# Hole in cylinder wall



## Sarah (Oct 14, 2012)

Hi Guys,

I am after a bit of advice please.

I have a small blind hole half way down a cast iron cylinder bore. The hole is approx. 1/8" dia. across and 1/8" deep.  Is it worth trying to fill the hole or is there anything else I can do?


Many thanks,

Sarah


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## Brian Rupnow (Oct 14, 2012)

If you are going to run it on steam, there isn't much you can do, except possibly bore the cylinder out and sleeve it. If you are going to run on compressed air, then you could try one of the epoxy based fillers like J.B. Weld. If the piston has rings on it, there is always the chance that the rings will catch on the edge of the hole and break.


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## ART (Oct 14, 2012)

Hello Sarah,
     You say that the hole is blind. Is it due to a void in the casting? If so you might be able to open the bore a little more to get rid of the hole, and modify your piston to fit the new dimensions. You have to take into consideration the  clearances of the ports so there will be enough material to incorporate them.

                                                                                                     ART


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## Tin Falcon (Oct 14, 2012)

cast iron does not weld well but a silver soldered plug could be an option. 
If this is to be a working engine to power say a steam boat  a sleeve like Brian
 said may be a better choice. 
How about an introduction in the welcome sub fora tell us a bit about yourself your shop and your interest in model building,and your location . this helps us help you . 
Tin


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## rleete (Oct 14, 2012)

I second Brian's comments.  If it's only to be run on air, JB weld it and (after plenty of curing time) clean up the bore.  If it's IC or steam, you're gonna have to sleeve it.  Sleeve can be quite thin (.030 wall?) so you won't have to bore it out too much.


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## Sarah (Oct 15, 2012)

Hi Guys,

I've put a bit about myself on the Wecome thread 

I will hopefully be running it on steam.  Can anyone point me in the right direction to look at sleeving the cylinder.

Many thanks,

Sarah


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## fltenwheeler (Oct 15, 2012)

Hi

What is the Bore and Stroke of the cylinder?

Tim




Sarah said:


> Hi Guys,
> 
> I've put a bit about myself on the Wecome thread
> 
> ...


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## Dr Jo (Oct 15, 2012)

Is this casting set a recent purchase from the original suppliers? If so they should replace the cylinder free of charge.

If not, sleeving is the best way to go. I have only sleeved gunmetal with cast iron before, it worked a treat. Bore the cylinder to take the sleeve, turn up a sleeve a good interference fit, put the liner in the freezer, heat up the cylinder, then make sure it goes in really quickly.

Jo


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## kvom (Oct 15, 2012)

Bronze is an excellent sleeve material if available.


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## Jasonb (Oct 15, 2012)

If sleeving make sure you are not going to cut into any cast steam passages when you bore it oversize. As you are using iron piston rings than the sleeve is nothing more than a tube turned from cast iron that is a press fit into the enlarged bore, you can add a bit of high temp loctite if you are not sure of your fit

J


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## Sarah (Oct 15, 2012)

Hi,

The Bore and stroke are both 1 1/2".  Apparently the casting set is quite old, the engine was built up and kept as a sort of display piece, but there are a number of machining errors on it.  I have taken it to pieces to see if I can get it working.  It needs new bearing blocks as there is an awful lot of play in them, along with machining a better fitting eccentric Strap.  There are also no paper gaskets or gland packing.

It's an interesting project though 

Sarah


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## terryd (Oct 15, 2012)

Sarah said:


> Hi,
> 
> The Bore and stroke are both 1 1/2".  Apparently the casting set is quite old, the engine was built up and kept as a sort of display piece, but there are a number of machining errors on it.  I have taken it to pieces to see if I can get it working.  It needs new bearing blocks as there is an awful lot of play in them, along with machining a better fitting eccentric Strap.  There are also no paper gaskets or gland packing.
> 
> ...


Hi Sarah,

The idea of sleeving the bore is a good solution, probably the best.  However as has been said there is a danger of boring into the steam passages if you go too far. 

