# Brass/Bronze inserts in cast iron/steel



## ozzie46 (Jan 29, 2010)

I want to make some larger cyls for steam. Need stock about 3 1/2 by 3 x 3 1/2 inches. Plans call for gunmetal castings but they are high $$$$. So I thought bar stock. Well brass/bronze is not cheap either. So I'm thinking maybe I could use cast iron, steel or aluminum and bore holes for pistons and valves and use brass or bronze pressed in then drill/ bore to size for the pistons and valves to keep from rusting.


  Project I'm thinking of doing is very long term Loco build. Talking maybe years to complete. Just kicking ideas around at this time.

  Comments good bad or indifferent. What do you think?

  Ron


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## Maryak (Jan 29, 2010)

Ron,

I would go for cast iron and forget about bronze sleeves. 

My 2 bobs worth and that may be overvalued. :

Best Regards
Bob


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## hammers-n-nails (Jan 29, 2010)

why not use regular cold roll? theres bound to be scraps around that size.


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## GWRdriver (Jan 30, 2010)

Maryak  said:
			
		

> I would go for cast iron and forget about bronze sleeves.


That's what I would do also.


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## bentprop (Jan 30, 2010)

I think what everyone means,but didn't mention,is to use cast iron for the cylinders,and brass or bronze for the pistons/valves.
At least,that's what I did:
http://smg.photobucket.com/albums/v401/bramleynz/cyls/
I haven't got much further than this:





The second pic doesn't show the cylinders or valve gear,but i have them made.
This looks like becoming a lifetime project :big:


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## Maryak (Jan 30, 2010)

bentprop  said:
			
		

> I think what everyone means,but didn't mention,is to use cast iron for the cylinders,and brass or bronze for the pistons/valves.
> At least,that's what I did:



Bp,

Thanks for that, I have never built a loco, (I admire all those who have). That to one side here's my take on it.

If the piston is to have rings then bronze is OK, without rings I would personally use cast iron for both piston and cylinder. If the valve is outside admission "D" valve then again I would use bronze. If inside admission piston valve without rings I would use cast iron.

Best Regards
Bob


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## ozzie46 (Jan 30, 2010)

Bob,GW,bentprop and hammer. Thanks all. I was thinking of the "sleeve", (sorry couldn't think of that word yesterday, *club* *club* ) because of the possibility of rusting after running if just iron or steel were used. Is that not a serious concern?


 bentprop, Nice work. What Loco is that? Could you post pics of the clys and valve gear?


 Ron


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## GWRdriver (Jan 30, 2010)

ozzie46  said:
			
		

> . . because of the possibility of rusting after running if just iron or steel were used. Is that not a serious concern?


Ron,
It is a concern, but it is also very much a function of how well an engine is "put up" after its run. Maybe a short description of typical model cylinder practice may help here, so in no particular order . . . .

CRS is not a good material for cylinders unless it is sleeved (in the cylinders) and faced (on the valve face.) It has poor rubbing bearing qualities and will rust no matter what. Cast iron on the other hand is the ideal material because of its inherent qualities, most importantly in wearing and self lubrication (by the graphite it contains.) Also, after a properly lubricated cast iron steam cylinder has run for a while it acquires an oily oxide coating on the cylinder walls and becomes somewhat rust-resistant (but not rust-proof.) C.I. on C.I is one of the best bearing combinations there is although most live steamers do switch to bronze for the slide valves. Bronze for cylinders is just beneath C.I. in suitability and bearing qualities but does have the advantage of being rust-free. Bronze on bronze is not nearly as good a bearing combination as C.I. on C.I.

A very large percentage of cast iron cylinders, from about 1.5" and larger, are also sleeved in cast iron, as were all full size locomotives, and the preferred material is centrifugally cast iron although we usually take what we can get. Bronze is most common these days for cylinders under about 1" diam and are usually never sleeved. One could sleeve a steel or cast iron cylinder with bronze but I don't hear of that being done too often. Oddly model stationary engines, such as Stuart Turner and others, are practically never sleeved no matter how large the bore, at least the original designs never call for sleeving.

All piston/cylinder combinations in any material and size will benefit substantially from having rings fitted. For small cylinders, perhaps 3/4" diam and smaller, O-rings have pretty much taken over as the easiest and most effective ring, especially in bronze cylinders. Above 3/4", or certainly 1" diameter, cast iron rings are the most typical material although I have heard of O-rings being used in larger cylinders. Also, there is a difference between iron rings for steam and automotive or IC rings. Steam rings are made to have a very low wall pressure rating while automotive/IC rings are made to have a high wall pressure and one does not suit the other well.

There are no doubt isolated exceptions to these guidelines but this is generally what is done nowadays. I will add to this if I find I've left out anything important.


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## ozzie46 (Jan 30, 2010)

Thank you GW, That is the info I need. However I'm a bit confused by this;

Quote(A very large percentage of cast iron cylinders, from about 1.5" and larger, are also sleeved in cast iron, as were all full size locomotives, and the preferred material is centrifugally cast iron although we usually take what we can get) Unquote.

 If the cyl is already cast iron why would it need to be sleeved with cast iron? A different kind of cast iron maybe? 

 Ron


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## SAM in LA (Jan 30, 2010)

The sleeve in the cylinder is considered a wearing part. It is much easier to replace the sleeve than the whole cylinder.

