# Two Engines in One or Elmer Gets a Makeover



## Sshire (Jun 20, 2012)

Two Engines In One or Elmer Gets a Makeover

This is a cautionary tale about what happens when you decide to build an engine but don't like some of the design.

Elmer Verburg is probably looking down on this build and either thinking, "Hey, what's wrong with square blocks as cylinders?" or laughing uncontrollably. Or, perhaps, both.
Let me explain.

Elmer's Radial has square cylinders. Not actually a square cylinder, but a round hole bored in a square chunk of metal. Now a bunch of you are saying, "If it's good enough for Elmer..."
It bothered my sense of design. I wanted a round hole in a round chunk and if that isn't enough, I wanted some of those cooling fins in the round chunk. There probably isn't a time in the foreseeable future when this will run on anything but air so the cooling fins are nothing more than another skill to add on to the very short list of skills I've acquired in the last 11 months since I've started this hobby. (My 5th grade teacher would have cringed at that fine example of a run on sentence.)

Not willing to learn enough CAD to create a model, I jumped right in. In the process of "design-as-you go", I've created enough parts for, at least two engines. Hence the title of this build.

Since the only thing I've changed from Mr. Verburg's plans are the cylinders, let's begin there. This isn't where I actually started, so you may notice that some parts, like the crankcase, pistons, rods, etc. seem to have magically materialized. Believe me, they did not and I will get to the build steps for those in due course.

The simplest approach seemed to drill and bore the cylinder, as Elmer intended, in a square chunk of 6061. Then put it in the 4-jaw and make it round. So I did. Bad idea. The air passage was too close to the outer diameter of the cylinder to cut the cooling fins.







Aha! I'll offset the bore to leave more metal where the air passage is drilled. 






Bad idea #2. Now there's not enough metal for the four through mounting holes. Plus ( or minus) the depth of the cooling fins is too wimpy.











Only one thing to do. Go upstairs and make a double-shot of espresso.






After thinking about this, I came up with two possible solutions (well, three actually but I disregarded, "quit and make more espresso.")
Plan #1. Increase the diameter of the cylinder (duh)
Plan #2. Forget the through holes for mounting and air passage and do them externally.
So I did both.






After turning a larger 6061 piece to 1.1" and boring the cylinder, I mounted it on a 5C expansion collet and milled grooves with a .125 ball end mill for the external hold down pieces.
The air passage hole near the bottom will also be a milled groove.






The cylinder, still on the collet, went over to the lathe and I cut grooves with a Warner grooving tool. I spaced the grooves equally with a dial indicator measuring the lengthwise travel and the depth with the DRO.











Three finished cylinders and they got to this stage in only 5 days of making "extra" cylinder variations.






My thought for the hold down pieces was to use .125 brass tubing. Cut to length, drill and tap 2-56. I would Loctite short pieces of 2-56 SHCS in one end and screws through the cylinder head at the other.

Now I needed to set of steps to make all of the tubing exactly (or as close to "exactly" as I can make them.)
So
1. Cut 12 pieces close to the finished length
2. Use a collet stop set for the length I needed. The 5C collet will be in a collet block.
3. Vise stop on the mill so I can return the collet block to the same position.






Clamped a straightedge to the jigsaw table. Fine tooth metal cutting blade in place. Cut all 12 pieces of .125 tubing about .1 over finished size. Deburred the ends.






I put one of the pieces into a &#8539;" 5C collet, set a collet stop inside, put the whole thing into a square collet block. The block then went in the mill vise and I milled the end to split a line I had marked on the setup piece of tubing. I measured the piece in the 1"-2" micrometer and found that I was .009 over. Easy enough the use the DRO on the mill to move X over by .009. Now I locked everything down and did the remaining 11 pieces.






Done and all the same size.

And now, a short digression.






The crankcase has 24, 2-56 threaded holes to be tapped. Never passing up an opportunity to bolster the economy, a Tapmatic RX30 mysteriously appeared in the shop. After some research and a very nice discussion with an engineer at Balax (they make wonderful form taps), and some discussion here on the forum about tapping oils ( some of which, apparently, are quite "fragrant"), thread percentage and other mysterious topics, I did a few test holes to set the torque. A butt-clenching period followed while I tapped all 24, 2-56 holes in about 3 minutes with nary a broken tap. I was prepared to break a few in testing, so I had ordered 4. I still have 4.
End of short digression.

So here's where we are.











Stay tuned for the next part where I try to figure out how to get air into the cylinder and make more espresso.

Best
Stan


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## arnoldb (Jun 20, 2012)

That's a great start Stan  Thm:

Somehow I don't think Elmer would mind; in fact, I think he'd approve 

Kind regards, Arnold


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## rleete (Jun 20, 2012)

Nice. Metalbutcher did one with round cylinders several years ago, and I started to copy him. So, you aren't alone in thinking square cylinders should be made round.


