What caused this exhaust valve to turn silver?
 

This cylinder had ZERO compression so I pulled the engine and replacing it with a spare I had. I don’t have time to tear the head off but this is what the valve looks like. Behind the valve you can see the casting, no carbon/black like water has trickled down causing lean condition? That’s my question.

Also I am guessing the valve is stainless steel and it dosen’t have hardened seats.

Looks like water to me. Stem is rusty, head is steam cleaned.

Anyone else?
No water in oil. I thought the valve would snap off with any amount of water.

Todays ethanol blends will make that reddish coloring. But like G4B said, the head looks steam cleaned. Also, zero compression with valves still in place almost certainly means a failed piston.

Aluminum :eek:

Looks a lot like my snowmoblile exhuaust pipes after its yearly meltdown :)

With zero compression, I would guess its aluminum from a hole in a piston.

Jim,
I think you are going to have to pull the head to find the real problem :( The valve does look real clean, which usually means water in the cylinder. Might be as simple as a leaking head gasket ?

If you plan on fixing the engine, dont wait too long to pull the head (s) We get several each summer where the guys had a water problem in the fall and just let them sit all winter :( Usually end up with too much corrosion in the cylinders to salvage.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

It could be a piece of trash on the seat making it leak so much, I tore a motor apart just because of the trash,I spun it over a bunch,taped each valve making it seat,still had leakage.that one sucked,
My car motors will have that color,I was told by NGK,Champion that the red tint is part of the unleaded fuel. Also on the car the exhaust temp will be 1400-1575.

2$worth:drink:


heres some picks on my blower motor

Thanks guys. Bill K. I will get the head(s) pull as soon as I get my spare engine up and running. I will post back with pictures:eek: