620R cooling

[Doctor]

I have, however, managed to talk to him and he was very pleased with the result and I sincerely hope this impression will be mutual. More tomorrow. 

[Shortshift]

*thumbs_up_thumb*

James

[Doctor]

Back home from the workshop - it works. It took me about 40min - traffic, A roads, double carriage - no bonnet and no nose one - the water temp never went below 70, mostly sat at around 80. All nice and warm when came home, time to start properly measuring some temperatures. I consider this problem solved and I'm moving on. 

[Shortshift]

Before you move on (wonder what's next on the list?) perhaps you and Mark could provide an idiot's guide to what you ended up doing?  Some photos of the modified components, the final installation, a few notes on teh principes behind the final deisgn, an outline BOM?

As much as for people who might come along in the future as for those who have been following this in real time...

James

[Mark w]

Here's a few shots of the modifications .

[Mark w]

James

My parts are still in a box ( 200 miles away !) when I get them I will document the changes as they are fitted on the car .

Once we've got two installations up and running Including a track day thrash we could perhaps look into seeing if there's interest in a group buy . 

The cold running appears to have been sorted , we just need to check we don't have issues with hot running after sustained thrashing on track .

We chose to go the all new parts route so that the mod was reversible , it's cost us several hundred pounds each , some of which was buying off the shelf components to see if they fitted , some was just buying in stock parts like the Caterham thermostat housing which retail at £180 each (plus the modification costs )

Maybe a quick show of hands from anyone who might be interested in doing the same ?.

 

 

[Shortshift]

I think there should be strong interest, both here and through Nigel's 620 Facebook group.  Subject to your thrash-testing, it looks like you will have successfully developed a properly thought through thermostatically controlled cooling system - well done you, Igor and Neil. 

Put simply, I can't see why anyone with a 620 wouldn't want to fit the update.

James

PS:  Hopefully, your work will be enough to persuade Mark (Ctr Mint - IoM) to stick with his lovely red car as well.

[Shropshire AR]

Does is make any difference whether the car has a heater or not with this modification?

[Doctor]

Hi Martyn, no, it doesn't. on 620R the heater has a take off from the hot rail (blanked off on my car) and it drains (through T connection to the header tank fill - that is connected to the bypass (hot side of the stat). With this modification you will place both header tank and the heater on the permanent circuit.  

[Doctor]

Sorry James, I didn't mean to be abrupt, I just didn't want to beat around the bush with this, especially following a few comments in this thread. Neil provided the theoretical basis, me and Mark knuckled down and now it's done. It works beautifully. Hasn't trashed it on the track yet, but gave it a good run up the hill visiting rev limiter quite a bit (ZZR and wet road - oh dear!!, but softening the rear definitely helped with the grip) and the temp has been sitting around 80'C. More after Anglesey - I hope I'll manage to get the new gauges installed by then. 

rear water outlet at the back of the head with the knee on the bottom with new gasket: £100 brand new from X-Power engines - Piero is a great guy, but the current one on the engine can be modified as there is a 16mm plug that can be pushed out and replaced with 90 degree knee that is an OEM Ford part and costs about £15 on EBay

thermostat housing - current part can be modified - haven't got the cost of the work yet. In order to keep things fully reversible, me and Mark have decided to outsource as a spare part (thanks goes to Chris at Red Line Components). The mods are: weld on on the stat face and blanking off cold permanent bypass from the rad, second hole and tapping the second thread on the stat face to properly fix the stat in two places, drill and weld on the additional tube above the rad return coming from the front of the car  pointing backwards - this is the permanent flow circuit to connect header tank +/- heater. plus new gasket - £6 OEM Ford part. I've changed the stat as well, but not necessary.  

bypass hose - Ford OEM part - give or take £20. comes with clips

the bottom hose from the header tank can be re-used, it just needs re-routing as the original space is taken by the bypass hose.  

Z bracket under the plenum chamber tensioning the throttle cable needs modifying (cutting off one corner) and mounting on the top of the brace rather than the bottom in order to create more space - costs just your time. I've changed the plenum to head gasket as I hate reusing them.  

Bravery of doing something most people are skeptical about. 

[Shortshift]

Hi Igor - I never thought you were being abrupt and I'm really glad that you and Mark are providing more detail for others to follow.  As you both say, just a rigorous trackday needed now to confirm that everything works in a stable manner even under harsh operating conditions.

I mentioned on the phone and it's perhaps worth repeating here.  Assuming all works as expected during track testing, I think that you, Mark and Neil have made this one of the most valuable and worthwhile threads on BlatChat for a very long time.  I really would expect anyone with a 620 to be interested in doing this mod, to ensure that the engine operates for more of the time in the 'correct' temperature range, and that the prospect of over-fuelling - with potential oil dilution and bore scoring risks - is mitigated.

If Mark Rodman / Ctr Mint is still on here (he was the original poster on this thread), it would be good to hear whether these mods will be enough to encourage a change of heart about selling-up?

James

 

[CtrMint]

Evening All, 

After lots of PMs over FB with James, he's convinced me to have a go at sorting this, he assures me the 620 will be worth it    No pressure then.  I'd like to also publicly thank James for his efforts, sounds a bit cheesy but there's some other difficulties which I'm managing that partially influenced how much time I've have for CC cr*p at the moment.  Any how James put a slightly different slant on some stuff and the end result, I'll give it ago.  Thanks also to John and Neil, they've also provided help along the way!

