How long to smoke a four pound brisket piece

I’ve smoked many flats or full briskets but this just a small piece that the wife bought from a local farm. It is 8 x 8 inches and 2.5 inches thick. Ultimately, it takes what it takes but I am not sure how long to plan for never having smoked something this shape. I’m guessing 6 hours but that is just a guess. Allowing for resting, that would be starting 8-10 hours before the planned meal time. Does this make sense?

I smoke on a primo grill, try to keep the temperature between 225 & 250 and generally don’t wrap but will if needed.

Does this seem reasonable?

Sounds like it’s just a section of the flat? If so, my guess is under 6 hours, in your temp range. Personally, I’d wrap it after about 3-4 hours of smoking, to keep it from drying out. But I tend to favor moisture over bark.

Some recent data points. Both examples using WSM running at 250 degrees. Did not wrap

2.8 lb smoked chuck roast = 4-1/2 hours to 203 degrees

5.7 lb brisket flat = 9 hours to 201 degrees

Hope that helps some

Thanks. That seems in line with my guess.

At 8 hours, it was still in the 170s so i wrapped and moved to a 250 degree oven to finish. It is now 10 hours and 45 minutes and its finally hitting 198. It eill end up being 11 hours for this four pound piece.