Finally Building an Engine

So I now have access to a cnc that can cut steel at my new job. I've been thinking about making an engine. I'm thinking of a configuration like the stuart sirius engine. Single acting, two cylinder, 1.5" x 1.5", but with rotary slide valves. At 80 psi steam this gives me around 1300 watts which is plenty for a moped sized vehicle. I'm not going to have variable valve timing, at least at first, so I can focus on other things. Bieng a high speed engine without reverse, I'll be able to make use of the 3 speed plus reverse transmission I made. I'm also thinking of using silly cone or viton o-rings for piston rings. I think I'll also use a belt clutch so I can leave the engine idling to run auxilliaries. I have a nice electric motor from a 24v 200 watt electric scooter I had when I was a kid that I've used in several projects that I might try to use as a generator/flywheel (it's got a lot of inertia).

Oh the cnc is a sieg KX1, it works really well.

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Edited 1 time(s). Last edit at 06/30/2020 07:43AM by IronChief.

It's a single acting twin with a planned ~40% cutoff. It won't be self starting, but I'll be able to blip power to the motor/generator to start it turning over with a diode bypass switch or something.

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Edited 1 time(s). Last edit at 06/30/2020 07:42AM by IronChief.

Just for clarification's sake, could you please expand a bit on "rotary slide valves"?

Regards,

Ken

Rotary slide valve, think corliss valves, but likely run by either a straight eccentric or a cam. However, I might try a poppet valve instead. Depends on how the design ends up flowing.


Couple of questions on materials. Probably won't be running over 400f. I'm planning on using DOM steel tubing for the cylinder bore, and I'm thinking aluminum for the piston? Also, for the rotary slide valve, should I use a steel sleeve in aluminum? That would be cheaper and easier to machine. I might have to make it a bit of a shrink fit so it doesn't come loose when the aluminum heats up. Although now that I think of it, I might have a steel bar of about the right size for the valve block. I'm thinking aluminum cylinder head? Brass and bronze are too expensive in general to really consider.



Edited 3 time(s). Last edit at 11/09/2018 02:16PM by zimirken.

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Edited 2 time(s). Last edit at 06/30/2020 07:39AM by IronChief.

Silicone O rings deteriorate in engine oil, and they are too soft (extrude in the clearance).
Viton needs good lube.

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Edited 1 time(s). Last edit at 06/30/2020 07:38AM by IronChief.

39mm (~1.5in) piston and ring for a chainsaw

I suppose I could skip the whole piston and ring design and build process and just buy a premade piston and ring, and use my original idea of DOM steel tubing for cylinder bored to 39mm.

Speaking of lubrication, is there a rule of thumb for ideal ratio of steam usage to oil usage? I wouldn't have any problem setting up an oil injector that was geared off the engine, but I'd need some sort of ballpark for flow rate to get the gear ratios and pump piston displacement volumes.



Edited 1 time(s). Last edit at 11/09/2018 03:33PM by zimirken.

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Edited 1 time(s). Last edit at 06/30/2020 07:38AM by IronChief.

Here's my stash of steam cylinder oil

Mobil SHC634.

"The cylinder oil consumption ranges from 0.1 pint to 4 pints per million sq. ft. of surface swept over by the piston (perimeter of piston X distance travelled) with an average of 0.8 pint per million sq. ft.. The average consumption per million sq. ft. will be less in large poppet-valve engines than in small slide-valve engines."

-- "Kent's Mechanical Engineers' Handbook", Robert Thurston Kent, Editor, 11th Edition, 1936, (New York: John Wiley & Sons, Inc), page 7-47.

Ask successful owners/operators of steam cars with engines similar to the one you plan to use, how much oil they use per mile, then convert to surface area per mile.

Personally, this is one of many reasons why I plan to use a Stanley-like engine; the engine oiling rate for good results is well established over many decades of practical road experience.

Hi Zimirken,

You have experience with the 3D printer, im working on a coiled and bent pipe for my engine. I use solidworks and am wondering if you could make an example that I can check the fit, once that is finalized I can then take the solidworks file and get the actual pipe bent.

Export a step file and post it.

Does this file work, just a test there are 2 types of step file

Yeah, it looks simple enough.

The only formula for Oil into a steam cylinder I can remember was on a site on the building of railroad engine type oil pumps. You may find it if you search building railroad oil feed pumps.
Rolly

Zimirken,

I just wanted to see if the files are compatible. The helix I sent you is the easy part. At the top of the helix a pipe comes out at a right angle. The bottom is a couple of free bends. I made the images solid because its probably easier that way. I would like to make a exact copy then install it and see if it fits.

Since were doing this in 3D I can use the cad drawing to send off to the pipe bender, its 1 inch tubing, this is my superheater. There needs to be a helix to heat in the fire, then one end into the engine intake and another drawing of live steam.

