2023 Toyota Prius - WOW!

[Isaac Zachary]

Originally Posted by cRiPpLe_rOoStEr

Not sure about Mexico, India and South Africa, but in Brazil many owners of Ford cars with the Zetec-Rocam engine say replacing the thermostatic valve by one with an aluminium housing instead of plastic improves cooling noticeably.

That could be.

On the other hand, there are also those cases of those who a couple people have an overheating problem and then everyone starts making their own conclusions. After a while there are ideas everywhere, many of which are complete myths.

Take the aircooled VW's for an example. There were those who'd remove the thermostat as soon as they bought a VW and there were those that swore the thermostat system actually helped cool the engine even better by directing the air towards the heads.

In my expeperience, with a mostly stock system I was climbing up long steep mountain passes on hot summer days and never broke 350°F head temps nor 210°F oil temps in the 1600cc VW Super Beetle.

[Piotrsko]

on an aircooled clean air engine, the thermostats flappers were known to stick shut and trash an engine. It's really hard to find one with working parts. It is also difficult to say if the directed air favored anything since they closed sideways. The best ones came off the early single ports and were installed on the cooling fan input

[Isaac Zachary]

Originally Posted by Piotrsko

on an aircooled clean air engine, the thermostats flappers were known to stick shut and trash an engine. It's really hard to find one with working parts. It is also difficult to say if the directed air favored anything since they closed sideways. The best ones came off the early single ports and were installed on the cooling fan input

See, I know people that are going to disagree. Some say the flaps would always fail open. All I know is I had +40-year-old flaps and thermostat on my Beetle and they never failed in the short time I owned the car.

[freebeard]

There were those who'd remove the thermostat as soon as they bought a VW and there were those that swore the thermostat system actually helped cool the engine even better by directing the air towards the heads.

You're half right.

Thermostat delete on the first rebuild. .... and it was the cool tin that redirected the air.

[Piotrsko]

I didn't find the cool tin to do all that much. Chts only went down 50 degrees driving through mojave on the highway. Got a better response plugging the fans heater outlets with block plugs

Having said that, there were several versions of cool tin available. I was running the chromed Cal Custom ones

[cRiPpLe_rOoStEr]

Originally Posted by Isaac Zachary

Take the aircooled VW's for an example. There were those who'd remove the thermostat as soon as they bought a VW and there were those that swore the thermostat system actually helped cool the engine even better by directing the air towards the heads.

Ethanol versions of the air-cooled VW engine in Brazil often had problems with the thermostat. Some folks simply removed it and ran on gasoline. I remember seeing a Beetle for sale in Pelotas in 2010, which originally ran on ethanol, yet after the thermostat failed it was simply removed and the car was running on gasoline.