Any decent/noticable gains going with +1 intake/exhaust valves?

[AdvanSRT-4]

I'm just curious if there is any gains/noticable power diffrence with the oversized valves. I went with +1mm Intake/exhaust valves on my new head.

[porksword]

Might be hard to get a good answer on this one. most guys that took the head off either had a problem to start with, had it ported, did an engine rebuild, or at least did cams at the same time.
I would like an answer to this as well since I just put in oversize valves also, but it might be hard to get a good answer.

The way I looked at it is, there are 8 exhaust valves and 8 intake valves. So with +1mm valves I gained 8mm of air flow on both intake and exhaust. At 20-30psi just think of how much air you can flow through an 8mm socket if it was attached to your air compressor. Might not be HUGE but every little bit helps.

[omnidog]

Just puttin big valves in doesnt do much. You might as well go with a full port job and increase turbo size to really need em. If i remember right your stock turbo.?

[a853rox]

Omnidog is on the right path here. If nothing else is done (porting wise) then I wouldn't expect to see much of any improvement even if the seat was cut properly for them. The real restriction in our heads is the short turn on the exhaust side and it needs the most attention (porting). A good portjob on the exhaust side, even with the stock valvetrain components makes a world of difference.

$.02