thermostst modification

[keri]

Hello hope this finds everybody well, i was wondering if any body had carried out the thermostat modification to their Gamma I've seen it is relocated to the top hose using a Renault stat and was wondering if this is done as maybe the original is no longer available or that it offers an improvement on the original set up, for me the original set up seems right as the stats is situated as near as possible the cylinder head  and block where the heat is, and by moving it to the top hose takes it away from the hottest place and a possible lower   temperature in the top hose compared to the cylinder head/block? Mine still has its original stats in the correct place so i will remove it and test it, are replacements available? if not in the top hose it is but maybe as close to the engine as is possible.
thanks
Keri

[inthedark]

I have a Renault 5 thermostat in
the top hose, butted up against
the output from the top rail.
I used a lower temperature stat
with lower temperature fan switch
plus a twin push fans.
All works fine for me.

[keri]

Hi thanks for that i have a renault stat rated at opening at 75 degrees so will fit this but i am interested in the fan switch you used with a lower switching temperature what was this off and how did you fit yours also is there any reason why the stats are now fitted at the top hose and not in the bottom one right next to where the original was fitted.
regards
Keri

[inthedark]

Heat rises so higher thermostat
reacts quicker, Theo recommends
Drilling a small hole in the operating
plate in the thermostat.
For the fan switch I just asked the
accessories shop for a 79 degree
Sensor of the same thread.

[Theo]

Yes, I think the standard Gamma thermostat is in the wrong place as heat rises so the hottest water will be at the top. Then again, I think one of the Gammas problems is that the water pump area gets very hot and once the water starts to boil at that point, the pump cavitates so there's no water movement and a vicious circle starts that causes the car to overheat. I do think a small 3mm hole in the Renault 5 thermostat in the top hose is necessary to get some circulation of coolant through the thermostat for better temperature sensing. Especially important if you remove the bypass pipe which normally routes water from the pump to the top rail when the standard blender thermostat is closed. I have blocked off that pipe and I think it should be when not using a blender thermostat. An impeller pump, which is what a water pump is, will not build up pressure if the pipes are closed but for temperature sensing you want to have some movement of coolant flowing through the thermostat. I have also added an adjustable thermoswitch for the cooling fan (or fans in my case, I have three!!) with its sensor probe in the top hose. I can therefore adjust the temperature that the fans start.

[keri]

just a quick on the adjustable  switch is this the one with a probe into the top of the radiator and the wire under the top hose to the adjuster if so did you have any leak issues at the hose where the wire exits i know the top hose is clamped but the wire still comes through?  thanks for all your replies
Keri

[Theo]

I've used something similar to https://www.ebay.co.uk/itm/402831865782

No leak problems as it comes with a rubber insert that fits inside the top hose with a channel for the probe.