# 25 HP Nash



## Sprocket (May 25, 2021)

I first saw this engine at the 2019 NAMES show. Can't remember for certain who had made it, but he also had a really nice Lanz tractor. I asked where I could get the plans and he said, "Be patient, watch Village Press ". If anyone knows the modelers name, help me out, that was some sensory overload, and while I took pictures, I didn't get good notes. Anyway I saw it again here, from Rustkollector, and he said the same thing, but now it was "very soon". and it was.
I got the book "The Engines of Doug Kelley" from Village Press. It has the Snow, Bruce Macbeth and Titan 5o, all were published in "Home Shop Machinist" except the Nash. 
This will be my first multi-cylinder, water cooled, and based on a real engine, model.
A lot of the crankcase parts were made of brass plate, 1/8" or 3/16" thick, and the heads were 3/4 'by 1 5/8" by 2" also brass. I had the steel, would have had to buy brass, it looked pretty expensive.
So I made it out of steel. I'm sure brass is easier to fabricate, but it's steel


  Crank case parts


 Stacked up to look like something... 



  cylinder holes and access doors

and I started on the crankshaft

 I made the webs double thickness and then split them 


Flywheels came from Martin Models. I got a smaller one for the non- gear end because I think I want a generator to go there. The larger one is the one designed for the Nash, it's 7 3/4" in diameter




I haven't begun silver brazing yet. I've been making a lot of parts, and waiting until it was warm enough to braze in the garage with the door open. I did try a little in the shop, but it was too smoky for a 
small room. Well, now it's warm enough, except that I'm having fun making parts. 

Thanks for looking,
Doug


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## werowance (May 28, 2021)

this looks interesting.  replying so i get notified when there is an update.

also have a question,  do you have a picture or image of what the final engine will look like?


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## joerom (May 28, 2021)

Village Press has the book with this and other engines in it...It is "The Engines of Doug Kelley".............


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## joerom (May 28, 2021)

I thought I would add a little more info on the book.. I have this book and it has some great engines in it and does not cost a lot, just in case the members here do not know about it.. I intend to make some of the engines... It has build instructions for the Nash, the Snow Engine, The Titan 50 HP Engine and the Macbeth Engine..


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## Vietti (May 28, 2021)

Where do you get it?  Amazon only lists the Snow book.

thanks, John


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## kuhncw (May 28, 2021)

Joerom, 

Thanks for mentioning Doug's book and posting the cover photo.  It is a great source of plans and information for model engine builders.
I have a copy, and recommend it.

Chuck


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## kuhncw (May 28, 2021)

John, you can order the book from Village Press.

Regards,

Chuck


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## Sprocket (May 28, 2021)

Village press is correct :

The Engines of Doug Kelley
It is a very good book for not a lot of money ($28.00)
Doug

Werowance, The Nash is the model in the upper right corner of the book cover. there also is a video of the finished model here



the model is Rustkolector's, and you can see some of his photos in this thread

The Nash Gas Engine Electric Plant


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## Sprocket (May 28, 2021)

I started to make the water jackets. Kind of an interesting problem to bore the undercut inside the water jacket.
  The inside contour sort of follows the outside contour, but you can't see what you are doing.

there is a mount piece that attaches to the bottom of the water jacket for bolting to the crank case


And cylinder liners that will be pressed (or he says, "shrunk") into the water jackets. They are just a tube when you are finished, but for a press fit in the water jacket, and piston fit inside



This will be two valve blocks when it is split in half. I started by boring the water jacket diameter, then shifted it .015 one direction in the 4
jaw chuck, back through center to .015 the other way. So this hole is .030 oblong, but it gives me room to make a saw cut in the center and
still end up with enough depth to come to the centerline of the water jacket.


So they look like this




Still nothing brazed together, but starting to look like an engine.

Thanks for looking

Doug


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## cobra (May 29, 2021)

Nice work


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## kuhncw (May 29, 2021)

You are off to a great start.

