New steam engine/boiler - advice wanted

New steam engine/boiler - advice wanted
Posted by komet163b on 18 Sep, 2019 11:27
I just came into a homebuilt 1929 engine/boiler combo.
I've added some pix to illustrate.

There are two areas of concern - the boiler and engine.
I'll start with the boiler.

The boiler has horizontal flue with 14 cross-tubes forming
seven 'X's' down its length. It did have a super-heating
loop but it was not very 'tasty' so I removed it for simplicity.
I can always put it back later. The boiler SV is a miniature
of the real industrial ones but is frozen - I believe it should
be able to come apart but it is stuck so to work on that. No
SV no steam. The part I'm not sure about is the heater that
came with it. I've included photos. I know part of it is a
blowtorch style burner, but the box (homemade) has no way
to fill it. I like some puzzles but what kind of fuel did this take?
I'm just curious as I'm guessing readers will suggest I go with
a modern burner. Any suggestions? I'm working on figuring
a way to pressure-test the boiler. I need to speak with my
old-school plumber on this one.

The engine has a valve problem (timing?) as the air flows right
thru to the exhaust when testing regardless of the position of
the valve shoe in the steam-chest. Either the timing is wrong
or the shoe is not properly seated, or worse, poorly machined.
One big question....when should the shoe uncover the inlet port,
before, at, or just after TDC? I'd like to avoid opening it up.

Thanks for any advice offered,
Wayne

#1 Reply
Posted by Dr.Rev.DelmarMacReady on 18 Sep, 2019 15:43
Crank should be at 90° top dead center with shoe just staring to uncover port. Centered between inlet and exhaust of course.
Take a peek at Keith Appleton's YouTube video on timing a steam engine. And I would just go ahead and bite the bullet and open up the valve chest, to replace gaskets and verify there isn't a dead bug or dirt dauber nest in it.
Can't help with the burner, I've seen them before but don't know much about them. I think I might try to find a blowtorch burner new for it.

It is a nice looking piece of work. Can't wait to see what you do with it.

#2 Reply
Posted by komet163b on 19 Sep, 2019 09:57
It is nice looking. I paid a modest price for it to the
owner, the grandson of the machinist who made it in
1929. When I get it running I'll put a video out there
as a thank-you to him and the community.

I'll take your advice re the video to watch and the timing.
If that seems to not be the problem, then off with the
valve chest. Photos at each stage of disassembly, of course.

As to the burner...I've seen burners for yard work and
I'm still looking. Any specific suggestions? The flame
has to be horizontal as the flue is. Would the flame from
a propane torch be too fine/pointed to use?

Anyway, I steamed up my Empire 43 for fun yesterday.
The cartridge heater I put in it is only 200 watts so it
doesn't run any faster than a couple hundred rpm, but
it will run forever. Chug, chug, chug.

Thanks for the reply,
Wayne

#3 Reply
Posted by Nick on 19 Sep, 2019 10:03
Well done Wayne, that's definitely one of the nicer home-builds I've seen Would love to see a video

#4 Reply
Posted by komet163b on 22 Sep, 2019 18:49
Well, I took the steam-chest valve-cover off.
A bit of effort with the fingers and it loosened.
Off it came. Not much in the way of gasket.
The sliding surface looks a bit...rusty. The only
iron is in the studs and the surfaces in question
are not iron. So, I suspect they are just mineral
deposits left there. These deposits on the
sealing surfaces may be the problem - lack of a
proper seal. I've added a photo of the miscreants.
The grid is 3/4".

Any suggestions would be appreciated. Hopefully,
the analysis is correct and the fix is easy.

Thank You,
Wayne

#5 Reply
Posted by Dr.Rev.DelmarMacReady on 22 Sep, 2019 19:17
Yep I'd guess that would definitely keep it from sealing. Looks like some maintenance is in order.

#6 Reply
Posted by komet163b on 23 Sep, 2019 09:33
I agree. The question is, how to clean it up.
Is there a chemical solution like lime-away
that removes scale build-up but will not affect
the brass? Or do I need to use a scotch-brite
pad? I hesitate to go to any kind of abrasives
such as 400grit wet/dry. And, when I get past
that, what to use for a sealant is the question.
There seemed to be no gasket before, so, any
suggestions?

Thanks,
Wayne

#7 Reply
Posted by Dr.Rev.DelmarMacReady on 23 Sep, 2019 11:54
I would be careful using lime away. Vinegar/water mix is less harsh. If you intend to use gaskets, and if the screws are long enough i surely would, then we're it me I would face the valve block anyway...flat plate and some wet Emory with light circular motion. Give a good clean sealing surface.
With the valve chest that crusty, I would go ahead and take the whole thing down. There are plenty of folks to help if you run into problems and it really needs it or you'll just be doing it later.

#8 Reply
Posted by komet163b on 23 Sep, 2019 14:01
I just finished a first pass at cleaning it up.
I used a non-abrasive scrub pad glued to a
narrow stick, tested it on some scrap brass
to ensure it doesn't abrade/wear and ran it
across the sealing surfaces. Seems pretty
clean and smooth - check out the pix, one
with flash and one without.

As for the gasket surface, I'd like to try it
as I found it - no gasket. I really do not
want to force the shoe any farther away
from the valve-seat. So, any suggestions
for a sealer? Preferably a sealer that can
be dissolved away if I need to open it up
again. I just want to seal it not glue it.

One operational question. What holds the
valve-shoe against the valve-seat? Nothing?
It seems a bit....illogical. All I can imagine is
that the steam pressure forces it against the
seat. Is this so?

Thank You,
Wayne

#9 Reply
Posted by Stoker on 23 Sep, 2019 14:49
Yes, exactly, it is the admission steam pressure that keeps the D-valve seated. That one has some rather rough looking machining, especially on the exhaust "pocket", but I've seen worse that still ran just fine, so if it works well, I'd leave it.

#10 Reply
Posted by Dr.Rev.DelmarMacReady on 23 Sep, 2019 15:06
Gasket material wouldn't change the relationship of the valve to the ports, it would only insure no steam leaks.

#11 Reply
Posted by komet163b on 23 Sep, 2019 16:22
The valve shoe is, so to speak, part of the
valve chest. If the chest is moved away from
the valve-seat by the thickness of a gasket the
shoe will be moved that far away from the sealing
surfaces. Not the way I would have done it. I
would have had a separate cover for the valve
chest assembly. Therefore, either use a thin smear
sealant or, if a gasket is needed, a very thin one.
I vote for sealant only, as originally done.

And when it works.....distilled water only, and blow it
out w/air after running. The only way to do it.

Thanks for the comments....give me more.
Wayne

#12 Reply
Posted by Dr.Rev.DelmarMacReady on 23 Sep, 2019 17:38
One piece...guess that limits you. I'm not sure what sealant, I've never used any on a steam engine. On mc engines, I use HondaBond, or Loctite grey case sealant(I can't remember the number). It is good stuff.

#13 Reply
Posted by komet163b on 23 Sep, 2019 17:51
Your advice sounds good. I'll look into the Loctite
line of products.

I'll check the sealant/adhesives aisle of my local
hardware store. I'll also check to see if there
are any lapidary adhesives that would be apropos.
Thankfully, the problem deposits look to have been
just surface deposits and there was no pitting.
I'm ready to go.

Wayne