620R cooling

[TomB]

Why on earth couldn't CC with an engineering team and budget come up with your solution?   Shocking how owners have to develop, modify and fix issues with these cars when won't or don't want to acknowldege a problem.  

[ScottR400D]

That’s a question being asked by many owners but the only conclusion to reach is that they just don’t care about customers once they’ve bought the car. 

Talking to various people there’s a lot of disquiet from the start of ownership, missing parts from kits, wrong parts, design changes which render the manuals out of date not notified, the shortcomings of the manuals per se, poor quality of certain parts that remains unresolved (radiators, diffs, sensors gauges......) and of course the endless debate of cooling systems. 

Why the 620, as designed, just doesn’t seem to work at all well, why recent cars are designed to run near boiling temperature when the same things used to run 20c cooler. Why radiator specs change for no apparent reason, causing more build issues.

The list goes on and on.

One discussion led to musing about how productive Derek H could be if he didn’t spend so much time correcting stuff! ( That’s tongue in cheek but it seems an anachronism after so many years that they can’t get that area right)  

 

[Titanium7]

Mark and Igor

Just thinking ahead for the possibility of some kits being made up if that's what you are suggesting. I for one would be interested in having one.

Some thoughts on keeping the costs down!

On obtaining the modified thermostat housing, would it be possible to send in on a swap basis our existing ones on a one for one basis. This would negate the need for purchasing new ones from CC.

Also I don't think I've seen how the modified rear water exit unit was arrived at, was it a new purchase at around £92 or was the existing one modified to get the additional outlet? Again if it was the original modified could we again work on and exchange basis?

 

Regards

Martyn

 

 

[Doctor]

Hi Martyn, loads of questions. I haven't really chatted to Mark yet about going commercial and since he was instrumental in providing info and parts, I wouldn't be able to comment without talking to him first. Truth to be said, we have only so far modified my SV, his S3 is yet to be done. 
 

We went in belts and braces as I didn't want to get stuck during the mod as I had Anglesey track day booked. So we've outsourced brand new 620 aluminium stat housing with a new gasket, new Duratec 82'C stat in plastic housing (that I broke off and used), bypass hose (original Ford item new from Caterham), new 90 degree (roughly 1m long) replacement hose used to connect header tank and hot side of the stat. I bought new Duratec water outlet and gasket from X-Power engines (1x M12x1.5, 1x 1/8 NPT, and a 90 degree 16mm knee on the bottom) as we wanted everything to be reversible. Plus it looks cool as it is billet and not cast. I've also changed the plenum gasket (has to be taken off) and put a new coolant into the engine as it needed to be drained. 
 

 

[PeterM]

#252 It should never be forgotten that 'people do business with people'. The right approach has always won the day for me.

[elie boone]

Nothing has changed then in all the years since the 7 is in production

[Doctor]

I'm not sure I share all of this pessimism - at the end of the day this has been a successful project. CC did not participate - so what? I will still give them the result of my work to consider. As for the rest - I'll just enjoy the drive. Now that I know it does not overcool. 

[ScottR400D]

#255

Absolutely, but that cuts both ways. 

[John Vine]

I've been following this thread avidly (purely as a spectator, mind) and I'm immensely impressed by the skill and determination you guys have shown.

I will still give them the result of my work to consider.

That's a very generous gesture.  I hope they appreciate it! 

In my personal experience, however, I have to say that CC are not as receptive as they might be to external suggestions for engineering improvements.  I suspect they tend to suffer from "not-invented-here" syndrome.

JV 

[Mark w]

One update on prices , I said in post #238 that the plenum gasket was £20 , it's actually £80 as it's a thermal insulating gasket although you might be able to reuse and I have found a manufacturer who will sell direct for circa £50 .

 

[7 wonders of the world]

ISTR the gasket you refer to is a phenolic spacer - to reduce thermal soak, which can easily be reused if cleaned carefully and sealed with appropriate sealer on either side.

[Shropshire AR]

It would be great if Igor and Mark could produce a written up schematic for heater and non heater cars with relevant part numbers and likely purchasing sources. Obviously the adapted thermostat housing is a bespoke part but relevant dimensions of the added pipe would help others who wish to go along this route. 

