Finally Building an Engine
November 09, 2018 07:55AM
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.
Re: Finally Building an Engine
November 09, 2018 09:52AM
Hi Zimirken, Vitron etc can be used for piston rings, although inferior to iron rings they do work but rely on continual lubrication, hot dry steam and no oil will damage them pretty quickly. I've used them in steampumps on the steam side and that has been the case. 1.5" iron rings are very common/readily available.

V-belt drives rob a lot of horsepower, would be better to use a neutral on the transmission. Some steam boaters use a simple pin on the propshaft - a sleeve with shaft inside, pull the pin for neutral, when they get ready to go, they insert a latch pin and that engages the prop.

Just a note on the flywheel, one is not needed on a twin simple, the simple twin is continually pulling with no dead spots. Adding a flywheel will help it run smoother when freewheeling, but it's not an absolute necessity.

-Ron
Re: Finally Building an Engine
November 09, 2018 11:52AM
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.
Re: Finally Building an Engine
November 09, 2018 12:27PM
I use a small brushed DC servo motor for a generator on the tugboat, works pretty good. I wired a three position switch to charge (through the diode), not charge for more engine power to the prop(disconnected) and power boost (bypass the diode to the battery). On the power boost, it doesn't really seem to make any difference. It puts out about 10 amps at 400 RPM. I only use it occasionally to top off the battery while underway.

The power boost was intended for low or no firewood situation, but it will not work that way. I've came close to burning my shoes to get home a few times smiling smiley

-Ron
Re: Finally Building an Engine
November 09, 2018 01:54PM
Just for clarification's sake, could you please expand a bit on "rotary slide valves"?

Regards,

Ken
Re: Finally Building an Engine
November 09, 2018 01:55PM
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.
Re: Finally Building an Engine
November 09, 2018 02:17PM
I wouldn't use steel at all for engine cylinder or valve construction. Steel will gaul without continual lubrication, gray cast iron which should be used (ductile works too) is much easier to work with and can be purchased as bar stock. Cast iron is similar to a sintered bearing material, it can retain oil and release it over time. It builds a glaze and that is what you want in the cylinder, cast iron is much less likely to rust due to it's ability to hold oil as well.

I planned years ago to build an engine without castings but never did. My plan formulated over many years of cranking the handwheels on manual mills and daydreaming, was to purchase cast iron bar of adequate size and bore it and then machine a flat on one side to attach a steam chest, face the ends with bolt circles to attach the heads. But once I could afford actual castings, there was no point in doing all that. Yep on the pistons, aluminum or gray cast iron. Aluminum for the cylinder head of adequate thickness etc should be fine.

Have a look at Internal combustion cylinder sleeves, they are cast iron and could used to line a steel cylinder.

-Ron



Edited 1 time(s). Last edit at 11/09/2018 02:19PM by IronChief.
Re: Finally Building an Engine
November 09, 2018 02:42PM
Silicone O rings deteriorate in engine oil, and they are too soft (extrude in the clearance).
Viton needs good lube.
Re: Finally Building an Engine
November 09, 2018 03:00PM
Scott, they sure will "escape" through a very small clearance if they are low durometer. When I first used them on steam pumps, I used soft durometer and if they get dry and stick to the cylinder wall, they can be squeezed through and out a .001" clearance. I pulled the pump apart and the o-ring was stuck in one of the valves, I went with high durometer (hard) neoprene O-rings and they held up just fine on steam and water pistons both. The key here with O-rings is lubrication, but I wouldn't even consider them for a engine cylinder where high RPM is sought and lubrication can be easily interrupted. A bench top spinner at the local hobby show, O-rings are ok, but a serious running engine, get some cast iron rings.

-Ron
Re: Finally Building an Engine
November 09, 2018 03:27PM
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.
Re: Finally Building an Engine
November 09, 2018 05:03PM
Quote: "I suppose I could skip the whole piston and ring design and build process and just buy a premade piston and ring"

Yeah, there ya go. That is how the famous Ray Hasbrouck engine was designed, it uses a Renault Dauphine? cylinder sleeve and ring set. I would find a piston, ring and sleeve kit.

Something like this, it even has the con rod with needle bearings:

[www.amazon.com]

How much oil? Simple answer, not much. There is some lubrication with saturated steam under 200 psi and no superheat, but oil is needed period. To give you a rough idea, On the Tugboat, 8 ounces lasts about all day. it's just a very tiny amount of oil. Steam cylinder oil is water soluble so it mixes with water and sticks to everything inside the engine. The steam oil I use is 680 weight.

How to administer the oil? Yes oil pumps can be used, but they can be troublesome with moving parts, seals and check valves. A much simpler way is by hydrostatic oiling where some steam condenses - water runs to the oil reservoir and displaces oil in to the steam line. Dead nuts reliable and there are no moving parts in operation and the biggie, no check valves. There are several easy to build design around for these, a good buddy of mine steamboater makes them about as simple as they can be - it's just an elbow off the steamline facing down with a nipple and cap on the bottom. Just fill the nipple with oil and as steam condenses in the elbow it runs down (water is heavier than oil) and pushes the oil back up in to the steam line. It doesn't get any simpler than that. The rate of flow will be the rate of condensing, too much oil, insulate the elbow.

-Ron
Re: Finally Building an Engine
November 10, 2018 10:03AM
Here's my stash of steam cylinder oil


Re: Finally Building an Engine
November 11, 2018 12:19AM
Mobil SHC634.
Re: Finally Building an Engine
November 11, 2018 01:24AM
"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.
Re: Finally Building an Engine
November 11, 2018 08:44PM
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.
Re: Finally Building an Engine
November 12, 2018 07:28AM
Export a step file and post it.
Re: Finally Building an Engine
November 12, 2018 03:41PM
Does this file work, just a test there are 2 types of step file
Attachments:
open | download - dr1.step (108.2 KB)
Re: Finally Building an Engine
November 13, 2018 11:51AM
Yeah, it looks simple enough.
Re: Finally Building an Engine
November 13, 2018 01:01PM
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
Re: Finally Building an Engine
November 13, 2018 05:31PM
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
Re: Finally Building an Engine
November 14, 2018 08:50PM
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.
Re: Finally Building an Engine
November 15, 2018 08:42AM
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.
Re: Finally Building an Engine
November 29, 2018 11:22AM
Is the oil pump in my Stanley EX
I’ve never had a problem with it.
Rolly


Re: Finally Building an Engine
November 29, 2018 09:27PM
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.
Re: Finally Building an Engine
December 01, 2018 04:49PM
Gee, how many Ferris alumni are there in the club? :-)
Re: Finally Building an Engine
December 01, 2018 07:40PM
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.
Re: Finally Building an Engine
December 06, 2018 08:27PM
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.
Re: Finally Building an Engine
December 06, 2018 08:39PM
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
Re: Finally Building an Engine
December 06, 2018 09:00PM
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 smiling smiley 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.
Re: Finally Building an Engine
December 06, 2018 09:57PM
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.
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