I was always told they were there to protect the pushrod tubes. At the very
least, they're there to protect the pushrod tubes.....though they may have
other benefits as well such as channelling air (doubtful), or providing a
level surface with nice grooves for water to sit on and rust/ a wonderful
surface for your oil pressure sender to short out on.
The two layer construction is......terrible. I had mine rust away
completely. I'm talking not salvageable.......you couldn't even figure out
really what they were. 50% of the metal was missing. The rust does indeed
get into the middle of the two layers, and does cause them to separate.

They rust. Have a spare set : )

-Craig
'85gl

On Sat, Jul 5, 2008 at 7:56 PM, Evan Mac Donald <vanagon_dad@sbcglobal.net>
wrote:

> While cleaning and welding new mount tabs on mine, I came up with a
> question about the "tin" - the sheet metal shrouds and covers on and around
> the waterboxers, to be specific -
>
>  First off - Why are there any at all? It ain't air cooled no more. Is it
> only to protect the push-rod tubes?
>
>  Second off - Why are the ones on the engine made of TWO layers of stamped
> metal? This construction method is a recipe for rust damage! Extra cost,
> too, because of extra processes, and handling during manufacturing...
>
>  Confused, curious, and enquiring minds want to know!
>
>  Evan
>