Stalls during brakeing

[Hal Copple]

I have a different opinion as to why my car, a custom stroked Windsor, with a Holley 750, properly set up, will try to stall as i brake at low rpm. I am accustomed to a touch of "heel and toe" to slightly blip the throttle, until i can apply more throttle, or until the car comes to a compete stop.

Here is my opinion. A "built" engine does not have much vacuum at idle. When coming to a stop at low rpm, the gas in the primary bowl wants to flow to the front of the bowl, away from the primary jets. Then, with the very low vacuum at near idle, there just isn't enough engine vacuum to signal via the "boosters" that some gas is still needed to run the car. Which has to pull some gas back rearward into the primary jets.

Assuming your carb is set up properly, as the posts above suggest, the only real cure is to increase your idle rpm a bit. I personally like the low intimidting idle of about 700 rpm, so i leave it set there.

So this is why in a highly cammed engine, with lots of valve overlap, this tendency to die at low rpm stops occurs. At least it makes sense to me.