# K28 Rebuild



## Kovacjr (Jan 2, 2008)

After seeing what a K27 coal fired can do I decidec to take on the job of making the loco breathe better and also replumb all the lines under the cab. An axle pump is also in the list of changes. For now I have taken the stock cylinders and bored out the passages along with making proper steam ports. I noticed that the OEM ports were not even drilled in a straight line. All the plumbing for the steam is being replaced as is the superheater. Most likely I am going to not have a superheater. If I need I will add a return flue style superheater. I have always had issues with the left burner and removing the tube should help. I took Asters style for the exhaust connection on the cylinders and soldered in a 5/16" nipple so I can slide in a 3/16 pipe with a nut and Oo ring for a seal. The T section is threaded 3/16 - 40 for a nozzle that will end at the petticoat I had previously fabricated. I took the stock lubricator and cut out the cender section and replaced it with brass tubing, the line that goes through has a no60 drill hole for the oil. I was going to do a dead leg but decided against it as the placement was not the easiest to work with. I also made new jet holders and a manifold so the gas line is also plumbed under the deck. All these changes can be done without removing the boiler and just the smokebox.


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## jmkling (Jan 2, 2008)

looks good. I like the way you did the fuel jets, have you tried firing it yet?


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## Charles (Jan 2, 2008)

Jay 
What size steam lines? Did you increase exhaust port and exhaust lines to lessen the back pressure?


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## Kovacjr (Jan 2, 2008)

Jon - Jets fire fine 

Charles - 1/8" copper lines thin wall something like .040" walls. The exhaust is 3/16" but will have a nozzle to restrict anyway. Jeff is using I think a No 60 bit in his C16 nozzle so I am thinking a 55-50 range should be about correct.


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## steam8hack (Feb 11, 2008)

Replaced the dry pipe too?


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## Slipped Eccentric (Jan 2, 2008)

Looks good Jay, beautiful work as always.


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## Kovacjr (Jan 2, 2008)

Dry pipe will be done right Ryan?? just have not gotten there yet.


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## livesteam5629 (Jan 2, 2008)

Looking good as usual . 
Noel


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## rbednarik (Jan 2, 2008)

Jay, 

Drypipe will be done with new 1/8" tubing. You might want to go bigger than a no 55 drill on the exhaust, no sense in restricting the exhaust when you went through all the trouble to make it bigger! Something along the lines of a 2mm drill will give nice deep stack talk and reduce accidental draft. I speak from experience on that....who knew an open smokebox could pull a draft? 

I'll take some pics of the cylinders I have here so everyone knows what they looked like from the factory.


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## steam8hack (Feb 11, 2008)

x /DesktopModules/NTForums/themes/mls/emoticons/hehe.gif


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## Kovacjr (Jan 2, 2008)

Well it's August 17th and I started this project back on May...I guess I'm on track. today I ran the K for 2 hours after the test firing Friday afternoon. Very worth the work. I can not belive the difference in pulling power over stock piping. I did do away with the superheater and I can tell a difference on the wetter steam but it certinaly does not make it run any worse. After speaking with some 1:1 steam guys that all talk that the superheaters when blown were not replaced and just plumbed direct on many locos as they did not benifet as much as hoped. Im sure there are instances that that is wrong but I also dont have a full size loco to test the therory on. TRhe valves had been redone after the 1st airtest proved too much blow by from my mis calculation on the exhause recess on the valve. Once that was correct and reinstalled she runs awesome! Very loud 4 beats per revolution where the factory tuned loco had only 3 that you can hear. i also get a very slow run now as more steam is able to enter the cylinders at a faster rate and the same for the exhaust. I will have to take some video of the loco running to show how it runs now. Next week i will be at Ron Browns and hopefuly will be able to test what she can pull. last year with the stock loco I was able to pull around 35 AMS cars plus a dead Mogul that ran out of cas and we didnt know. Come a few weeks I will double head with Justins K27 and hopefully pull every narrow gauge car that is on hand at Jim's fall meet. Jon make sure you bring cars....Heh You too Dave.


