HELP! what to do about a pit in the core of my iron cylinder

[TimothyG94]

I have purchased castings for a coles puffin billy switcher and in the image below, there is a huge pit in the cored hole of the cylinder, too deep to machine out. What really disappoints me is why this casting was sold to the guy i bought it from. Where is quality control anymore?
[img]100_2935.jpg[/img]
does anyone have any suggestion s on how to fill this hole in? I don't want to machine this bore out too big!

[Greg_Lewis]

If it won't clean up after machining, I think the best solution would be to sleeve it. While it might be humanly possible to get down in there and fill it with weld, I think that would be a compromise that would not be guaranteed to succeed. And you'd need a welder of considerable skill to do that anyway. I'm not aware of any compounds such as JB Weld that I would trust on such a critical part.

[FLSTEAM]

Looks from here like you have lots of metal to machine and the pit does not look too deep. I would try the bore. If all else fails like the earlier post you can sleeve it.

John Buckwalter

[Al_Messer]

Yep, I agree--machine the bore and keep the possibility of making a sleeve in the back of your mind. What is the diameter of the finished bore supposed to be?

[Fender]

The casting looks like cast iron, but seems to have a yellowish tint, so might be bronze. (?) I'm assuming the void doesn't intersect with the steam passages. If it does, that's a whole different problem. If not, I'm with the others, just put in a sleeve if need be.

[TimothyG94]

The casting looks like cast iron, but seems to have a yellowish tint, so might be bronze. (?) I'm assuming the void doesn't intersect with the steam passages. If it does, that's a whole different problem. If not, I'm with the others, just put in a sleeve if need be.

the color is from my desk lamp, it is cast iron. that's another thing the pit is about an 1/8" deep and i only have to remove less than 1/32" of iron for correct size bore i do't want to bore oversize and have an engine that runs sluggishly and inefficient.

[Trainman4602]

Something doesn’t add up here. You say you only have a 1/32 of and inch that .032 in the bore! It seems like you should be b boring out no less then ¼ inch .250.

Cored holes generally are out of round by 1/16 .062. I don’t think you can set up a rough casting accurately enough to bore of 1/32

Are you sure these figure (.032 1/32 is correct)?

[Harold_V]

I am not the least bit familiar with the casting in question, but I am familiar with castings in general. The very notion that there's only 1/32" of material that is to be removed sends up a red flag. It is generally desirable that a first pass in cast iron be no less than .05" deep (per side) to get beneath any surface chilling and sand that may be included. I would expect that the cylinder in question would have been cast with that idea in mind.

Are you, by chance, altering (by reducing) the intended size of the bore? As Dave said, the chance that the core will be properly located and allow such a small amount to be removed is doubtful. I would think that those that produced the casting would know that.

Harold

[Fred_V]

i agree with the last 2 replies. also it looks like the bore is off center from the outside of the cyl. by quite a bit but unfortunately to the wrong side.

[TimothyG94]

maybe this new pic will clear up confusion. also the cast rough bore is pretty round by itself and has a diameter of .985" the recommended bore is 1.0625. The reason i don't want to go bigger is because i am also using little engines wheels that need 2.187" of stroke and the drawings only require 1.75" of stroke, dont worry about that i already compensated for piston length and other things.
Also, i should add that the maximum recommended bore is 1.375" which is huge

Back to the topic i want to know about sleeving. Should it be grey iron stock, how thick should the wall be and how do you secure it inside? press fit?

[cbrew]

I have used these cylinders on my booster truck, they are bored out to 1.25"
so your solution is as simple as boring out to 1.25" and then install a sleeve with an ID of 1".
this solution will take care of all the foreseeable issues

[TimothyG94]

If i bored to 1.25" and if there is only a small pit left will it still work?