620R cooling

[CtrMint]

I didn't exactly cry for help.

I spent an hour on a Zoom call with Simon presenting my case on the matter in a very logic manner.  This included the behaviour of the dealer network and technical realities of the car.  After which we reached an amicable agreement to move forward.  I didn't post the info publicly as I didn't want to place CC under any undue pressure.  They needed sometime to start the ball rolling. I did pass on the info to Mark who graciously handed over the design for review.  I also updated Martyn as he'd been supportive through applying subtle pressure too.

[Shortshift]

Great team effort!  So plaudits to Mark, Mark, Igor and Neil.

James

[Doctor]

Apologies for my absence in this very relevant thread. Way too many hours under the rear of the car due to the diff oil leak. All well and good now, I've even managed to sneak in some of the promised upgrades. The car now reads oil pressure/water temp on one gauge and engine oil/gearbox oil temps on the other. all wired up and ready for the track day test. Have been investigating the oil stats and gearbox oil cooling system in the meantime. Well done to Neil for his guidance and Mark W for pushing me the right direction to accomplish this and also for forwarding our project to the relevant people at Caterham Cars. Let us hope that something good comes out of this. 

[CtrMint]

For completeness, I thought it worth mentioning my 620R has now had it's cooling circuit revised, though sadly due to some biblical rain testing has been prevented.   More to follow.

[Mark w]

Mark

Thanks for the update .

Any chance that you could post a few pictures showing the modification undertaken to your car ?

[Benton]

Certainly interested in the solution / outcome of your testing.

[CtrMint]

Trying to document the modification has not been easy, as you know it's pretty tight under the bonnet.  I've captured a video of the part which I guess is of most interest.

The car also now has a new standard thermostat housing with a metal insert to reduce the pressure on one of the ports, plus new hoses all round and a joint some where under the plenum.  A new 95c thermostat has also been fitted.

[CtrMint]

This one is awful, you are warned ;-) Trying to get the thermostat housing.

 

[Mark w]

Hi Mark 

Thats definitely an awful video   but it looks as if you now have a very similar arrangement to that which Igor and i 'developed '.and wrote up for Low Flying .The circuitry is all identical , just detail is different.

The only thing i cant quite see is where your expansion bottle connects - the small spigot on the thermostat housing ?

CC have done away with the aluminium thermostat housing and used the plastic ford part ( cost saving there for them ) ,hose clearance near the supercharger must be very tight now ( although it looks as if the routing is now nearer the side skin ?)  

Are you sure you have a 95 degree stat now ? Thats in conflict with the fan switch on and off temps  in the previous CC map ( fan on before thermostat fully open etc ) 

I think you will find the car comes up to temperature quickly and holds a more steady temp in colder weather ( mine does ! )

Thanks for sharing .

 

[CtrMint]

I'll try and get another video to show the expansion bottle connection, though probably over the weekend.

Pretty sure it's a 95/98c stat.  It didn't seem to cause any issue when testing, the rad was hot when the fan kicked in too.  Even if it's slightly early I guess it will help keep the temps on the safe side, rather than over hot etc.

If it's dry over the weekend, I'll run the car up the Mountain it will be around 7/8c or up there, and at speed it will be a good test.

[CtrMint]

I've finally had chance to run the 620R to Ramsey and back over the Mountain Road.  Conditions were cold and damp.  I swapped the wheels/tyres to ZZS from my 420R.  Ambients temps in Onchan according to the BBC weather app are 10c so I suspect less than 8c on the Mountain, maybe lower with wind chill, and it is windy up there!

I drove away from the house with the car good and hot, having let it warm through, at the end of the day it's been over cooling and not over heating.  Temps were around 90c, the fan did kick in at a set of traffic light in Onchan, but quickly went off.

Driving too and from Ramsey the temps ranged between 80 and 90c.  The drive didn't included any hard acceleration and nothing over 4k.  I did reach around 90mph on the return run, which is usually where I see the 420R temps dip, I guess the wind direction is more noticeable.  Temps still didn't dip below 80c.

I appreciate that's not track driving, but it's a huge improvement.

[Benton]

Sounds encouraging