Chuck


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## Sprocket (May 29, 2021)

Part of what I found attractive about this engine is the heads. There are 14 bolt bosses on each head, around a curved and radiused surface.
So 14 hex heads sticking up on top of each head. I think it just looks cool. But there are 28 little bosses to make.
I decided to leave the edges square as long as I could for easier holding and measurement.


   the bottom of the head has a cut out for the coolant channel, and a plate is brazed in for the top of the combustion chamber. Rounded the front, and radiused the curve with the rotary table






Trimmed and radiused the straight edges, and stuck the bosses in just to see how it looked.



  The bosses will be soft soldered after the top of the combustion chamber is brazed.

I think that's all for tonight. Thanks for looking.

Doug


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## Sprocket (May 31, 2021)

I skip around a little when I make parts. Sometimes it's how much time I have or a set up I can use again.
Somehow I had a setup that would bore the about 1 9/16" diameter of the water jackets, so I made the mount pads for the water inlets
and the hand grip. They will be soft soldered on to the water jacket after brazing other parts.





The valve arms are another interesting part. They will be soft soldered to the crank case and support the cam shaft in the nearer hole and the rocker arm pivot at the end. These were also supposed to be brass, but I made them from steel too. The camshaft will run in a bronze bushing, and the rocker arm pivot in brass. They are a left and right with the only real difference being a ledge on the inner side, so I made one double thick, cut a ledge on each side and split it. The shape is "mill whittled" to get the shape and angles.









I continued to make little valve train parts, but that will have to wait ..

Thanks for looking, 
Doug


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## Sprocket (Jun 15, 2021)

Back again.
Next parts were the rocker arms. Not typical rocker arms, the cam rides on a wheel in the center of the arm, pivot at one end and lifter at the
other. They are tapered top and bottom, and narrow in the mid section with  "dog bone" ends . They were spec'd to be 7075, but I didn't have any, so I  practiced on some 6061 while I waited for the good stuff. 



The 7075 came eventually. I started 6 when I needed 4. That was practice too.   
(Why is it that when the supplier has a warehouse in CT and I'm in VT, they only have the right stuff in Seattle?)

With the rotary table centered under the spindle, I clamped the part also centered on the spindle on a sacrificial plate.


 (I made a video of this, but I can't load it here. I'll get it on you tube later)
So, rounded both ends, thinned the centers


 and slotted for the wheel and lifter.

The lifters are soldered from two pieces of steel. Plans say it is critical that they be perpendicular to the axis. so I mad a little fixture to hold them while I soldered.





And all the parts together





I've started brazing the crank case together. It's a little ugly right now. I'll post some pictures after I clean it up.

Thanks for looking, and I'll get that video on you-tube. Don't know why it wouldn't upload here, only 30 seconds.

Doug


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## kuhncw (Jun 15, 2021)

Nice work, Doug.  Thanks for the pictures of your setups.

Chuck


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## gbritnell (Jun 16, 2021)

Great looking work. The head is really unique looking.


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## Sprocket (Jun 16, 2021)

Got the videos of end rounding loaded     End rounding on the rotary table - YouTube 
finishing the ends - YouTube 

Chuck and George, thanks for your comments.

 Chuck - Set ups are funny, everyone sees a process differently, so there are many ways. I guess all that really matters is that you get where you want to go. I always feel like I'm making it up as I go along, but that's kind of fun.

A few more parts:
Valve adjusters are 1/4" hex, one end drilled for the valve lifter, the other threaded 5-40 for the valve.
I started with a round 
 and milled enough for two hexes. The Hex collet holder made this pretty easy, back and forth lathe to mill. I turned the ends to size, drilled and tapped both ends, then split it in two and drilled the lifter hole



The last of these parts so far are the spring retainers. They mount on the valve stems , and compress the springs between them and the valve
housing.





The holes in these are tapped 2-56. I couldn't get my allen key to fit the recess in the set screw. finally figured a .050" key doesn't fit
in a 2-56 setscrew. Gotta order a smaller one. .035" I think. Won't really need it for a bit anyway.

