Configurator (neat tool!) suggests that the 620 nosecose is wider across the top than the standard 420:

https://www.caterhamcars.com/en/configurator?pagemode=web&configuration=%2B270%2BKBT%2BNDR%2BNTR%2BNTK%2BCLB%2BBPTPGBS%2BIC7PP7I%2BA01%2BRBCPGBS%2BSZ3%2BFST%2BSPC%2BNSD%2BNFW%2BNSO%2BGS5%2BSRD%2BNAB%2BBST%2BMIN%2BSML%2BNCP%2BINTPINC%2BDSHPDSS%2BCST%2BLRSPLLS%2BISB%2BMOMPMOL%2BHTR%2BSSF%2BITTPITV%2BNAP%2BNIR%2BONC%2BOFW%2BORW%2BAFCPSLP%2BCPCPSLP%2BSSS%2BHHL%2BLPO%2BINPPOAW%2BESE%2BMBF%2BSRB%2BWST%2BNWD%2BHDOPITV%2BNAU%2BNRM%2BNHO%2BNBG%2BBOOPITV&width=1920&height=1080

If you display the front view, and then flip-flop between 420 and 620, this becomes apparent.  (I'm assuming that the 420 S3 race nosecone is the same as the 620?)

So, it would seem that the race nosecone might well solve the problem, assuming CC are willing to offer one.

JV

[bjw]

If you display the front view, and then flip-flop between 420 and 620, this becomes apparent.

Indeed it does:-

Quite a bulge.

Cheers

 

 

[CtrMint]

John, 

I believe they are intending to send me another 420 race radiator of the same type, assuming there is a manufacturing tolerance issue with the one I have, may be its drilled in the wrong place etc.  I guess if the mounting bolts where in a higher alignment it would lower the radiator in reference to the chassis, although It's impossible to determine how much clearance there is at the bottom.

As for a "race" nose cone its never come up and I've not approach the matter, I'm personally reluctant to start replacing the nose cone for either the same I have or a race one.  I can just seem them failing to get the paint or even bonnet strip right.  If I push the matter and then I'm not satisfied it will be on me, and CC will fall back on that.

At one point CC did offer the old design,  when I accepted via email, they became reluctant to supply.  Very frustrating.

They've not clarified what they mean by modifying the chassis mounts, I can see two options, they re-drill the current holes let the radiator sit lower in an enlarged hole, that might work, it would ruin the powder coat and be a botch of a solution.  I'm not going to accept that.  They may re-weld new tabs onto the chassis equally I don't want to accept that.

Each time I'm offered and explanation which may include me declining a course of action I offered the excuse of the is normal of low volume car production.  

PBS = PBC too.

[CtrMint]

Jim,

Through conversation I found out the race teams originally used the configuration without a bobbin but it was added back in due to reliability concerns, this might explain how this situation arose.  I also agree a bobbin change might do the trick.  With a smaller height bobbin say 10mm instead of 15mm there might be sufficient clearance, however the radiator is built with M8 bolts and I can't find a bobbin less than 15mm on M8 bolts.  I'm not bending the radiator to get the bolts out in case I damage it.

A little more product testing and CC could have identified a M6 bolts might be better on the radiator.

[John Vine]

At one point CC did offer the old design,  when I accepted via email, they became reluctant to supply.  Very frustrating.

Did they say why? 

I'm personally reluctant to start replacing the nose cone for either the same I have or a race one.

I understand your reluctance, but that means you're rejecting what could be the best solution, namely a race nosecone.  I think it would be a good idea to raise the topic with CC.  IME, they are fully capable of producing one-off GRP components in the correct colour (and with stripes).

I'm not bending the radiator to get the bolts out in case I damage it.

In post #127, Mark W suggested it was indeed possible to bend out the mounting bracket to extract the bolts.

However, I think the basic issue here is that you should not be expected to re-design the car on CC's behalf.  That is why I (and others) have been advocating a solution based on swapping parts (nosecone or rad) rather than bending, sawing or otherwise adapting what you have.

JV

[CtrMint]

"Did they say why?"

Nothing specific other than not wanting to throw the towel in just yet.  I suspect if I were stronger in my insistence they may have provided the earlier configuration, however I was probably too sympathetic to their approach.

Yes I agree totally, I should not be re-designing, or modifying the parts supplied.  I'm just not confident to demand they supply the race nose cone especially considering CC clearly state the standard nose does fit.  I think the issue is the tolerances are so close any flaws in production can easily create the situation I have.  I'm not being dismissive of the recommendation regarding the race nose cone, I just can't see CC wanting to comply and I don't have any experience from which to justify with any strength in my argument.  Also any unforeseen issues with the race nose cone would be on me too.

