Goes on the intake manifold near the firewall.

Mine broke off when I was trying to remove the short hose that attaches to this doohickey.

Edited November 10, 2025Nov 10 by tadslc

It is a thermostatic switch to close off the manifold coolant line (the tube across the manifolds).

A remedy for over heating the fuel, that did not function well. IMHO

15 hours ago, Terrapin Z said:

It is a thermostatic switch to close off the manifold coolant line (the tube across the manifolds).

A remedy for over heating the fuel, that did not function well. IMHO

Thanks!

Not really sure how that would work but more power to Datsun!

I think I'll just leave it off and install some sort of standard nipple.

4 hours ago, tadslc said:

Thanks!

Not really sure how that would work but more power to Datsun!

I think I'll just leave it off and install some sort of standard nipple.

I plugged mine off but it doesn't get very cold down here. Less chances off leaking, losing coolant was my main reason. Lots of info in these threads...

https://www.google.com/search?q=plugging+water+to+carbs+240z+classiczcars.com&sca_esv=77dc914585b7f4b2&rlz=1C1VDKB_enUS1121US1121&ei=1oETafjINaKHp84P-LudoAw&ved=0ahUKEwj4i8S_3uqQAxWiw8kDHfhdB8QQ4dUDCBM&oq=plugging+water+to+carbs+240z+classiczcars.com&gs_lp=Egxnd3Mtd2l6LXNlcnAiLXBsdWdnaW5nIHdhdGVyIHRvIGNhcmJzIDI0MHogY2xhc3NpY3pjYXJzLmNvbTIFEAAY7wUyCBAAGKIEGIkFMgUQABjvBTIIEAAYgAQYogQyBRAAGO8FSJZBUOkFWKcfcAF4AJABAJgBlgGgAcYIqgEDMC45uAEMyAEA-AEBmAIKoALsCMICDhAAGIAEGLADGIYDGIoFwgILEAAYsAMYogQYiQXCAggQABiwAxjvBcICCxAAGIAEGLADGKIEwgIKECEYoAEYwwQYCsICCBAhGKABGMMEmAMAiAYBkAYIkgcDMS45oAfSHLIHAzAuObgH5wjCBwUwLjguMsgHFA&sclient=gws-wiz-serp