Restoring a modified Allen 2-4-0 barn find

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Pontiacguy1
Posts: 829
Joined: Thu Apr 26, 2012 10:15 am
Location: Tennessee, USA

Re: Restoring a modified Allen 2-4-0 barn find

Post by Pontiacguy1 » Mon Oct 23, 2017 4:21 pm

Get yourself one of those locoparts burners and convert that thing over to Propane. I know of one guy in our club who did that to his Allen Ten Wheeler. Had a Bagley burner in it, but was inconsistent and hard for him to keep steam. Now he can lift the safety valves whenever he wants.

Second thing is to get the timing better, which you've already discussed. Best thing in my opinion would be to get someone local who has built several successful Stevenson gear locomotives to just look at your valve gear and try to get it tightened up and set better. Granted, it's running and I've heard a whole lot worse, but you'll be much happier with it and it will pull and dig in so much better once that timing is square. An experienced person can tell you where the worst spots are in your valve gear and can set that timing for you, which will save you a lot of time replacing parts that may not really need to be replaced. I've seen someone just rip out the valve gear and replace everything on their locomotive when 80% of their looseness was in 2 places that could have been addressed pretty quickly. Still, it's a lot of fun just having something to run.

Third... get some more run-by shots instead of just shots over your shoulder while you go around the track. I'd like to see the locomotive going by... And your shirt kinds creeps me out... Just kidding! I saw your other video too, but would like to see you running across that bridge or something like that.

In all seriousness, You're doing a good job with this, and actually being able to operate it is quite a success. Keep working on it and you'll be working that thing with a big cut of cars soon. I've enjoyed your thread. Love seeing these dormant old locomotives become active again. Wish it would happen more.

Steve Alley
Posts: 184
Joined: Thu Dec 20, 2012 12:30 am

Re: Restoring a modified Allen 2-4-0 barn find

Post by Steve Alley » Sat Jan 13, 2018 9:20 pm

Just wondering what is the late's on this Loco. Curious minds want to know, with pictures please.

tyleire
Posts: 53
Joined: Thu Sep 24, 2015 3:18 pm
Location: North Hollywood, CA

Re: Restoring a modified Allen 2-4-0 barn find

Post by tyleire » Mon Jan 15, 2018 2:12 am

After running the 2-4-0 quite a bit this past fall, I had a pretty lengthy wish list of fixes to the locomotive that required a full teardown: the timing was still off due to loose eccentric straps and worn valve gear, the axle pump (which I rely quite heavily on to save steam) started pumping less water than before, and the locomotive as an oil burner proved to be quite difficult to operate and really messy, plus with the TM triennial coming up, propane seemed to be the way to go.

When I started working on the 2-4-0 two years ago, I promised myself I wouldn't rush the rebuild. I wanted to take my time, learning as I went and do things right... Well, after investing a couple hundred hours and lots of money into the project towards the end of the process I really wanted to finally see the dang thing run. My excitement and ignorance overlooked a few critical items that should have been fixed at the beginning. Thanks to many, many brilliant and helpful people both on this board, the facebook builders group and Los Angeles Live steamers, I've learned a small amount in the process and excited try some of the things that have been rattling in my head for the past few months.

So here we go. Part 2 of the Allen/Harpur 2-4-0 rebuild.

First up was pulling the cylinders to lap the valve faces. I'd seen and heard the nice pop noise a freshly lapped cylinder and valve makes when compression is perfect and I wanted that on mine. I feared pulling the cylinders wouldn't be easy because of the rust damage this loco experienced sitting in a barn for decades and it didn't disappoint.
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Regular steel flathead fasteners underneath were fused together with corrosion, requiring my friend and I to grind off the heads, assuming we were good to go. But the cylinders still wouldn't budge. Off came the front apron and leading truck. Still no luck.
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After it occurred to us the cylinders and saddle were fused together with rust, we then placed a piece of wood on the bottom of the cylinders and smokebox saddle as a buffer and pound it off with a rubber mallet.
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The steam and exhaust line plumbing was badly in need of replacement too.
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tyleire
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Joined: Thu Sep 24, 2015 3:18 pm
Location: North Hollywood, CA

