Once again BMCU members were the beneficiaries of the generosity of the Wasatch Mountain Jaguar Register, this time at a terrific tech session on carburetors presented by Jay Jennings at his place of business, Therm Pro.
In his customary thorough manner, Jay reviewed principles of combustion, properties of a well tuned automotive engine, the design, operation and maintenance of several popular carburetors both American and furrin’.
An entertaining sidelight was Jay’s discussion of how modern carburetors have evolved, notably the Holley, in response to increased performance and emission standards. He pointed out, however, that carburetion was doomed as standards tightened, which is why all cars today rely on computer controlled fuel injection.
Also fun were Jay’s stories on drag racing, and how the demands of that application turn most conventional wisdom upside down. Example: who cares about efficiency or smoothness at less than 3,000 RPM? All that matters here is maximizing fuel delivery, pure and simple.
The session ran lively hour and a half, with many attendees offering tips, insights, and tales of woe — with the latter with morals, of course. One particularly clever suggestion was to use letter “P” sized drills, which are 0.1″ larger than 5/16″, as impromptu pilot reamers on throttle shaft bushings. The trick is to grind down the diameter of the end inch or so of the drill to 5/16″ so it does pilot alignment in the far bushing while the near bushing is reamed to 0.1″ oversize as required by many replacement throttle shafts, e.g., as sold by Moss.
The turn out was terrific, with standing room only. Seen in the crowd were: Mitch Johnson, Larry Farrington, Doug Bareck, Al Gordon, Barry Engstrom, Werner Prochaska, Rob Wiseman, Pugs Pivirotto, Mike Cady, Bud Merritt, Chris Macan, John Progess, Richard Hughes, Bonnie Hughes, Marshall Wright, Rob Foye, Chris Jones, Larry Bishop, Rudy Vanderniet, Tony Earl, Glen Hawkins, Dennis Hoagland, Steve Moore, and your obedient scribe,
–Gary Lindstrom