12 posts / 0 new
Last post
GulfSeven
GulfSeven's picture
Offline
Last seen: 5 hours 27 min ago
Joined: 28/12/2020
Water swirl pot

I'm having an issue where the coolant is rising to the top of the expansion tank on track. It looks like its a common issue with the 270 and 310 because they don't have the radiator bleed hose to the expansion tank that was fitted to the earlier Sigma-engined cars. My car is a 2020 310R with the later radiator too, so there's no room to lower it to fit the common return hose mod either.

Has anyone fitted a water swirl pot to solve the same problem? Do people fit these to Caterham race cars?

7 wonders of th...
Offline
Last seen: 4 hours 41 min ago
Joined: 17/04/2014

Duratec's dont run a rad bleed either - the problem is a variation with expansion bottle manufacturers with some having a slightly larger borer (some been sleeved) in the bleed pipe which allows too much water to be pushed into the bottle which displaces the air which then finds a new home in the rad.

You can restrict the bleed flow into the bottle by simply inserting a roll pin into the bottle pipe use the one with the tightest fit, leave a small amount proud in case you eve need to remove it.

My first bottle was perfect, replacement needed this tweak - no other changes to the system at all, now normal service has been resumed.

GulfSeven
GulfSeven's picture
Offline
Last seen: 5 hours 27 min ago
Joined: 28/12/2020

I've also had it suggested that the system sucks air out of the expansion tank under heavy braking on track, which is why I was asking about swirl pots..

What size roll pin did you use? I assume you inserted it in expansion tank return pipe?

Tim.

Gulf Racing 310R

7 wonders of th...
Offline
Last seen: 4 hours 41 min ago
Joined: 17/04/2014

Hi Tim,

insert the roll pin into the bottle itself, I have a small box of pins and selected one that just tapped into the plastic neck, this reduces the ID yet offer a sensible bleed flow without filling the bottle.

GulfSeven
GulfSeven's picture
Offline
Last seen: 5 hours 27 min ago
Joined: 28/12/2020

So just to confirm, this insert is standard on some cars? Or is it just that some expansion tanks have smaller ID return pipes?

Tim.

Gulf Racing 310R

ECR
ECR's picture
Offline
Last seen: 12 hours 6 min ago
Joined: 17/04/2014

I have a swirl pot fitted to my VX 2.0. With the original pancake header fitted above the front crucifix the engine would be covered with water spray after a hard session on track. It's perfectly dry now. It's fitted in the top rad hose and just fits under the nosecone

GulfSeven
GulfSeven's picture
Offline
Last seen: 5 hours 27 min ago
Joined: 28/12/2020

Do you have a photo of the install?

Tim.

Gulf Racing 310R

GulfSeven
GulfSeven's picture
Offline
Last seen: 5 hours 27 min ago
Joined: 28/12/2020

Okay, so I can confirm that my car does not have a restrictor in the expansion tank return pipe.

 

Tim.

Gulf Racing 310R

Dixa1225
Offline
Last seen: 5 hours 54 min ago
Joined: 16/10/2015

I have just check my 2020 academy car. No restrictor in the tank. Not had any issues you are having on track.

GulfSeven
GulfSeven's picture
Offline
Last seen: 5 hours 27 min ago
Joined: 28/12/2020

I think I'll ask Caterham themselves for an opinion before I proceed with anything...

Tim.

Gulf Racing 310R

GulfSeven
GulfSeven's picture
Offline
Last seen: 5 hours 27 min ago
Joined: 28/12/2020

Caterham and Williams have both independently advised against modifying the cooling system and have suggested it could be an air lock or possibly another faulty expansion bottle cap. So I'm going to get the system bled and fit another cap before my next track day in July.

Tim.

Gulf Racing 310R