(OT) Car stuff, but not Ford or Toyota

snipped-for-privacy@n20g2000vba.googlegroups.com:

That's the old school way; some engines do it "backwards" which is one reason that the thermostat may be mounted in the lower hose not the upper. The main advantage to that is that it cools the heads more efficiently allowing for higher compression ratios, which of course means More Power (argh argh argh)

That too. Most of the heat of combustion is shed to the heads, so cooling them first does BOTH allowing the heads to run cooler (allowing more compression) and also reduces the temperature difference between the heads and the cylinder bores.

nate

N8N wrote in news: snipped-for-privacy@z19g2000vbz.googlegroups.com:

The Hondas and Toyotas I've seen and worked on that have had the thermostat in the lower hose still direct the coolant the "old school" way: Block first, head after.

I suspect that if you would study your new Impala's cooling system, you may find it has "old school" coolant flow as well.

Aha, the famous exception that proves the rule. Very interesting indeed. I can see the advantage to reverse-flow in high-performance applications, especially those applications that are subject to impossibly strict emissions regulation.

However, that advantage must be limited in scope, or not as great as it might seem, otherwise the system would have spread well beyond the one or two specialized GM engines that actually use it.