do over sized valves increase performance?

[malmojoe]

Are oversized valves for better performance or just a last resort when you've knackered up your valve seats? (not that I have mind )

If you were going to have your valve seats recut, would you go for the oversized?

this 4 stroke stuff is a bit foreign to me.

[garyd]

Simple answer...Yes

More air/fuel in = more power.

You just need to make sure that the rest of the engine will allow that much air in.

[Mark Tiller]

Free flowing exhaust bigger carbs and air filters will have the greatest effect, but gas flow, big valves, cams and higher comp pistons all add to the mix. And of course there no substitute for CC

[Keefleaf]

If you want Head work check with Buzzard.Twickenham/Hampton area.
P .M. on the way

P.S. I know where there`s a stock of valves. Inlet and Exhaust.
Standard and 1mm oversize.
He does make valve guides also but can`t get Phosphur bronze material?
"Foundry shut" Anybody know of a source?

[Robw]

Hi, I got my Z1000R head done by Alan Cooper at Kipkawa. It has oversize inlet and exhaust valves, its been gas flowed, it has APE cams fitted with undershim buckets and it has had the twin plug mod done as well. I also have fitted CRS 33mm carbs and a Kerker exhaust and it is bored out to 1170cc. It puts out 115bhp at the backwheel. I had it dynoed before the head was modded and it put out 90 bhp, so it does make a difference.

Rob

[chrisu]

buzzard did a cracking job on my project Z900 head.