ef9frank

ok here's the deal, just built my ls/vtec. heat treated crank micropolished and balanced, with heat treated ls rods, and je 12:1 pistons. car cranks and everything but while i'm cranking it makes like a knocking sound from the motor. it only does it when i crank it after that it seems to be fine no knocking or nothing after it cranks. it stills pull hard and everyting. can some one help me?