[Shortshift]

I think that, in response to a suggestion made by Jonathan a while back, Mark and Igor (and Neil?) are planning to do a methodical write-up for posting here and also for publishing in Lowflying.  Get it all summarised in one place.

James

[Doctor]

There was no sealer on mine. What should be used?

[7 wonders of the world]

did yours have gaskets bonded to each side then...?

[Doctor]

It looks that way. The original one came off with ease and without damage. I don't seem to have any loss of boost. 

[Mark w]

So ive now converted my car , did a "drive way test" to fully bleed the air out ( and check for leaks ! ) and logged the results .

Going to road test it tomorrow if time and weather allows .

Mark ( Ctr Mint ) 

Can you do me a favour please  , plug your 420 into Easymap and see what temperature the rad fan switch on and switch off are set at  ?

TIA

[CtrMint]

sure will do.  From memory, I think it's about 103c, but will check and confirm.

[Doctor]

Hi Martyn, 

there is very little difference in non-heater/heater cars as the outflow from the heater and the fill side of the header tank are connected together before they are connected to the stat housing. No difference on how the mod works. The thermostat housing (the same as water outlet) is not bespoke, it is in fact a modified original part (even though for a speed of the process it might not be the actual part from your car). 

[Doctor]

James, yes, this very likely needs to happen. The problem is - other projects are popping out like no tomorrow - new instruments, gearbox oil cooling, different intercooler air flow, mapping for more power and less fuel going in - the list is long. 

[Shortshift]

I had to back-track to see what you were replying about!  Ah - the Lowflying article.

I think the key topic here is the cooling project so I do hope that you and Mark (and Neil) will find time to write that up.  It will be of interest to a large proporrtion of 620 owners.

Good luck with the rest of your growing list of things to do.  Shows that upgraditis applies even to 620Rs!

James

[Doctor]

It is not upgraditis I'm afraid. It is making sure I can keep nailing it and knowing I've done my best to make it reliable. Essentially I'm finishing it off the way it should have been made. 

[Doctor]

Dear all, another successful day at Croft Circuit track day yesterday. Driving there - setting off at 05:00 on M62 over Pennines - raining all the way there and about 10-15'C outside temp - the water temp sat at 75'C. Average around 70mph. 
 

Giving it a good go on the track - when doing silly speeds the water temp went down to about 65'C, but on the out lap comes up immediately to about 80'C. When stationary in the garage the heat from the compressor and the engine oil (possibly a gearbox as well) bring the fan on again. It runs a bit longer than before but it brings the temp down. I think it needs better extraction of the hot air from the nose cone over the top cut out. An additional fan (or two - another one for the intercooler) might be on cards. I would wire them with the main one and as my car does not have a heater, I have a two step switch available on the dash. As far as the track day goes - I've managed to get a set of ZZS just in time, put them on, and it was a blast. Anything less then 24PSI and they were sliding around. Once proper pressure in, very stable. 

 

Journey home with stable temps without dramas. A cracker of a day.

[Mark w]

Finally managed to find some time to run my converted car today and log some temperatures . Red is coolant temperature , blue is engine revs . Ignore the scale numbers , that relates to data ive removed from the graph .

The total run time covered by the graph is 49 minutes . The car took 5 mins from cold to reach its working water temperature in the mid 80s and over the course of the test it never fluctuated out of the 80-93 degree range ( as recorded by the engine ecu - still waiting for my dash gauge to be returned  by Cairbont ) .The first and last sections of the test were on pretty busy  suburban type roads and the engine was reaching fan kick in temp at 92 degrees a few times when stationary . The blue peaks represent three motorway slip roads and high revs to the limiter range followed by a run at " national speed limit " You can see the coolant temp immediately drop given the increase in revs , open thermostat and cold air flow but that was quickly arrested  as the thermostat closed .No extreme drops into the 60s as some unmodified cars seem to exhibit .

I was a bit worried that keeping the temperatures higher would generate another problem such as the fan staying on for long periods but that doesnt seem to be the case .It kicks in at 92 and ,in todays 17-19 degrees ambient it was off again at 90 in less than a min  .

Pretty pleased with these results .

Next step is to try it on a much colder day and see how it performs . 

[Shortshift]

Really encouraging results.

James