How much adavantage from oversized vales

[dajoker]

I was thinking of buying a new head for my 6 bolt full engine rebuild. I just got my new Ross pistons and Crower rods in, and i was looking at BJ's racing heads, If any of you guys know the web site for BJ's products please tell me because i cant find it. And to my question is there much advantage for oversized valves. thanks.

 

[flinguist]

Originally posted by dajoker
I was thinking of buying a new head for my 6 bolt full engine rebuild. I just got my new Ross pistons and Crower rods in, and i was looking at BJ's racing heads, If any of you guys know the web site for BJ's products please tell me because i cant find it. And to my question is there much advantage for oversized valves. thanks.

Here's the link for BJ's.http://www.bjscylinderhead.com/custom_products.php

 

[Suparata]

Originally posted by dajoker
I was thinking of buying a new head for my 6 bolt full engine rebuild. I just got my new Ross pistons and Crower rods in, and i was looking at BJ's racing heads, If any of you guys know the web site for BJ's products please tell me because i cant find it. And to my question is there much advantage for oversized valves. thanks.

It's hard to say how much advantage you can get out of Oversized valves . Any modification done to your car will take into consideration the total setup of your project.
All I can say is that it is worth using Oversized valves if different than stock valves are wanted not only because generally these valves are higher quality(forged SS) of material and better design(http://www.engintecs.com/gallery/album07/SSValves2 ) but also because when machining is done to accept OS valves the geometry of the seats and ports are improved for a greater engine breatheability.
Stories like loss of bottom end when OS valves are used are just that: stories. Air flow velocity is dictated by geometry and size of intake runners rather than the last restriction which is the very end of the path.