We'll Call it Metisse........

[Stilldrillin]

Time for another, orphan rebuild session!

This, distressed non runner. A Seig HAE 03/ Grizzly H8104, arrived last September.........





I pulled it out of the orphanage a couple of days ago.
Couldn't think what to call it. A pal suggested Metisse.

As it will be a bit of a mongrel, by the time it's done. I thought, that will fit nicely!

Apologies to any bike men out there who were hoping for a different project. I don't think the Rickman Brothers should be too concerned!


It's been mangled together, by a bad tempered gorilla. Nothing is in line/ square. Even the factory installed displacer bush is leaning!




The cooling fins had been jammed on at half mast. Then someone has tried to "unscrew" them. Breaking the swaged joint......
A few days soaking in WD40, allowed the ring to be pulled off. Giving access to the displacer, cylinder flange screws.

The square flange would spin, like a ball bearing.......




M5 screw, to drive the flange. Plus a digging in tool.........




Came apart nicely........




Silver soldered........




Wicked through, nicely.......




A 3 thou' flick across the face. Near enough........




That's the first bit, straight and square.......




Shouldn't take too much to sort..... Mebbe!

David D

[Stilldrillin]

Pressed out the lop sided displacer bearing.......




Made another,  with a couple of thou' hole clearance and larger, 12mm dia base.

Held in with sleevelock, it should stand square.......




Also a new shaft, as the bent original had also been chewed with pliers.   


The main bearings had been hammered in........




So, I drilled 'em out.

Then opened out the holes to take 9mm o/d ball races.......




Didn't have a 9mm reamer. So, I triple drilled to size. Finally, using my 9mm "brass" drill.
The bearings are a beautiful sliding fit! Two, in each frame.


Got to tackle the crank, next........




Thanks for watching........

David D

[AussieJimG]

It is always nice to watch you work on your "orphans" David, lots of lessons there.

Jim

[vtsteam]

A very lucky hot air engine to have fallen into your hands!

I will be enjoying this one.   

[Stilldrillin]

Jim. VT.
That's much appreciated......... Thank you! 

During a quick look at the crank assembly, I thought they had used a roll pin, for the crankpin!
Then I realised, the crack, (inclusion?), continued along the shaft too! 

With the lop sided big end eye. (See last pic). We need a full rebuild.......




Tried to use the original throws. But couldn't get them into alignment........




Made a pair of new ones.........




I don't do filing too successfully. Prefer to mill, where possible.

This is the set up for the r/t. M4 caphead and nuts, plus 4mm silver steel shaft.........




Grip on the nuts. Drive via the shaft........




Swap around for t'other end.........




Loctite plus pin, for 3 of the joints. And one, M2 grubscrew to allow dismantling........




Opened the 'orrible big end eye to 5mm dia.........




Made up a flanged bush, and matching washer.........




A spot or two of loctite, and it went together nicely, ready for reaming.........




Looks ok, I think.........




Wonder if I should have made balanced throws? We'll see!


All ready now. For clean up, lick of paint, and rebuild, next week.......




Thanks for watching! 

David D

[Stilldrillin]

Well. It's next week, now..... Not such a happy chappie, today. 

I've got a big (ish) day tomorrow. So, I assembled the finished engine. Hoping to have a new toy....... 

Put a temporary light under.......




And NOWT happened!   

After 20 mins, the whole engine was hot.
No attempt at running. Just a couple more rotations, in the correct direction. Compared to the wrong direction.

So, I let it cool, and fitted a temporary heat shield.........




That made no difference!

The assembly was "neat", rather than sloppy. Probably needs some slop.

So, I pushed out the double bearings. Replaced with single, to allow some crankshaft wriggle........




Faced all square. Polished the cylinder bore..........




No difference!   

Detaching the power piston big end, proves the displacer section will spin freely........

So...... The problem is with the power piston. I eased the piston o/d. Twice. No difference!   

So...... I hit it with my little blowlamp!!! THAT, made it run, for a few seconds. Then it stopped.........  Again! 


Thinking calmly.......   

Who in their right mind, makes a cylinder from a section of copper pipe. And fits an alloy piston? 

Unless, someone knows differently?   

David D

[vtsteam]

David, is that because they don't run together well or because the coefficient of expansion is different?

Well the difference in expansion of aluminum and cast iron is worse, yet they are used together. But maybe you need more clearance to compensate for heating up.

Other thoughts -- Is the compression good when you flip it over? That vertical line it the pipe/cylinder -- is that a seam?

A leak somewhere in compression is a real killer for hot air engines. Should be strong compression when rotated by hand.

[Stilldrillin]

VT.
I don't know how they "officially" run together. But, I have never seen a copper cylinder before. 

The original bore was, "as extruded water pipe", with fine polish/ scuff marks from the piston, in places.
The piston had a ground finish, with matching polish/ scuff marks.

There is now more clearance between the components.

I think the two materials are galling together, but there is not enough power to cause obvious damage.

Trying the piston fit in the bore, immediately after stoppage, feels a really nice fit. But the engine's power forces are much less than a "nice sliding fit".

The engine feels all it should be. Just doesn't want to run.

I think it's the copper cylinder at fault. Will see if I can sleeve it with a steel liner.

David D

[sbwhart]

I think you are getting to grips with this one Dave    the copper doesn't seem right as you said its probably expanding with heat and making things to go a little to tight.

Stew

[vtsteam]

I'm sure you'll work it out David. 

[John Rudd]

  the copper doesn't seem right as you said its probably expanding with heat and making things to go a little to tight.

