Anybody experienced cast iron degradation?
 

I'm looking at the bores on the crusty flatty. It's a 39/40 99 model.

Certain parts of the bores on 3 of the cylinders have (I can't think of a better expression) "degraded". The surface has a consistency like, carbon, is the best way I can describe it. I scrape through this soft layer and there is good metal behind it but it is very uneven. It's not like scraping some rust off where you can sometimes have a surprisingly good surface beneath.

Anybody else found this?

Mart.

Re: Anybody experienced cast iron degradation?
 

Severe blow by can cause stuff like that. I've also seen hardened valve seats crumble to pieces. Stellite is kind of a funny material that can do some weird things when exposed to the right (or wrong) conditions. The old cast iron quality left a lot to be desired too. The modern mixes are a lot more resistant to stuff like that. It's kind of like a heat corrosion or erosion.

Re: Anybody experienced cast iron degradation?
 

Iron boat engines used in salt water can get soft cast iron, almost like clay--- I was robbing a crankshaft out of small block chevy that clammers had used till it rusted through---3 speeds foreword, slow reverse--- it had wrong prop, ran better in 2nd,

Re: Anybody experienced cast iron degradation?
 

Hi Mart,


I've seen this in old buried cast iron piping. A project I worked on for a municipal gas distribution system had this problem in their old piping. It was especially evident in acidic soil used for back fill.


https://www.google.com/search?q=cast...PzVCgd1_QSChM:

Re: Anybody experienced cast iron degradation?
 

Gray cast iron sometimes show the effect of selective leaching out of iron in mild corrosive environments. The surface layer of the iron becomes like graphite and it can be easily cut with a knife. Because of the attack, the iron or steel matrix is dissolved. The graphite becomes cathodic to iron and a galvanic corrosion cell is formed. Iron is dissolved and a porous mass of voids and complex iron oxides is left behind. This graphitized cast iron loses its strength and other metallic properties

Re: Anybody experienced cast iron degradation?
 

Now and then a person will find an engine block where someone has tried to fill in imperfections. They will try everything from solder to epoxy sometimes.

Re: Anybody experienced cast iron degradation?
 

Yeah, I struck that soft graphite sorta stuff in an inlet port of a C69A block I was porting; it just kept going....I ditched that block. I'd never encountered it before, just thought it was some imperfection in the iron. I, [probably incorrectly], formed the opinion since then, that the post war blocks were cast of an inferior grade of iron to the pre war offerings, because I'd never struck this before. I do know the later blocks don't weld as nicely as the early ones....Interesting that you've found it in a 99 block, generally considered to be one of the 'better' blox.

Re: Anybody experienced cast iron degradation?
 

I thought I'd replied to this but must have fat fingered it. Whoops.

The scenario described by Murre seems to describe what I found quite well.

I was wondering if the attack on the metal may have been caused by someone applying some sort of substance into the bores in an attempt to unseize it? The damage is in three bores and all above the pistons. The bore where the pistons were sitting is sound.

If it was cauised by a substance, any idea what that substance may have been? I'm not sure, but did I read somewhere that molasses can cause a problem like this if left too long? Have I imagined that?

I'm baffled.

Mart.

Re: Anybody experienced cast iron degradation?
 

Scotch whiskey - somebody was storing their stash of whiskey by pouring it into the engine via the carb - hence the reason the degradation is above the rings. :D:D:D

Re: Anybody experienced cast iron degradation?
 

Old and highly used engine oil becomes acidic. Sulfuric acid is one of the byproducts especially due to oxidation.


Glenn

Re: Anybody experienced cast iron degradation?
 

A little off, but i had a head on an A M C 327 marine engine that looked as though it was delaminating....flaking apart above an exhaust port .

Re: Anybody experienced cast iron degradation?
 

I had that happen with a 59AB block I had.
I took it to the machine shop to get boiled out and magnafluxed.
He called me to come and take a look at what was left.
The passenger side of the block was full of holes and the areas around the valve seats were bad as well.
The block looked OK from the outside but was toast on the inside. No ridges or cracks in the cylinders though !

Re: Anybody experienced cast iron degradation?
 

Fire maybe? I've never seen a problem inside an engine but its pretty common for the cast exhaust manifolds to turn brittle and break during removal.

Re: Anybody experienced cast iron degradation?
 

Yes ,
Fairly common to find 2 cylinder JD tractor blocks-heads with mushy metal .
Seems to be in ones that sat with water in the horizontal cylinders for years .
If deep enough it effectively ruins them .

Re: Anybody experienced cast iron degradation?
 

I had this on a 59AB, while scraping off carbon I soon realized I was digging into the block. The cast iron was about as hard as pencil lead. No saving that one!

Re: Anybody experienced cast iron degradation?
 

The recent 59AB block I did had a rot hole in the lower portion of the water jacket. Hole was the size of the pencil eraser

We did not find it until it was baked and blasted. It was caused by a ton of crap that settled in the water jackets and left in there and eventually ate through the cast iron. We epoxied the inside and out using Belzona 1212 epoxy.