have a 53 239 cui ,new carb, fuel pump and fuel filter when it sits for a few hours or over night,cranks for a long time before it will fire off ,seems to start ok when engie is hot, shut off & restarted in a short periord of time..any ideas??? fuel pumps is a brand new napa

 

Sounds like the carb is drying up and it takes the pump a long tome to refill it. The pump is new did you replace the pushrod? At least I think the late flat head still had the pump mounted back on the center of the intake. Too short a stroke of the pump would limit the volume of fuel delivered. kotzy

 

I'm thinking fuel drain back as well

 

the guy's are right about it draining back but i'll be dained if i can figure how with a mech. pump . maybe like suggested to short a stroke on the rod and / or maybe your rod is bent ?was gonna be a smart aleck and suggest you yell contact and spin the fan a lil' harder..... or threaten to replace it with a more modern v-8....

 

Back in 1953 carburators all vented externally so if the heat riser on that engine is stuck in the closed position the carb base is pretty hot. Shut off the engine and the fuel boils out thru the vent. Later carbs vented in the throat and flooded engines resulted in the same condition, these are one of the ways to drain the carb bowel. Also a high float level will result in siphoning of the fuel out of the bowel. With a needle and seat controlling the level it can't return to the tank thru the fuel pump. kotzy