Stew

If the cylinder is copper and is expanding surely the bore will become bigger?

[vtsteam]

Actually copper has a relatively low coefficient of expansion compared to "aluminum". Which would explain increasing tightness. However, expansion depends on the particular aluminum alloy. And Aluminum is the metal used in most iron cylinders in IC engines. However - a special alloy. -- also cast iron rings do most of the active hard contact. Also lubrication is different in an IC engine than in a hot air engine. Hot air engines don't like oil in the displacer -- so it is difficult to lubricate the power piston. Graphite is a good material for power pistons therefore. Also the natural graphite in a cast iron power cylinder might be a help for hot air engines -- something I've been thinking about since I have been casting iron.

[Stilldrillin]

Hmmm....... Graphite. That's a thought. Thanks Fellas. 

I will clean the synthetic 5-W30 oil from the piston/ cyl assembly, and try it with graphite lube, tomorrow.

David D

[Bluechip]

Hi Dave
 
Happy Birthday, it seems ....         here's to many more ....
 
That motor looks a bit of a strange configuration ...    I think you are right to put a deflector on it. Otherwise you have a hot end and a 'very nearly as hot' end ... not good ...
 
The other thing that strikes me is that the power piston works against gravity, assuming the power stroke is upwards, so it's at a disadvantage to start with.
 
At the risk of being grossly misinterpreted, have you tried it lying down, ie. horizontal. That way the flame would tend not to heat the ally fins and the piston would not be acting against gravity.
 
Net images can be a bit iffy, but just how heavy is the piston/con-rod ?? Rod looks brassy on my screen, but that's not certain.
 
Maybe add lightness by poking some holes in it ??
 
You'll get there, I'm sure ..
 
Dave BC
 
PS
 
My mate's daughter told me the other day that I didn't really look old. My reply was that's all very well but I don't really feel new.
 
 

[Stilldrillin]

Hi Dave.
Thanks for the birthday wishes. I guess, every day is a bonus from now on........ 

This type of engine is the same as the Robinson type. Too much heat rises to the cool end....... 

Funny you should suggest a horizontal format. I tried it that way, yesterday! Still didn't work....... 

Have thought of junking the columns. But the engine is diagonal, across the platform. Not insurmountable, I'm sure!

Frankly, I think the displacer/ piston ratio is not enough at 1.8. Guess we need a smaller power piston, like Robbo! 

Love your "not new" punchline! 

David D

[vtsteam]

Well, happy birthday David!!!
And I think you may have something there with a smaller power piston.

[Stilldrillin]

Thanks VT!

Yesterday, was a good day....... 


No available shop time, this morning.......

But. A quick calculation, gives a displacement ratio of 1.834. Not a lot, in my opinion. 

Sleeving the cylinder bore, to give 14mm dia, gives 2.394.

Think I'll give it a go. Unless anyone else has any ideas?   

David D

[vtsteam]

Can you sleeve it with cast iron instead of steel?

[Stilldrillin]

Can you sleeve it with cast iron instead of steel?

I could....... But it seems such a waste, to reduce the only piece of c/i I have, from 30mm down to 16mm dia! 

David D

[Stilldrillin]

I roughed the cylinder sleeve o/d, to just over, size, minus 2 thou'.
Drilled out 13mm. Then bored carefully, until I had a finish I was happy with.

Around .540" bore.........




Topped the o/d. Until the cylinder would push on.

Then, polished it with the Scotchbrite pad........




THAT, was when I noticed the flange was loose on the cylinder! 

Another assault with the digging in tool. Another soldering session. 

Soft solder, this time.........




Looks ok, I think........




Assembled. Before owt else goes wrong........




Made a piston blank. Plus .010 on the o/d.

Made a fixture, with M3 screw thread.........




Finish turned the piston blank. Polished the final resistance marks away with Scotchbrite........




And....... Assembled it.


Oiled, where necessary.


And lit a temporary burner.


And waited.


For about 20 seconds.




And.............




Oh.......... HAPPY DAY!   


That's another little engine, doing what it's supposed to do......... 


Thanks for watching!


David D

[ieezitin]

You nailed it David.... well done..

Enjoy the fruits of your labor...

Anthony..

[Bluechip]

I had every confidence in you Sir .... just KNEW you crack it ... 
 
Except ... a blurry still is no substitute for an all-action video .. 
 
Dave BC
 
 
 
 

[sbwhart]

I had every confidence in you Sir .... just KNEW you crack it ... 
 
Except ... a blurry still is no substitute for an all-action video .. 
 
Dave BC

Bugger clicked on it and sat watching for 10 minutes for it to load 

 

Well done Dave

Stew

[Bluechip]

Stew
 
Not on your own. Trouble with Photobucket is it's hard to tell the difference between a still and a video ..
 
Often much the same ... 
 
Except the stills don't usually sit there buffering ???? Or do they ... ??
 
Dave BC

[Stilldrillin]

Thanks Anthony!

I will, when it's finally tidied.......



Dave, Stew.

Thanks for the laugh, Chaps!

You'll get your vid. A real one. Around mid week. If I'm spared, and you're lucky........ 

It's not over, just yet. Parts are rather loose, to eliminate any doubts over friction areas.

I think I will fit brass main bearings, which will allow the crank to centralise better. Or, I might just put the twin ball races back in......

Don't have to make a burner........ Found one, from the Maiwald, about an hour ago! 

The crankpin threads are at an angle to the disc face. Need to sort that, somehow! 

Thanks for watching!