1mm longer valves

Hi i was wondering why they made these valves p4286794 exhaust walve 1mm longer why would you need the longer valve. thanks.

Longer valves were used with camshafts lifts when they got over around .550" lift. Eventually the follower will want to walk right off the end of the valve tip. Preferably, you want the follower to be riding near the center of the valve tip, so the guides wear more evenly. Ask the C6 LS7 guys about whether this is important or not (lol). Also when you are using existing valve seats like many people do on +1mm valves, you could use the extra length of +1mm longer valves. What you don't EVER want to do is sink the valves to get proper spring height. As you just kill flow when you do that.
Todd

Todd that does help a lot I have a few questions about a cylinder head that I have I will send you a pm thanks.

Unless it's something secret please keep it public!

Longer valves are common in other Engines.

I've been thinking about this recently also.

Curious about your head?

Things are very quiet.

When Todd posts.

I listen!

Thanks
Randy

PS: Thanks again for helping me out!!

domi058 went above and beyond.

if my memory serves me right don't swirl heads use a longer valve than a G head?,mixing the 2 can lead to problems, I did this once on my first G head I shaved the bottom of a lash adjuster to make it work i needed the car, it was my DD

You are correct Dick, swirl valves are longer.

Thanks
Randy