Thanks for looking,

Doug


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## Sprocket (Jun 26, 2021)

I finally got to brazing the crankcase. There are eight pieces in the bottom of the crankcase, and eight in the top. I needed to make a little fixture to hold the valve bodies aligned with the base of the water jacket, but it also worked to hold crankcase pieces together. The four sides and center piece are all bolted together, and the bolt heads ground off after brazing.





I had milled a shallow groove in the base plate to make it easier to align the box with the base, then clamped it in the fixture to attach the bolt rails, then flipped it over and brazed it to the base.





I was brazing from the inside and heating until it flowed through. the outside is pretty easy to clean up, and the inside doesn't really matter.
The top of the crankcase is pretty similar. I tried using White Out on parts of this one hoping for easier clean up. 








The White Out helps, I guess. Not entirely sure I'm using it correctly, but it turns to chalk dust and brushes off.
No more room for pictures, I'll post more in  a little while.
Thanks for looking,

Doug


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## Sprocket (Jun 26, 2021)

The next step was to mill the mating surfaces. The bolt rails stick up a bit from the ends and center, and are milled down so all the parts are flush.








Your browser is not able to display this video.




















I also milled some from the outside to blend the brazes in and take off the overflow. The end mill has a little chamfer on the corner, not really a ball end, but it made fillets in the corners. (A corner chamfer end mill. I looked it up)




Still some cleaning up to do, then drill and tap the bolt rails so I can hook the top and bottom together and bore the holes for the bearings 
and bearing caps.

 I am amazed at the DRO. Finding more ways it makes stuff easier. these holes were drilled with the bolt circle function, and it worked slick. But I guess that's what it's supposed to do.
Anyway,
Thanks for looking,
Doug


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## kuhncw (Jun 26, 2021)

Nice work on the brazing, Doug.  What kind of torch were you using?  Oxy/acetylene?

Chuck


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## Weldsol (Jun 27, 2021)

Superb work you have done, keep it up

Paul


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## Sprocket (Jun 27, 2021)

Chuck and Paul, thanks for your comments,
I have been using oxy-acetylene for brazing. In the past, I have tried propane and have had little success except for very small parts. It may be that 
propane will work, but I'm not sure I have the patience to wait that long. I also like being able to tune the flame which you can't do with propane.
When I first started brazing, I read that the flame should be a "long, soft carburizing flame" and that is what I've been using. That was a while ago, and I don't remember where it came from, but it works. I use the largest tip I have (#5) . I've been using Safety-Silv 56 and it works nicely. I have some 45, and the melting temp is just enough higher to make it difficult. some of these parts have a fair amount of mass, and take a while to heat up. I haven't done the valve body to the water jacket yet, but the valve body is 3/4"thick and 1 1/2" wide or so and will require some heat. Instructions say to use ribbon braze .005" x 1/2". haven't got that, so I guess I'll use the 1/16" wire.
Later.
Doug


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## burn0170 (Jun 28, 2021)

Doug - When I brazed the water jackets for the Snow, I had issues with small pin holes, I found that Green (wicking) Loctite worked well.  I just smothered that on after it cooled and cleaned up.  Filled the pin holes and sealed up well.  Hopefully you're a better brazer than I am, but if you have any small holes, this trick helps.
Jim


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## Sprocket (Jun 28, 2021)

Jim,
Thanks for the heads up. I hope it won't be necessary as these cylinders are pressed, (he says shrunk) into the water jackets. I may see if I can wick some Loctite in from the ends as a backup. Haven't ever used the green, but this seems like a good place to try it.
Thanks,
Doug


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## Sprocket (Jul 9, 2021)

Another little detour.
 I decided that rather than make the coolant manifolds from soldered brass pieces, I'd make them from miniature plumbing parts. 
I got "T's" 90's and 45's from PM Research in 1/4", and tubing to match. the castings come either un-machined on trees, or for a lot more money, machined. I bought the casting trees. 
They are pretty small to hold and machine, so I made a little vise to hold them.







  you have to do the first side while the part is still on the tree so it can screw on to the rod to
slide into the vise. It works for 90's and "T"s, haven't tried 45's yet, but I think it will just clamp at 45 degrees in the mill vise.







