Keeping Cool (Post # 22)

What takes the most time in a restoration?  A lot of categories vie for that honor, but at the moment I would say it is "details."  If you pay attention to the details and do things right, it will be worth it later on, but while you're actually doing it there is a little voice whispering "Is this really necessary?"  Who is ever going to see it, and even if they do, how would they know the difference?

Case in point is the harmless-looking widget below.  When I disassembled the engine room it was embedded in the top tank of the Alfatross' radiator with just the small shaft sticking out.   What the . . . ?   Immediately in front of the radiator was a louvered frame, obviously meant to open and close to assist warming up the engine.  A rod on a pivot was attached to the middle of the top louver and the others were linked to it to follow its motion.  I reasoned that the widget had at one time been connected somehow to the louvers, but there was nothing there now.  The louvers were wired up in the full open position.

The radiator widget.  The numbers in the upper left corner of this photo are
stamped into the bronze body.  IPRA is probably the manufacturer.  The  "4"
above is probably a size and the numbers below are probably the temperature
ranges at which it opens and closes the louvers as the
water in the radiator warms up.

Here's the louver frame that sat in front of the radiator.  The rod in the middle
of the top louver was intact, but how did it connect to the widget?

For many years I was at a loss to find a replacement widget or figure out how the linkage between it and the louver box worked.  The breakthrough came when I saw the car below at a show in 2002.  It had only recently come to light and was on display as an exciting new "barn find."  While other spectators were admiring the remarkably intact interior and engine room, I was peering through the narrow openings in the nose to see if the louver actuating linkage was still there.  It was!

The car that solved the mystery.

Normally, it would have been impossible to photograph the linkage, but as luck would have it the car was missing the grill frames on either side of the central grill and the unobstructed openings were just big enough to get my digital camera inside.  The photos revealed that the linkage was intact and operational, which was great, but also that it consisted of no less than 9 parts and was not the sort of thing that could be duplicated from photos alone. 

Here is the 9-part linkage in the barn find car.  The widget is invisible inside the
radiator.  As the coolant in the radiator heats up, something inside the widget
 expands and pushes the end shaft out against a roller mounted on the lever arm.
 The spring helps to push the end shaft back into the widget as the radiator cools.

I figured that finding an intact, operational, linkage assembly like this was unlikely, but maybe the owner of this car would be willing to take it off and send it to me so I could duplicate it for my car-especially if I sent him my front grill frames so he could duplicate them for his car!  And that's exactly what we did. 

In addition to lots of photos shot from every angle, it was critical to record all the dimensions and types
of metals used: bronze for the lever arm, spring steel for the spring, brass for the rivets, mild steel
for the cotter keys, and hard steel for the roller and axle.

Recording the linkage assembly was the easy part.  Making it was hard.  The lever arm was the hardest part to duplicate because it was a solid piece that had to be cast.  I didn't want to send the original to a foundry, so in addition to photographs and dimensions, I also made a mold of the roller and lever arm assembly and cast it in resin.  I sent this to the foundry for final casting.

The resin cast of the lever arm that was sent to the foundry for duplication in
bronze. 

The next challenge was the spring.  I knew I couldn't do this myself, so I farmed it out to a specialty spring maker in Corpus Christi.  I was astounded at the cost estimate: $250!   It was the last spring they ever made.  When I went to pick it up the owner was locking the doors and closing up shop for good.  I guess that even at $250 each the specialty spring market is pretty thin.

How do you measure a spring, anyway?  The important is figuring out its "springiness"

So the Devil really is in the details.  All this, spread out over about 10 years, for a part that would fit in the palm of your hand, a part that the car really doesn't have to have and few would notice the difference if it didn't . . .

. . .  and I'm still trying to figure out how to open the widget to rebuild it!