[bishopts]

I'm putting valves in a 3rd gen ecotec today and i noticed the exhaust valves are magnetic on the stems but not on the head.

[GreenZLE]

Originally Posted by bishopts

I'm putting valves in a 3rd gen ecotec today and i noticed the exhaust valves are magnetic on the stems but not on the head.

Thats how my inconel exhaust valves are. My Ti intake valves are not magnetic at all.

[bishopts]

Originally Posted by GreenZLE

Thats how my inconel exhaust valves are. My Ti intake valves are not magnetic at all.

The intake valves on this one are magnetic all over. I just thought it was kinda weird for the exhaust valve stems to be magnetic but not the rest of it. I was thinking maybe it's a hollow valve with a magnetic metal filler. But I've never heard of that either. I've really only heard of sodium filled valves as a filler metal.

[GreenZLE]

Originally Posted by bishopts

The intake valves on this one are magnetic all over. I just thought it was kinda weird for the exhaust valve stems to be magnetic but not the rest of it. I was thinking maybe it's a hollow valve with a magnetic metal filler. But I've never heard of that either. I've really only heard of sodium filled valves as a filler metal.

I sold my stock heads and bought CID heads direct from CID. The inconel exhaust valves CID supplied are magnetic to about 2/3rds down from the top of the stem, then they are not magnetic at all. I expected the seam to be close to the valve head instead of somewhat mid stem.

[ctrlz]

I think the differences in magnetism have to do with the metals used and the hot forming process. The video below is interesting.
If you heat a metal beyond its Curie point it will lose its magnetic properties. When hot formed, the crystals will not be aligned within the metal. if you form it by hammering it, particularly as it cools, the crystals will tend to align, and you will have a magnet.
Among the many things I am thankful for are the crazy videos on just about any topic you can find on youtube!