stage 1 v8 hot starting

[Brendan321]

i have been having an issue for a while with my stage 1 which i have put up with for a while and spent some money on trying to fix but... didnt get anywhere and have now found a rather strange problem. basically when the vehicle has warmed up it would take like 5-7 seconds of cranking under full throttle to actually start.

after much poking around trying to eliminate anything that could be problematic before sending it back to the place that tuned the carbies recently (which i sent it to them to fix this issue) i have found that the vehicle starts perfectly when the 2 crankcase breather pipes from the rocker covers are disconnected and just let vent to air.

what i suspect has been happening is when i 1st hit the starter hot, it fires a lil bit then doesnt fire for much cranking, then, after a while with full throttle, it fires up. the 1st few power strokes are enough to generate some blowby into the crankcase which get drawn into the carby, over richening the mixture which takes a while to clear. the over rich mixture doesnt matter when cold.

the rest of my crankcase ventilation is good, new flame traps, the breather at the back of engine is clear and working. i do not have the charcoal canister installed and the 2 vent pipes from carbies which are supposed to connect into it just go straight to the fuel tank breather. but disconnecting/blocking these has no effect.

anyone have any thoughts on what to do? all i have thought of so far is to put PCV valves in place of the flame traps, but this wasnt original so shouldnt be needed?

[disco2hse]

Two things come to mind: vapour lock either in the carbs or in the fuel line (more likely), or leak/blockage in distributor vacuum tube.