99 Black Bird T/A

iTrader: (4)

Does Head Porting Affect Reversion?

Saw info on an import page that claimed, their special porting techniques reduce reversion and allow for bigger cams with 4-valve heads.

Is there any special porting techniques to ask your head porter about to get a set of LS1 heads ported to reduce reversion?

I want to use a B1 or similar cam and avoid misfire codes at low rpm so my cars PCM can pass the new OBD-II scan test. Just disabling the test/code will result in an automatic fail, so I can't do that.

Any comments appreciated.

Thanks

HP-GURU

The more air your head flows into the cyllinder, usually the more air it will flow going backward through the port.

I'm sure valve type can determine what happens with the air

LS1derfull

99BBTA, you could help reversion by insuring that exhaust ports are not same size as header opening,sinking exhaust valve in cyl. head ,and by shaping intake valve head to not promote back flow into intake port on overlap sequence.
David Vizard has a excellent book about head porting that illustrates these procedures.

99 Black Bird T/A

iTrader: (4)

Thanks for the info.