SAM


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## bearcar1 (Jan 30, 2010)

Thank you as well GW for your information, I found it to be informative as well. OZ, my guess would be that CI cylinders would be sleeved with CI for long term maintenance reasons. That is if the bore were to get severely worn in the casting without a sleeve the casting would have to be removed (not necessarily) and the wear pattern corrected by machining or a completely new casting installed in its place $$$$$$$. With a sleeve installed, if the same wear conditions were encountered, only the sleeve would need top be replaced to correct the wear pattern. Much more cost effective than the first discussed setup that did not use a sleeve.

BC1
Jim


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## GWRdriver (Jan 30, 2010)

ozzie46  said:
			
		

> However I'm a bit confused by this;. . . If the cyl is already cast iron why would it need to be sleeved with cast iron? A different kind of cast iron maybe?


 Ron,
Yes, maybe. In a perfect world C.I. sleeves would be certrifugally cast. Centri-cast has a more homogenous consistency and texture and distribution of alloyed metal. It's getting very hard to find, at least for amatuers and model builders.

As for sleeving, there can be several reasons for that,
To make the bore a higher grade material or a more consistant material
To eliminate the problem of porous castings or flaws or inclusions in the bore (These days this one is becoming a more common issue as the quality of some castings declines)
To allow milling or drilling steam passages (in the cylinder casting) which otherwise couldn't be milled or drilled
To mill or drill steam entry ports in the cylinder wall which could not otherewse be put into a casting 
To allow repair or replacement of the bores without increasing cylinder diameter and in some cases without having to dismantle the entire front end and remove the cylinders to do it

There may a few others but these are the ones which come to mind and which have apply in the model world as well as in full size.

Following - Jim and Sam have it right, sleeves are a "wear" part.


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## ozzie46 (Jan 30, 2010)

Jim, Sam and GW, AAAHHH the lite goes on. Very good info. To think I have a mechanics back ground too. I should have thought of the maintenance aspect. DOH! 

 I have a cast iron tractor weight that will supply stock for the cyls. It machines very well. So far I've not found any hard spots or voids in it.

 Bought some 1/8 mild steel for the chassis yesterday. So its a small step. I will post something in WIP when I have actually done something. ;D ;D 

 Still haven't decided if I want to build a "Simplex", "LBCS Doris" or something else. I may get Kozos "Virginia Switcher" book and try it. Decisions decisions decisions. scratch.gif scratch.gif scratch.gif scratch.gif scratch.gif

 Ron

 Ron


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## GWRdriver (Jan 30, 2010)

FWIW . . . I understand the SIMPLEX is a very popular engine in the UK these days, for all the reasons an engine might be popular. One of the suggestions I received from more than one source when planning improvements to my 2X TICH project was to substitute SIMPLEX cylinders. This was duly noted, but I ended up making my own patterns, etc.


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## hammers-n-nails (Feb 3, 2010)

for the engine im working on i will have to use steel for the cylinder because i need to weld the valve face on to the cylinder itself. GWR says crs is no good and i believe you then i have to decide what material to sleeve it with, you say cast iron is good but i can get a 4.5"IDX5"od 304 stainless seamless tube for about the same money, how would that be? ive never delt with anystainless but i hear it can be a PITA. also taking into consideration if i where to go with cast iron i would have to bore the rod to 4.500"dia 7.5" deep, i can see where this would not be fun also.


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## GWRdriver (Feb 3, 2010)

hammers-n-nails  said:
			
		

> GWR says crs is no good . . . . then i have to decide what material to sleeve it with, you say cast iron is good but i can get a 4.5"IDX5"od 304 stainless seamless tube for about the same money, how would that be?


Is this for a steam engine, which you will use to do real work? If so, and its the same money, I would definitely go for the cast iron. There are dozens and dozens of stainless steels and many of them (most?) can be a PITA to machine if you don't aren't equipped to do it and I don't know enough about the various Ssteels to say which one would be good and which one to avoid.

You could stay with the CRS, finish the bore really well, use cast iron piston and rings, and keep it well lubricated, and it would run just fine, but sooner or later rust would become a problem. My guess would be sooner, and then you would have to rework the cylinder, and probably sleeve it.

What I would do first is check with automotive cylinder sleeve suppliers. There is a vast array of finished and ready-to- finish cast iron sleeves made for automotive re-sleeving. You might get lucky.


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## hammers-n-nails (Feb 4, 2010)

yes this is for steam engine. i have been looking for cylinder sleeves from IC engines but havent come up with much(dont really know where to look, online at least) what i have found wont work because its such a long stroke for the bore. i want to make this right because im probably going to have a couple hundred in the cylinder by itself and i want it to last a long time.


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## GWRdriver (Feb 4, 2010)

If you want it to stand up to hard work (or some work) and last a long time then I would definitely prefer cast iron.


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## GWRdriver (Feb 10, 2010)

Ron,
Someone I heard from recently found C.I. liners in the required size for their live steam locomotive at Melling Cylinder Sleeve Co in Iowa. You might have a look at their cat which is available in pdf on their web site.


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## ozzie46 (Feb 10, 2010)

Thanks Harry. Will look into it.

  Ron


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## GWRdriver (Feb 10, 2010)

I just downloaded their cat and their open stock goes from 2" ID to 8.5" ID. I have no idea how much their products cost but it would be interesting to find out.

Not long ago I did the cyinder liners (1-5/8" ID) for my current locomotive out of a Durabar-like continuous cast iron bar. I hated to have to machine away a 1.5" diam plug but there was no way for me to get it out in one piece. A friend out of state offered to EDM cut out the centers so I sent them to him for the job. What's done is done but this was a "Doh!" moment . . . the shipping back and forth cost me far more than a new piece of 1.5" diam bar, plus the time and bother. Considering all this, the price of a commercially made liner might not be so bad after all.


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