Getting Head

[BFT]

In couple of weeks I will be getting some L 36 series II heads. From there I plan to have them flow tested and then ported/polished if they are ok. What I've a question about is redoing the valves. Do you just use bigger valves on the exhaust or intake side, or can you do it on both sides? These heads will use the ZZP ER rockers as the valve train upgrade, and those have a larger opening on the exhaust side. Any help would be appreciated.

[GTP Dad]

You can do both if there is room although I the most benefit will be on the intake side since air is drawn via vacuum and pushed out by compression on the exhaust side. A cam with a slightly higher lift and duration will allow for more fuel and a longer duration on the exhaust will get rid of more exhaust gases. Porting an polishing is always a good move.

[BFT]

Cool, but the ZZP's are supposed to be like 1.9's I believe althought they never really released the true specs on them. So a can is out of the question.So I could switch to a lighter valve that; say .......... has a bigger intake side as you say right?

[GTP Dad]

You are correct. But check the heads first as they may be maxed out on the size valve you can use. Some of the newer heads already have the largest size valves you can put in them. Aftermarket heads are often better suited for such applications but there aren't too many people making them for the V6.