here's one for the more experienced guys

chuck stevens

chuck stevens

Well-known member
While taking down this 49 8BA, which was left with water in the cylinders, I found the iron VERY soft between the valves and the cylinder. I could dig it with a screwdriver as you can see in the photo. It was real dark in color and acted like lead, or graphite very soft. I know this engine is very rusty but I have never seen cast iron act and look this way before. Is it possible for iron to change, other than rusting? Love to hear your comments sound off Ron, Walt,... thanks Chuck.
 

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My take: If the area is where the screwdriver tip is only araound each valve, and you cannot dig in the area between where screwfriver i and the cylinder, you are not digging iron...you are digging out an amazingly deteriorated valve seat insert, made out of something much harder than iron originally and composed of something I sure can't identify!
Whatever it is, it deteriorates in water way differently than iron.
 
And...take a good stiff wire brush to the area. I think you will end up with a nice machined groove remaining, the iron socket that took the seat.
 
I'll cast my vote with what Bruce said. I have a transmission that had some water in it. The cast case cleaned up real nice, but the water ate the daylights out of the hardened gears.
 
That Stellite is some funky stuff. Its got cobalt and chromium with some tungsten thrown in for good measure. Maybe a few materials I'd have to look up on the atomic chart. Crazy thing is that they still use the stuff to this day. Some things just thankfully don't change much.

Kerby
 
Thanks for the input, I guess this block is a good candidate for relieving. I'm fairly sure this was fresh water, rain down the carb. Today I'll see if there is good cast iron between the valve seats and the cylinder. I'll post some pictures, thanks Chuck.
 
Have the block "BAKE cleaned"This will show you the usable material. No block is a good candair for relieving.
 
I think what you have there is a case of de-alloying, where the iron in the cast has turned to an oxide and disolved away, leaving behind the graphite flakes that were originally in the casting metal. The graphite flakes are very soft, and will ding easily with a screwdriver. I've seen this before with cast iron pipe fittings.
 
Lyndon-Ron,
I think you have hit the nail on the head. I have never seen cast iron that looks and behaves this way. I wonder if it was the long term storage with other metals near by, or limited oxygen in the chamber. In any case I don't have alot of confidence in this block.It's to bad I didn't see any cracks, but I don't think I'll use it.
Thanks for your ideas, Chuck.
 
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