I agree that running in the 200 degree plus range won't hurt an engine, if
the gaskets and seals have been replaced with modern materials in the last
10 years or so. New cars typically have 195 degree thermostats, and
temperature controlled fans which kick in at temperatures in the 215 to 220
range. Certainly 220 isn't going to hurt any metal parts!
The danger comes from localized boiling, which can cause vapor pockets in
the heads, resulting in extreme overheating in a small localized area - thus
the need to keep the coolant boiling point as high as can practically be
achieved. Uneven heating is what causes warping of heads etc., not simply
high temperatures.
Dick Benjamin
----- Original Message -----
From: D. Dardalis <dardal@xxxxxxxxxxxxxxx>
To: <mailing-list@xxxxxxxxxxxxxxxx>
Sent: Sunday, April 21, 2002 9:29 AM
Subject: Re: IML: coolant system, overheating?
> At 06:28 PM 4/20/2002 -0700, you wrote:
> >HOWEVER: In any Imperial with the cooling system in such a marginal state
> >that you have to worry about things like this, you need to clean it out,
> >including the block (see IML archives for procedure). These cars were
> >(OVER)-designed with a cooling system that tolerates years of abuse and
> >accumulated crud, even in severe environments (like Texas), so if it is
> >telling you there is a problem, it is in really, REALLY bad shape. Clean
> >the poor thing out before you warp a head or worse!
>
> Thanks DB. The "auxiliary" radiator (from a BMW motorcycle) keeps the
> temperature below 200 most of the time in the summer. Sometimes, it
> reaches 210 on a continuous high speed drive if I have not flashed the
> system for a while. After I flash it, and let much of the rust out, it
> runs cooler. These temperatures are well within the tolerance limits of
> the old and still very powerful 440. This is the Sedan engine with the
big
> cam. My guess is that once I repair the AC, the little auxiliary radiator
> will not be sufficient, and the temperature may start rising again. But
> till then, my unusual conversion protects the engine. Until I installed
> the BMW radiator, the temperature would often exceed 220 (I had seen
> temperatures as high as 240, in which case I would pull over and slowly
> poor cold water on the radiator with the engine idling, this would cool
the
> engine down). The only damage the overheating did was to kill the valve
> stem seals (I think the two were related). So since then, the car puts
two
> good puffs of blue smoke when started, but the smoke disappears within
> seconds of running. The problem is certainly NOT from the rings, since I
> have not had to replace/cleane the plugs since 1996 (over 40,000
> miles). Also, the engine has enough power to keep up with ease on the
open
> road with an Audi A-6 2.7 twin turbo!
> D^2, 2x68s
>
>
>
Back to the Home of the Forward Look Network