I will spend some time on the CAD drawing and send you the actual complete 3D drawing in a couple of days, we can go from there

Tell you what, im going to build the whole section of bends from the helix and well will see if your 3D printer is large enough.

Im going to whip up a 3D model and we will have a better idea can be done.

This is one of those things that has to be custom fit. With a working plastic part I can then go thru the process of making it with a CNC tubing bender or something. I have a guy that will bend the pipe as long as he has the CAD master file.

I visited with TomK years ago and he was pointing out to me how this guy made a bourdon tube by banging two rocks together to flatten and shape the bourdon tube. I heard that and looked down then went of on another topic.

I admire Zimirken he got a bachelor degree from Ferris, I was there for about two years have an honor point average but can't get my degree unless I take one more class.

When I was out of Ferris I became a ASE Master tech strait away. I recertified so I have 23 years of certification as recertified ASE the certification because you have to re-test every 5 years I had a customer the other day he came into my shop and I was doing what was suppose to be an easy repair... Well it turned into a nightmare and the guy waited in the office. You can say what you want but you MUST be calm and not throw a hissy fit when mechanically challenged.

In the end he mentioned that he looked at my ASE certification's (Im also certified Advanced level Specialist) The customer went on to reassure me that I was highly educated, and he is a good judge because he was a Collage professor and he pointed out everything was in range.

My print bed is 200 x 180 x 175 mm. I haven't used it since spring so it's due for a tune up.

Is the oil pump in my Stanley EX
I’ve never had a problem with it.
Rolly

Sounds very similar to the Westinghouse "high speed" engine I have on the 4x4 truck., 2 cy single acting with a rocking cylinder valve similar to the corliss valve, It is 5x5 bore/stroke. has a flywheel governor controlling the valve travel, reduces eccentric throw as the speed increases. Of course all cast iron and weighs a good bit. Probably somewhere in the region of what the original V8 engine did. Only picture of one like it I could find on the web had a push/pull valve instead of rocking action. It isn't the best engine for mobile use but we'll try it for awhile until I get around to building a custom engine to replace it. Then maybe relegate the old engine to stationary service.

Gee, how many Ferris alumni are there in the club? :-)

I wish I was alumni but I have to take "shop floor" for a whole semester, no way I can do that...

However Ken, you could petition Ferris to give me school credit, for being a re certified ASE Master tech for 23 years.and Certified ASE Advanced level specialist.. Not to mention 3 US utility patents. And a member of SAE for five years.



Edited 1 time(s). Last edit at 12/01/2018 07:49PM by Jeremy Holmes.

I just sent for my transcripts from Ferris it was back in 1990 to 1992. If I get them I will be surprised... But its worth a shot.

One thing that I like about SACA is that it embraces education. I think last year there was many engineers that are an asset to the club during the meet. Which is a good asset for the club.

Jamison mentioned to me that alot of the stuff is over his head, I said no its not... to do what your doing makes you an engineer.

Hi Jeremy,

The university may give you credit for your experiences. They won't, in any way, pay attention to a thing I would say. Mostly it would depend on whatever documentation you can provide, plus their policies. I've transferred credits from one school to another on a few occasions, usually it's painless but sometimes you have to dicker....the same thing applies to 'life experience'.

Regards,

Ken

Hi Ken,

Quote
Frustated
They won't, in any way, pay attention to a thing I would say. Mostly it would depend on whatever documentation you can provide

I know that was kind of kidding with you.

Im going to wait and see if my transcripts are able to be produced, then go from there. If I can... My goal is to get back in school as an engineer.


Best

Jeremy



Edited 2 time(s). Last edit at 12/07/2018 07:20AM by Jeremy Holmes.

I received conformation that my Ferris collage transcripts are located.and being sent to me. One other thing worth noting is that I was a process engineer for an automotive alloy wheel re-manufacturer(for over ten years). I built these huge lathes that have a 24in swing and were constructed by me. there were 3 total with 30hp direct drive (belt) and spun about 850 rpm. I learned from old timers on how to calibrate the NULL of the dual axis hydraulic tracers. Also I used ladder logic to program the PLC which returned the tracer to start position.(also built in safety interlocks) I also assembled the drawbar to 12in chuck tongue and groove master soft jaws, these are multi-step pie jaws. The run out was .010 concentrically and the wheel could be in the jaws and closed in 1 second then spun up instantly. I also showed how to rebuild quartz heaters to dry the clear-coat on the rims. Then I later refitted the template machine with an air turbine (for making the pattern for tracer pin to follow). And then I was a aluminium TIG welder and trained new users. There's more but I don't want to hijack this thread anymore, sorry for the rant. .



Edited 2 time(s). Last edit at 12/11/2018 07:24PM by Jeremy Holmes.

All files from this thread

File Name	File Size		Posted by	Date
111018a.jpg	133.2 KB	open | download	Jeremy Holmes	11/10/2018	Read message
dr1.step	108.2 KB	open | download	Jeremy Holmes	11/12/2018	Read message