Chipped valve?

[Geeshik]

What would cause a valve to chip? i have the heads off of my 3.0 and i found a valve has a notch chipped out of it. Is this an indication of a timing failure? It's a 93 engine. What is the part number for a new valve from Ford?

 

[Wicked_Sludge]

most likely a foreign object in the engine.

any auto parts store should be able to get you new valves.

 

[shadetree]

What looks like a chip is usually a burn. The valve starts leaking, and the combustion slowly burns the valve.shady

 

[Geeshik]

Okay. Burned valve; makes sense. The notch is about a 1/4 inch square out of the edge. One of the Autolite spark plugs was missing an electrode, but i don't think it would have wrecked a valve.

When i pulled the valve out tonight, i noticed that the valve was hard to remove from the head where the keepers usually sit on the end. Is that normal? Did i do something wrong? i had to gently drive it out. The guide doesn't come out of the head, does it?

 

[Beef52751]

you dont want to drive the valves out, it can ruin your guide, take a file and file it down a little bit, its not uncommon to have a bur there.

 

[Geeshik]

So i mic'd the valve shaft and it's .3125 inches. Is this correct? i thought earlier engines had larger valve shaft diameters. Napa lists one in .3275 also for this year. What should i order?

 

[Geeshik]

most likely a foreign object in the engine.

any auto parts store should be able to get you new valves.

Foreign object?!? Is that like a honda or something?

 

[Wicked_Sludge]

you really gotta watch it around those nissans, they'll chip a valve like NOTHIN'!

 

[shadetree]

Stem diameter:

1993/94 Intake = .3416 to .3423
Exhaust - .3411 to .3418

1995 on Intake = .2746 to 2754
Exhaust = .2736 to 2744

The valve was hard to get out because the upper part of the stem gets a carbon buildup as does the inside of the valve guide. Wire brush it off the stem, and the valve will come out easier..)shady