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TR4/4A Thermostat for a TR4

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Alex_McMillin

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Hi Everyone,

Just wondering if there is a generic thermostat I can use in my 63 TR4 or is it very specific to the car. I thought I heard Triumph used the some one in just about everything from TR3 up to the TR8. I prefer not to have to order it from one of the big three if I don't have to.

Thoughts?

.............Cheers, Alex
 
The original tstat would have had a sleeve to block the bypass hose as it opened.

A generic tstat in the temp of your choice will work but leave that bypass hose open. Some think this reduces cooling by sending some hot coolant back to the block w/o it going through the rad. Some don't think so.

Some partially block the bypass hose to compensate for the lack of a sleeve. Some think this is a bad idea. Some think it is okay but probably doesn't help much.

Me: I use a ordinary modern tstat at (I think) 160*) and block the bypass hose with a 3/4" copper pipe cap with a 3/16" hole drilled in it.

Lots of opinions and approaches here.
 
Aloha Alex,

I concur with Geo. I also restricted flow through the by pass hose using the same method.
 
The later TR4A thermostat housing has this restriction built in to the bypass hose casting. So if you have a TR4A (or TR4A housing), a generic thermostat will work fine too.
 
I have used both style thermostats and found little to no difference in performance. I currently have the modern version installed and run at about 165 degrees. I did not block the bypass at all.
 
I also played with blocking the bypass in various ways, and decided it didn't make enough difference to worry about. I run a modern 185F Tstat with the bypass open and no overheating problems even in 115F temps.

But I also have a Modine core with no crank hole, an electric fan and a 7 psi cap, so YMMV.
 
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