Inlet on the water jackets, outlet on the heads. The attachment plates get soft soldered to the manifolds, then bolted to the mount plates,
with a thin gasket. There will be more piping to do, but it will be connections, not pieces like this.
The parts are tapped and threaded 1/4-40 Model taper pipe thread, taps and dies also from PMR.
More a little later, 
Thanks for looking,
Doug


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## Sprocket (Jul 13, 2021)

Back again.
Before I could bore the crank shaft bearing holes, I had to join top and bottom pieces and even off the surfaces.





just a bunch of drilling and tapping to get to this.



There is a symbol for surface finishing on the ends that looks like a square root symbol with a second line next to the left side.
So I surfaced the ends. (Couldn't find a reference for the exact meaning of that symbol if anyone knows?).


Which should have made me ready to bore the ends. So now comes the "Oh, crap" moment.
Somehow in setting up to braze, I flipped the top piece, so the holes were exactly 1.00" from the wrong edge. Maybe a good reason not to have bored them earlier, but it seemed like a good idea at the time.
Moving holes is not an easy thing to do, but it seemed easier than trying to un-braze the top.
So I made half circles, and hole plugs, brazed them in place, and re-bored the holes in the top








And now I'm back where I was a couple of days ago, but at least the holes are in the right spot.
Out of room for now,
Thanks for looking,
Doug


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## kuhncw (Jul 13, 2021)

Doug,

That was a nice bit of salvage machine work.

Chuck


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## Sprocket (Jul 13, 2021)

So, I got  back to the point of boring the crankshaft bearing holes. I'd been thinking about it way too much, got to go ahead and start.
The holes are about 1- 3/16" in diameter and go through the ends and the middle plate. I suppose if I had a very long boring bar, I could do it all from one end, but I don't. It also seems you would magnify any error by going all the way through. So my plan was to bore one end, and through the center plate, then flip it over and do the same from the other end. You also have to place the cam arms on the top of the crankcase and drill for the cam shaft. It's marked as a critical distance for gear mesh from the crankshaft center, so it seemed a good time to do add those also.
I got the crankcase mounted on the not quite big enough angle plate, vertical in two planes, and square to the table travel.




It took a shim between the angle plate and the top of the base to get it vertical.
Then I found the center of the crankshaft, and measured to where the camshaft should be, and soft soldered the first arm in place.



Added the brass plug for the camshaft bearing and drilled the cam shaft hole, then went back to the crankshaft center, drilled the mount holes for the bearing retainer, then drilled and bored the crankshaft center hole.





So the bearing retainer fit in.



Repeat for the opposite end, and it looks like a crank case. The tips on the arms are soft soldered, they are the pivot for the rocker arms.




I think I must have worried about this just enough, because it came out ok.
Thanks for looking,

Doug


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## Sprocket (Jul 27, 2021)

Crankshaft.
This part was difficult. It would seem that the way it's made would keep it straight because everything is symmetrical. It didn't work out that way.
The first one was just as the plans. It was hard to keep parts positioned for brazing, and ended up with too much bend when it was finished. I tried to straighten it, but couldn't make it better.

So i did things differently the second time.





Made the crank throws in pairs, as I did the first time, then split them. Turned the shoulders on the outside throws, then rounded the outer ends. I centered the rotary table, clamped a piece of aluminum to it, drilled a hole at the center, and another one crank throw (.656") away on the X axis, then tapped the two holes. Made bushings to fit the two holes, and clamped the parts down. I Moved X axis to clear, and then rounded down to the end of the part for a radius of 9/16". 




The other end, or center is 5/8" so I blended the sides


I also made the crankshaft 1/2" instead of 7/16", so I could turn it down to take out any bend. To keep things spaced, I made little half 
circle spacers for the throws and center section. After cleaning and assembling all the pieces with flux, I wired all the parts together.






Brazed the center section, then cut the wires, knocked the spacers off and brazed the ends, let it cool down mostly, then scrubbed it.
Out of room for now, more in a little while.
Thanks for looking,
Doug


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## gbritnell (Jul 27, 2021)

It's sure coming along great! Even though silver solder is pricey I think I would have gone that way just for ease of construction.