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## rebush (Jun 20, 2012)

Stan: Looks like it's going to be a good one, I'll enjoy watching you're progress. One thing baffled me ??? about the same time that a Tapmatic RX30 mysteriously appeared in the shop did you notice a decrease in the balance of the check book. If not you need to share that trick with the group. Roger


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## steamer (Jun 20, 2012)

Great work Stan!

Dave


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## Don1966 (Jun 20, 2012)

Great work Stan I will be following along also. That tapmatic must of hit your checkbook hard all the ones I priced were way more then I can justify. 

Don


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## Sshire (Jun 20, 2012)

Thanks for the kind words. I came upon ( what I think) is an elegant solution to piping the air to the top of the cylinder. I'm putting the pix together for tomorrow's installment. Of course I won't know how elegant it is until I get to the point of trying to make it run. 
About the Tapmatic. You bet it wasa expensive. I originally bought one on EBay. The previous owner had cut the stop rod to a 1" length which made it unusable. I was going to make ( or buy) a new part but decided to return it as it generally looked tired.
I bought the new one from Enco with a coupon and spare change. Everyday when I come into the house, all pocket change goes into a large can. I've been doing this for year's and it's amazing how it adds up. Long story short, with the coupon, the current crop of change ( about a years worth and a bit more, I had my RX30.
Stay tuned and thanks
Stan


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## Troutsqueezer (Jun 21, 2012)

The cylinders are looking good. I am also building this engine although taking my own sweet time. Like Metal Butcher, I am making the cylinders round. Air supply is through a separate pipe. I'll post a pic in the next day or two.

Trout


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## Blogwitch (Jun 21, 2012)

Stan,

I keep repeating this over and over, if you want to make yourself a unique engine from plans, as long as you stick to the basic critical dimensions, bore, piston stroke, porting etc, then everything else is fair game.

You can usually cut away half of the rest of the engine, support plates etc, without causing any undue concern.

Yours is starting to look very well indeed.

John


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## bearcar1 (Jun 21, 2012)

Hey Stan, you never know, Elmer might be watching and saying to himself "now THAT'S how I should have done it"  ;D  I like the slugs round, as opposed to being square (pie are square you know) *sorry Marv* :big: Should be a sweet looking engine when you are done.

BC1
Jim


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## Sshire (Jun 21, 2012)

Trout
Anxious to see your photos. Im never above "borrowing" ideas.

John
I have absolutely read your posts about making unique versions and they obviously stuck. Look at the many, many variations of every engine posted here. Some people build beautiful engines precisely to the drawing while others just follow their own path.

Jim
It's a shame that Elmer can't see what he started with that book. Thousands and thousands of Elmer's Engines.

Stan


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## Sshire (Jun 21, 2012)

Part 2 of

Two engines in one - I need air


When we last left our intrepid engine builder (after the magnificent engines I've seen here and at Cabin Fever, I'm not calling myself a Machinist), he was mulling over how to get air to the top of the cylinders.

I looked at a lot of other engines, build threads and photos that I took at Cabin Fever. Since my cylinders no longer have a through hole to carry air from the crankcase up to the cylinder top, it seemed the external piping is the only way. Due to the position of the already-drilled port in the crankcase, the "pipe with a 90 degree bend at the top" technique is not going to work.

After staring at the cylinders, and liking the look of the four half-embedded hold down tubes....Aha! Mill a fifth groove in the cylinder in line with the air port in the crankcase for another piece of .125 brass tubing and send the air through that. Not a new idea, MetalButcher used an air tube to the head in his build which I just found.

First, it would retain the consistent look of the cylinders 
And
Second, I couldn't think of another way.

Milling the extra groove only required precisely placing the groove at a 45 degree angle to any of the existing four grooves. I already had a through air hole in the cylinder.

And I get to use that Shars 360 Degree Universal Bevel Protractor that was in Rick's thread a few months back. I have used it on a few other projects and it was how I learned to read a Vernier scale.











I drilled a hole at 45 degrees in the base of the 5C expansion collet for a locating pin, put the cylinder on the collet and ran a 1/16" brass rod through the port in the cylinder and into the locating hole. Then it was into the collet block, onto the mill and cut the groove with the same .125 ball end mill I had used for the other grooves. Quoting some other folks on this forum, it "worked a treat."

Now the question was, Alright, I've got air from the crankcase into a brass tube. How to seal it and how to port it to the cylinder?

Looking at the cylinder heads, I thought that I could do a .125 hole that the top of the air pipe could go into, a hole that would allow air into the cylinder, and a cross port to connect them.






I drew a 2X C.O.C. and measured, drew, erased and scratched out until it looked like it might work.






The length of the pipe was calculated by measuring the distance from the top of the crankcase to the bottom of the cylinder head and adding a bit for the counterbores that I would put in the head and crankcase.






The mill DRO was as useful as always in precisely positioning the air pipe hole and the center port.






Centering the head for drilling the cross port.











The cross port drilling went perfectly and I cleaned out the hole with this brush that I get from my dentist. You can also get them in the pharmacy in 10 packs.