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## Taperpin (Jan 6, 2008)

Jason , 
Sounds like you got agood result for the work. The K28 runs well enough in stock form but the better performance avallable by imporving the steam cicuit is substansial and the cost is only the labour involved! did you finish up reworking the combination levers?


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## jfrank (Jan 2, 2008)

Excellent work Jason. Thanks for sharing with us. I have pulled as many as 20 AMS cars and it's quite a load. How do the couplers hold up with 35? That is a huge load to pull. My k28 has always run well so I have done little with it. I guess I got a good one.


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## Kovacjr (Jan 2, 2008)

So far I wanted to confirm the valve ports and valving is correct before I messed with another variable..I also found that the rod that controls the links was out of balance and borh sides had different centers..Is that what you were describing Gordon on foward and reverse?? Or is this just another variable? Heh The reason is was messed up was the set screw was stripped and the arm was locktited on to the rod the otherr just loosened with the screw. I ended up replacing the 1 arm and what a bitch that was without taking off the boiler and shell. 

This weekend i am going to video the loco for sound and for capabilities. 

I made a nozzle for the pipe at 3/32 which is just under the smallest pipe or hole ID. 

A new Drypipe is next to complete the passages. 

Gordon, none of this would of came together the way it did without your help throughout the work..Thank You very much!!


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## Kovacjr (Jan 2, 2008)

After running the K28 with the new ports and pipework, I figured its about time to put the changes to use and complete the valve gear with working combination levers and a new union link and correct valve with lap.

I had made the necessary measurements on the combo lever for the center to center points and also aquired the steel to make the new parts. I had picked up some tool steel in .062" x .125" along with .062" and .078" round for pins.

All the pivot points were drilled and reamed to spec for a moving or press fit. The upper pins I used the .078 as the rarius rod was threaded M2 for the orignal connection. That was drilled and reamed to be a pressfit. The union link was fabricated by silversoldering on two tabs that end up being the yoke of the link. It connects to the OEM point on the crosshead. 

Orignally I had connected up the valve gear as built from Accucraft but later found out that the valve rod and the radius rod need to be swapped on the combo lever as the valve events were set for a cross ported cylinder. I did not do any cross porting as I did not mind the radius rod in the opposite position from the 1:1 version. 

Once all that was completed I had air tested again and it runs like a champ on ait down to below 5 PSI. 

I also had removed the OEM Oring setup on the piston and replaced it with a dual split ring setup made of Tetron C ( It is a graphite impregnated PTFE, also very solid and heavy) That gave me a very good seal and great compression.

Since I rerouted the steam under the boiler to get rid of my burner woes I had lost the superheater, so I had habricated one from some 1/8" stainless tubing from Mcmaster-Carr. Bent with a mandrel bender and produced a very clean bent product. Once the fittings were soldered on I had wrapped part of it along with the complete underside pipe with a scotch 66 fiberglass insulation tape. It is rated to 450 degrees hopefully it will make a difference. If not the 2 flue superheater will heat it back up and dry it out. The superheater extends about 5" into the flue about 4" from the end of the burner.

I had also a few months ago added a rockguard to the pilot. It shows up in many books and photos on the K's and though it would make it stand out a bit from the crowd.

There is also a photo of the OEM ports on the cylinders, notice that the valve was not even riding fully on the face. I had lapped the cylinder, valve and steamchest on a lapping plate all the way to 3000 grit. What a great find that plate was. I found a 14x16 lapping plate 2 faced one smooth one .500 checkered. Found it in the garbage along with a bunch of other tools that were being thrown away in front of someones house. What drew me to it was the wooden toolmakers box sitting next to a pile of milk crates and boxes. Most of the stuff was rusted to **** but this along with a small crate full of tooling was not. The chest of course had seen much batter days and was left.

So next up is a new valve rod guide/yoke as the OEM one is too long and also does not guide the rod in any way. There is way too much deflection and I kept wearing out the valve rod oring as thats the only thing that centeres the rod in any way. I am also going to extend the valve rod with a new one that will also have a guide in the front of the chest.

