Exhaust valve color

[NotStock]

Any thoughts on why I would have such a huge variation in exhaust valve color? Two pictures here, but the valves on the 4-5-6 side are all very white. The 1-2-3 side is dark. I’ve done a lot of work to eliminate any sources of vac leak, injectors are new, plugs are new, wires are new, cap and rotor are new. Leak down is good and consistent across all cylinders. It’s a 3.2

Cylinder 4 is white.



Cylinder 3 is sooty



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[tsuter]

They should not be all black like that. Indicates worn valve guides and or mixture is too rich. The white color is what you should see. I attached a picture of one of mine. Engine is out on the stand and the cold leak down was 1% ea. on all six. No carbon or oil build up on exhaust valves.
That oil seepage you see just behind the valve cover in the fins is most likely either the return tubes or rocker shaft seals (ie., no seals).

[NotStock]

Originally Posted by tsuter

They should not be all black like that. Indicates worn valve guides and or mixture is too rich. The white color is what you should see. I attached a picture of one of mine. Engine is out on the stand and the cold leak down was 1% ea. on all six. No carbon or oil build up on exhaust valves.
That oil seepage you see just behind the valve cover in the fins is most likely either the return tubes or rocker shaft seals (ie., no seals).

Fantastic, thanks! Good to know. The car doesn't smoke at all, but valve guides was one of the culprits on the short list.

I don't think I've got rocker seals. I'll be installing them at some point. I suspected thats where the leaks were coming from too. The tubes seem good, but they will be replaced. The reason the exhaust is off is to install cylinder baffles that were left out for some unknown reason (they were in the trunk when I pulled this thing out of the barn).

[Tea Tray]

What do the plugs look like?

[NotStock]

Originally Posted by Tea Tray

What do the plugs look like?

Figured that was coming. I’m wondering the same thing. Car is in the air right now. I’ll drop it down and pull those plugs as soon as possible.

[icarp]

I am not sure that I agree with the Idea that the valves should be white .
As I recall, we installed the exhaust temp probes in the primary pipes , just 2"-3" from
the manifold, this being the hot spot in the path of the exhaust. So the color was still black
in the exhaust port. The first color change was just after the temp probe ,
to a light grey color in the primary .

Then the telltale color was 2"-3" after the exhaust collector merge , this is the point is where it is a good sign to see the white color , sometimes very white , depending on fuel type .

The light tan color is what we want on our spark plugs , we all have a color chart with us at all times , where you ask? Our forearm is our color chart , look at the underside of your forearm down near your elbow .

This is the leaner end of plug color but still good

We all should talk about this more

Just my thoughts
Ian