As for the car, I finally have some pictures of the differences between the heaters from a Mk1 and a Mk2. The biggest difference seems to be the integration of the footwell flaps into the box vice separate units. The older heater with the separate footwell flaps had a lot of gaps in it when I put it back together. The redesign seems to provide a much tighter fit, though it's clearly not air-tight.
|Mk1 heater footwell flaps. "Removable".|
|Mk1 front plate...note no footwell flaps and small holes for core pipes.|
|Mk2 front plate with integrated footwell flaps and elongated core pipe holes.|
|Side view of integrated flaps. The motor side cover has the air vanes.|
|First try. I used a pair of sharp pointed scissors and a large drill bit, by hand, for the holes for the tach/speedo cables.|
|Comparison of thickness between old and new. Close and the new stuff is more compressible.|
I then came up with a way to pressure test the cores using a garden hose. Worked pretty well, though I should have used regular hose clamps vice the "old style" as I had some leakage problems. I think this can be mostly attributed to using a Nylobraid hose vice rubber. I was happy with it and, surprisingly, there were no leaks from either core.
An inherent weakness with my design is that you do not know what pressure you are testing to. I'm sure I could have come up with a solution, but I'm also pretty sure it would have been cost-prohibitive.
|Pieces-parts. All told about $15.|
|The rig all assembled and attached.|
I had entered into testing thinking the Mk2 core was leaking since the inside of the heater box was pretty nasty with rust. There was also some green discoloration from copper corrosion. What I did not consider was that the heater boxes can be exposed to the elements if the drain clogs or otherwise doesn't work. Because of this I had cleaned up and painted the Mk1 heater box.
However, after successfully testing both cores, I cleaned up and painted the Mk2 box to take advantage of its better design and the fact that it's original. It was raining most of the afternoon so I didn't get a chance to apply the final coat of paint. Hopefully I can get that done soon and get it installed.