Back to the collet block to cut the top of the tubing so that air can actually get into the cross port.






Back to the .125 end mill for the crankcase counterbore

The next group of photos are the test fit. I found that .125 tubing ranges from a measured .124 to a bit over .126. Another learning experience. Picking the larger size allowed me to put it in the lathe and use a 400 grit paper wrapped around a parallel until I got a very close fit in the crankcase and cylinder head counterbores. I'm hoping that this will be enough of a seal but, if not, Loctite should work.
















The cross drilled hole will have a Loctited plug.






That's all for today. In the next installment, Elmer wants the fixed connecting rod to be perfectly aligned with the central hole in the hub. (he actually said "Try to make the rod centerline pass through the hub centerline.") Try? What happens if you fail to do so can't be good, so I made a fixture. 

Best
Stan


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## Troutsqueezer (Jun 21, 2012)

That is almost exactly how I did my intake pipe. There's not too many options to choose from, simple ones, at least.


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## Sshire (Jun 21, 2012)

Trout
Were you able to get a good seal?
Best
Stan


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## Troutsqueezer (Jun 21, 2012)

I haven't sealed it yet. You can see from the pics, I'm not too far along. I do have a tight fit. Considering using Locktite, but the kind you can release without too much trouble. 






I drilled the port hole from the rear and used a set screw to seal the hole. 






When I'm done, this will be a highly-polished version with the stand of my own design.


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## miner49r (Jun 21, 2012)

Stan,
The square cylinders on Elmers Radial are a big turn off for me too. When fall comes and I get back to working in the shop the radial will be my next build after I finish #44. I will be watching with great interest.
Alan


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## Sshire (Jun 21, 2012)

Trout
Looks great! I usually wait to polish until i have all parts completed. Otherwise, I scratch something and have to start polishing all over again.
Very nice idea with the screw to plug the hole.
The fun never ends.

Best
Stan


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## Sshire (Jul 3, 2012)

Brick wall

Well I have a bunch more build pix and made all of the parts.
If I hold my thumb over the end of the cylinder, the piston stays in and when my thumb comes off, the piston slides out. I'm told this is a good thing.
I put the engine together, hooked up air and.....nothing. 
It turns with nary a bind by hand, feels smooth. I "ran it in" on the mill for about two hours and still won't run on air. I switched the airbrush compressor for the shop compressor. Won't run. Doesn't even feel like it is trying.
I took the heads off and air is coming out of each air tube to the appropriate cylinder at the right time.
I read an old Madmodder post (pretty sure from Bogs) about the rotary valve being very touchy. I took a few thou off the valve housing to tighten up the tolerance until the valve wouldn't move then with 600 grit, sanded down the valve until it just moved again. No luck.
There seems to be a lot of air coming out the exhaust port, but even holding my thumb mostly over it to keep more air in the valve housing, nothing happens.

If anyone has another suggestion I'll certainly try it. I've reached the end of what I can figure out.
Help.

Thanks
Stan


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## mzetati (Jul 4, 2012)

Providing I've found the correct intake (not sure about that)  air should go the red way. Any chance it goes the blue way too, or the green way on wrong cylinders?

Removing the valve cover and applying air to the correct spot with the valve in the correct position should let You have it turning 120deg at the time, it may help solving the issues.
Removing the heads and closing each one with fingers at the right moment should do too, and will let You check for eventual unexpected flows on the other cyls.
HTH
Marcello


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## mzetati (Jul 4, 2012)

Well, I see there's no valve cover, the valve housing being the cover itself.
This is an interesting engine, I still cannot figure how it would work.
Worth building.
Marcello


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## tel (Jul 4, 2012)

Via an offset drive Marcello, same as my Pseudo Cygnet


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## mzetati (Jul 4, 2012)

Got it! 
The connecting rod hub doesn't make full turns, it slides on the cranckshaft pin. 
That would be the "offset drive", I suppose.
Marcello


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## Sshire (Jul 4, 2012)

Marcello
My guess ( since Elmer doesn't say) is that the intake is the red line.
I did as you suggested and removed the valve housing and applied air to each intake. I did get 120 degree turns from each intake. So it appears that the cylinders are getting air.
When I try with the valve and housing in place, I feel a "push" from one cylinder only which makes the valve the problem.
After measuring and checking the plans the only difference is that the recess in the side of the valve that faces the intakes is .08 larger in diameter than the plans. I'm remaking the valve now. If I had some clear lucite, I would almost consider making the valve in that to see what's going on with the intake. 
Thanks so much for taking the time to help with this. 
I'll report later today on the new valve.

Best
Stan


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## arnoldb (Jul 4, 2012)

Hi Stan

I took a bit of time before replying because I wanted to give the plans a bit of a study.

The valve faces must be very flat and parallel, as must be the inside of the valve housing and the face of the crankcase against which the valve runs to minimise blow-by

This might sound like a silly question, but did you put the valve in the correct way around ?