Re: Restoring a modified Allen 2-4-0 barn find

Post by tyleire » Mon Jan 15, 2018 2:43 am

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These cylinders looked pretty worn and rust damaged with deep pitting. We lapped them on 120 and 220 grit sandpaper taped to float glass and 3 hours later, didn't have much to show for our efforts other than sore muscles. I also noticed the valve face was wearing more on the edges either due to bad technique on my part or sandpaper that wore off unevenly or both. No good.
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The cylinder on the left represents 15 mins of lapping vs 3 hrs on the right.
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Several people on the FB builders group recommended fly cutting to shave off about 10 to 15 thousandths. I'd seen videos of flycutters spanning the full width of the face but not having access to one, we tried using a smaller diameter instead and making two parallel passes. It was a little rough and our jig kept shifting, but we got reasonably close and finished it off with another hour or two of lapping with 120 grit and finally 400 grit.
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NP317
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Location: Northern Oregon

Re: Restoring a modified Allen 2-4-0 barn find

Post by NP317 » Mon Jan 15, 2018 12:03 pm

Wow! Welcome to Serious Restorations.
~RN

tyleire
Posts: 53
Joined: Thu Sep 24, 2015 3:18 pm
Location: North Hollywood, CA

Re: Restoring a modified Allen 2-4-0 barn find

Post by tyleire » Mon Feb 26, 2018 4:27 am

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Besides resurfacing the valve faces, I spent some time this week cleaning up each cylinder and the associated corrosion buildup between the saddle. In fact it caused the cylinders to spread apart so far on the frame that I suspect it broke the exhaust line solder joints on the blast nozzle. The tabs on the saddle looked bent upward from the strain, and a quick fitting up revealed the cylinders would splay outward when bolted down, revealing a pretty big air gap, so we shaved about .013 off the tabs in an attempt to square up the cylinders on the frame. It's too bad the Allen design doesn't allow any room for a frame spreader at the front end or something to hold the cylinders plus frame together horizontally.

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Definitely an inprovement, however there's still quite a gap and tighter fit on top than on bottom so gasket material might be a problem. Currently my best bet seems like high temp RTV. Not sure if I should use it in conjunction with a thinner gasket material or just use by itself.

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FItting up some of the new smokebox plumbing took the better half of a day trying to figure out how flared fittings work and organize an operation for 5 different attachments in this tight space when the cylinders finally get bolted down.

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Marty_Knox
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Location: Michigan, USA

Re: Restoring a modified Allen 2-4-0 barn find

Post by Marty_Knox » Mon Feb 26, 2018 8:14 pm

That was a weak point on the real Wabash 573. You can find pictures her with steel bars alongside the cylinder, with steel rods going across to the other side clamping the cylinders and saddle together.

Steve Alley
Posts: 184
Joined: Thu Dec 20, 2012 12:30 am

Re: Restoring a modified Allen 2-4-0 barn find

Post by Steve Alley » Tue Mar 13, 2018 6:54 pm

So last time we talk you were fighting the surface of the cylinder mating to the saddle. What did you do to fixing it?
Steve

tyleire
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Joined: Thu Sep 24, 2015 3:18 pm
Location: North Hollywood, CA

Re: Restoring a modified Allen 2-4-0 barn find

Post by tyleire » Sun Jun 10, 2018 12:35 am

Steve Alley wrote:
Tue Mar 13, 2018 6:54 pm
So last time we talk you were fighting the surface of the cylinder mating to the saddle. What did you do to fixing it?
Steve
Pieces of .010 stainless shim did the trick. Then it was on to the valve gear. I had a massive amount of valve rod slop when running the locomotive last year, so I knew I'd need to replace a lot of stuff.
I started by ordering the Allen EDM cut expansion links and die blocks. New link pins for the die blocks were made on the crap-tastic Harbor Freight mini lathe with a few attempts made to get the tolerances right.
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We were less than amused to discover the original expansion link saddle didn't match the plans and therefore the new EDM expansion link, so we made our own.
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Next we made new eccentric rod clevises with a built in offset designed for the rods to feature left and right hand threads for easy adjustments.
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The hex was drilled out through the center and soldered on the rod to allow a wrench to adjust.
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Then lifting links were measured and holes drilled. Next eccentric straps were removed, lapped with Timesaver Lapping Compound to prevent any material embedded in the bronze, test fitted, repeat the whole process, and finally reinstalled with a tight, slop free fit.