Now for some photos....


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## CLRRNG (Sep 26, 2008)

*Jay,*
* Nice work. Can't waite to see it in action. *

*Glen*


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## Mark Scrivener (Jan 7, 2008)

Cool Jason - that is quite a bending job on the superheater tube. You are going to have one awesome K-28 when your finished. 

BTW - I couldn't help notice the steam lines to the cylinders are soldered. Was this the way Accucraft supplied the engine? I guess there is no issue if you don't plan on taking off a single cylinder.


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## Kovacjr (Jan 2, 2008)

Thanks - Yes the steam pipes were soldered to the chects from the factory. I just used 1/8" piping in replacement. If I did the chest as I did the exhause you still have to remove the smokebox to get to the packing. Either way the smokebox comes off. The steam shesta also also not part of the cylinder and have a gasker above and below it to the cylinder block, so if you were to remove the cylinder you could drop it from the blowk if necessary. I find it much easier to work with the SB off though. 

If the superheater proves o bee to much bends I will just make a new one that is a single flue.


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## Mark Scrivener (Jan 7, 2008)

Thanks Jason. BTW - you mentioned earlier that the linkage was setup for cross porting, but the cylinders weren't. One way to cross port your existing cylinders would be to put a plate in between the cylinder and the valve and mill the cross port into that plate - this is how Aster did the Berk (and probably a few other engines). One nice benefit to this approach is you can remove/replace/rework the valve face without removing the cylinder. 

Nice work and keep the photos coming....you are getting me inspired to rework my K27.


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## Kovacjr (Jan 2, 2008)

yes it requires to mill off the plate thickness from the cylinder though otherwise you will raise up the valve centerline by probally .100" if you were to make a plate with a .050" passages with say an .125" endmill. Yes I though of it, but did not want to bother as the linkage position didn't bother me.


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## insanerocketkid (Jan 2, 2008)

Jason, 

I have a suggestion: Consider making a dual blast nozzle, in the sense that there are actually two exhaust nozzles, but they are formed into a single body (either that, or make sure that both jets fire through the stack). 

I would think that despite the exit being open, it would still direct some backpressure to the other cylinder. If nothing else maybe you could consider this as an ideal test method... Test it as it is now, and then maybe consider making a modified exhaust, featuring the same tee as you have, but somehow prevent pressure from being able to transmit to the other cylinder. You might notice a bit more power in the end... 

Just my 2 cents.. My 2-8-0 features an exhaust nozzle that has two exhaust passages, but a single nozzle (IE it does not Tee like yours does). 

If you decide to undertake this, let me know. I'd be greatly interested in the results, and could offer input if you so desired. 

Mike


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## Semper Vaporo (Jan 2, 2008)

It has been said many times that no Chief Mechanical Officer was worth his salt if he didn't try to redesign the front end!


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## Chris Scott (Jan 2, 2008)

Posted By insanerocketkid on 02/01/2009 10:11 PM
Jason, 

I have a suggestion: Consider making a dual blast nozzle, in the sense that there are actually two exhaust nozzles, but they are formed into a single body (either that, or make sure that both jets fire through the stack). 

I would think that despite the exit being open, it would still direct some backpressure to the other cylinder. If nothing else maybe you could consider this as an ideal test method... Test it as it is now, and then maybe consider making a modified exhaust, featuring the same tee as you have, but somehow prevent pressure from being able to transmit to the other cylinder. You might notice a bit more power in the end... 

Just my 2 cents.. My 2-8-0 features an exhaust nozzle that has two exhaust passages, but a single nozzle (IE it does not Tee like yours does). 

If you decide to undertake this, let me know. I'd be greatly interested in the results, and could offer input if you so desired. 

Mike

Sounds similar to a Lempor Exhaust System: (links

1. http://home.ca.inter.net/~mguy/A%20Lempor%20Exhaust.htm 


2. http://www.trainweb.org/tusp/lempor/lempor.html


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## insanerocketkid (Jan 2, 2008)

Chris,

indeed.. this is the one I was talking about: http://home.ca.inter.net/~mguy/Tube_in_tube_Kordina2.jpg

I spoke to Ryan about that last night, and he expressed some interest in experimenting with an upcoming project of his... 


