Robinson B4 stripdown

So noticed when I had a run over the weekend my Robinson has an air leak in the displace cylinder.

Here is the last run before I stripped it down.



Thankfully there isn't much too them, the paint is a bit stubborn and the primer filler is hard work.

Main casting.




Other bits


Displacer/Regenerator



And the issue... the cylinder for the displacer, it is low pressure but is leaking enough to blow the flame out from time to time.




Nothing concerning just time consuming.

Fascinating! Always admired hot air engines - that's quite a large example.

Alan

Yeah it's a decent size, I would have like a 7 3/4" Rider but at about 7ft tall it wouldn't go in the garage, plus 13k out of the house budget would be noticed...

Stripped and repainted the B4. sealed up the crack with some high temp gunk. Wasn't too worried about it cracking further as it looks like an old crack, If I've got to reapply every 6 months or so I'm not too fused.

Paint on the cylinder needs a sand down and touch up, I'm out of practice with brush enamel!
I needed to align it all while running, it's rather critical on alignment, but got it running to the usual knock over compression.

video heres, flame is no longer being blown out by the displacer leaking.
https://photos.app.goo.gl/pzqhrTGBU2HEvFgt5

Interesting engine you've got there, I'm not familiar with hot air engines but you seem to know what you are doing with them.

I feel your pain with painting, I find it to be a very testing and long winded process, with differing results. There are so many variables such as temperature, humidity, paint quality and brush type, all of which need to come together to make it successful. Hopefully you will be pleased with the end results.

Neil.

They are an interesting beasts, I've had quite a bit of help in the back ground on this and the few hot air I've had building up to this one.

I think my problem is too much paint too quick, I've rubbed it back now and will leave it for a few more days be going near a brush.

Repaint done, not the best in the world but OK at rope distance...

Looks good from here, well worth persevering with the painting, hope it runs as well as it looks. Would love to be able to see it from behind the ropes, looks like you have enough room available there, to hold your own rally!

Neil.

Cracking job.  
I bet it didn't look as good when originally sold.

Thanks Neil, there should be a new video in the Google photos shared folder. Didn't really get it going long enough to warm up really.

Luckily I was able to obtain a replacement displacer cylinder for my Robinson B4!



Some new photos in here.



https://photos.app.goo.gl/pzqhrTGBU2HEvFgt5

Thought I had my computer on mute until the owner started making noises, that's a super quiet hot air engine !!
Compare it to the Upipe video at the top of this thread.

It is rather quite now, most the noise was from the "big end", there is a slight noise from the small end but it is rather nice now.