Starting to take shape!
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tyleire
Posts: 53
Joined: Thu Sep 24, 2015 3:18 pm
Location: North Hollywood, CA

Re: Restoring a modified Allen 2-4-0 barn find

Post by tyleire » Sun Jun 10, 2018 3:05 am

When I first purchased the locomotive, one of the rocker arms for the valve rod broke at the pin. When we looked closely, it appeared the slop in the gear had allowed the rocker arm to extend a bit farther in its travel, slamming into the crosshead guide yoke. Our solution at the time was to re-attach the broken rocker arm slightly aft of the 180 degrees specified in the plans. I now know this wasn't smart as it limited the valve travel on the engineers side and contributed to timing issues. What about the crosshead guide yoke clearance? Turns out it was close, but with the slop removed from the valve gear, the rocker arms could be reset at 180 degrees as they were intended and clear the yoke.
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Test fitting the new Locoparts burner manifold. Because of the position of the eccentrics directly underneath, the base of the manifold will sit right up against the mudring which puts the burners quite high up in the firebox.
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NP317
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Re: Restoring a modified Allen 2-4-0 barn find

Post by NP317 » Sun Jun 10, 2018 9:09 am

You will enjoy that new valve gear! Nicely done.

As for the propane burner being too high in the firebox, a better burner would be with slots or holes in the horizontal tubes.
But then you would need an air/fuel mixing tube, and where would that go? So just assume it will work as installed.

When operating the burner at high output, make sure you are not blowing flames down toward the eccentrics!
Sufficient blower is your Friend.

~RN
Burner 1 small.jpg

tyleire
Posts: 53
Joined: Thu Sep 24, 2015 3:18 pm
Location: North Hollywood, CA

Re: Restoring a modified Allen 2-4-0 barn find

Post by tyleire » Sun Jun 10, 2018 1:46 pm

NP317 wrote:
Sun Jun 10, 2018 9:09 am
As for the propane burner being too high in the firebox, a better burner would be with slots or holes in the horizontal tubes.
But then you would need an air/fuel mixing tube, and where would that go? So just assume it will work as installed.
I was very interested in this style of burner for a while but came to the same conclusion that the design would be difficult to implement in my locomotive due to the position of the eccentrics.

The plans call for tapered pins to secure the rockers, however we noticed on the locomotive that eventually the pins wear loose and cause a significant amount of play in the valve rods. Our solution was to silver solder them, however the bronze doesn't seem to take heat well. We replaced the rockers with new bronze castings but I think machined regular steel rockers are a better way to go.
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Timing and reassembly was a breeze as we've done it so many times by now we could do it blindfolded. Extensions were added to the blast nozzle to raise it up closer to the petticoat to reduce draft.

A stainless steel arch was loosely installed for testing. We also knew a baffle plate would be important for separating primary and secondary air. At the recommendation of Riverside live steamers member Richard Ronnie, we elected to build a baffle plate in sections for each individual propane burner, so that we could easily add or remove as needed through the firebox door.
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On first fire up, the locomotive was very sluggish to build steam requiring a lot of gas and blower with very orange flames. Fire would also constantly lick out the back door and up towards the manifold. We decided the arch blocked too much airflow and managed to remove it without pulling the boiler. Big difference! From first fire up to popping off was less than 20 mins. We checked the stack to make sure fire wasn't licking out into the smokebox and it looked good. We took the loco out to the main and she charged up the hill with safeties popping, huge grins on our faces. Using the injector would kill our steam pressure before we converted to propane. Now with the axle pump on most of the time, we use the injector just to keep the safeties from popping.



Next on the list is bushing the rods to quiet them down, tweaking the timing a bit (reverse sounds perfect but forward is still about 90% square) and fixing the very sensitive throttle (trying to find a ball valve solution for the steam dome). I also plan to improve the propane controls and build a more permanent solution in the coal bunker of the tender.

But so far, after 2 years of work it's pretty fun to have a locomotive that FINALLY runs well! I'll be bringing it up to Train Mountain for the triennial in few weeks and hope to have a few more improvements done by then.

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