Thinking about valves for my n/a Series II L36 project heads:
http://www.bonnevilleclub.com/forum/...ic.php?t=77163

zzp (and others) sell stock-diameter SI stainless steel valves for the Series II 3800; about $80 for either intake set or exhaust set (so about $160 all around).

(Note: Up-sizing valves is completely out of the question budget-wise)

Pros: Compared to stock valves, these are one-piece, all stainless, undercut, swirl-polished.
Theoretically, this should make them stronger, better able to withstand/conduct heat, and have better low-lift flow (or so goes the marketing...)

Cons: Compared to stock valves, these valves cost money

So, are they worth it? Maybe just on the exhaust side?

A local machine shop claims they can undercut the stock valves for a reasonable cost...given our valves are two-piece friction-welded design (I think), I'm a bit wary of this idea; should I be wary?

Is this all overkill for a lightly modded n/a?

Please discuss...

well i don't think so i think the head and the cam are the 2 most important factor in the n/a engine to get more air in so youre asking if you should buy these valve or spend the money for a 3 angles valve job on the stock one .for steet use i think the stock valve are ok whit a 3 angle valve job they should flow well ,that whit a light porting and cleaning of the port that what im looking to do for this winter[/quote]

For a lightly modded n/a I don't really think they are worth the price.
If you’re keeping the EGR, the valves will get carbon build up and negate the swirl polish. And over time the exhaust valves will have build up on them as well.
On my Milzy heads with the SI valves, the exhaust valves definitely lost their polished finish after 10k miles. I saw this when I pulled my motor out.
The under cut part will still help out though since the area around the valve is still opened up more.
And as far as undercutting the stock valves...I would be wary of doing so since they weren't designed to have material removed.

I think you may get the most hp/$ wise if you just cleaned up and polished your stock valves. Carbon will build up eventually build up with if they are polished it will take a little longer.

OK, so for safety'* sake the idea of having a shop undercut the stock valves is out.

The shape of the stock intake valves, IMO, looks pretty darned good...for now, the plan will be to just polish and reuse those.

However, I maybe could see some flow benefit to having undercut exhaust valves. I could also see some potential benefits to having exhaust valves that can "take the heat" better, especially as I am formulating some ideas on the EGR system in the n/a engine.

Anyone else have any opinions on valves?

(I realize this is kind of uncharted territory, since there aren't all that many dudes out there hopping up their L36'* :P )

Andrew you just keep the ideas FLOWING (play on words haha)

well where not many but you have all are attention on youre work progress keep it up