2000TransAmWS6

iTrader: (12)

so i've been working on porting my own heads (241 castings), and i've been trying to read as much as possible about it, although i believe i'm about 80% done removing material.

https://ls1tech.com/forums/generation-iii-internal-engine/414121-ls6-head-porting-questions-pics.html
i was reading this thread, and on post #16 the guy is talking about opening up the valve seat. could someone who has done this before explain to me in more detail what he is talking about?

xfactor_pitbulls

iTrader: (16)

Its easy, you have the machinist do that for you on a seat and guide machine. You want to have your valve job match your seat throat. 90% is a rule of thumb, pretty much every well done performance valve job isnt going to be exactly that though. You should not do ANY work to the seat with a hand grinder, atleast not at this point.

GuitsBoy

iTrader: (4)

I knew i wasnt going to have a valve job done on my DIY heads, so I simply opened up the bowl by hand to about halfway up the first seat angle. It was a rough estimate using some calipers and eyeballing it.

2000TransAmWS6

iTrader: (12)

thanks guys!