I'm in the middle of building my b20/vtec and I had some 0.5mm oversized intake valve laying around, and I'm wondering would it be a good idea to throw them into my build

stock b20 bored, rs machine seleves
9.1 84.5mm cp pistons
crower rods
type R head
R cams and springs

 

I don't see how oversized intake valves could hurt any NA/FI build. I'm curious to know whether or not there is a downside though...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Noob4life &raquo;</TD></TR><TR><TD CLASS="quote">I don't see how oversized intake valves could hurt any NA/FI build. I'm curious to know whether or not there is a downside though... </TD></TR></TABLE>

Its all about air volume and speed. Putting larger valves in a head without headwork can slow down the air going into the cyl which can *DECREASE* performance. However with a turbo pushing air into the cyl you dont have to worry about it too much. All motor though is a totally different story.

If your head is stock i recommend keeping it stock. If you want to do work on the head - i would let whoever you get the work done with make a recommendation. Im sure they would know what will work best with their headwork.

liam

 

iirc the b18c5 head has a mild p&p from the factory.
The only time I've ever heard of oversized valves being used on the head is with NA apps, which is why I wondered about this.

 

well, I just have some valves laying around, just wondering if it's a good idea