Preparing to run on air

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Preparing to run on air

Post  elwood-59 on Wed 09 Jan 2019, 4:40 pm

question to those who have down that road already:

Now I am ready to try running the engine on air pressure as per instructions.

With that I hope to iron out the leakages around the boiler and accessories, by using soap water to see the bubbles being made by the air leaking out, as suggested.

So far I did or still need to do:

Everything is mounted that havs a connection to the boiler. At this moment I can barely turn over the crankshaft due to all the bearings and excentrics, was good before I assembled conrods and 3rd. gear hub. Therefore I will temporarily fit the flywheel for additional leverage to turn over the engine while fitting everything.

As the tender is not fitted yet for some other reason I will not use water pump at this stage and keep steam valve for injector closed. Mount both water gauge and pressure gauge, as also the boiler check valves and the blowdown valve.

At this stage I plan not to mount the oilers yet but will manually (over) fill the parts to be oiled. The exception being the lubricator as I want to make sure that pistons are well lubricated.

The regulator linkage I will mount as per plan, the starting valve will be in open position so to have more torque for run in, the compound version will be used later. Right now I only have to find a place to mount the reverser link to, as without tender I cannot mount the lever yet.

As I will be using my trusted but small oil-less air compressor that but only has a max input flow of 240l/min, so at 145 psi I expect only a flow of about 50 - 60 l/min. Surely not enough for permanent & continuous running but hopefully enough to let the Engine turn over some revolutions before running out of sufficient air.

But what about the Governor? Can I merely blank off the mounting pad on the cylinder and leave the Governor to a later date? Or does liner and valve need to be installed?

Have I missed anything?

Cheers

Elwood
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Re: Preparing to run on air

Post  lynnr on Wed 09 Jan 2019, 5:04 pm

Hi

Quick answer on the Governor. Just blank it off. Mine is in place but no parts inside so only there for show and to fill the hole.

Crank will be heavy without the flywheel. I used a pair of clamps on the gear end. Just leave it out of gear so only the crank bearing and motion will be moving etc.

Do not get over worried if she does not run on your air supply. Crystal would not run on air at all. Makes sure your valve pucks are free to move on the spindle but not loose. They do need to be able to fall away from the valve face under cut back and braking activity. (Otherwise you can bend the spindles)

Remember to put the fusible plug in as well. I got an enquiry a while back when a chap tried his engine on air and panicked when he could hear air rushing out the firebox.
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Re: Preparing to run on air

Post  elwood-59 on Wed 09 Jan 2019, 7:10 pm

Hi Lynn,

Answering quick as always, and helpful!

Fusible plug is in, first thing I did when I started to fiddle with the boiler, but good to mention just the same.

after putting on the 3rd gear hub with the two keys crankshaft started to get a hard spot, did not help much with conrods installed, either. Before I could turn the crankshaft by hand, now I have to pull on the balance weights to turn over the crankshaft. Hence idea to fit the flywhell, did not want to risk the splines on the gear side with my clamps.

Strange your remark on Crystal not running on air at all, others seem to have been able to run theirs at 2 bar, sorry 30psi. Also I’ve seen your youtube on preparing and firing up Crystal especially turning the crankshaft over with relative ease, it looks. But I take them films were taken not at first run Smile

Governor: looking at cross section I already asumed that the “innards” ar not needed, still good to get a confirmation, thanks for that.

how are you with the “remote” lubrication of rear axle oiler? Think to remember you wanted to move the oiler up next to second shaft oilers, too...

Thanks again

Cheers

Elwood
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Re: Preparing to run on air

Post  lynnr on Wed 09 Jan 2019, 8:23 pm

Hi Elwood

On the 3rd gear hub. You might be catching the edge of the bearing housing casting if the crank was "free" before but not anymore. There is videos of Crystal in light steam even before the flywheel had been painted.

The remote lubricators are coming along. Just need to save a few pennies to get a couple of elbows for the two main axle gunboxes will be dry with oil piped right into the axle holes. The moving of the 2nd shaft oilers has been accomplished successfully. It is impossible to feed the pipework how I want with the final 90 bend already in the pipe. That is without taking the backhead completely off, which is not happening!

Now that Crystal is tucked up in bed under her covers I will not be working on her until March now. I am in the middle of stripping the two wagons apart to repaint the chassis, springs etc. (only -10C at the moment)


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Re: Preparing to run on air

Post  Capricorn1 on Fri 11 Jan 2019, 5:34 pm

The decision to run on air is entirely down to the builder, it is not compulsory, I didn't as I don't have a compressor.

You need to get the crankshaft to turn reasonably easily with the flywheel and gears fitted - ie it should run on if given a good flick. If the crankshaft with all the motion built up is almost too tight to turn by hand then you need to identify what is tight and ensure the big ends are lined up with the cylinder bores and the slide bars are fitted correctly etc . It's no use just running the engine until it loosens off.

If you have used proper gasket material with a little graphite paste or cylinder oil, your flanged joints should be fine, likewise is you have used a reasonable coating of graphite paste on screwed fittings and they are tight you shouldn't have any issues. Other than a little cylinder oil I fitted the following gaskets dry - safety valves, valve chest covers, front cylinder covers. You can use PTFE tape on screwed fittings but avoid winding on so much tape the fitting looks like a badly bandaged finger...

The governor doesn't govern the engine as you cannot scale down weights verses steam pressure. I would remove the internals and keep the top works if you wish.

You will probably find the simpling valve (some prefer to call it the starting valve) will leak allowing steam to constantly feed the LP valve chest, the remedy is to lap in the seat for the ball and fit a stronger spring.

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Re: Preparing to run on air

Post  elwood-59 on Sat 12 Jan 2019, 2:54 pm

Hi Capricorn1,

Yes I know, still have to fit the excentric straps so cannot say finally how hard the crankshaft turns, only added the expansion links and die blocks just now, excentic rods and straps still needs to be fitted. Had a broken hand recently and still suffering from it, so I cannot proceed as I would like, nature takes it‘s toll.

In the threads of all „permanent“ studs like cylinder etc I used Steam Seal, on the plugs I expected to remove again at some time I used PTFE tape, but sparingly to avoid damage to threads and plugs, so I hope to have a quite air tight engine from the start. I only guess that using air with a shut-off valve might be helpful, easier to sort out a leak when the boiler still is cold and no steam hissing out of the leak.

As for gasket material, yes that‘s what I figured, too, gasket material liberally smeared with cylinder oil.  

And yes, I ventured and bought a compressor when I started with the build, helpfull to blow out holes and to remove debris from a within, and of course to put air into Governments bicycle tyres (you have to have a reason to spend money and to justify it to Government Very Happy )

Still a few odds and ends to to but hoping to get there soon.

Cheers

Elwood
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