If you still have problems after checking that and/or re-making the valve and still get a lot of blow-by, try to use some thickish oil (diesel engine oil or slideway oil) to generously lubricate the valve and see what happens; this might just do the trick by providing some additional sealing.

Kind regards, Arnold


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## Sshire (Jul 4, 2012)

Hi Arnold
Thank you for taking the time to decipher the plans.

Not a silly thought at all. In my numerous removals and reinstalls of the valve housing, I did once put the valve in backwards. 
The faces are as flat as my face mill, very fine grit Clover, and my skill level can get. I actually face milled a bit off the valve housing until I got a slight binding of the valve. Then, with very fine grit wet and dry, polished the valve until it just ran freely. That's why I'm remaking the valve, in hopes the the new one will like it's new home better than the last one.
I have been lubricating with Starrett Instrument oil but will use a heavier oil when the new valve is finished. I won't get a chance to try it until I return home this evening from the July 4th festivities. 236 If Bogs or any others from the UK are reading this post, the festivities are a yearly reminder that 236 years ago, we won. ;D

Best
Stan


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## Captain Jerry (Jul 4, 2012)

Hi Stan

I'm a little late to join in on this thread. I hope you don't mind if I comment on this valve design at this point. I have studied it and I have used it as a model on some of my wobbling engines with some variations in air flow and size. In essence this is no different than a slide valve. It just happens to slide in three different directions. It is also different in that it is an inside admission slide valve,(the pressure is in the cavity of the slide and the exhaust is outside). There is also no way to adjust the timing except by changing the dimension of the various parts. Elmer's engine runs with dimensions that he used so if you are off in any of the critical dimensions you may have changed the timing to the point that it won't run. 

These are the critical dimensions

Valve travel or eccentric throw. Elmer shows the offset of the small pin on the end of the shaft as 3/32". This control how far the valve body travels in one stroke.

Steam Port. Elmer shows these as 1/16" diameter. It's location is shown on a 5/8" PCD or 5/16" from shaft center. Any error in this dimension would be the same as changing the location of the steam ports in a slide valve.

Valve disc diameter. Elmer show this to be 3/4". If this dimension is off, the valve disc will open or close the exhaust port too soon or too late.

Valve face width. This is the difference in the outer diameter and the inner diameter of the valve disc on the engine side of the valve disc so it is vital that both inner and outer dimensions be maintained. If the valve face is too narrow it will open the pressure side while the exhaust side is still open and may fail to close the exhaust side completely.

Timing angle. The offset pin at the end of the shaft must be set at 90° in advance of the crank.

This is a single acting engine so air on the bottom side of the piston has no effect. The crankcase breather equalizes this with the atmosphere.

Minor differences in valve timing makes all the difference in performance and on this valve, the dimensions must be exact as there is no adjustment. By exact, I don't mean + or - .008". Elmer used fractional dimensions so 1/64" error shouldn't keep it from working.

I hope this is of some help but if I have not helped you understand the workings of this unique valve, I will be happy to elaborate on any point.

Jerry
In my designs, the size was changed so those dimensions are of no use to you. If you


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## Sshire (Jul 4, 2012)

Jerry
Thanks so much for that excellent analysis of the rotary valve.
I checked all dimensions and all were way within Elmer's tolerances (if 1/64" is .0156). My largest error is .004 except for the valve.
I did remake the valve as the I.D. was +.008. It's now +.001.
I made it a few thou over Elmer's .250 thickness so I can reduce it and keep fitting until it just runs freely.
I expect to fit and test when I get home from the BBQ.

Thanks again. 

Best
Stan


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## Captain Jerry (Jul 4, 2012)

Stan

One other point about the valve. The number and size of the holes through the web are of no significance. If you make them bigger or add more holes, you can see what is happening at the valve face better. Pick any piston and set it at TDC. With the valve cover off, look at the valve port corresponding to the cyl at TDC. It should not be visible on the outside of the valve ring (exhaust) or the inside (intake) looking through the holes. Slowly rotate the shaft in the direction of normal rotation. The valve port should should begin to open on the inside of the ring and should be fully visible when the piston is at mid travel (90°) and begin to close being completely closed at BDC (180°). As you continue to rotate, the port should begin to open on the outside of the ring(exhaust) as the piston rises in the bore and is again fully closed as the piston comes to TDC.

It is wrong to consider the port and the tube as just steam (air) pressure inlet. It is also an exhaust tube and port, depending on the direction of the piston travel.

Actually, I guess I had two things to say. The hole in the center of the valve body should be a free or loose fit on the pin. Any binding at this point might tend to lift the valve body off of the port face.

Good luck with you trials. You are almost there.

Jerry


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## Sshire (Jul 4, 2012)

Jerry
I think that's what's needed. I really need to see what's happening.
I know that the piston/ cylinder/air passages are ok because, without the valve, air hose directly on each hole in the port face rotates the crankshaft 120 degrees. I've tried that in both clockwise and counterclockwise and it works every time. That leaves only the valve.
I'll add 4 more holes and make them a bit larger so I can see what's what tomorrow.
That leaves only a road trip to Florida for a consultation ;D

Thanks again for all of the help.

