Cooling circuit on new Duratec S3

[Q Catcher]

Helping a friend build a (non-dry-sump) Duratec 360R, with a heater.  Does anyone have a cooling (including heater hoses) system diag, so we can figure out where the hoses are supposed to go?  The two big rad hoses are pretty obvious, but where does the expansion tank lower connection go to?  Where does the supplied plastic T piece go?  Why is there a stubby stainless connecting pipe (not a T) which is the same diameter as the two large rad hoses?  And so on ...

Many thanks

[Jonathan Kay]

Do you already have the last text-heavy Assembly Guide and the current pictorial version (v2.1)? Please let me know if you need copies.

But on the specific question of cooling Duratecs there's a vast amount of experience and several suggested improvements in the archives. If one of the experts doesn't arrive soon I'll add some links...

Jonathan

[Geoff Brown]

Try CtrMint's build blog. There are two sections on cooling plumbing. May be for a 420 but Duratec plumbing is the same.

Caterham 420 Detailed Build Blog – An alternative to the Caterham 420R build manual

[edo]

shout if you need pictures of a new car. all be it a 420

[Q Catcher]

Jonathan: the build manual shows a Sigma!

Geoff - great build blog, but doesn't appear to have a heater.

edo: yes please!

[Jonathan Kay]

Which manual is that? If you send me a Private Message with your email address I'll send what I've got for Duratecs.

Jonathan

[ChrisC]

Are but it does now :-). 
 

So assuming all the big hoses are done, there is a photo that used to be sent out to help.  Let me see if I can find it.  
 

https://3.bp.blogspot.com/-bHXbo1qs1ZM/Uh5UYmOzmyI/AAAAAAAAAK8/qfeHZAv-JW4/s1600/SuperSportRCoolantRouting.jpg
 

The only thing to be careful of is the metal T (called the submarine), make sure the gauge sensor wiring (very short) reaches the sensor in the submarine.  So cut your hoses with that in mind.

[Jonathan Kay]

Same image as above:

Jonathan

[7 wonders of the world]

The above is incorrect as theres no bypass circuit...........

 

[ChrisC]

Yes it's just the hoses you have to fit as a builder, the bypass hose is pre fitted.

[Purplemeanie]

Hopefully this will help and not hinder. It's for a dry-sump 420 on the oil side but I think should help explain the water cooling.

https://purplemeanie.co.uk/index.php/2017/09/23/build-session-17-5-caterham-420r-water-and-oil-overview/

John

[paul richards]

If there's a plastic T piece suggest you replace with a brass one for the little expensive involved. The plastic T pieces are like chocolate and likely to deform and fail over time. 

[Geoff Brown]

QCatcher #5 - I thought that the heater was the Duratec ? Save weight ditch the heater & make the plumbing less complicated.

[John Vine]

Re #12:

If there's a plastic T piece suggest you replace with a brass one...

That's an interesting thought.  Any idea if there'd be an adverse reaction with OAT coolants?

JV

[Jonathan Kay]

"Any idea if there'd be an adverse reaction with OAT coolants?"

I don't know of any pertinent observations. And, as I think we've discussed with aluminum radiators with brass fittings, it's probably wisest to match the coolant to the engine rather than to any external component...

Jonathan

[Handwheels]

"If there's a plastic T piece suggest you replace with a brass one..."

Chris covered this in his build bible  https://caterham420detailedbuildblog.co.uk/2019/12/19/engine-plumbing-part-1/

(sure he'll be along soon...)

I tried to get the 250C rated replacement that he suggested when I did my build last summer, but unfortunately I couldn't track one down. It's on my winter list to try and find one, or something very similar. I'm not confident with the CC supplied one that is only rated to 110C

UPDATE - just been on ebay and someone is selling the high spec Gates T Piece. Wish they had been selling them last June!!  Just ordered one as yet another Caterham stocking-filler. Sure my wife will be pleased.

