[T3] Heat exchanger advice

[Jim Adney]

On 28 Nov 2014 at 7:43, Jacob Adam Schroeder wrote:

> I am in the process of rebuilding the engine in my 1972 Square.  I located
> a nice pair of heat exchangers from a local scrap yard, and had them
> blasted and ceramic coated--they look beautiful.
> 
> My old heat exchangers had the insulation on them, with two metal tins (one
> along the bottom, and one along the curved part) over the outside of the
> insulation, with everything held on by a series of metal straps.

VW installed the insulation up thru '72, but then left it off as they 
were cheapening up everything for the last year of production. I 
think the insulation makes a difference, especially in cold climates, 
so I've always wanted to have it there, but in SF it's probably much 
less important.

As far as rust goes, I've found that the insulation tends to get oily 
after a few years, so this tends to retard rust. The only rust thru 
I've ever had is on my '73 without the insulation, where some of the 
inner fins seem to have rubbed thru the skin. It's possible that the 
insulated ones did this, too, and I never saw it, but in that case, 
the insulation still kept the hot air from leaking out.

The metal shields are just there to protect the insulation. Those 
were also left off of the '73s.

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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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