 

[Jim 123]

With the nose cone option, given what I think you have said about the car you might want to apply a few checks and balances particularly as your car is Lotus Toxic Green.

The nose, wings and bonnet are likely to have been placed on a Caterham specific jig when TSK originally painted them.  When it comes to colour match on adjacent parts (e.g. nose to bonnet); and specifically with mica and metallic paint effects; the jig is important as it ensures that the small sparkle effect flakes within the drying paint film are in exactly the same concentration, and  all they orientate in the same horizontal plane before setting,  If you are shipped an alternative nose cone you may notice a mismatch.  Normally with an aftermarket repair to the nose, it would be painted and the new coating would be "blended" into the bonnet.

If your car has a bonnet stripe going on to the nose, alignment and uniform dimensions may need to be referenced to the existing bonnet.

You should also check how the Caterham Toxic Green is achieved.  I read somewhere that Lotus use a tinted clearcoat in this application.  The issue with coloured clearcoats is that the depth of film does have a bearing on result, esp with hand spray application.  In the aftermarket, the nose clearcoat would be blended into adjacent panels. My guess is that TSK have a formulation that does not use coloured clear, but worth asking.

Don't be put off the new nose cone option it just need thinking through to avoid unanticipated frustration.  You might want to consider an unpainted nose to get you through the IVA.  The assembled car could then be given to a bodyshop, who would get the as new result you expect.

 

[CtrMint]

thanks for the input Jim, though that seems a lot of hassle over an ill fitting radiator.  My conclusion is to stick with the nose I have and CC fix the radiator. 

I've compared the 7 to the Exige and certainly under the garage lighting which is pretty good I can't complaint about the colour match, its close enough.

[ScottR400D]

I still say that the old rad and cooler are your best solution. 

No nose fitting issues.

No rad fitting issues.

No oil pipe fitting issues.

No ‘modifying’ mountings.

The top hose will fit as designed  

 

[John Vine]

I still say that the old rad and cooler are your best solution. 

I agree (and for the same reasons), especially if, as Jim suggests, getting a good paint match on a replacement race nosecone could prove problematical.

At one point CC did offer the old design [of radiator],  when I accepted via email, they became reluctant to supply.  Very frustrating.

Did they say why? 

Nothing specific other than not wanting to throw the towel in just yet.

I'm confused now.  Is it CC or you who don't want to give up just yet? 

Given that CC offered the old rad design, I think you should encourage them to do exactly that.  And it would be cost-effective for them as it would avoid the possibility that the alternative race rad might not fit your nosecone anyway.  After all, it's possible that it's the nosecone, rather than the rad, that's out of spec.

JV

[John Vine]

@bjw:  I forgot to ask...how did you do that?

JV

[Mark w]

Whilst I can see the benefits of going with the “old “ rad as a quick solution does that not create an issue for the future ? 

We all know that Caterham’s have a tendency to get through radiators fairly quickly . If a radiator fails and only the new ones are available at the time due to changed supplier / obsolescence then the problem reappears to be solved then .

ive been out in the garage this afternoon ( initially to fit a smaller bobbin under my engine return pipe ) And it became apparent that the two top radiator support brackets on my car are aligned differently .One is fairly horizontal and the other angles down at say 5-10 degrees . I guess it was built or modified like this .

I can see a situation where the fairly minor tolerances combine to give a clash . 

Assuming there’s sufficient clearance under the radiator / oil cooler I think I would be inclined to push the top brackets down a tad ( carefully so as not to damage the chassis finish ) and slot the bottom rad fixing plates so the rad can drop . ( or just bend the chassis fixing under the coolant pipe and slot the radiator bracket for the other 3 fixing points  ) 

It would seem from the earlier pictures only 3 or 4mm drop is needed . 

Just a thought .

i do agree that changing the nose , with all the associated paint issues should be s last resort .

 

 

[John Vine]

Assuming there’s sufficient clearance under the radiator / oil cooler I think I would be inclined to push the top brackets down a tad ( carefully so as not to damage the chassis finish ) and slot the bottom rad fixing plates so the rad can drop . ( or just bend the chassis fixing under the coolant pipe and slot the radiator bracket for the other 3 fixing points  ) 

Provided the OP is prepared to do a bit of fettling, I think that could very likely work.

