420 dry sump

[Keechy]

Hi all, picked up my long awaited 420 today and I'm after a bit of advice from anyone with a 420 regarding checking and topping up the oil in the dry dump.  I have read the Caterham hand book but it's not overly clear.  Many thanks

[Michael G]

Not overly clear?  I'd use rather less polite words to describe the very unhelpful language used by Caterham to describe this important datum!

If you look into the dry sump tank with the engine off - yes, off - there are two horizontal baffles each with a large central hole, arranged vertically one above the other.  Dependent on the oil level you may of course see either one or two baffles - or no baffles at all if the oil level is above the uppermost baffle.

The upper of the two baffles is roughly mid-way up the oil tank, which may go someway to explain the handbook's reference to the correct oil level being approximately "... 5mm below the middle baffle level..." 

You will now think "Ah, got it.  It's easy.  All I have to do is to take the oil tank cap off with a hot engine and, with the engine running, shine a torch in there to see where the oil is, and I'm looking for the level to be 5mm below the hole in the upper baffle.  Piece of cake!"

Wrong!  It's nearly impossible to see the level.  Once you shine your torch in there I find there's virtually no way you can get your eyes into a position where you can squint past your torch to see with any confidence where the level is.   At best you get a monocular glimpse of a "boiling" mass of rapidly circulating oil thrashing around.

So, good luck and please let me know if you find a way which allows you to confidently check your oil level.

I'm rather hoping someone has come up with a mod which will allow an accurate check without the need to take half your car's bodywork off which of course includes the need to lie on the - probably wet and dirty! - ground to do this.  Anyone, please?

Michael

[Keechy]

Hi Michael, many thanks for your response, I've have a R500 k and a CSR 260 and now a 420 R and always struggled with the oil levels for the dry dump, worries me to death, I guess the answer is over kill with oil quantity as it will go into the catch tank if overfilled.

 

Steve.

[ScottR400D]

My experience of the triangular tank is that they can drain back to the sump differently. When I used to measure the level cold engine off (as well as hot and hot engine off) it varied. Sometimes just below the baffle, sometimes above, sometimes just on it.  I've taken to checking as soon as it's switched off, hot. It only takes a minute or two to remove hood and nose and the level is then about a centimetre over the baffle. It seems fairly consistent. I reckon that's about 7 litres and I get nothing coming into the catch tank. 

[Michael G]

Thanks guys.

My car goes in to Williams for its 1k service in the coming week, so I'm only just beginning to build up some experience on this issue.  I'll chat to them again on the subject and will pass on any pearls of wisdom.

I too have found that the apparent level is different on different days even although I'm adhering to the stipulated engine hot and running procedure.  As I've already said, it's difficult to determine visually the actual level but, even so, I can't understand why/how it should vary.  I'm perhaps being a bit anal on the subject but it does cause me some anxiety in that I do not know for sure what the oil level is.

 

[DRH]

I'm not familiar with the dry sump but would it be possible to use something that could be used to make a dip stick of some kind to measure the oil level.

[SKC]

We've converted several of these tanks by putting a sight tube on the rear of the tank that allows you to see the level without the need to remove the nose or the filler cap.  What's really interesting is the difference in oil level between hot and cold oil.  With the engine idling, there can be as much a 1.5" to 2" in the oil level.

We should hopefully have one of these converted cars on display on our stand at Donington at the 60th.  Please come and have a look.

Regards

SKC*byebye*

[Michael G]

SKC, that's really interesting thank you.

In fact a couple of days ago I was looking in there and wondering about fitting just what you describe!  I'll follow this up.

Michael

[Michael G]

DRH, 2 issues for me:

I'm keen to make the task easier, in particular by eliminating the need to lie on the ground and remove the nose cone.

Also, the turbulence in the tank caused by the rapidly recirculating oil would make dipping the level problematic I reckon.

Thanks for your thoughts.

Michael

[ScottR400D]

The oils higher when running because the scavenge pump keeps the sump fairly empty. When the cars left to stand it drains back down after a while, which is why I check it immediately after switching off. It appears to be consistent this way. 

I like the idea of a sight tube but on the other hand, I don't find it uses much oil so I'm not checking it every time it's used, just maybe every month or so. 

 

[aerobod - near CYYC]

In terms of removing the nose cone to check the oil in the tank, I have found that the right sized coin for the dzus fasteners works wonders, enabling the removal without getting down on the ground, just a reach under the nose cone and a twist with a coin, you can soon get used to finding the slot by feel. A Canadian quarter fits exactly, as should a US one. Probably could find a washer for an M12 bolt that fits well too.

[ECR]

The lower dzus fasteners are a pain to use. I stopped using them and fitted a spring instead (as per the bonnet catches). I now don't have to grovel in the dirt to remove/replace the nose cone.

[Stu_420R]

Hi Mike, only had the 420R a few weeks myself with a dry sump system...

Hoping to get a better solution to checking it too... :)

Thanks for starting the thread, saves me cluttering the forum!

Stewart

[7 wonders of the world]

As mentioned it should be checked hot with the engine running, oil should be just below the top baffle plate, its not as critical as the wet sump as you have more tolerance with the capacity, if its over the top baffle tough it will discharge it via the breather into the catch tank.

I keep a small stubby screwdriver in the tool kit under the seat 

[Geoff Brown]

After six years with a dry sump & the front mounted triangular oil tank - the first year or two were frustrating due to the inadequacy of the oil level description in the owners manual - I now check the level with the engine hot immediately after shutting the engine down. This means one needs to be prepared first. Bonnet & nose cone off.

Then using a 'normal' torch for less reflection (ie non LED) check the level & it should be just below the uppermost baffle by about half an inch. +/- half an inch on that approximate level is not going to make a heap of difference with about six & a half litres of oil on board. Six litres being the recommended minimum for an oil change in a R400D. 

No good trying to check the level with the engine running because the continual scavenge feed in to the tank obliterates the view.

[aldebout]

Hello,

I had the same worries about this. So I bought the dipstick to Caterham parts for my 485 (I am french and living now in the UK). Reference:  380E0001A.

https://caterhamparts.co.uk/oil-system/6968-dipstick-duratec-dry-sump-tank.html?search_query=Dry+sump&results=130

Not the cheapest, not a perfect system as you hardly can see the oil on the stick (it is a dry sump after all, not a wet one) but I now get a tool to check the oil level (with engine just warm, keeping always the same procedure). I am less worried.

Alex

[7 wonders of the world]

If CC had put the DS tank in the proper place you wouldn't have that problem..... and it de aerates the oil more efficiently too.

Mines a doddle to check  

[CtrMint]

The CC dip stick for the dry sump tank makes measuring oil levels hot and cold super easy, I'd highly recommend it.  

I also received my 420 kit approximately 12 months ago and it was included, I guess I was lucky.  I don't believe you are the first to have not received one, my advice is to go back to CC and ask (push) for one.  Having a dip stick isn't unreasonable.

 

[22daz]

I was worried about the oil level on my 420R and would also recommend the CC dry sump tank dipstick. It is integrated into a new cap, is well made and has a hot - cold level marker on it.  It isn't cheap at around £70 but that is considerably less expensive than the alternative. Money well spent I would say..

 

[ChrisC]

And it's standard fit now