Looking from another angle would the performance be too compromised if you reduced the size of the piston and sleeved the existing bore? From your description, personally if I were to attempt this and performance was not critical I would lightly skim the bore to clean it up, make an accurate thick walled sleeve and use one of the suggestions by other posters to fit it, then bore it to suit a turned down piston (I once saw an 18" diameter sleeve fitted into a loco cylinder for repair at a heritage railway, it was soaked in liquid nitrogen for several hours in a metal dustbin before fitting and the guys had to work fast, believe me).  You would of course have to make new rings (if fitted) but that is not too difficult.

Regards
Terry


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## Orrin (Oct 15, 2012)

I've used JB-Weld with great success.  Some people have even used it to successfully repair pitted bores in internal combustion engines.  If it can tolerate ignition temperatures, it will most certainly stand up to anything your application will throw at it.

Orrin


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## chipenter (Oct 15, 2012)

In years gone by we used to fill blow holes with White metal(babbet) , melts about the same temp as lead use solder flux .


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## Bastelmike (Oct 16, 2012)

Tin Falcon said:


> cast iron does not weld well but a silver soldered plug could be an option.
> Tin





Tin Falcon said:


> cast iron does not weld well but a silver soldered plug could be an option.
> Tin


Thats true in general, You shouldn't expect much strength from such a weld.

But I've seen often enough how defects in new large castings were repaired by welding.
The defective area is removed with an angle grinder, or by milling if its large. A piece of cast iron is fitted into the gap and welded.

One thing is noticeable about welding: You can use basic sticks, the weld won't be much weaker than with special welding sticks. But You can't machine the weldng (exept grinding). Hardness is usually such that you don't have luck even with carbide tooling.
If you need to machine it you need special nickel based sticks. They are pretty expensive, 5-10 times higher priced than basic sticks. And they are not very "user-friendly" during welding.

Another point is to keep heat stress low during welding, only short welds at a time.

In general in industry they think twice before they scrap a new casting of several tons.

Mike


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## tel (Oct 16, 2012)

Frankly, if the bore is good, other than the blowhole, I would be inclined to ignore it, especially if fitted with CI rings, even with soft packing you will get away with it more often than not.


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## Ken I (Oct 16, 2012)

I tend to agree with Tel - suck it and see.

If the hole has a clear path to the outside you might consider drilling & reaming it out and plugging it with a drive fit pin turned to suit. Cleanup is a PITB though.

Ken


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## Sarah (Oct 18, 2012)

Hi Guys,

I'll sort out the other problems with the steam engine and try running it to see how it operates.  If there is a problem I'll try the JB weld, then if that doesn't work I will investigate making a sleeve, though there is not much extra diameter to play with.

Many thanks,

Sarah


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## mrspoom (Nov 16, 2012)

depending on where the hole is located you could drill and tap the area and thread a piece of brass and screw it in then cut it off just a little long and peen the end so to swell the brass to swedge it in place and dress off what has come through the cylinder wall.


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## Sarah (Nov 17, 2012)

Hi,
The hole is quite hard to get to as it is on the steam chest side.  I have cleaned it out and filled it with JB weld.  I'll find out when it's built if it works 

Regards,

Sarah


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## Niceonetidy (Nov 18, 2012)

Ignore the hole. Use cast rings. Two stroke engines are high revving with the piston rings continually passing over large edges. Should not be a problem


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## Philipintexas (Nov 18, 2012)

I don't know how thick the wall of the cylinder is, but can you drill/ream through the side and press (loctite) in a "plug" of the same material, then re-bore the cylinder and finish the outside surface?


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## Sarah (Nov 18, 2012)

Hi Guys,

Unfortunately the hole in the cylinder is on the steam chest side, so if I fitted and filled the occlusion from the inside/outside I would be messing with the steam chest ports.  The piston rings are actually wider than the hole so should not really loose much steam through it.  At the moment I'm going to wait until I've rebuilt the steam engine and see how we'll it works.

Regards,

Sarah


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