Griffin's Table

Griffin · Griffin's Table

Hello, and welcome to my display table, well actually the kitchen table

.

For this years STWWW I am going to place the emphasis on a generator theme, well a pair to be precise.

I intend to show a power comparison for three Jensen engines, a #20G, #55G, and #95G turbine, all working under load driving not only their own generators, but that of another engines also.
All three engines are standard stock examples, and all use the 3” boiler utilising the 660W immersion rod heater. The only differences are the motors themselves. Ranging from a big bore single cylinder, to a smaller bore twin, and finally an impulse turbine rotor.

I will post the relevant pictures and video of each engine running as the event progresses

I have often wondered which engine design will perform the best, so now I have captured it for my display on this weekend event.

Here is a picture of the line up of the three candidates.

First up is the twin cylinder Jensen #55G powering its own generator, and that of the #20G. The rest of the #20 is being used as ballast.

I forgot to mention in the video footage, but the engine still manages to reverse on the fly whilst under load. The engine was working quite hard, but still had a bit of “umph” still left.

whistleman

way hey. well done Grif!

Dampfmaschine

Great stuff - love the photo of 3 Jensens in a row as well.

Sandman

Love it Steven.

Looking forward to more mate.

Les

A wonderful array of Jensens.

Griffin

Second up for the power trial is the Jensen #20G with its large ¾” bore and stroke cylinder.

This one was pretty much un- phased by the load, and I tried the experiment using a third generator, but sadly to no avail. I must add this was not due to the engine lacking power, but a case of the flywheel slipping inside the primary drive band. A point of interest, springy drive bands are not up to driving three generators at once

. I am convinced given an effective transmission this engine could power a load of three generators.

Dauntless

Steven,

they are great mate! Love the threeway lineup!

Its really good to see them working!

Paul

redryder

Steven,
You have a great line up there and a terrific set of video demonstrations.

Gil

Griffin

Now for the last contender, the Jensen #95G turbine.

This engine needed a little coaxing to run this set up, as the engine needs to be spinning quite fast to deliver a decent amount of torque to drive the load. I found if you waited until the engine was running before you screwed the bulbs home into the sockets it would hold the load.

I am convinced with a slightly higher working pressure this one would drive the load un-aided.

So to some it up, the #20G wins hands down. That big 4” flywheel and the ¾” bore and stroke piston produce loads of torque. The #55G is not as powerful, smaller pistons and a smaller lighter flywheel, so I don’t think it would handle a third generator, especially at the standard steam pressure. That is if you could over come the slipping band problem. To cap it off the #95G turbine is the least powerful of the three, but I must add this engine was certainly trying hard to turn the load, and has the potential to do much more, if given a higher working pressure..

Wallace

Great to see it working mate. It sure pumps out the steam

redryder

The 95G has plenty of grunt if you have enough pressure.

I used a pressure guage instead of a safety valve. This can be done fairly safely only if you do not walk
away and do not take your eyes off it. My throttle tends to relieve pressure as well but not as low as the SV. At 20-25 psi it will easily self start a pair of generators.

Gil

Sandman

What a great experiment Steven.

Really interesting stuff mate.

IndianaRog

Steven, you have answered a question I have wondered myself...good job of sorting it out.

You can easily modify a Jensen SV to permit higher pressure...I routinely ran my 95G at 25 PSI and they do indeed increase their torque and staying power at that pressure. I never thought it was challenging the boiler safety at all...those are some of the thickest boilers on the market combined with silver soldered seams.

As I have said before, you have the nicest Jensen collection outside the US that I am aware of...keepers all!!

Rog

Griffin

Now this one is not a trial of strength, but does still stay in the parameters of the two generator theme.

Here we have two Jensen #10’s. A late 40’s Horseshoe magnet type, and a single year 1951 Round magnet type.

Horseshoe Magnet

Round Magnet

Here is a video of them both running together.

The video does not capture this, but the work top was shaking with the effect of these two roaring away

. You also have to ignore the fact that they were drawing a combined total of 900 Watts of electric to power two 3 volt bulbs

. All adds to the fun though!!!

IndianaRog

Good to see the horseshoe magnet 10 running so well Steven. It went to a very appreciative home!!!

I personally would have to say that demo was a tie, it appears both the late '40's and 1951 were on par with each other in the light generating dept.

good stuff!

Rog

steamgranny

Oooo....an overdose of Jensens!!

Very impressive & no ill effects whatsoever: quite the contrary, in fact!

Griffin

Just thought I would do a quick showcase on the Jensen #55G, as this was the engine that started me off down this track back in 2007.

I will compare it with an early black firebox #55 dating from the 50's, and I will highlight some of the differences between the two.

Notice the difference in sight glasses

Close up of the change in style of reversing lever.

Well, that brings to an end my display table for this years event. I would like to thank you all for dropping by.

Also could I congratulate you all for putting such fine dispays together, and the admin team for organising this event.

It has been a pleasure to have been a part of it!

Thanks

Steven.

IndianaRog

Nice compare and contrast on the Jensen 55 Steve. They are still 90% the same, but subtle changes have come in over 50 or so years of manufacturing them. The biggest change has been from the water tube external sight glasses to the round porthole window types across the Jensen line. I personally like the external type, but they can be finicky when they get a bubble in them. The window type are pretty foolproof, but not quite so charming.

Thanks again for sharing your marvelous Jensen collection...I especially liked the generator comparisons as to which engines could bear the load better,

cheers,
Rog

Sandman

What a great way to end your presentation Steven.

Really interesting, and well photographed.

You've done us proud mate.

Well done.

Enjoy the rest of the event.

Dauntless

wonderful Steven,

its great to see two engines displayed so perfectly!

Paul

johnreid

I was so very fortunate to see most if not all of those engines in person, a collection that any Jensen enthusiast would die for.

redryder

You've done a bang up job sharing your Jensen collection with us.

Way to go Steven !!!!!

Gil

igy569

Excellent. What a nice line up. A collection to be proud of!

metalhead100

Nice collection!

Glad to see the 20G fair so well as its the engine I want myself.

Thanks for the tests!

Jim