Richard

[John Vine]

Interesting that ChrisC found that the blue TEFEN T-piece "malformed due to temperature".  That's the same part that came with my 2008 kit.  So far, I've had no trouble with it, but I did pop a brass T-piece in my spares pack just in case.

Re #16:

just been on ebay and someone is selling the high spec Gates T Piece

Can you give me vendor details, please?  I've just searched ebay with no success.

JV 

[ScottR400D]

#17 what temperature does your car run at. If it's 80c or so it should be fine. If it's 95c+ maybe not, so may depend on what stat you're running. 
 
I've got the original CC T, never been an issue, but my water temp is around 80c. 
 

 

[ChrisC]

Don't know the exact date they switched from the 80c to the 95+ stat, but it was some time near the introduction of the new model numbers.  My 360R was an Oct 2015 kit, which had a 95+ stat and a ECU which switched the fan on at 90c, so the fan ran constantly.  Since I couldn't change the fan on temperature, I changed the stat to the 80c alternative.  It was at that point I noticed the T piece deformation. It was made worse with the location of the washer bottle at that time putting pressure on the hoses going to the T. 
 

My 420R Sep 2019 kit, is happy with the 95+c stat and the fan switch on/off points are fine. The combination of pressure and under bonnet heat didn't end well for my expansion tank, which expanded a little to far for the nose cone on the way back from IVA, but the Gates plastic T has been perfect, highly recommend. 
 

 

[Jonathan Kay]

From Chris's blog:

T piece alternative
My 360R kit’s T-Piece malformed due to temperature within the first few weeks, thankfully Caterham now supply a stronger alternative. Using the manufacturer name, I was able to discover the maximum operating temperature for the supplied T Piece, which is 110°C. To me, this seems a little marginal, so I am changing it for a Gates 19mm T Piece, which is rated to 250C, which seems much more suitable. I sourced it from eBay using the Gates product number (7315-00935) part number (28635).

...

Today I found:

https://www.ebay.co.uk/itm/184942797612

Jonathan

[John Vine]

#18: ...what temperature does your car run at. If it's 80c or so it should be fine. If it's 95c+ maybe not, so may depend on what stat you're running.

Both water and oil run normally at an indicated 80C (same gauge, same type of sender), with water rising to maybe 85C or so in traffic, and oil rising to 90-95 after some spirited motoring (my oil cooler is blanked off).  The 80C puzzles me as I seem to have the non-82C (long) stat:

This is the original (2008) item, and I can't reconcile the higher(?) stat rating with the 80C.

#20: Thanks for the link, JK, but I don't really need five!

JV

[Handwheels]

The T piece I've just ordered is https://www.ebay.co.uk/itm/115121342570

This is slightly different from the link Jonathan put in his message. Think I've ordered the right one (GATES T CONNECTOR - 19MM - 7315-00935)

[ScottR400D]

I'm not sure about the 'long' stat but my car, one of the last R400D, supplied as a kit in December  '14 has the 82 stat and the water runs at about 80c. Never more than a degree or two above that except after a few hard laps and even then it cools back to 80 quite quickly. Pootling about and then booting it on the road will cause a short term drop to just under 80c but again, it soon recovers to 80. 

As Chris says, I think they moved to the 95c stats sometime in 2015.

 

 

[Jonathan Kay]

"The T piece I've just ordered is https://www.ebay.co.uk/itm/115121342570(link is external)

"This is slightly different from the link Jonathan put in his message. Think I've ordered the right one (GATES T CONNECTOR - 19MM - 7315-00935)"

 

19 mm, part number 00935 looks fine to me

 

And packs of one won't create a secondary market! : - )

 

Jonathan

[John Vine]

Thanks, Handwheels.

And packs of one won't create a secondary market! 

Good point!  I'll happily order five if others will take at least two from me. (Sort of mini-BulkBuy.)  And what's the significance of the "A" suffix, I wonder?

JV