My question is how much hp can be achieved with stock size valves before it becomes a flow issue or. also what hp gains have some of you guys seen on going oversize. The reason is i bent some valves and i have the chance of staying standard or go over size for the same price. I searched but i cant find the answer to this particular question

 

bump

 

bump pls

 

Not MUCH of a gain, but a nice idea if you have the chance to, especially when you need to do a 3 or 5 angle valve job.

 

Why dont you think there is much to gain from large valves? I bet you can gain more from large valves than aggressive port & polish.

 

not doubting but would like to see some proof or more information on the real gain from oversized valves.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J-Brooks &raquo;</TD></TR><TR><TD CLASS="quote">not doubting but would like to see some proof or more information on the real gain from oversized valves.</TD></TR></TABLE>

me to

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">Why dont you think there is much to gain from large valves? I bet you can gain more from large valves than aggressive port & polish.</TD></TR></TABLE>

With a good deshrouding maybe.

 

I don't think there is much of a large gain in most of the powerband that exists with the way that many VTEC heads work because of the fact that flow test of many of these same heads are great the way they are. Many cylinder head professionals found that a small gain in efficiency would result in such a change, but not as much as one would think, especially in a useful powerband greater than over 1000 rpms in that band..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TheShodan &raquo;</TD></TR><TR><TD CLASS="quote">I don't think there is much of a large gain in most of the powerband that exists with the way that many VTEC heads work because of the fact that flow test of many of these same heads are great the way they are. Many cylinder head professionals found that a small gain in efficiency would result in such a change, but not as much as one would think, especially in a useful powerband greater than over 1000 rpms in that band..</TD></TR></TABLE>

This is what I heard which is why I was skeptical on the above information... still not saying its not true.

So if you got the money... do it.

If not don't worry about. 1 psi will probably over compensate.

 

The B16 head I did for John Ferguson/James Innes has stock valve sizes and it made 719 whp and has gone 9.61.