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## Sprocket (Jul 27, 2021)

To continue,
The crankshaft cleaned up nicely with soapy water and a wire brush. 




Had to make sure I cut out the right parts, then rounded the  inner ends of the throws, and milled out the center of the throw.



To maintain the distance in the throws, I'd made some little "T" nut pairs to clamp in the spaces.
then turned the ends to 7/16" 








I'll need to make the center bearing 1/2" instead of 7/16", but I'd planned a little change in that anyway. I think this one is going to work.
That's all for now. I'm caught up with what's done.
Thanks for looking!

Doug


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## Sprocket (Jul 27, 2021)

George,
I really like silver brazing. My first real silver brazing project was a mountain bike frame that I rode for several years, Fillet brazed, no lugs.
It has gotten more expensive since then, but I still like working with it.
Doug


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## Vietti (Jul 27, 2021)

Looks good!  I've made a few built up cranks, so far pretty straight.  I find by cutting a deep chamfer aka counter sink, in the webs prior to soldering I get a stronger joint, I think, looks good any way.  Don't put them on the insides of the rod journals cause you cannot cut out the excess solder.  The ends of the rod throws are easily rounded in the lathe when the job is done before the crank sections are cut out.  Also had pretty good luck straightening the crank in the lathe with a soft hammer.  Never thought of making the crank oversize and turning straight, good one!

John


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## Sprocket (Jul 27, 2021)

John,
On the first version I made of this crankshaft, I did round the ends on the lathe. I thought it might look better more rounded, and as long as I was doing it again...

 first time 
 second time
It just seemed it needed to be a smaller radius than I got turning it on the lathe. Purely visual.
Thanks for looking

Doug


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## Sprocket (Aug 4, 2021)

There is a center bearing that goes in the hole bored in the center plate of the engine. The plans show a split bearing 3/16" thick
and 1.188 in diameter, screwed together with 2-56 SHCS. I decided that as long as I have the space to do it, I'd make the bearing surface longer.
My plan was to make the bearing about 1/2" long and make a saddle to sit over the center plate. Eventually, there will be a set screw from the
bottom (through the bottom center plate) to lock the bearing in place. Being wider, I could use 3-48 x 3/8" SHCS to join the two parts.




Counterbored, drilled and tapped, cut the center, and cut the top loose, then milled both halves to the same thickness and bolted them together.

  Centered the part in the 4-jaw chuck, and cut the profile and drilled/reamed the center hole.
The other end was done partly on a mandrel, partly holding that 1/16" x 3/4" boss in a collet.


  The side ridges locate the bearing on the center plate.



 and the crankshaft in the bearing.

Still needs some cleaning up and polishing, but so does the crankshaft.
Thanks for looking.
Doug


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## Sprocket (Aug 10, 2021)

Connecting rods.
These are a little different from what I've made in the past, mostly because they are built up and brazed, but also because the ends are cast iron.
As messy as it is, I like the way cast iron cuts. The big ends are pretty standard. I cut a piece off of a scrap of cast iron and milled it to thickness, and width with a little extra length, drilled and tapped the bolt holes to attach the caps, then cut off the cap ends and milled them to length.
Same with the other piece. I had marked the pairs for orientation, but by the time they were correct length, some of the marks were gone.
Bit of a puzzle, but I got them sorted out. The top ends have a 45 degree cut off on the corners, so after drilling and reaming the crank pin holes,
I cut the corners off.




The big ends are 3/4" square. The small ends are .44" diameter on the ends, and taper to .31" at their bottom end, and are .595" overall. 
So this is what I did.  Started with another cast iron rectangle of correct thickness and excess width, drilled and reamed the two wrist pin holes, 1.375 " apart for plenty of extra, then rounded the ends on the rotary table.




I used the part like a tiny sine bar to mill the taper on the part, then cut it in half, drilled the holes in the end.




