Steam & Excursion > Latest 2926 Photos

The latest batch (2) of photos of the restoration of the 2926 are now available. Sure are impressive. Especially the continued work on the staybolt assemblies & the "tramming" work. http://www.nmslrhs.org/

Question: The narrative now talks about "honeing" (hope I spelled that right) the cylinders. I think I have a grasp on what that's about but would like it if someone could chime in with a more detailed explanation & the reasoning behind it.

Thank you in advance.

Paul



Edited 4 time(s). Last edit at 09/22/14 21:31 by 4000Class.

4000Class Wrote:
-------------------------------------------------------
> Question: The narrative now talks about "honeing"
> (hope I spelled that right) the cylinders. I thing
> I have a grasp on what that's about but would like
> it if someone could chime in with a more detailed
> explanation & the reasoning behind it.


http://en.wikipedia.org/wiki/Honing_(metalworking)

After reboring a cylinder, the cylinder walls are extremely smooth, and the piston rings sweeping the cylinder will remove all the lubrication on the cylinder walls. Honing roughs up the machined cylinder walls to create places for lubrication to cling.

Honing is part of an internal-combustion engine rebuild as well, and there are videos of the process on youtube.

Wow, I was going to purchase another flue tube spot, but they are SOLD OUT. That sure will help the restoration cause.

nycman Wrote:
-------------------------------------------------------
> Wow, I was going to purchase another flue tube
> spot, but they are SOLD OUT. That sure will help
> the restoration cause.


According to their website, there are still 59 available. I have already bought a couple of them myself.

http://www.nmslrhs.org/Shop/Superheaters/superheaters.php

-Fred-

And all of this with volunteers .......Pay attention UP.

Ah, my mistake. The sold out sections are the tubes and flues themselves. The ones still available, and I will buy another, are the Superheater tubes.

johnacraft Wrote:
-------------------------------------------------------
> After reboring a cylinder, the cylinder walls are
> extremely smooth, and the piston rings sweeping
> the cylinder will remove all the lubrication on
> the cylinder walls. Honing roughs up the machined
> cylinder walls to create places for lubrication to
> cling.

True, but there is another purpose as well. Unless the boring machine is absolutely rock-solid (and I mean mounted on bedrock granite, and no earth tremors during the boring) there can be some minor imperfections here and there in the cylinder profile. Remember that a boring head only touches the cylinder wall at one point, progressing in a spiral down the cylinder. Some roughness or the like is always expected. The hone removes very small amounts of metal, for the most part only taking off high places. Unlike the single-point boring head, the three or more long stones on a hone contact a relatively large part of the cylinder profile at once. Combined with a relatively random movement pattern while spinning, it grinds off any high spots and leaves a smooth (but not glass smooth) cylinder.

Another reason for honing is to smooth up the diameter of the cylinder after long use. The rings on the piston (at least in an infernal combustion engine) do not traverse the entire cylinder length. So they wear on the middle part of the cylinder and not the ends. Over time the middle of the cylinder wears a little larger than the ends. The end piston rings take on a taper to match the step in the cylinder wall. But if you for some reason have to replace the rings, you are in trouble. The new sharp-edged ring will hit the step in the cylinder wall, and possibly break the ring, damage the piston, or damage the cylinder, or some other bad combination of things. So you break out the hone and use it to smooth the cylinder profile. When you are done the steps at the end of travel have become gentle ramps, or possibly you have enlarged the unworn part of the cylinder to match the worn part. This also breaks up the glassy surface the rings make. Of course if the wear is bad enough you need to rebore or reline the cylinders. But that is major overhaul rather than minor overhaul work.

Thanks for heads up on 2926 pics. Steam Onward!

Thank you, one and all, for your feedback. I do appreciate it.

One thing's for certain. If the U.P. Steam Program is in dry dock (or dead - God forbid) the NMSL&RHS will provide us a sterling example of mainline steam through their continued work & operation of the ATSF 2926.

Consider a donation for their cause.



Edited 2 time(s). Last edit at 09/22/14 21:41 by 4000Class.

Proper honing leaves a crosshatch pattern in the bore which holds oil and helps the rings seat. Honing is also used to correct the bore if it's "barrel shaped" or slightly out of round and will straighten the hole. When we restored 1522, our air pump cylinders, the power reverse cylinder and the cylinder cock bores were all honed at my work.
Real precision honing can be used internally and externally to hold tolerances and finish so accurate that it's used in the precision machinery and gauge industry.
I worked for Sunnen Products in St. Louis for 27 years. We had a small demo part we called a spinner that we gave away at shows. It had a steel sleeve that was honed out. It was about 2-1/2" long and fit onto a 3/8 pin about the same length which was seated in a steel base. The sleeve had a rubber plug in one end and when the assembly was put together, you would locate the sleeve about 1/4 from being fully on the pin, put the plug in and it would spin on an air bearing. The fit was so close that you could pull the sleeve off the pin and touch the pin and your fingerprint wouldn't let it spin. That's close!
If it didn't spin for a prescribed length of time, it was rejected.
BTW, Sunnen makes honing heads and accessories for bores this size. We cleaned up 1522's cylinders and valve cages with them.



