BBC Main Seal

[rondv]

Embarrassed to ask but... I'm putting together a BBC 427 - 2 piece rear main seal and I cannot remember which way the rear main seal goes in. Does the lip point to the transmission or to the front of the engine ? ... or does it matter ?
Thanks,
Ron D.

[R Pope]

Just remember that the seal relies on crankcase pressure to push it against the shaft, so it has to "lean in" to that pressure.

[lt1s10]

Originally posted by DennyW
Pcv system, neg pressure in crankcase.

there is none in mine.