3 groove/1groove valve stem keepers

[Jerry Poole]

I am getting ready to purchase parts for a full race head build using 6MM valve stems and wondered about the choice between single groove keepers and 3 groove keepers which seem to be popular with 6MM stemmed valves. Will be used with "Beehive" style springs and steel retainers. Engine RPM will be 8500-9000 RPM. Any insight or information on this topic? Thanks, Jerry

[sbcharlie]

its best to use single groove keepers if possible . AV&V valves has a good explanation why to do this sbc

[modok]

With beehive, I think it makes more sense to use single groove, because you usually want the retainer high up on the stem.
VW diesel for instance, use a three groove as close to the tip as they can, but it's so close to the top can't even fit a hard tip. Which is fine. They don't NEED a hard tip because it's a steel stem. Will your valves be steel stem too?
3 groove on 1 piece stainless valve......is a fools errand.

3 groove VS square.....probably same strength, but I have seen problems with the fit of the three groove. If it does not fit right it can PULL the stem right apart. POP. Where;d it go? It's in the rafters. A single radius groove should be strongest.

[user-17438]

I am getting ready to purchase parts for a full race head build using 6MM valve stems and wondered about the choice between single groove keepers and 3 groove keepers which seem to be popular with 6MM stemmed valves. Will be used with "Beehive" style springs and steel retainers. Engine RPM will be 8500-9000 RPM. Any insight or information on this topic? Thanks, Jerry

What is the application? How big are the valves? What kind of spring pressure? Single beadloc can hold a lot of spring. I think you are overthinking. Call the company that is making the valves. And ask them.

I think the most important part is to make sure the lock fits the retainer properly(correct angle) and that the lock fits the stem properly. I like xceldyne and Pac. If you are using DelWest, Xceldyne etc just order the retainer and lock for the spring combo you are running from them. PAC,MANLEY VICTORY all good sources

[ProPower engines]

It also depends on what engine it is. Most multi groove valves are done that way for valve rotation not really what you want in a HP engine but many manufactures did it for years but the seats did suffer.
A square groove compared to a radiused groove is about strength of the valve tip. They both work the same as far as rpm capability goes but I would say with a 6mm stem the open load will not be high enough to worry about it.