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Cheap remote thermostat
DIY Si - 12/12/10 at 10:10 AM

Morning all.

I've been having a bit of a read up about the K series and it's possible fitment options in my Sprite. As some of you will know, the standard K series thermostat is in the return line from the radiator. This works fine for Aunty Mavis going to the shops and back once a week, but is rubbish for anything else.

QED do a remote/inline thermostat, but being tight I don't fancy paying £150 for it. Does anyone know of a production car that has such a thing, or a cheaper after market source of something similar? Or if not, a cheap and easy(ish) way of making something like it? It doesn't matter about hose sizes and that sort of thing, as I'll have to make a water take off plate for the head anyway. It would be a benefit if it uses standard thermostats too, as then I can then experiment with running temps easily.


rusty nuts - 12/12/10 at 10:40 AM

IIRC CBS list one for not a lot of money?


marcjagman - 12/12/10 at 10:41 AM

Plenty on ebay for about £25-£35


MikeRJ - 12/12/10 at 10:42 AM

Yes, Rover made the part you need; the PRT (or PRTT). This was fitted to the MG TF and Rover 75s with the 1.8 K series after about 2003, and the 1.8 Freelander also had it added at some stage.

The SELOC Wiki has part numbers and pictures.


bimbleuk - 12/12/10 at 10:44 AM

Something like the following?

www.rimmerbros.co.uk

P/N: PEM101020

Remote thermostat housing.


DIY Si - 12/12/10 at 10:57 AM

They all seem to be similar to the things I'm looking for. I'd rather have something with a removable thermostat if possible though. I'm just not sure I trust something that I can't open up and have a look at. If such a thing doesn't exist then I'll give the PRT stuff a try.


MikeRJ - 12/12/10 at 11:01 AM

The PRT isn't just a thermostat though, it has a pressure relief valve built in that will allow coolant to pass even if the 'stat is closed if sufficient pressure builds up i.e. running the engine at high RPM. This helps to prevent any formation of local hot spots in the engine before the 'stat opens which was a contributory factor to head gasket failures.


britishtrident - 12/12/10 at 11:48 AM

It is originally a Landrover TD5 part on ebay they can be found for less than £20 inc P&P as well as the thermostat a 32mmm equal T piece is required for the top hose this can also be found on ebay from Koy Carp fish pond supply companies ----- Once fitted they give a very constant temperature at the top hose and good circulation.



Rover remote thermostats come in several varieties the original black type opens at 88c and has no pressure relief feature, the cream coloured type opens at 90 c and the grey type at 87c, both the grey and the cream coloured ones have the pressure relief feature.
I have a spare black one sitting and a Tee piece and would want £10 + postage for the set. If you are interested U2U

[Edited on 12/12/10 by britishtrident]


britishtrident - 12/12/10 at 01:00 PM

quote:
Originally posted by DIY Si
They all seem to be similar to the things I'm looking for. I'd rather have something with a removable thermostat if possible though. I'm just not sure I trust something that I can't open up and have a look at. If such a thing doesn't exist then I'll give the PRT stuff a try.


All that is inside is an ordinary thermostat and in addition on the PRRT type a spring loaded pressure by-pass valve ---- simples


The PRRT stats just don't fail but if they do fail they will fail open and they an be tery easily ested just like any other thermostat by removing it pouring in boiling water.


Some of the remote thermostat housings that are sold for the K series are really badly designed (the QED is OK) they don't have by-pass connection so can't work properly.


DIY Si - 12/12/10 at 04:29 PM

BT,

I was planning on running the 'stat in the top hose between the head and the rad, with the bypass running through the heater, with maybe a hose off to the header tank. I was then going to run the rad bottom hose straight back to the pump along with the heater return. Seeing as you know the K series, can you see anything wrong with doing this?


PS, thanks for the suggestions everyone. Looks like the grey one is the one I'm after and it'll be £22 from Ebay. Locostbuilders to the rescue of my wallet once again!

[Edited on 12/12/10 by DIY Si]


britishtrident - 14/12/10 at 08:05 PM

Rover and many other manufacturers switched to controlling the outflow from the rad rather than the inflow for good reasons in that it gives much better control of cylinder jacket temperature, the plumbing looks a bit untidy but is very effective.


beaver34 - 14/12/10 at 08:40 PM

i could do with one of these,

edit,

think ive found what i want

[Edited on 14/12/10 by beaver34]