Valves in relation to cams for an NA build: Oversize or Standard?

kacz07 · 06-19-2009, 11:23 AM

I am building an NA 2006 revup engine and I was wondering if I need to upgrade the size of the valves I'm using or if that is more commonly used for turbo applications. Any input on valves and their relation to camshafts would be great.

I was looking at getting Ferrea +1mm valve train, but I've seen some conflicting information in the interim.

I will be using S7 (262) or C8 (272) JWT cams.

Thanks for your help.

kacz07 · 06-19-2009, 11:49 AM

bump

Z1 Performance · 06-21-2009, 08:33 AM

Best bet is to ask the person building your heads

IMHO, stock valve size is not any sort of limitation. Aftermarket valves are a bit lighter, stronger, and will lead to a bit more complete combustion. I chose to leave the stock ones, and have had no issues, but it's all up to personal preference. If I had to do it over, I would not do oversized units, as they would not provide any significant benefit .

eric02specv · 08-11-2009, 10:52 AM

If you choose the C8's or C8R's you must at least upgrade from stock springs. The S7's however can be used with stock springs/valvetrain.

I'm going to be going C8's on my VQ and I'll be using JWT springs as well.

1cockyZ · 08-11-2009, 02:16 PM

So you start a build thread a while back and now you are asking about parts that are listed in the build thread. Look at rednezz build he used big valve cosworth cnc heads with nismo headers..I see your research is a little short.

eric02specv · 08-11-2009, 09:20 PM

There's really no point in upgrading the valves. Believe it or not.. the factory valves are superior in terms of strength, versus Ferrea's standard stainless valve. The factory valves are stainless/inconel, and friends of mine have taken them as high as 8K.. I know people who have gone 8500 on them.
Nissan actually builds some pretty nice valves.

__jb · 08-14-2009, 06:32 PM

I'd say it depends on what other mods you're doing.

I have C8R's and did not go with the 1mm larger valves. Unlike everyone else here, if I had it to do over again, I would go with the larger valves.

That doesn't mean it would be right for you... or even that it would be really right for me... but I would do it...

-jb

kacz07 · 08-14-2009, 07:52 PM

This thread is 2 months old. I made it before I ordered my valvetrain, so I'm not sure why I'm being criticized by you, Cocky, but I guess it's good to get some opinions. Thanks for the buzz. I'm sure someone will appreciate it.