Thermostat - Which One

[over_the_hill]

My Chim has been a bit erratic temperature wise the last few times out. While sitting in traffic the temp. gauge has been heading north of 90 and yesterday hit 100. (I quickly pulled into a side street and stopped for a while to let it cool down. Subsequently had a hot start problem so was there a bit longer than intended but c'est la vie.)

Anyway this is fairly new behaviour having never done this before so I suspect the thermostat is on the way out. The fans were blowing away so I think they are OK but I will probably change the otter switch at the same time for good measure. Previously it used to be pretty rock solid at about 70 on the gauge, maybe going up to 80'ish in traffic.

I have read around a few other posts on this topic but opinion seems to be divided so I would like to ask which thermostat is recommended. I have also seen "big bore" mentioned and assume this is to increase water flow rate. Is this a TVR only adaptation.

I would like to get one from my local parts place if possible so that if there is a problem i.e. wrong size, I can easily nip back and change it rather than having to wait for a mail order part again. Therefore is this a standard part (Lucas ?) and if so what is the number.
Until I get the old one out I haven't got a clue what's in there at the minute.

thanks

[Green is good]

http://www.pistonheads.com/gassing/topic.asp?t=989...

I'm not sure how to paste links but this may help.