Ugly Duck wrote:
Carburators actually vapourize the fuel a whole lot better than port fuel injectors do, especially when the intake is heated through one method or another. I could turn off the choke on my truck by the time I hit the bottom of the hill in the winter, but all my Megasquirt experience tells me that I need at least 20-50% enrichment, even to within 20-30* of operating temperature, for smooth warmup driving. The poorly atomized fuel sticks to cold port walls a whole lot more than the fuel coming out of a carburator sticks to the entire intake tract. EFI Volvos seem to lose about 20% mileage in my driving during the winter, and I'm really gentle on them & avoid unnecessary idling. Same goes with my truck, and Roberta's 850.
Makes sense. Now that you mention it, in cold weather, my (at the time) non-intercooled 240 drove real nice lol...12psi non-intercooled is kind of fun. K-jet injectors have a pretty good patten right around the intake valve though. I completely agree that a carb with heat either from the exhaust or coolant will run real well cold, but I was pleasantly surprised at how well the k-jet worked. The cop car would start and run nice on the mountain (like -10F) where my LH car never really would. 7.5:1 compression and a T-cam on k-jet also plays nicer than ~12:1 on a K and LH i'd imagine. Same oil and good batteries between them though...mostly by chance...0-30 mobil with large interstate batteries. Water cooled turbos also make for nice heat going up a mountain.