Edited 1 time(s). Last edit at 09/23/14 07:27 by Frisco1522.

Guys, if you just go the web site, www.nmslrhs.org/ and see what a fantastic job these volunteers are doing, you would be extremely impressed. See the great video inserted at that website. Shouldn't the U.P. with the Big Boy and all their PR money have something like that to see? Remember, the Santa Fe 2926 people are all doing this on their own. They are not part of a billion dollar company. Just saying...

lwilton Wrote:
-------------------------------------------------------
> johnacraft Wrote:
> --------------------------------------------------
> -----
> > After reboring a cylinder, the cylinder walls
> are
> > extremely smooth, and the piston rings sweeping
> > the cylinder will remove all the lubrication on
> > the cylinder walls. Honing roughs up the
> machined
> > cylinder walls to create places for lubrication
> to
> > cling.
>
> True, but there is another purpose as well. Unless
> the boring machine is absolutely rock-solid (and I
> mean mounted on bedrock granite, and no earth
> tremors during the boring) there can be some minor
> imperfections here and there in the cylinder
> profile. Remember that a boring head only touches
> the cylinder wall at one point, progressing in a
> spiral down the cylinder. Some roughness or the
> like is always expected. The hone removes very
> small amounts of metal, for the most part only
> taking off high places. Unlike the single-point
> boring head, the three or more long stones on a
> hone contact a relatively large part of the
> cylinder profile at once. Combined with a
> relatively random movement pattern while spinning,
> it grinds off any high spots and leaves a smooth
> (but not glass smooth) cylinder.
>
> Another reason for honing is to smooth up the
> diameter of the cylinder after long use. The rings
> on the piston (at least in an infernal combustion
> engine) do not traverse the entire cylinder
> length. So they wear on the middle part of the
> cylinder and not the ends. Over time the middle of
> the cylinder wears a little larger than the ends.
> The end piston rings take on a taper to match the
> step in the cylinder wall. But if you for some
> reason have to replace the rings, you are in
> trouble. The new sharp-edged ring will hit the
> step in the cylinder wall, and possibly break the
> ring, damage the piston, or damage the cylinder,
> or some other bad combination of things. So you
> break out the hone and use it to smooth the
> cylinder profile. When you are done the steps at
> the end of travel have become gentle ramps, or
> possibly you have enlarged the unworn part of the
> cylinder to match the worn part. This also breaks
> up the glassy surface the rings make. Of course if
> the wear is bad enough you need to rebore or
> reline the cylinders. But that is major overhaul
> rather than minor overhaul work.

Posted from Android

And if you are using a hone to fix that lip on an engine you will screw up anyhow.
Ridge reamer required to take the unworn portion off first. And if you have that bit of a ridge you might as well bore it as now its worn excessively. I've measured a ridge on a Chevy that was .007". Not good. And Softer bores (e.g.. Chevrolet) usually wear quicker. Ford traditionally had harder iron blocks. Didn't need boring as much. The boring process "squares up" the hole. No more taper, and in line with all around it.
Honing is a finish prep. Like primer to paint. You can hone to suit whatever rings you wish to use. Different ring material requires different honing grit to finish.
Rings, at least in autos can be cast iron, chrome moly, or ceramic to name a few..lwilton Wrote:
-------------------------------------------------------
> johnacraft Wrote:
> --------------------------------------------------
> -----
> > After reboring a cylinder, the cylinder walls
> are
> > extremely smooth, and the piston rings sweeping
> > the cylinder will remove all the lubrication on
> > the cylinder walls. Honing roughs up the
> machined
> > cylinder walls to create places for lubrication
> to
> > cling.
>
> True, but there is another purpose as well. Unless
> the boring machine is absolutely rock-solid (and I
> mean mounted on bedrock granite, and no earth
> tremors during the boring) there can be some minor
> imperfections here and there in the cylinder
> profile. Remember that a boring head only touches
> the cylinder wall at one point, progressing in a
> spiral down the cylinder. Some roughness or the
> like is always expected. The hone removes very
> small amounts of metal, for the most part only
> taking off high places. Unlike the single-point
> boring head, the three or more long stones on a
> hone contact a relatively large part of the
> cylinder profile at once. Combined with a
> relatively random movement pattern while spinning,
> it grinds off any high spots and leaves a smooth
> (but not glass smooth) cylinder.
>
> Another reason for honing is to smooth up the
> diameter of the cylinder after long use. The rings
> on the piston (at least in an infernal combustion
> engine) do not traverse the entire cylinder
> length. So they wear on the middle part of the
> cylinder and not the ends. Over time the middle of
> the cylinder wears a little larger than the ends.
> The end piston rings take on a taper to match the
> step in the cylinder wall. But if you for some
> reason have to replace the rings, you are in
> trouble. The new sharp-edged ring will hit the
> step in the cylinder wall, and possibly break the
> ring, damage the piston, or damage the cylinder,
> or some other bad combination of things. So you
> break out the hone and use it to smooth the
> cylinder profile. When you are done the steps at
> the end of travel have become gentle ramps, or
> possibly you have enlarged the unworn part of the
> cylinder to match the worn part. This also breaks
> up the glassy surface the rings make. Of course if
> the wear is bad enough you need to rebore or
> reline the cylinders. But that is major overhaul
> rather than minor overhaul work.

