StevehS3

Agreed. Anyone with OAT coolant able to take a measurement? 

I read something on the internet that set me thinking about the possibility of electrolytic corrosion. Our radiators are mounted on [insulating] bobbins so there isn’t a direct connection to the chassis of the car. If there is a potential difference between the radiator and the chassis, current will flow. The water in the rad becomes the electrolyte, and perhaps an even better one with a OAT (acidic) additive.
My battery is away from the car at the moment so I haven’t tried to measure the pd but I did check the resistance between the rad and the chassis which is 3.5M ohms. 
It would be easy to add an earth strap across one of the bobbins. Any thoughts?

Lots about it on the internet. Have a Google. Here is a starter https://www.northernradiator.com/knowledge/Electrolysis

I have used R888R and would be happy to return to using them when my ZZS are worn. I noticed Yoko A052 for sale by Northampton Motorsport in suitable sizes. Can anyone advise on how they compare against ZZS or R888R? 
https://www.northamptonmotorsport.com/product-category/yokohama-tyres-northampon-motorsport/yokohama-advan-a052-tyres/
 

Geoff, your running the engine over winter regime may help.

Mine was thoroughly flushed through by Premier Power then after a few hundred miles I replaced the coolant with new. Just to be sure. 
 

Each time this crops up I never know what to make of it all. Perhaps Radtec see more problems with OAT because that’s what the vast majority of cars use - although their photos do seem to show that the coolant has caused damage. 

I have never had a problem with OAT coolant and the standard CC rads. I have seen lots of reported (some very early) failures of Radtec rads used with OAT coolant. Do Radtec warrant their rads when used with OAT coolant? 

This is the problem, along with potentially damaging hoses too.

PP changed mine from pink OAT to blue. I think OAT is commonly used for our daily drivers because of its long life between changes and the cars are generally regularly used. It different with the 7. Ours can be stood over winter without running. Personally am more than happy to change the coolant every 2 years. It is cheap and I take the water from the cellar dehumidifier. Bluecol has excellent compatibility with [I think] all engines and can even be mixed with other coolants. 

Williams might want to keep to CC’s factory standard but either way please let us know their opinion. 👍

My first thoughts were that the hose in the photo is silicone. I bought silicone hoses for my last 7 and it included a note about OAT coolant damaging the hoses. I know it has been debated thoroughly before but I think Bluecol is a better bet for the Sigma. Premier Power changed my from OAT to blue. The only downside that I am aware of is it needs changing every 2 years which I am more than happy to do as it is cheap and keeps the cooling system fresh.

If it helps my factory built 310R came with Caterham branded silicone hoses. 

I can’t get comfortable with the thought that if one fails you are left with no headlight as a bulb can’t be swapped. Also, when my Classic Car LEDs failed they failed on each side on the same day. 

Gosh! Why wouldn’t they state this on the spec sheet or, better still, provide protection electronics in the unit.

Is it assuming too much to say that if the headlight must not be wired such that dipped and main operate together they would have prevented it in the internal electronics? It wouldn’t be difficult or expensive to do. 

I believe a standard H4 bulb is 55/60W.

An excellent find. More valuable information for Blatchat technical.

I quite like to have a break from using the 7 for a few months over winter. It’s a time to catchup on those little jobs and sort out a bit of fettling. Spring is a wonderful season to look forward to and isn’t it great to start it up for the first time and head out for a blat. I really look forward to that. A lovely experience and a new year ahead to make the most of the 7. 

This is an easy to spot identifier near the drain plug on the Mazda box. 

Hi Mark, I have changed my Mazda gearbox oil. Mine doesn’t look the same as yours.

Steve

I think rain or condensation can enter a headlight easy enough and be trapped in there resting in the bottom. There isn’t much in the way of sealing.  I have wiped the inside of the bowl with a very light film of corrosion protection and during winter remove every light lens to take a look inside and dry out if necessary.

Whilst I don’t think the powder coating is always great there are a lot of older Caterhams with totally corrosion free chassis. The main difference comes down to when it has been driven, how it has been stored and how well it has been maintained.

3 minutes ago, John Vine said:

Steve, YHM.

Reading the WN again, I seem to recall that the problem came about because the original RHS bracket, which was used to carry the speed sensor, had different dimensions to the LHS bracket required for cars with the ARB.  This led to a pre-load on the ARB (as Paul mentioned above).  The fix was to use a revised RHS bracket to match the LHS (I think).   Although my car has Watts and an ARB, I'm not sure the "Watts" reference itself is relevant.  The WN seems to relate more to (early) cars with a rear ARB, with or without Watts -- but I stand to be corrected! 

It would be worth checking whether your ARB brackets are symmetrical.  If they aren't, maybe that's why your droplinks have different lengths?   Also, you could detach one droplink with the car is on level ground, and check whether that droplink still lines up with the ARB arm (as Colin-T mentioned above).

JV

Got the WN thank you John. The above makes sense. I will take a closer look at the brackets but that may well be the reason why one droplink was set longer than the other. I am fitting new droplinks over winter. I am thinking that I will fit the O/S that was shorter first and see how the N/S one lines up then check for preload with the car sat on the floor. 

2 hours ago, John Vine said:

Looking more closely at WN460 (I can send you a copy if you want -- just PM me your email address), it appears that the droplinks could well be unequal length depending on whether the car has Watts rear suspension.  Earlier cars with Watts tended to suffer a pre-load on the ARB due to drop-link mounting brackets of unequal length.

What year is your car and do you have Watts?

JV

Thank you John. I have sent you my email address.

Great information thank you both. Much appreciated. 

PlastererPete, I have just fitted these LED sidelights. I chose them because they give a bright white light without the blue tinge and the LEDs are within a glass bulb so not exposed. Time will tell…

https://amzn.eu/d/1dDSw3q

I must admit I am undecided when it comes to upgrading the headlights to LED. I only want legal, so that rules out fitting LED bulbs into the existing lights. My main concern with changing the units for LED is if one failed a long way away from home on a multi-day trip I can’t do a simple bulb swap. I know that LEDs last much longer but I have had both LED sidelights fail (Classic Car LEDs) and a rear light LED when I had those. Maybe it’s the vibration or damp or something?