triumphs
[Top] [All Lists]

RE: 6 blade fan

To: "Triumphs" <Triumphs@autox.team.net>
Subject: RE: 6 blade fan
From: "Randall Young" <ryoung@navcomtech.com>
Date: Sat, 18 Jan 2003 09:58:29 -0800
> It also stated that
> the thermostate should not be removed completely because it slows the flow
> of water and allows it to absorb the heat.

That's a very old myth, used to explain that some cars will overheat if the
thermostat is removed completely.  It's been handed down as gospel for at
least 50 years, probably longer.  Only problem is, it makes no sense from a
thermodynamics point of view.

What actually happens is that the radiator is so restrictive that without
the throttling effect of the thermostat, the water pump will build up enough
pressure at high rpm in the top of the radiator to blow coolant out past the
pressure cap.  When the rpm drops, the cap sucks air.  The cycle repeats at
every gearshift until there isn't enough coolant left to keep the engine
cool, so it overheats.

TR3s do not seem to suffer from this problem in my experience, so I suspect
Kas was just repeating the myth.

Note that most modern cars now have the pressure cap on the suction side of
the radiator, which prevents this particular problem.  Coolant recovery
systems do a lot too (and are a worthwhile retrofit to earlier cars with
overheating problems IMO)

Randall

///  triumphs@autox.team.net mailing list
///  or try  http://www.team.net/cgi-bin/majorcool
///  Archives at http://www.team.net/archive


<Prev in Thread] Current Thread [Next in Thread>