Best
Stan


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## Captain Jerry (Jul 4, 2012)

Sure Stan. Gas prices are down and Florida daytime temps seldom exceed 95°F this time of year.

Jerry


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## mzetati (Jul 5, 2012)

> When I try with the valve and housing in place, I feel a "push" from one cylinder only which makes the valve the problem.



You mean that by rotating the shaft 120deg none of the other two cylinders gets any air you can feel on the finger? There should be, however leaky the valve might be.
Either the valve is not rotating, or its not clearing the port. Have You not misplaced the 1/8drill into the valve crank?

Marcello


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## mzetati (Jul 5, 2012)

I'd remove the covers and the valve housing, plug three of the four holes into the valve (a strip of adhesive tape on the inside should do) and apply thin air to the fourth to find out when (if ever) and in which position of the piston each cylinder gets air, by turning the crank by hand. 

Marcello


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## Sshire (Jul 5, 2012)

Marcello
If I remove the valve housing and valve and put the air hose over a port the crank rotates 120 degrees. Put the hose on the next port and the crank rotates another 120 degrees. Put the hose on the third port and the crank routes another 120. This tells me that the all of the cylinders are getting air and not binding. The only thing left to prevent this engine from running must be the valve. 
I'm going to take Captain Jerry's suggestion on drill more holes in the valve to see what is actually happening when the valve rotates. Hopefully, this will reveal the problem.

Best
Stan


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## Troutsqueezer (Jul 5, 2012)

I knew there was a good reason for my taking so long on my version of this engine and that is because all the great advice you are getting here will help me immensely as I go along. This is a worthwhile thread, Stan. Thanks to all for the inputs. 

-dennis


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## Sshire (Jul 5, 2012)

Dennis
I agree. Jerry's troubleshooting analysis is excellent. I'm determined to make this a runner.


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## Captain Jerry (Jul 5, 2012)

Stan

In spite of what I said earlier, it is hotter than blazes in Florida, and my shop air conditioner can't keep up with the afternoon heat when the shop roof looses the shade of the big laurel tree on the south of the shop, so I will entertain myself by thinking about this engine and valve. Here are a couple of other thoughts.

When you send air directly to the cylinder through the face port, you get 120° of rotation. You should get very close to 180° of action. The force may be smaller at each end of the range due to con rod angle but with no resistance, air at the top of the cyl, force should kick in just past TDC and should drive the piston all the way to BDC. True, in a 3 cyl engine, each cyl is only responsible for only 120° but they all operate closer to 180° with some about 60° of overlap.

I found it very difficult to get this valve to operate reliably with a face groove and instead came to rely on flat valve faces and a very close fit on the opposite valve faces with the valve face and cover, lapping to final size as you have done.

I also prefer to use a lighter viscosity oil and generally use 10wt or lower. There is almost no load on these faces and 10wt gives better coverage and penetration between the faces.

Don't overlook air leak at the valve cover joint. Oiled paper works just fine. You can lap the valve to a tight fit and then add the gasket at assembly to provide clearance.

If you have to make the valve body again, I would leave the inside diameter slightly under and the outside diameter slightly over. This might rob some power at TDC as it will cause the valve to open slightly past TDC but the improvement in performance of eliminating air leaking over to the exhaust side of the valve face through the incompletely closed port will be beneficial.

While you have the paper and scissors out, you might think about a paper head gasket as well.

Another place to check is piston blow by which is very easy with a single acting acting cylinder and a closed crankcase. Just put your finger over the breather and apply air to one of the clinders. Any pressure in the crankcase has blown by the piston. If it is much, you may need to add O-rings to the pistons. You may find that
plugging the breather hole or restricting it will allow the engine to run but I would only do this as a test and at low pressure.

In my experience, a loose engine is a smooth engine. There is no oil circulation and no oil filter. I generally like to leave bearing caps just snug during run in with plenty of oil. Flipping the flywheel with a finger should get at least three full revolutions before stopping. I am happy to see contaminated oil flowing from the bushings. I like to put a tachometer on the engine and watch for speed changes as I snug up the bearing caps. If I can stop the engine by doing this, it is time to look at the shaft alignment.

This turned out to be longer than I had planned but it is really hot outside.

Jerry


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## Sshire (Jul 5, 2012)

Jerry
Excellent! More to try. I've used Teflon sheets in other engines as gaskets and they seem to work well. I make a custom punch for whatever size I need.
I am only getting 120 degrees per port when air is applied directly. 
Since I'm getting really quick at making valve bodies, I'll try one with your ideas.
I did drill extra holes in the valve and did as you said. My results match what you said should happen on each cylinder.
Even though I detect no binding, spinning the flywheel only gets me a bit over one rev. I can put the pistons back in the 5c collet and use wet n dry to very slightly reduce the O.D. it's a whole lot easier to make a new piston than my round, fancy cylinders if it gets too loose.
More to come.
Best
Stan


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## Captain Jerry (Jul 5, 2012)

Stan

Ignore much of what I said.  I'm going to sober up and try again tomorrow. The error? Air is supplied to the radial input, not the axial one. The valve is outside admission, not inside admission. I don't know what I was thinking. Everything else that I said is true except that the direction of rotation is reversed. When the shaft is turned in the direction of normal rotation, the face port should appear outside of the valve ring. There may be other errors in my thinking.