It took a little fixture to hold the parts vertically so I could drill the end holes



"Oops, we ran into some problems" no more room.
Continued below

 Thanks for looking
Doug


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## Sprocket (Aug 10, 2021)

To continue,
I used a piece of brass rod to align the two parts, and the wrist pin holes to suspend them in the vise,




Milled half way through and to length, then flipped it over to finish





Next time I'm brazing, I'll make a little holder for length and alignment and braze these together. There was probably an easier way, but this is what I came up with. Probably could have done it all on the rotary table (little ends) but the angle was 9.7 degrees for .375 inches, and I wasn't seeing a way to make all four of them the same that way.

Thanks for looking,

Doug


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## Sprocket (Aug 31, 2021)

Well, I spent  a lot of time in the last two weeks working _ on _the shop, not _in _the shop. but I have a lot more room now and made room for
a bead blast cabinet that had been in an un useable position, and a big air compressor to run it. Still need to find homes for a few things, but it's much better.
So, this weekend I worked in the shop. I had made the cam mounts and started trying to set up to cut the cams





The rotary table was centered, the blank clamped in the V block and that was centered then the V block was clamped to the rotary table
so I could release the blank to remove it to cut off the first cams, then raise it for the second set. That part worked fine. The problem is getting the cam lobe the width specified in the plans. I thought I had worked out how many degrees I had to rotate it before moving the X axis to make a flat, but that made a point, not the lobe I expected. I ended up just sneaking up on the dimension by rotating a few degrees at a time.







The cams were parted off a little long, drilled and tapped 2 places each, 2-56, then clamped on a mandrel to face to thickness.






In the picture above, the intake cams are on the left with a narrower lobe, one mounted on a cam mount, and as they will be on the camshaft.

Thanks for looking,

Doug


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## Sprocket (Sep 21, 2021)

I took another bit of a detour from the larger parts I'd been working on. I was working on the valve blocks, thinking how to pipe the carburetor, but didn't have a carburetor. The S/S carburetors are no longer available, I understand. I had gotten a Traxxas carb, but it really doesn't look like it fits with this model. So I made one. There was a discussion on carburetors a while back, and out of it I got a couple of different plans. The one I used was George Britnell's from a 4 cyl OHV engine.  
https://www.homemodelenginemachinist.com/attachments/4-cyl-ohv-sht-j-pdf.38086/
It seemed like the right kind of carb for this engine. I thought I would use MIL-TFP-41 (M) * and really tried to make it like it was drawn, but there were a couple of things I had to change.





The body is turned in the 4-jaw, on three of its four sides, the third picture is a gauge plug I made to see when the bottom of the cone reached .260". Couldn't think of a good way to measure that, my snap gauges don't go that small. I just snuck up on it until to gauge would just go through.






This is one place I deviated from the plans. The intake cone is tapered on the outside, also and .150" longer than original.






Throttle barrel, the fuel jet, and because I expect to power this with propane, a compression fitting for fuel.


  The bug catcher screen wasn't on the original, but I thought it needed one. I had expected the 2-56 idle stop screw and 3-48 air bleed screw to be difficult to make, but they really weren't. And no, I didn't single point them. I did mostly on the 10-40 threads for the fuel jet, then finished them with a die.
I'm out of room. More in a little bit.
Thanks for looking,

Doug

*MIL-TFP-41 (M)  = make it like the freaking plans for once (mostly)


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## Sprocket (Sep 21, 2021)

There is a groove in the throttle barrel for the idle stop screw to ride in. It locates the barrel in the body, and should provide a stop for idle position. Eventually I figured out how to do this.





The through hole was set vertical, an .085 end mill lowered to about center, moved in in small  increments to .088" deep then .003 wider to finish, and rotated to 16 degrees short of horizontal.


 This ends up with a slot that ends in a flat bottom.

Because this is an engine that will run at a constant speed, with no need to VROOM,, VROOM, I thought it needed a throttle quadrant for
speed control. And a few more deviations from the plans.