Interestingly, pretty much the same thought occurred to a few of us in a recent "offline" (PM) discussion:

"Is there enough room to just put a vertical slot in both the radiator mount (making the existing slot either a “T” or inverted “L” shape) and doing the same in the mounting bracket or bending the mounting bracket down a bit?

Hmmm....that might work.  So, just thinking aloud...

A vertical slot in each top rad mount, running downwards from the existing horizontal slot, would allow the rad to be raised, increasing the gap between inlet pipe and bobbin, but it would also raise the height of the rad with respect to the nosecone.  Mark [the OP] tells us that the clearance between the top of the rad and the nosecone is already very tight (too tight, even).  However, bending the top rad-brackets downwards by a similar amount would compensate for this.  Of course, to allow the rad to sit lower, you'd then have either to bend the lower brackets downwards as well, or cut a vertical slot upwards in the bottom rad slots.  Would that adversely affect the location of the oil cooler too much (chassis clearance, ground clearance)?"

JV

[bjw]

>>@bjw:  I forgot to ask...how did you do that?<<

Hi John, answered in your PSP thread: https://www.lotus7.club/comment/2274327#comment-2274327

Cheers, Barry

[Jim 123]

What about elongating downwards the 4 existing chassis mount holes with a mouse tail file? This would mean minimal and possibly invisible touch up to the powder coat.

Whilst it may not be significant,  might bending the chassis mounts down then render their front mounting faces off vertical which would tilt the top of the rad back towards the inside of the nose cone.

[Mark w]

Of course, to allow the rad to sit lower, you'd then have either to bend the lower brackets downwards as well, or cut a vertical slot upwards in the bottom rad slots.  Would that adversely affect the location of the oil cooler too much (chassis clearance, ground clearance)?"

I dont think i would try to bend the bottom rad mounts , they are quite short but if the 420 is similar to the 620 in terms of height ( and i see no reason why it wouldnt be ) then i am sure theres space to grab 5mm .The bottom of my oil cooler is quite a bit higher than the other low bits on the car .

[Mark w]

What about elongating downwards the 4 existing chassis mount holes with a mouse tail file?

The problem with that is that the inlet pipe will clash with the top bracket stopping it going down .You need to bend this one bracket as a minimum . All the rest could be slotted ( or the rad holes slotted ) 

I have to say looking at the welding on my rad today ( pretty basic - rough )  i can see the possibility of another rad actually fitting if the side plates were welded marginally higher up the side pods .

CC changed the original intercooler design on the 620 and added an additional cooling row .In the case of these radiators maybe they need to remove a row and reduce the height if its marginal on fit .

[John Vine]

Thanks, Barry. 

JV

[John Vine]

 ...i can see the possibility of another rad actually fitting if the side plates were welded marginally higher up the side pods.

I wonder whether CC's "alternative" rad (post #151) has been modified exactly like that?

JV

[ScottR400D]

Reply to:

“Whilst I can see the benefits of going with the “old “ rad as a quick solution does that not create an issue for the future ? 

We all know that Caterham’s have a tendency to get through radiators fairly quickly . If a radiator fails and only the new ones are available at the time due to changed supplier / obsolescence then the problem reappears to be solved then.”

Replacing the old style rad should never be an issue. 

When I got my kit the first three rads supplied leaked  I gave up at that point and had one of the two I kept repaired at a place in Brackley, for a few 10s of £. They offered to just make me a new one, exactly the same but properly made, for less than CC charge. 

I have no doubt others can do the same  

 

 

[CtrMint]

"I'm confused now.  Is it CC or you who don't want to give up just yet? "

I clearly asked CC for the old system taking them up on an earlier offer, and then received an email implying CC wanted to do further investigation.  Essentially SimonL wanted to speak to Derek, from that point forward they've been avoiding sending the old system.  I've not insisted, and they've decided to send another pre-tested race rad.  I've avoid posting the email thread as some forum members felt it was bad form, would have made it easier to explain.

[CtrMint]

Thanks for all the posts again. 

Given I need to the radiator to be lowered it would seem elongating the chassis tabs is easiest option with the current radiator.   However, I don't want to do that as it will damage the powder coat, I'd prefer to see CC cough up another radiator which has the mounting slots in the correct location.  Hopefully that is what they are going to supply in the new year.

I'm not sure I follow bending the tabs, surely I'd have to bend them a significant amount to achieve ~5mm which is what I think I need.  That's not going to be good for bolting up.

I did go into the garage to work on the car today, whilst I was there I photographed the nose on the car, just for interest thought you might like to see it on.