I will issue you a credit, good for any additional doubtful information that you may need.

Jerry


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## bearcar1 (Jul 5, 2012)

Captain Jerry  said:
			
		

> I will issue you a credit, good for any additional doubtful information that you may need






Will there be any sales or promotions for that item anytime soon? *beer* Rof} Rof} Rof}

BC1
Jim


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## Captain Jerry (Jul 5, 2012)

Jim

For members in good standing on HMEM you will always get a substantial discount by including the PROMO CODE "WTF" with all request.

Jerry


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## bearcar1 (Jul 5, 2012)

Good one Jerry Thm:

BC1
Jim


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## Sshire (Jul 5, 2012)

Jerry
So the air supply should be coming in opening in the side of the valve housing, not the front?
I've tried it both ways. Whatever. I've also drilled out the back crankcase cover and loctited a new bushing in because I detected a small amount of runout in the crankshaft.
Engine is now disassembled and cleaned. I need to make it a bit looser. Piston reduction begins in the morning. I'd do it now but went out to dinner and won't go into the shop after the (as I believe ArnoldB says) fine Scottish produce consumed. Heavy machinery and all that.
The radial merriment continues tomorrow.

Best
Stan


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## Captain Jerry (Jul 5, 2012)

Stan

Like most air/steam engines, swapping inlet and exhaust just changes the direction of rotation. Either way would probably work, but as I was thinking about this engine, it came to mind that someone had fabricated and fitted a neat little diffuser/muffler to the axial port on the valve cover face. I can't remember whose build it was but it was a nice touch.

Jerry


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## mzetati (Jul 6, 2012)

> So the air supply should be coming in opening in the side of the valve housing, not the front?



Stan, 

now I've read the instructions, Elmer confirms that

"Drill #23 through the backwall for later tapping the 3/16-40 MTP exhaust connection", on page 44 in the valve housing paragraph.

Now, the visual check of air admission to the piston at TDC is trivial. I suppose the valve should open slightly after that moment (and have a perfect seal both on the other two admission holes and the backwall itself, having no means to take advantage of the steam pressure to gain that). 
Much less an 'easy' design for a straightforwad build that it looked at first sight.
Thank You for starting this thread.

Marcello


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## Sshire (Jul 6, 2012)

Marcello
I must have read that 100 times and if I recall, I started with the intake on the sidewall and then switched it to the back wall. I'm reassembling the engine now so I will check the "timing" of the outer ports (outside of the valve).
I'm also going to plug the flywheel outer edges with brass around the O.D. to get some additional mass. Elmer specs a 2" flywheel (he doesn't say, but I'm assuming steel). I had a 3" flywheel in 6061 already on the bench so I used that.
Back to the shop

Best
Stan


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## mzetati (Jul 6, 2012)

I was around the 30th reading when Jerry and You came with that and spared me with the next 70 or more.
Marcello


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## Captain Jerry (Jul 6, 2012)

It is still to hot in the shop so here is some 3D model entertainment.

http://www.youtube.com/v/pm1CYaaKvE0?version=3&amp;hl=en_US&amp;rel=0

Jerry


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## Sshire (Jul 8, 2012)

WTF revisited
I haven't died. I haven't given up on making this run.
Progress report. Pictures later.

So I'm thinking about the movement of the valve (this valve design must have been done when the original designer was either on drugs or or thinking "Ha! This should give those engine builders fits.).
When I drilled more holes so that I could see the valve movement and the air passage holes, I was looking at the inside of the valve and everything was good. At that point the air was entering on the valve axis (the front of the valve housing.)
Then I said "Huh? If this movement is correct for the inside of the valve with air coming in the front and I move the intake (per Elmer ) to the side, it can't work. No air gets in."
Looking at the drawing of the valve crank, never having seen a set of engine plans until 11 month ago, I assume (correctly or incorrectly) that the front view is looking at the front. (What the hell did he just say?) and that the .125 hole for the crankshaft pin is on the right. So the other day, probably because I don't know any better, I figured that if I drill another .125 hole, the valving should work with the intake on the outside of the valve. It did.
Maybe problem 1 solved.
Then I was seeing some off-center movement of the crankshaft because of a crappy center hole in the rear crankcase cover. Plugged, recentered in the mill, drilled and reamed .251.
Maybe problem 2 solved.
There is some just perceptible binding somewhere. I've disassembled, filed, sanded, oiled, just about every part. I've narrowed down the binding to one 120 degree area of rotation.
I'm going back down to the shop to work on that. I still think it's the center hole in the crankcase cover even though I "line bored" it to keep it in line with the center hole in the front of the crankcase. 
Any suggestions to have both holes line up "dead nuts" (another addition to my vocabulary since joining this forum)

I have pix of this entire fixing process and I'll post them once I get this binding fixed.

