Need to know valve length 3.4 dohc

[iceman4160]

I am in need of some help. When I had my heads done on my 3.4 dohc the machinist told me he "shaved a little off the top of the valve stem" but he couldn't tell me how much, I have been told this is critical for the opening and closing of the intake and exhaust valves if they are to short stuff will happen and i will be tearing the engine down again and I don't want to do this again.

[pocket-rocket]

Why would he have shaved them down? I can't think of anything that would need you to do that, unless you had some wild custom cams made that had a huge base circle (which wouldn't work anyways if they had tons of lift) which would cause clearance issues in the cam carriers. If he did it for valvetrain geometry, this engine is pretty much exempt from it because it isn't a pushrod engine where it would matter. Did he ask you before doing this to them?

[iceman4160]

I have found my answer. I went to a local machine shop and they had the info I needed

[55trucker]

*End Facing* a valve stem is not out of the question...but when this is done the installed height has to be checked to ensure that the installed length is now not too short. I'd be somewhat wary if the Machinist said to me in these words *I shaved a little off the top*...instead of saying *I had to End face a few valves to clean up the face of the stems*...and how could he NOT know how many .000 he set the valve grinder up to machine off? Odd indeed.

[pocket-rocket]

Did the guy that did it tell you why?

[iceman4160]

I have found my answer on the length of my intake and exhaust valves. I went to a local establishment and they had the info I needed. Yes, he did say "I shaved a little off the top" but you have to know this person to understand his lingo, I have checked all of my valves and they all are where they should be as far as length.

[Schurkey]

Why would he have shaved them down? I can't think of anything that would need you to do that

If you grind the seat, the valve sits deeper into the port throat.

If you grind the valve face, the valve effectively sits deeper into the combustion chamber.

Both factors move the valve tip "up" in the head, changing the valvetrain geometry in a pushrod engine; or increasing the hydraulic lifter preload on a DOHC 3.4.

Grinding the valve tip to compensate is a great idea--until the machinist takes off enough to weaken or completely remove the hardened area on the valve tip.

[pocket-rocket]

If you grind the seat, the valve sits deeper into the port throat.

If you grind the valve face, the valve effectively sits deeper into the combustion chamber.

Both factors move the valve tip "up" in the head, changing the valvetrain geometry in a pushrod engine; or increasing the hydraulic lifter preload on a DOHC 3.4.

Grinding the valve tip to compensate is a great idea--until the machinist takes off enough to weaken or completely remove the hardened area on the valve tip.

See, I was thinking of only the tip end geometry. That makes sense to me. Thank you