P90a Valve question

[NismoC32]

I have a P90a (Non Hydr) that i'm planning on oppgrade with new larger stainless steel valves and

I wonder how large valves can I use before the valve seats needs to be replaced ?

And is it necesarry to do anyting with the valve guides to use stainless steel valves ?

 

Thanks.

 

 

[skirkland1980]

The valves are already stainless. Larger valves are likely not needed.

[Xnke]

P90 and P79 valves are 2mm shorter than earlier valves. Currently they are not readily available...read that as custom valves.

 

A 45mm intake and a 36.5mm exhaust can be fitted in most heads on the original seats. Unless you are getting the head ported, are converting to a solid rocker post and aftermarket camshaft, and are going to adjust the valve sizes to suit your engine, it is not productive.

 

If you are getting the head ported, then consider the expense incurred in setting up the rest of the head and valvetrain, before spending the money on custom valves that may actually hinder flow, depending on sizing and placement.