Stay tuned

Best
Stan


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## Sshire (Jul 9, 2012)

A Runner (Finally)
More fiddling, filing, cutting gaskets, and then IT RUNS!!!

I'll be posting the final installment of this build log, or "Everyone from Florida to Italy figures out why this won't run"
Thanks again to Cap'n Jerry, Marcello, Arnold and everyone else whose input was amazing.
Pictures of all fascinating operations and troubleshooting "fixes" will be posted over the weekend, but meanwhile...





Best and Thanks again
Stan


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## Captain Jerry (Jul 9, 2012)

Nice going, Stan Thm:

Nothing beats success and the harder the battle, the sweeter the victory!

Jerry


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## Sshire (Jul 9, 2012)

Thanks again Jerry.
I really had no idea where to begin and your posts and the animation got me going.
I still have a few parts to finish: The blingy finned caps on the cylinder heads, a proper crankshaft support, a muffler and, maybe, a propeller because there isn't much to see when this engine is running.
Then a good cleaning and polish and I'll call this one done so I can start on Bill Reichart's Epicyclic Engine.

Couldn't have done this without you.

Best
Stan


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## Don1966 (Jul 9, 2012)

Woo!! We have ignition finally, congratulations Stan job well done. Nicely done Stan.

Don


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## miner49r (Jul 9, 2012)

I've been watching this from the sidelines. Glad to see you got it running. 
Alan


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## arnoldb (Jul 10, 2012)

;D There you go Stan - Well done!
Looking forward to the finished engine Thm:

Kind regards, Arnold


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## mzetati (Jul 10, 2012)

Well done, Stan.
Looking forward the fixing pictures.
If You should add a coupla shots of the finished engine, maybe a video, I would not protest. 

Marcello


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## Sshire (Jul 10, 2012)

Thanks everyone
Oh yeah. I've got pix of the fix. Or fixes.
I'm out of town until tomorrow but will post the rest of the build pix over the weekend.
Hope to finish the head covers this weekend also. I'm going to attempt a form tool for the first time to make them. Furious polishing will follow.

Best
Stan


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## bearcar1 (Jul 10, 2012)

Good onya Stan! I can't wait to see what all you had to do to get things to go. Be safe on your little excursion and we will all be here upon your return to civilization. 


BC1
Jim


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## AlanHaisley (Jul 10, 2012)

Congradulations Stan. I'm waiting with scratch.gif to see all of the fix choices.

Alan


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## Sshire (Jul 15, 2012)

Two Engines in One - The Final Episode

The engine runs. It turns out that none of the changes to the engine (except one) were the culprit. All of the other pieces are to Elmer's dimensions. After the "customization" of the cylinders, the rest of the engine is in the "don't screw with these parts or it probably won't work" category. You'll have to wait for the the end of this post to find out the multiple causes that made this a non-runner and the fixes that made it a runner.

I'm not going to show stuff that you've seen and done hundreds (or thousands) of times, like "Hey, here's me facing a .250 rod on the lathe." 

I'm going to hit things that, as a very beginning builder, I had to figure out a way to accomplish. Most of you can just page down over those things, but they may be helpful to novices like me. I've learned so much from Works in Progress that I really have a need to pass those on.

One piece of tooling that was extremely helpful was learning about the tiny live center that Bogs showed a few months back. I ordered it from ArcEurotrade and have used it a great deal. The connecting rods are a perfect example. Thanks, John.







Elmer wants the fixed connecting rod to be perfectly aligned with the central hole in the hub. (he actually said "Try to make the rod centerline pass through the hub centerline.") Try? What happens if you fail to do so can't be good, so I made a fixture. If the fixture looks suspiciously like a mis-made Grasshopper part.






I drilled three holes (not the big ones) to match the hub center, the pin for the rod and the wrist pin hole. With those in line, a little Loctite and done. Take that Elmer! 






For my next trick, turning the tiny pin in the valve crank offset. (we'll be coming back to that valve crank later) Elmer sez "Do it in one piece" Not a prayer. More Loctite (remind me to check their stock price. It must go up when I build an engine). Then into a 5C collet and turn the spigot down until I can just see the pin. Precision at its best.





















The vent plug. Pretty straightforward but I liked the way it ended up.
Turn down a piece of brass rod, thread and center drill, knurl and some lathe filing.
















I made the flywheel from 6061 aluminum. Probably should have been brass for mass but I had none here. I later decided that additional mass at the outer edge would help. Drill, ream .375, press in brass plugs.











I then put the flywheel on a tapered mandrel and faced it. 






The crankcase cover has an oil passage but Elmer doesn't give an angle for drilling it.
I put the small sine vise in the milling vise (only so I wouldn't have to re-align the vise) and eyeballed the entrance and exit points for the drill by eye.