I drilled and tapped the mounting holes in the sacrificial plate clamped to the rotary table, cut the arcs, the first to clear the throttle barrel, next to thin the piece and make room for bolt heads, then scored the detents with a spotting drill, and cut it loose with the third arc, and the mounting bolts held it in place.
It seemed too thick at the edge, so I flipped it over, angled the mill head, an thinned the back side. It was time to tram it again anyway.  The last picture has all  the parts but the needle valve. I think the handle that is on it now is a prototype, but it works for now.
Out of room again.

Thanks for looking!

Doug


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## kuhncw (Sep 22, 2021)

Very nice, Doug.  I especially like the throttle ratchet plate.

Chuck


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## Sprocket (Sep 22, 2021)

Thanks Chuck. 
It seemed that a constant speed engine would need to have something like that, and it was a kind of fun challenge.
Doug


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## Sprocket (Oct 3, 2021)

Well, since I wasn't using the carburetor that was used originally, I couldn't really use the manifold either, so I made one from miniature pipe fittings and brass.






Next was valves and valve cages which are pretty straightforward, but took a lot of time and fussing. The valves are two pieces, threaded 5-40
on one end and a stainless head silver brazed to the other end. I made a little fixture to hold the head about the right distance from the end for brazing




I made the valve cages outsides, then set up to do the insides, valve seats and valve tapers in the same setup. (I had made a couple of extra valves to practice on).





The last picture is the whole valve train, the lifter that attaches to the rocker arm, the valve adjuster, spring keeper, cage and valve.
The valve blocks need to be silver brazed to the water jackets before the cages are pressed in. I was going to try to use 1/16" silver braze wire on that joint, but the plans suggest .005" ribbon braze, which I found at Brownell's. It's an area 3/4" wide and more than 2" long, so I'm sure the ribbon braze will make it easier. I think that will be the next step, and also the last large braze.
Thanks for looking
Doug


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## Sprocket (Oct 12, 2021)

Back to brazing. I had some parts ready, and decided it was time. Brazing the valve blocks to the water jackets had concerned me some.
Its a big area to heat under a fairly large chunk of steel. Took a lot of heat, but wasn't as bad as I thought it would be. The .005"x.5" ribbon braze worked great. If you have need of a large area braze, I'd definitely recommend it.
I had made a fixture to hold theses parts together, and another to locate the connecting rod parts.




The water jacket/valve block fixture holds the square base plate, and a clamp on top of the valve block. I squared the valve block to the base with flux and ribbon braze in between and heated .




The joint filled just about right. The next step was to finish the top surface on an expanding mandrel in the lathe. 










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Now they are ready to drill head mounting holes and valve cage holes.
Time for lunch!
Thanks for looking
Doug


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## Sprocket (Oct 13, 2021)

The cylinder with the valve block attached is an awkward piece to hold. There are 14 head mount holes, one coolant passage and two valve cage holes to drill in each, and I didn't want it moving. The base piece was clamped in the mill vise, then the valve block placed against an angle plate and clamped that way. May have been overkill, but nothing moved.





I drilled and reamed the heads for the spark plug bushings, then pressed the bushings in. You can see the coolant space in the head if you look in the bushing hole.





I found that a piece of solder draped around the bosses was just about the right amount to fill the space. I had used less on the first head I did, then had to add, and that was hard to control.






A little more sanding, and the heads will be done. When I blow air into the water jacket it comes out the head, which is as it's supposed to be. I need to press the valve cages into the valve blocks and the cylinder parts will be done. I lapped and honed the cylinder liners, so I think the next step will be pistons and rings.
Thanks for looking!
Doug


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## Sprocket (Oct 26, 2021)

Pistons and rings.
Pistons seem fairly straightforward, .002 smaller than the bore, ring grooves, and a pocket for the wrist pin. But that pocket wasn't so easy.
It's drawn as a rectangle, about .440" deep at the bottom of a .5" deep bore. The corners of the rectangle are rounded looks to be .063 radius.
But an 1/8" end mill doesn't really have the reach to do that, and you can't see down in the bore while you are milling. I figured how far I could move from center, X and Y, for the outside of the 1/8" end mill to cut the correct dimension. It felt awkward, and not being able to see what was going on was hard, but it worked out. I had to extend the end mill in the end mill holder to reach bottom. I don't have anything longer.





