V8 Thermostat - Which direction in the housing?

[FoxTVR430]

I have a (stupid) question.
I am busy rebuilding the top half of my engine and I realized that I had forgotten which way the thermostat fits.
Can some one help?

I took a photo of how I think it should be. (spring inside the manifold)


Also I found this.


Please confirm.

Thanks.

[BIG DUNC]

The way you have it is correct.

I think you will find that if you turn it round the other way then the housing will not fit over the top of it. Then you have proved it to yourself.

[Steve_D]

You have it facing the right way but also worth commenting that the breather hole (with the brass bit in it) should be at the top.
You have it correctly positioned but this may just have been chance.

Steve

[BIG DUNC]

Very good point Steve.

I did think that, but completely forgot to type it.

Don't ask me how I know how important it is.

[ruhall]

Just for added reassurance, if you think about it, the thermostat needs to get heated up before it opens, so the wax section needs to be 'inside'.

A 'Blue Peter' type of video should also reassure and provide endless hours of entertainment

[FoxTVR430]

Great, thanks for all your answers.

Also the tip about putting the bleed hole at the top.

[Sardonicus]

Back in the day witnessed lots of DIY owner efforts putting in thermostats the wrong way round on Ford Pinto and CVH engines easily done when your daft and didnt take note of how the old unit came out I guess rapid over-heating ensued

[Jobster]

So what happens if you misaligned the bleeding hole?

[Jobster]

So what happens if you misaligned the bleeding tip?

[phillpot]

[Jobster]

phillpot said:

Haha. And now a serious answer whilst I still have the dyno unbolted.

[phillpot]

As I understand it the hole is just there to allow air to bleed out when filling the system, stat will be cold so obviously closed. Higher the hole the more air can/will escape.


Google says.......

[Sardonicus]

phillpot said:

As I understand it the hole is just there to allow air to bleed out when filling the system, stat will be cold so obviously closed. Higher the hole the more air can/will escape.


Google says.......

pretty much on Honda cars the rubber seal also index's the stat so it can only be fitted with the jiggle pin upper most and no other way for good reason

[Jobster]

clear, thanks. And is it how it should be that when the engine is cold and I remove the thermostat hardly any coolant leaks out? Expansion thank is half full.

[Jobster]

update: today I added 2ltrs of coolant...... Which shows that an expansion bottle that's half full doesn't mean a thing at all.

[Sardonicus]

Jobster said:

update: today I added 2ltrs of coolant...... Which shows that an expansion bottle that's half full doesn't mean a thing at all.

Of course it dont it just means its run hot enough to spit out the block contents into the expansion bottle

[Jobster]

Sardonicus said:

Of course it dont it just means its run hot enough to spit out the block contents into the expansion bottle

anyway. Not sure whether this will blow a whole in my wallet but we'll see.