Amazingly, it came out perfectly!






After thinking about the base for days, I came up with a half-cylinder with the flywheel recessed.

I used the height gauge to scribe a line and then clamped the brass tube to keep it stable while it ran through the bandsaw.






Then clamped the cut piece in the vise and face milled the cut edges to level everything up. Have I told you how much I love that Glacern 45 degree face mill?






Then inverted the piece and milled the recessed for the crankcase, flywheel and rear bearing






And done. Drilling for mounting bolts ensued.






Family portrait.






OK. Enough making parts. Now to the section at least 2 of you have been waiting for.
If you've been following this thread, you know that it wouldn't run. Neither gaskets, nor higher pressure ("More pressure Scotty!" " I've given you all she'll do Captain,"), nor "running it in" on the lathe, nor Clover, nor gloom of night would make it run. Captain Jerry and Marcello kept sending great tips and things to try. One of these from Jerry was to drill more holes in the rotary valve so that ( with the valve housing removed) I could see exactly what was happening as far as piston position, air passage opening and closing, etc. 
After determining that everything was doing what it should, I'm pretty sure that Jerry and I had the same though at the same time. The inside of the valve is the exhaust part and the outside of the valve is the intake control.
That meant that the valve action was reversed. The air was entering the cylinder at bottom dead center and exhausting just after top dead center.
Hmmm, that could prevent it from working.

So, for the 1,265th time I looked at the plans and saw this (hope this isn't a copyright violation, if it is the moderator will remove it and everyone can find the valve crank on the plans)






Maybe it's my inexperience at reading drawings or whatever, but I assumed that I was looking at the rear of the valve crank. Someone out there is saying, "Rear? Where did he learn to read plans? That's obviously the front of the valve crank. Jeez!!"

The only way I could see to reverse the intake and exhaust points was to drill another hole on the opposite side.
Did so and here's what happened. (The air passage for intake is the tiny hole just above the rotary valve)

A bit past Top Dead Center







A little further down






Botton Dead Center







The engine ( for the first time, felt like it wanted to run. It did 2/3 of a rotation and stopped at the same place each time. Something's binding and here it is. I know, it's not pretty but my hand filing skills are improving. Really.







This rod was not moving through its full range within the hub. Just a few strokes with a file and it's swinging the entire arc.

Now it turns better but still feel a tightness when rotating the flywheel by hand. Disassemble. 







Reassemble feeling for binding at each step. No binding. Turns smoothly by hand. Put it back on the stand for yet another test. Now it's tight again????? Gotta be the stand. Arrrrrrgh. The two bottom cylinders are just touching the stand enough to push them out of line when the attaching screws are tightened. I just need to make recesses in the stand to eliminate contact with the cylinders. OK. Get to use the 1" end mill.







Reassemble for the 369th time and it's starting to run but not easily. I suspected air leakage and used the Precision Engine Leakage Tester (Dollar Store Bubble Wand Liquid). If anyone remembers Lawrence Welk, his bubbles had nothing on mine. The bubbles from the head leaks were all over the shop and quite pretty.

I cut paper gaskets for the heads. No leaks.

So, one misplaced hole in a crank, one sticky connecting rod, air leaks and one modification to the stand and I get this:







As frustrating as this was at times, I probably learned more from this engine than any I've built.
The troubleshooting was worth the price of admission. Without all of the help on this forum, this engine would have gone in a round tuit box under the bench. I'm glad I have a runner. My only regret is that, compared to the Grasshopper and the Open Column Twin with Poppet Valves, this one doesn't look very interesting when it's running. I'm going to put a propeller on it.

Best
Stan


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## Troutsqueezer (Jul 16, 2012)

Congratulation Stan, a worthy model which will look fine on any shelf in the house (or workshop). I like the propeller idea too. Oh, and the heads themselves as well, they look like they should have been part of the original design. 

Question: How did you eventually seal the air tube going up the sides of the cylinders? Is it friction fit top and bottom? 

-dennis


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## Sshire (Jul 18, 2012)

Dennis
The air tube is indeed a press fit. Seems to be fine. Im not seeing any air leakage on a bubble test but if I do (sometimes taking these things apart and reassembling causes new problems to pop up) i may try a tiny bit of Permatex.

I hate this new forum software

Best Stan


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## rhitee93 (Jul 18, 2012)

I love the engine Stan.  I am not normally attracted to radials, but you have me thinking about building this one.

Give the software some time.  Changes suck, especially when they are sudden, but this is the same software that is used on another forum that I frequent, and it has it's perks over what was here yesterday.


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## rickoshea (Nov 30, 2015)

I'm not sure if this the right place to put my 2 cents worth in as this is my 1st time so here goes, very impressed with the forum, both questions and answers,
I am building the same radial engine and have had a few queries in my mind about valve timing etc.so am reading, following this with interest.keep up the good work.cheers Kiwi Pathttp://cdn.homemodelenginemachinist.com/images/smilies/smiley.gif


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