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Mark w
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Why ? I've got a car and can see it !

Jonathan Kay
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It might help CtrMint and other Members on their own cars, and would definitely help me to understand the discussion.

Jonathan

Mark w
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Jonathan Kay
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Thanks

Jonathan

Mark w
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 Water outlet , no bypass pipework .

Mark w
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Apologies , top photo is upside down ! 

7 wonders of th...
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Hi Mark,

The hose to the pressed in metal pipe above the stat housing is the bypass hose and is designed to circulate water from the rear of the head and discharge directly onto the wax bulb of the stat, which aid warm up as there is a circuit around which coolant can flow and makes for rapid, timely and accurate activation of the stat.

Your system has a tiny tiny bypass as this hose is fed via the bleed hose to the expansion bottle and therefore does none of the above to any great effect.

Do you have a photo of the stat they use..? as if they are merely taking the guts from the OE ford one this will create another problem as it is designed to close the bypass as the stat opens - if it does this in your set up it we block the bleed circuit from the bottle (this bleed circuit would normally feed back in via the heater return via the 16mm hose which is in the OE plastic stat housing and has been omitted form your ally housing).

 

ChrisC
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Isn't there also a bypass effect with the drilling / shape of the thermostat housing, although not so much bypass, more like "stat close, low flow through the rad, and bypass via the expansion tank", "stat open, high flow through the rad" 

Mark w
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Hi , Sorry no stat photo .My guess is its a traditional unit that just sits in the machined recess in the deeper alloy flange on the replacement pipe inlet pipe  .

The flange has a recess milled into the back at the top that coincides with the position  of the " bypass connection " on the block , possibly overcoming the potential problem to which you refer ? 

I do agree that its possibly odd that there is no bypass pipe from the rear of the block to the stat but its worked fine since 2014 .

The only issue is the one that Mark alluded to in the first post and thats one of overcooling in low ambient temperatures .Most Caterhams dont get used much in the winter ,if i use mine i just blank the rad a bit and its sorted . Other wise it works fine , holds a fairly constant temperature and never overheats .

CtrMint
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I've asked Oakmere to check with CC, see if they can confirm if my 620R has a thermostat.  I'm still none the wiser.  Oakmere said they thought all 620 models had thermostats, the concept of no thermostat was a new one to them too. 

 

Caterham 420R S3 Lotus Toxic Green,  awaiting Caterham 620R delivery. Blog: https://www.caterham7diaries.com