Intake/Exhaust valves

Hey Bill,

I can only report on what I found with my head and talking to others, Doc or someone else might have more info. But here's what I meant:

Bill Dedman said

2 questions, please:

1. Just what is the lift-limit (you said not much over .500") for stock valves/retainers? I'm assuming the retainers run into the valve guide bosses or the valve-guides, themselves, at some point, limiting the amount of lift possible, and....

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Yes, stock there is not much clearance between the retainer and the top of the seal (maybe enough to run .450 lift? I don't know.) Running positive seals helps. I had my machinist cut my guides down to have enough clearance to get .500 lift and he told me that I could not go much further without making the valve guide so short that it would not support the valve properly. That's why people want to run longer valves.

2. You said :"rocker geometry issues though. Beehive springs would help with that." How could valve spring configuration (beehive???) affect rocker arm geometry?
I am confused about that. Just trying to understand this...

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Sorry that was not very clear - I was talking about if you use longer valves - if the angle between the rocker and the valve gets crazy the edge of the retainer hits the bottom of the rocker. Some guys on SS.org ran into that problem. The beehive springs have retainers that are a smaller diameter, which gives more clearance.