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| Mark-One |
Jensen 55Got the first 3 vids uploaded. Well, they weren't the first 3 I shot, but rather the first 3 I want to show... Got to get my moviemaker mojo going on the othershttp://www.youtube.com/watch?v=sBc8BLWlnbg Just pointing out the leaks that I know of. This beast collects a PILE of water on the lip of the engine base in front of the cylinders, though, so the rags are going to be a must have feature, even though they offend mine eyes.. http://www.youtube.com/watch?v=Cc_72fx7ByA Took off the exhaust collectors so you could hear it chuff in stereo. The whine is coming from the generators that are providing a bit of a load http://www.youtube.com/watch?v=oBxlX8TAUdY illustrating the self-starting action and how the speed can be varied with the valve controls alone. I'm not playing with the regulator at all here. It would have a much smoother transition in speed and direction if it wasn't driving anything. Generator trials coming. As a preview: somewhat disappointing in terms of raw power. I suspect the 55 doesn't crank quite the RPMs that the 25 does. My breadboard is disassembled, though, and I've burnt out half my LEDs now (watch those capacitors...) so I don't have the usual test loads available. I should standardize on a resistor of known ohmage, then current could be calculated.. I just mainly wanted to run the oil out of it so I could try patching it...didn't do that yet.. Edit: I forgot. Rolled up in the stack was a sheet with instructions on one side, and a price list for Jensen parts on the other. I could scan if anyone wants to gripe about inflation? |
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| johnreid |
I wonder, if you put a regular light bulb, probably 6 Volt, with a switch, into the circuit. Then once you shut off the engine, switch on the lamp and drain the Capacitor. I have seen similar things in some circuits before.
Disappointed or not, I still envy you for that engine, Its Nice! |
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| Mark-One |
I short the thing out when I remember to, but it just takes a few stray flicks of the pulley to get some charge in it again. I didn't realize how efficient they were at holding on to the little buggers. It 'tis nice. Certainly stouter than the D22. A bit cheap in that it's got the brass line model 25 cylinders and gear rather than the older iron 25 stuff. Should eventually some day maybe look for an earlier one. I need to find out if those steam chests are silver soldered or soft soldered. If it's silver in there then I could be really careful and fill the holes proper with lower temp stuff. If not, then the glue gets first crack. |
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| johnreid |
I wonder if that isnt part of the reason I am disappointed in the power output on my repaired Hobby Grade 25, I am comparing it to my Cast Iron based one. That could be a big part of the difference too. Thanks for making that point. | ||
| IndianaRog |
[quote="Mister Occlusion] I need to find out if those steam chests are silver soldered or soft soldered. If it's silver in there then I could be really careful and fill the holes proper with lower temp stuff. If not, then the glue gets first crack.[/quote]
Mark, the cylinders to steam chest joint is lower temp, plumbing type solder...only the boilers are silver soldered. Also...see pm I sent a moment ago with some other thoughts for upping the output of your 55. cheers, Rog |
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| Mark-One |
Mark, the cylinders to steam chest joint is lower temp, plumbing type solder...only the boilers are silver soldered. Also...see pm I sent a moment ago with some other thoughts for upping the output of your 55. cheers, Rog[/quote] Ta, see reply 
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| Mark-One |
I don't know if it makes a big power difference. It's just the fit and finish is so much nicer on the older ones, where the parts look more hand made than machine stamped. It runs smooth enough with the big iron flywheel and the solid engine mounts. They certainly feel like they've got more go, though, but maybe that's an illusion. I don't know. When I get that reversing 25 I'll be able to compare them more directly |
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| Cedge |
The reversing gear is sometimes the culprit when a 55 seems sluggish. You might need to toy with the positioning of the small arc brackets. If they are not aligning the eccentric rod along the engine's centerline, then the engine is probably running slightly off time and will not operate at its optimum. By adjusting them ever so slightly, I got about 30% better performance from my own 55.
If you expect a doubling of output power, its not happening. The twin is still using 25 sized cylinders for each power stroke. You are simply getting twice as many power strokes which basically eliminates the lag normally handled by the inertia of the flywheel. The flywheel has much less "coasting" travel between power strokes. (every 90° vs every 180°)To double the output power would require a larger bore cylinder like the model 20. The 55 can be bit more finicky than the 25 since it has double the operating mechanism. When running perfectly, its hard to beat the engine for pure harmony. Steve Who also suggests superglue as a first line stop leak solution. |
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| Mark-One |
By not being aligned, do you mean the eccentrics themselves being shifted along the shaft laterally so that the rods are not parallel to the piston/con rods?
I didn't notice anything being particularly out of plumb, but I'll check again. I did give the screws on the eccentrics an eyeball to make sure they lined up with the crank pin screw thingy, like the 25 instructions had said, and they looked fine. I must admit I have no idea how that eccentric is held in place by a single sideways screw, and I'm not at all certain that I want to mess with it in order to find out. ...I've not exactly been having a wonderful week for plans coming together. Wasn't expecting Double the power, because there is also about double the drag, if nothing else. I was expecting a bit more unf* though.. I'm going to slap a gauge on it and see just what it's running for pressure too. |
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| Cedge |
Mark
My 55 has an older design reversing mechanism with a single flat spring. By gently flexing the reversing linkage, I could detect a "sweet spot" that was just beyond the range of the "arc plate" when it was in it's normal position. By slightly adjusting the spring, I was able to make the sweet spot fall within the range of the prescribed arc. Unfortunately, the later reversing linkages design is a little less adjustment friendly. It can be done, but a bit of very careful bending of the rods comes into play, assuming that you are able locate a hidden sweet spot first. A new safety valve spring could be all you really need. Steve |
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| Mark-One |
Okay, most of that went over my head except for the later ones not being adjustment friendly, so I can safely assume there's not much I can do about it 
I thought these things were all lovingly tuned by Mr Jensen himself 
The SV that came with it has a much stiffer spring than my modern ones, so I've left it. Will pop the pressure gauge on it the next time it runs to see where it lets off. Still, my main problem isn't with max pressure, but rather with maintaining it during a sustained full bore run. The SV doesn't let off at 10lbs after all. None of my engines will hold at more than 10psi indicated when going full bolt for anything longer than, say, half a minute. I like the notion of dual heaters... I just don't want to undertake a $100+ mod right now. Edit: I forgot. Uploaded another video showcasing my pathetic attempt at an AC generator
http://www.youtube.com/watch?v=qEh085wycuU It was originally part of a moviemaker amalgam, but I did not notice it was 105MB and youtube refused to upload it, the busterds. |
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| Cedge |
Enjoy your engines, Mark....
Steve |
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| Griffin |
Mark, your #55 runs well. My #55 also slow's after an initial start up burst, and has the 660W immersion rod heater. Most likely due to the high cubic displacement of the motor, and yes it does consume a fair ammount of water. | ||
| johnreid |
I dont know if you have a line shaft or not, I think we discussed that before, but I wonder if you have tried to run things from the Flywheel as opposed to the pulley wheels. The combined Horsepower should still be there, but you sure would have a different gear ration and RPM on the motors. | ||
| Mark-One |
Uploading a video that does a comparison between running off the pulleys vs the flywheel. It's interesting in that there was maybe 1volt difference. Wasn't running much for loads, either. I need to get a new torture test rig set up. It *did* run, however unwillingly, with one of the generators accidentally shorted out, so there's certainly a good bit of go. Didn't get a run in today. Too much other stuff to do (like my weekly reports that I am still procrastinating on). edit:here it is. http://www.youtube.com/watch?v=utOMk3F7mNA |