I'm still not convinced I can modify the car as you guys are doing, although if you manage to mature the modification into kit form then maybe.  In the meantime I'm going to have a go at a remote thermostat bypass mod and see if that gets the temps up and stable for road use, at least then I can use it.  The approach will be reversible so if it doesn't work no harm and if the mod being developed here does get to "kit" form then I can use that too.  It might be interesting to have a comparison.

I'm also going to step up on the blogging, I'm launching a new blog dedicated to the 620 and these problems too.  That will follow soon.  Although I'm probably being optimistic on the time I have available.  John's recent build commentary vlog has also inspired me to have a go at a vlog, again probably being optimistic.

Lastly, I hope you don't mind if lean on the BC regulars for guidance when I try my own approach.  I might make a complete and utter hash of it and probably will.  If I share my plans first, I hope regulars will be happy to comment.  I guess I should start a different thread.

Thanks

 

 

[Mark w]

Kit of parts 

And if you think you have the skills to strip the plenum off to get access , you can fit it . 

[SLR No.77]

After the difficulties you've had this sounds really positive, hang in there it'll be worth it.

Stu.

[Mark w]

Sorry , forgot this which wasn't in the box .

Mark

After we've run one car at Anglesey on track ( on the 10th ) just to check its ok , we have agreed to write this mod up as an easy to follow guide . All the parts bar one are available off the shelf , the modified thermostat housing is more problematic but I am not adverse to sorting out a bulk buy if there was enough interest . As a guide the cost would be £400-£500 for the thermostat housing ( starting with a new one from CC at £190 ) plus £100 for the water outlet £ 20 for the bypass hose , say £15 for water gaskets and £20 for plenum gasket . 
This assumes we use the chap who prototyped the design Igor and I developed to manufacture some more thermostat housings , possibly the easiest route if not the cheapest .

 

[Shortshift]

Hey Mark - that is brilliant news!  I am sure that Mark, Igor and Neil (7 Wonders) will be available online to give you as much help as needed to fit their developed cooling kit.

I know you can't leave the island right now for a Club trackday but maybe things will ease a bit so that our future events at Croft or Donington Park might work for you.  Failing which - maybe two week's enforced quarantine is a price worth paying for driving your 620R on track??!!

James

[CtrMint]

Thanks All, 

I'll be watching the developments here closely, hope the testing goes well, I'm keen to see this mature and not too bothered about the cost.  It would have been great to attend the track day too, even as a spectator, but its just not possible.  

I'll post a new thread just to detail what I'm doing, making it clear it should be treated as a lesser solution, but an interesting comparison.  With a bit a luck my parts will be here during next week and I've got an experienced mate coming over to help me out next Saturday.  

Could I just ask what the ID of the hose is which connects to the unmodified thermostat housing.

Thanks

[Mark w]

Hi Mark 

Did a bit of " testing " with the Easimap logging today , didnt drive the car just wanted to see if i could graph the temperature output .

It worked ! 

Excuse the poor quality , it was a screen grab on the phone ,but at least i got temp and engine speed logged OK .Thanks for your help in putting me on the right course .

Idle speed in green at the bottom , temp sat just under 80 for most of the time , the last section was when the fan kicked in at 92 .

Next stage is a log of our modified installation on Monday ......

 

 

 

[CtrMint]

That looks nice and steady.  Good work.

I might be beat already before out of the gate on my approach, I'll post on the alternate thread.

 

[Mark w]

That's an unmodified car ! But it's only idling .

it was a test of logging not the modified installation .

 

[CtrMint]

ahh did look amazingly steady

[Doctor]

Hi everyone, very pleased to report the results of today shakedown - I was changing the springs, so wanted to make sure it all works fine. The car drove flawlessly today for about two hours in all sorts of conditions - full beans, pottering along, stop and go traffic, sticking to the speed limit at economy (higher) gear. The water warms up quickly and throughout the drive the original Caterham gauge was reading between 70'C and 90'C. Very happy with the result, more on Monday after a track day. Just quick gearbox oil change tomorrow and the car is good to go.  

Softer springs effect - soooo much better, especially at the rear. Much better grip out of the corner.   

[Mark w]

Just to update on testing .

We ran Igor's car on track at Anglesey today , was pretty hot in the morning and rainy / colder in the afternoon .

The car replicated the road testing and ran in a similar temperature window without violent swings . The gauge in his car is version C which pretty much replicated the temp the ECU is seeing . If you have version B it's probably undereading ( sticker on the back ) 

I am going to proceed modifying mine now with the additional parts we sourced and had manufactured and give it more road testing as we move into autumn .

Not  much more to say , happy with the upgrade .

[Doctor]

Thanks Mark, nothing to add. The car doesn't boil and when on the go and not nailing it, it holds a good stable water temp. Next step - upgrade the instruments and start looking at numbers properly. 

[7 wonders of the world]

Been offline for a while,

Glad you finally got the parts made up locally - a pita but the results are worth it - you now have a cooling system that performs as it should do, CC take note !