Mike


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## Kovacjr (Jan 2, 2008)

Here is the test videos I took yesterday. yes Ryan it runs faster then I wanted to run it with no front pilot truck on. The track was not the smoothest with such a fat loco.

The smokebox was still removed for work and I threw on the inner brass wrapper along with some aluminum foil to keep in the heat. 

http://www.youtube.com/watch?v=vjbRMOjwXBE


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## cabforward (Feb 18, 2008)

jason 
the video says that the video is no longer available 
matt


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## Kovacjr (Jan 2, 2008)

Works as of 8:50AM for me???


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## rkapuaala (Jan 3, 2008)

When do you sleep and eat Jason


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## Kovacjr (Jan 2, 2008)

So I took Richard's advice and took a nap and ate. That gave me the energy to turn and mill the bronze I ordered for that I had to do next. I started with a new rear valve guide as I knew with this the rod would be much more supported. if you ever took it off you would see the guide has a 4mm hole for a 3mm rod, the only guide is the Oring. So far after reassembly that took care of the issue and I do not need to extend the valve rod and add the front bushing that I turned.

When I took the measurements for the new guide I noticed that from the photos of the 1:1 the Accucraft yoke is way too long to hide the incorrect pivot joint. Since I corrected the pivot for the Combination lever I was able to shorten the new yoke and have the guide actually ride in the guide area as shown in the last 2 photos showing the full extended travel.

Now with this wrapped up I can reattach the repainted/stack/door and complete the wiring for the lighting that is ready to install. 

The new guides will be painted after a few trial runs that prove successful


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## livesteam5629 (Jan 2, 2008)

Great Work Jay! 
Now go buy that mill you want. You are having way too much fun. 
N


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## Kovacjr (Jan 2, 2008)

Thanks Noel, 

It was funny cause I asked John if he had any ball mills, his response was I have any size you will need. The purchase of the mill is not the issue its the purchase of the assorted tooling and addons. Of course a major purchase would be about 500 for DRO's They make like and work a breeze. Id really like a set for the lathe too but for now dials indicators are working so far.


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## Mark Scrivener (Jan 7, 2008)

Jason - 

I hear you on the dial indicators - they have served me well on my lathe. My next step is a CNC mill - once I get the cash. For gauge 1 I think something small like the Taig or Sherline would be great. No need for a manual mill - just look at the "wizards" under Mach 3 control software - makes most mill operations automated without CAD/CAM.


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## Kovacjr (Jan 2, 2008)

With the upcoming meet at Scranton Pa I wanted to have the k wrapped up for the most part to run. yesterday and today I spend doing the electronics. All lighting was ready to install but all the wires had to be ran so the door still opened. All front lamps terminate behind the air compressor, then routed in the handrail for the headlamp and the markerlamps are routed underneath, I seperated the 2 just in case I wanted to run just a headlamp someday. I also added 2 lampos in the cab that light up the pressure gauge and glass for night running. After the 1st run witht he RC everything was mounted in the cab and it was very cluttered and bulky. This time I have everything installed in the tender under the doghouse and just 2 connectors a 3 and a 4 pin that power everything to the cab including a spare servo lead for the whistle thats to be installed still. I also upgraded the throttle gear on the servo to a larger one for more turn on the throttle. 




























What a mess of wires, the charging jack and power switch is located int he hatch along with a green lamp to tell when its on just in case. The receiver is connected to the adjustable voltagfe regulator to power the lighting and controlled by a switch off the AUX channel.




















Lamps in the cab and markers are 1.5v. Headlamp is a 1.5v maglight bulb and a 1.5v behind to light up the number boards.




























Finally painted the rock guards too, also tpouched up the whole loco and painted the new handrails. Still have to bend up the front section that will be a slip on unit.










Added some glazing to the doghouse. What a difference. i want to add to the cab too but the side sindows have no clearance for glazing.


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