Westbury Heinrici Stirling engine

[lazylathe]

Hi All,

My last find was this Edgar T. Westbury Stirling engine.

It was seized and full of grime from sitting for many years!

After a thorough cleaning and oiling everything turns again!

Although it too will not run!
Turns over a few times and then stops.
I figure that the displacer rod is loose in the brass bushing as i can rock it back and forth.
This is the part is suspect!

The piston is a perfect fit. It will fall down on it's own but when i put my hand underneath
the suction is so great that i cannot move it in the cylinder.

I have concluded that air must be escaping through the space between the bushing and the rod.
Would you agree that this could cause it not to run?

I am battling to remove the hot cap from the main casting.
It has been together for about 30 years!
I need to remove it to get the displacer out and see what my options are when it comes to replacing the bushing.
I was laso thinking about maybe using an o-ring to seal it?? Any thoughts on this?

I still need to finish off some of the engine.
The burner plate needs some feet to be machined because the feed pipe is below the plate.
And also a chimney needs to be fashioned and attached to the back.
There are no drawings for this part so i guess it is up to the builder to sort it out?

Also would this be water cooled?
It has an air jacket around the cylinder and the plans call for it to be tapped to fit 1/2" gas fittings.

Also he has left the flywheels solid.
I will change these to spoked designs when i have some more experience!
Think they look a lot better!!

Another project on the go now...
Should be pretty cool when it works!

Any help or insights appreciated!!

Andrew

 

[Blogwitch]

As far as the lists go, I don't think there was ever a full sized plan for this engine. I can have a look thru my archive and see if it is in any of his books.

Here is a video of one running, that shows what the flywheels look like.

[ame]http://youtu.be/em7lYJxFaJg[/ame]

It looks like it should be air cooled, and for yours, they have welded up a water tank to enclose the cylinder.



John

 

[lazylathe]

Hi John,

I have the original plans for this engine and he built it to the plans.

The plans say:
1/20 H.P Hot Air Engine (Heinrici Type)

Here are two pics of the enclosed cooler.

To me everything is in order and built to spec.
The plans do say "Adapted Design"
They are very old and yellow and held together with masking tape!

I was watching that video last night!
Looks like he may have had a few different designs.

Andrew

 

[Blogwitch]

Sorry Andrew, it was me.

When I read the list

http://modelenginenews.org/etw/etw_steam_engines.html

I must have read the one underneath instead, which said no plans. But I will still have a look to see if it was put into book form.

Looking at the list, it shows what looks to be the Model Engineer issue it was shown in.


John

 

[fcheslop]

Hi Andrew,I think Reeves 2000 still sell the drawings and castings for a version of this engine
best wishes Frazer

 

[metalmuncher]

Hi Andrew, I bought a set of castings for this engine off ebay and it had a aliminum aircooled cylinder. I have since done a bit of research and found it was also made to be water cooled like the one you have. I really need to find some drawings to complete this engine as the book I have doesn't give the complete dimensions. Hope this has helped.
Regards Metalmuncher ( keith )

 

[Longboy]

Turns over a few times and then stops.
I figure that the displacer rod is loose in the brass bushing as i can rock it back and forth.
This is the part is suspect!

I have concluded that air must be escaping through the space between the bushing and the rod.
Would you agree that this could cause it not to run?


I need to remove it to get the displacer out and see what my options are when it comes to replacing the bushing.
I was laso thinking about maybe using an o-ring to seal it?? Any thoughts on this?



Should be pretty cool when it works!

Any help or insights appreciated!!

Andrew

.........Not so fast on the pushrod bushing! Your conclusion that air is leaking from this area is correct, however in Stirling its allowed to at this point. You do not seal it with an O-ring. If there is gauling at the rod/ bushing by all means correct the situation. The pushrod can benefit from lube as a dry gland bushing will stall the engine. If the pushrod is not scarred it is most likely to have run with enough lube, the bushing is sized correctly and your problems lie elseware. I would use spray oil on the gland. I would also remove the power piston and cover cyl. with a cap with a small hole in cap to hold a blow-off nozzle from air compressor to at low pressure. This will expose air leaks and tell you how much air flows from that bushing! Make sure your cyl. phasing (if adjustable) is at 90 degrees. Dave

 

[Stan]

I have built a couple of Stirlings and both designers called for a precision fit on the displacer gland. One called for a lapped fit. The air in the displacer has to be accessible to the power cylinder, not to atmosphere.

 

[lazylathe]

I will take a short video of what i am seeing and post it tomorrow.
It visibly rocks backwards and forwards quite a bit.
So much that the displacer knocks against the heat tube.

What i have also noticed is that when i move the piston to the top of the cylinder with the vent plug open
so that the system is full of air and screw the vent plug back, the piston will move down to the bottom of the cylinder.
It does not take very long for this to happen.
This also leads me to believe that their is excessive air leaks around the bushing.

Andrew

 

[metalmuncher]

Hi Andrew, If you have airleaks in a stirling engine it will never run. I have a small one I made a few years ago and I can't get any commpression in it but can't find a leak anywhere. If the displacer is rattling about you need to remake the bushing and get as near perfect fit as you can. There should be some bounce back when you flick it over. Hope you sort it out and get it running they are nice engines to see running.
Regards Metalmuncher.

 

[lazylathe]

As promised here is a short clip of the movement of the displacer rod around the bushing.
Seems a little excessive to me.

[ame]http://youtu.be/U00qfY3482o[/ame]

What do you think?

Andrew

 

[mklotz]

As a test try oiling that bushing with a heavy, sticky oil such as gear or way oil and see if the engine will run a little.

If it does, you have some assurance that refitting that bushing is worth the effort.

 

[lazylathe]

woohoo1 WOOHOO!!!!!!!!!!! woohoo1

It lives again!!!!! th_confused0052
I made a new bushing from and old oilite bearing from an old printer and lapped it in using some mag wheel polish.
Added a drop of way oil to the top of the new bushing and a drop onto the piston.

[ame]http://youtu.be/95qvsb8STV4[/ame]

Heated up the hot end for about a minute with a small soldering torch and gave the flywheels a spin.
It took a few gentle nudges but then away she goes!!
Still needs some work as it turns over very slowly but maybe the propane burner will sort out that problem.

Still need to finish off some bits and hopefully get it running a lot better.

Thanks for all the help and tips!!

Andrew

PS- video camera giving me troubles...
Tried 3 times to get the video without success...
4th time it worked but i forgot to add the drop of oil to the bushing so there is a clicking noise....

 

[Catminer]

Looking good Andrew, guess this makes you the hot air king of Woodstock :big:
Next is the Rider engine.
Peter

 

[lazylathe]

Hi Peter!

I have also got the Rider working!!
Seems it likes a hotter flame...
The DNA I was using was just not
Hot enough to get it to turn over.

Talking about Rider Ericssons.... I have
a 1 1/2 inch bore kit on the way...

Andrew