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School me on Valves (P90)


HuD 91gt

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Hello,

 

I currently have my P90 head under the knife.  I am attempting my first port and polish job.   Currently unshrouded the valves, blended the seats into runners, as well as polished the chambers.  I'll be smoothing out the runners here shortly without doing any reshaping.  Although, I did slightly smooth out the metal around the valve guide on the exhaust side only.

 

I currently have Colt Cams up here in Vancouver BC grinding away on a cam for me.   I've purchased the Schneider springs/retainers from MSA and have yet to decide if I will run the outers only, and stock inners or run the whole setup.  TBD.

Next up is a new set of valves.  I just got off the phone with SI valves in California and they no longer stock their swirl polished valves in the P90/P79 lengths.  He mentioned people who generally need that, are already replacing all the valve train and it is all adjustable.  He still stocks the OEM stainless units.  The only swirl polished unit's he stocks are the shorter version from the earlier heads.   I am not shaving the head any large amount as this will be used in a turbo charged application.

I honestly can't fathom what is adjustable in the head other then large amount of valve guide being ground away.  What am I missing, and can I use the shorter valves in my application?

Secondly, I've searched and searched and SI valves was the only place I found who made valves for the P90.  Anyone know of any other options?

 

Cheers

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Just wanted to point out, you have something backwards. The p90/p79 are the short valve heads, hence why when they are shaved and cam tower shims are used you install the longer valves. Ferrera still makes the shorter valves you need.

Edited by 1vicissitude
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