Posted from Android

nycman Wrote:
-------------------------------------------------------
> Ah, my mistake. The sold out sections are the
> tubes and flues themselves. The ones still
> available, and I will buy another, are the
> Superheater tubes.

Are they sold out just for now and will make another batch at some other time, or what? I'm confused?

I don't know if this is fact or not. I got on one of the pages on the 2926 website which showed all of the tubes and fllues (not the superheater tubes) as all sold out. I had previously donated to the superheater tubes and just a few days ago they were showing 59 still unsold. Thinking that the page I was viewing was superheater tubes, I was amazed that all the remaining ones sold so fast. Later, I found the superheater tube page and indeed there were 59 remaining. I suspect, but don't know, that there was a fundraising effort some time ago to "purchase" the tubes and flues, before the fundraising effort to "purchase" the superheater tubes, which as you know fit into the flues designed for them to fit into. I hope this clears up my wrong earlier post.

I am concerned about them welding up new staybolts then machining them
to size. Not sure that procedure is kosher.

Why not make them the right size to start with

Keystone1 Wrote:
-------------------------------------------------------
> Shouldn't the U.P. with the Big Boy and
> all their PR money have something like that to
> see? Remember, the Santa Fe 2926 people are all
> doing this on their own. They are not part of a
> billion dollar company. Just saying...

Maybe if they ever do some work on the Big Boy,
they will.

As hard as it is for some people to grasp, no
work is being done at all on any of the 3 UP
steam locomotives. And there hasn't been any
work done on them for months.

That would make a very boring website.

nycman Wrote:
-------------------------------------------------------
> I don't know if this is fact or not. I got on one
> of the pages on the 2926 website which showed all
> of the tubes and fllues (not the superheater
> tubes) as all sold out. I had previously donated
> to the superheater tubes and just a few days ago
> they were showing 59 still unsold. Thinking that
> the page I was viewing was superheater tubes, I
> was amazed that all the remaining ones sold so
> fast. Later, I found the superheater tube page
> and indeed there were 59 remaining. I suspect,
> but don't know, that there was a fundraising
> effort some time ago to "purchase" the tubes and
> flues, before the fundraising effort to "purchase"
> the superheater tubes, which as you know fit into
> the flues designed for them to fit into. I hope
> this clears up my wrong earlier post.

These must be made in "limited run" special production batches or something. Is my guess. Otherwise, the entire steam industry--such as it is--would go under in just a few short months or a year or two or whatever. I guess the suppliers just have to have X-amount of orders for a "batch-run" for all of this equipment each and every time, and depending on locomotive, etc. (I.E., the 2926 requires different flues, superheaters, etc. than the SP 4449, than does the SP&S 700, than does the UP 844--that horrid story--than do the smaller locos all across the Nation).

Red Wrote:
-------------------------------------------------------
> These must be made in "limited run" special
> production batches or something.

In some cases, may be. But in general probably not. Pipe is pipe. 21' is a standard length. I'd bet pretty strongly that when Alco and other ancients were designing their boilers, they went out and bought stock boiler tubes from the Acme Boiler Tube and Anvil Co., rather than deciding that this shiny new engine really needed to be metric with 504.37 mm tubes with a 13.875/37ths inch wall thickness that they machined themselves.

Stock boiler tubes were probably something like schedule 80 seamless 5-1/4" tube or the like. Now while we don't do steel in the USA anymore, you can probably still find something real similar in the oil patch industry for drill tube and use it. Or more likely, the Amalgamated Boiler Tube & Videogame Co. still supplies that tubing size for use in stationary boilers.

But where is it going to run?

4000Class Wrote:
-------------------------------------------------------
> >
> One thing's for certain. If the U.P. Steam Program
> is in dry dock (or dead - God forbid) the NMSL&RHS
> will provide us a sterling example of mainline
> steam through their continued work & operation of
> the ATSF 2926.