Re: Performance Cooling mk2 setup in mk1?

[Neal Tovsen <ntovsen@piper.hamline.edu>]

On Thu, 5 Aug 1999, Jody Bailey wrote:

> Mark Peele wrote:
> 
> > My 1982 Scirocco (MK2) does not have the remote - I plan to upgrade to
> > the later style when I put a bigger motor in.
> 
> I too have the non remote tank type radiator in my 82.  Does it have
> less of a cooling capacity than the later style?  My 82 has a RD engine
> in it with a shaved head and full exhaust and runs quick, but also runs
> farely cool.  I mean with a lower temp switch and thermostat it never
> runs above the red light, and oil temp is never above 100.  Would it be
> worth it to convert?  TIA
> 
> Jody Bailey

It probably runs cool in your case because you don't NEED any additional
cooling when you live that close to the Artic Circle!
;-)

Seriously, the tank should provide additional cooling capacity for two
reasons. First, assuming your radiator is the same size, there's more
coolant in the system with the resivoir, which allows you to dissipate
heat over a greater volume. This probably isn't really significant though,
because the majority of coolant in the tank doesn't ever actually travel
into the radiator.

The big reason it should run cooler with the tank is because the tank
allows you to run the coolant system completely without air. Without a
tank, you have to have air gaps in the system to allow for the coolant to
expand as it heats up (air compresses, liquid doesn't). These air gaps
reduce the capability of the system to carry fluid, so it may make your
car run hotter. If you could only include as much air as you needed to
allow for your coolant to expand to *exactly* the capacity of the system
when hot, it wouldn't matter, since once hot, the system would be
virtually completely water. Unfortunately, a degree or two beyond that
point would blow the system, so you have to have more air just in case.
With an expansion tank, the coolant expands into the tank, and the air is
retained in the tank only, so there is no air in the rest of the system.

Exactly how much difference does this make? Unfortunately, I've forgotten
my thermodynamics from my college days. I would tend to think that it is
noticable, since my previous two cars (Fords) had radiator leaks, and I
could tell by the gauge when the system was starting to suck in air.

Here's the big question: If your car doesn't run hot, why mess with it?

~Neal


--
To unsubscribe, send "unsubscribe scirocco-l" to majordomo@scirocco.org.
If you experience other problems, email: scirocco-l-probs@scirocco.org