This has been a long time coming and fix that was dearly needed. If you haven't been following the blog, the pilot has been an issue since I first got the car over a year ago. It would refuse to vaporize fuel for any period of time over about five minutes. This was a major problem because once it started to spray liquid fuel it would become ultra rich and eventually pool in the burner pan causing an unwanted fire.
I decided to call Don Bourdon from Bourdon Boiler Works to see if he could help me understand why the Packard pilot would refuse to run properly. After much discussion we came to the conclusion that the reason the pilot is not vaporizing must be because of an excess of fuel and/or a lack of heat.
It had crossed my mind to make a longer vaporizer so that the fuel would spend more time in the heated area before reaching the nozzle. This would have involved bending a piece of 5/16" Stainless tube in a mighty tight 180 degree bend which didn't seem all that easy. After some thought I made the choice to put a piece of cable in the current vaporizer to decrease the inner diameter by about one third thus decreasing the amount of fuel sitting in the vaporizer at any given time.
To my delight this approach has work out very well. I have been able to keep the pilot running constantly for approximately 200 miles without the issues of spraying liquid fuel.