Are these valves burned?

[TracieS]

there out of a b16 head and oil was coming out of that corner or the head its the exhaust side on the number 4 cylinder.

[Jarrett]

They don't look to be burned. They just look covered in oil and carbon build up. Clean them off and see if you notice any pitting or irregularities in the circumference.

[dj_ender]

Looks to be just carbon build up. Can you scrape it off? As long as the valve itself is in tact, you're fine.

[TracieS]

Thanks guys thats the answer I was looking for. Ill try and clean this up before I go buy another set.

[TracieS]

heres one cleaned up

[wherm]

heres one cleaned up

looks good! Burnt valves, in my experience, look like there's a hole melted in the edge. When that happens you loose a lot of compression in that cylinder and your car runs like poo.

What did you use to clean them?

[TracieS]

So I lapped the valves and this is what I got

[F20A CB7]

What is lapping? The edges look more crispy.

[reklipz]

What is lapping? The edges look more crispy.

http://www.v6z24.com/howto/valvelapping and http://www.dsmtuners.com/forums/arti...lap-valve.html

Valve lapping is basically recreating a perfect matching contour between the valve seat on the cylinder head and the valve itself. This allows for better compression due to a better seal; less/no "valve blowby."

[F20A CB7]

Thanks^

I was lookin at the pics. After clean up I seen knotches and scratches.. now the edges r smooth lookin. Is that the lapping?

[oyajicool]

So I lapped the valves and this is what I got

To me, contacting surface look too wide and there's no margin at the edge. I would consider consider head work if it was my engine.

Or, just take the head to the engine builder and ask for advise.

[ON_N20]

Did you use a sawsall blade to clean away the carbon?

Im a little worried about all the scratch marks. Hopefully they dont extend high enough up the stem to contact the valve guide. If they did, the guide could wear much faster. Also the scratches give future carbon a better place to cling onto.

In the future, using a chemical solvent soak, or a gentle wire brush is the best way to remove carbon. Much safer to the valve.

[Jarrett]

Actually, he's right. The picture was somewhat unfocused and I couldn't really tell before. You may want to sand and polish the stems on these to remove those grooves.

[TracieS]

To me, contacting surface look too wide and there's no margin at the edge. I would consider consider head work if it was my engine.

Or, just take the head to the engine builder and ask for advise.

Did you use a sawsall blade to clean away the carbon?

Im a little worried about all the scratch marks. Hopefully they dont extend high enough up the stem to contact the valve guide. If they did, the guide could wear much faster. Also the scratches give future carbon a better place to cling onto.

In the future, using a chemical solvent soak, or a gentle wire brush is the best way to remove carbon. Much safer to the valve.

Actually, he's right. The picture was somewhat unfocused and I couldn't really tell before. You may want to sand and polish the stems on these to remove those grooves.

I did the work for a friend if it was my motor I would've upgraded everything.
Yea and the cleaning was spur the moment souldve soaked them like you said.
And everything turned out ok car has been running smoke and oil leak free for about a week now. And that cylinder had 180 compresion and the others were around 190.