What is this?

[Christo K]

Dear Brains Trust,

What is this that I am looking at? Is it a valve stem seal, part of the valve stem guide, or something else? I have searched the manual, looked at diagrams on 'magazip.net' and have watched Dream Warrior's 'VMAX 1200 assembly, part 1 and part 2' a half dozen times. I still cannot determine exactly what this is.

TIA

 

[MaxMidnight]

The end of the valve guide, part #'s 5 & 11.

 

[Christo K]

The end of the valve guide, part #'s 5 & 11.

Thanks Max, That is kind of what I suspected, but it looks more like a rubber seal (to me) that sits at the end of or beneath the guide, rather than something metal like the guide itself. This is somewhat new territory for me, so I'm trying to eliminate as much guess work as possible before removing the engine and taking it apart.

All the various valve guides that I've looked at look like solid metal; and, if that is the case, I'm trying to understand how the one in my image has what appear to be a ringed groove. Is it possible that the guide is sitting lower than what it should? What I've circled, looks damaged and should be seated flush with the surface above it.

Cheers

 

[Fire-medic]

Whatever the OEM valve guide is for its length, it's not uncommon to have it protrude into the intake or exhaust tunnels. Some people cut-off the valve guide to reduce or to eliminate the intrusion, and to make less resistance to volumetric airflow. in the passages. That's more-of a racing thing, as they do all their airflow tricks, and cumulatively, it increases airflow cfm. The fact that because of a shortened valve guide length, the valve stem is less well-supported doesn't matter, as competition engines are torn-down and inspected frequently.

Perhaps that tapered valve guide is a compromise between overall length and the volume and impediment to airflow. of a full-width non-tapered valve guide.

 

[Christo K]

Whatever the OEM valve guide is for its length, it's not uncommon to have it protrude into the intake or exhaust tunnels. Some people cut-off the valve guide to reduce or to eliminate the intrusion, and to make less resistance to volumetric airflow. in the passages. That's more-of a racing thing, as they do all their airflow tricks, and cumulatively, it increases airflow cfm. The fact that because of a shortened valve guide length, the valve stem is less well-supported doesn't matter, as competition engines are torn-down and inspected frequently.

Perhaps that tapered valve guide is a compromise between overall length and the volume and impediment to airflow. of a full-width non-tapered valve guide.

Thank you Fire-medic,

Very informative and definitely helps in guiding me to where I might go with this engine if I have to take it apart.