Finally: Something new

Mister Occlusion · Finally: Something new

It's been awhile, I know. Been sidetracked by work and work-related stuff, and other stuff of an even less fun nature, so today was the first time I've lit a burner in months.

Decided to take out my Jensen 75\20 for a boot. I removed the problematic superheater and installed a spare steam line I bought a few months back (with a badly leaking valve, unfortunately).

Decided to see if my Bowman'ish burner element would work or not. I had trouble with it in the past, probably due to lack of fuel flow. Well, it ran flawlessly for hours, blowing it out only to refill the boiler. I figure the steel wool packing must be breaking down a bit.

I figured out a trick to lighting this thing, by the way. It's a vap burner that features thin slits cut across the twin tubes at intervals, and it's a bugger to preheat to the point where it will stay lit.

Solution? Get the meths flowing into the tubes. Lay a (small) scrap of paper towel across the tubes, blocking a couple slits. Dribble some meths on it and set it alight. It will slowly wick more meths from the slits, preheat the burner, and by the time it is consumed the burner is hot enough to work on its own.

Beats playing a pocket torch over it for a few minutes.

Anyway, I decided to have a go with this little scotch yoke engine I bought on ebay a few months back. I was curious to see if it could run off the exhaust of the 75.

Here's the first decent video I got. It was a pain to get running, but once it had warmed up it went okay.

http://www.youtube.com/watch?v=09AnzpbJM-I

After much regular oiling - I'd unhook it to shoot a gob of steam oil into the hose every 5 minutes or so - it was running so smoothly that while shooting this next video I discovered that it didn't need to eat the exhaust of the 75 to run, but would operate quite well on steam blowing through the 75's engine when it was parked half way through a power stroke. You'll see that towards the end.

Oh, and if you think this is all running smoothly, let me remind you that if the "Scotty" is unhooked, the 75 would be racing at over 3000 RPM, such was the head of steam that I was getting, thanks to the unexpectedly vigorous burner. I had white ash on a boiler for the first time instead of soot.
You might not hear it in the video, but the 75 sounded to me akin to a petrol engine missing when Scotty was hooked up.

http://www.youtube.com/watch?v=UL3k2wZvHtk

TRAPPERKEEPER

The jensen exhaust pipe is ever useful

Nice little engine you have there they sound great together

Mister Occlusion

Ta. I'm still nuts for that model 20 flywheel on the 75. It just makes it into such a beast (in a good way)

Graham-Jilly

very interesting engine there thanks for showing it

johnreid

I am impressed, that shows that the boiler is capable of producing enough steam to operate two engines!

Les

Nice to see and I bet it would run three engines.

steamyman

neat little engine.

IndianaRog

Mark, it was great to see another "O Labs" production, been too long!!! I was impressed with the videos, especially the second one where I could swear the two engines had to find a certain synchronization to run perfectly. The Scotch Yoke is a new one to me, very impressive little thing.

Again, thanks for sharing...

Rog

Mister Occlusion

Ta.

It was a bit odd in that the 75 sounded like it was missing. I can probably attribute that to variations in the back pressure as the second engine cycled.

But it was interesting that after it was run-in it would operate from steam blowing through the 75 engine, even if the 75 was stopped mid way through a power stroke (it would not operate if the 75 was left at one of the two dead spots in the cycle).

They come up on ebay every so often, and the fellow makes a few different sorts of engine, but I have not seen any lately.

The mechanism just intrigued me, so I waited until I was able to get one for a reasonable price.

If I can hook it directly to a boiler I'll see if it's powerful enough to run anything. Running this way it has next to no torque. I expect anything more than a colour wheel or free running tool would overcome it.

toxx

... simply great, Mark!

Do you have a link to the gentleman who makes these scot engines?

Mister Occlusion

Dug through my own feedback and found the listing. He has nothing for sale now, but here's the old listing for you. I think mine is about the cheapest one sold for recently. Hopefully that's not why he's not selling any right now...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120221136483

rangerssteamtoys

Nice engine, a scotch yoke engine? I have heard of that engine before.

Nice to see a new engine in the colection.