I'm pretty sure it was Rustkollector who said he put an oil ring on these pistons, and that seemed like a good idea, so I re-spaced the grooves,
to accommodate a third, wider ring. The compression rings are nominally .045" so I ground the back end of a parting tool to .045" and made
compression ring grooves. The oil rings are .063 wide with a tapered groove .010" deep and .035" wide at the bottom.  A 1/16" parting tool worked for those grooves.




The needle in the second picture is about .035". Form tool for oil ring grooves.






I had a mandrel from a previous build that was bigger than this one, so I could modify it to work here. The rings were brought to just over
width on the mandrel, and holes drilled in the oil rings. I used a #70 drill (.028"), and made 6 equally spaced holes. (Trimble says he broke off a #75 drill so only 1/8" stuck out of the chuck and made 8 holes) I didn't have to break off the drill, it went far enough in to the chuck. I used a sensitive  feed drill chuck so I could feed it with finger pressure. Got through 30 holes without breaking the drill.

  (I only need two oil rings and 4 compression rings, but I made some spares)
Out of space for now. 
Thanks for looking.

Doug


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## Sprocket (Oct 26, 2021)

Just a little follow up.
The head bolt bosses needed to have their solder fillets blended into the head better. A little abrasive cord worked really well for that.
Somehow I had never had need of abrasive cord, but I really liked the way it worked for this, and was impressed how well the abrasive stayed 
on the cord . This was .080" 150 grit .Made by Mitchell abrasives, got it on Amazon.    






The head bolts are 4-40 x 1". The one on the top came from American Model Engineering/Godschall's Custom Machining.
The one on the bottom came from Mcmaster-Carr. The taller, and 1/64" smaller hex heads seem to fit the bosses better.
At least, I like the look better.
Next, I plan to finish the ring spreading fixture , split the rings and get them heat treated. 
Thanks for looking.
Doug


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## kuhncw (Oct 26, 2021)

Thanks for the abrasive cord tip.

Chuck


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## Sprocket (Nov 13, 2021)

Rings were finished by splitting with the tool Trimble described. It worked much better on the compression rings than it did on oil rings.





 The fixture is also as per the article. I wrapped a piece of brown paper around the whole fixture, then seeing as how I was only planning to heat them to 975 degrees, I sealed it all in aluminum foil. I don't know if it really helped, but the paper charred enough that I think all the oxygen was used up, and the paper wasn't all ash. I sent them over to Rick's Overnight Heat Treating, and he baked them at 975 for two hours. (Thanks, Mayhugh 1).
When I got them back, the aluminum foil seemed to be intact, and Rick had kept track of the heat and times. (Thanks, Rick!)






The ring gaps stayed as they were when I took the pin out, and the fixture should be good to use again.
I don't know if the aluminum foil really helped, but it seemed like it should limit oxygen while it was heating.
I am unlikely to buy stainless foil, but at this heat, aluminum seems to work.
Any thoughts on the subject are welcome.
I've been working on flywheels and flywheel clamps, but that will be for the next post.
Thanks for looking,

Doug


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## Sprocket (Nov 29, 2021)

The flywheel castings are an interesting part to hold. I am using two different sized flywheels to accommodate a generator, some day.
The larger flywheel is 7 3/4" diameter with 6 spokes. I held it in the 4-jaw chuck and centered it then drilled and reamed the center hole

The flywheel clamps are to be press fit into the center hole, but somehow the .0005 over was not tight in the bore. I would have thought a reamed hole would be accurate enough, but it wasn't. I was actually kind of happy to make the clamps over, as the first pair, made from a rectangle of 1018 had some wicked hard places in it. They showed up as rings in the turned part and tough to slice areas in the saw cut.



After I broke a slitting saw, I decided to go with an easier material. I have 12L14 rounds big enough to yield that end rectangle, and that's what I used. I found it much easier to make a square from a round than a round from a square. No interrupted cuts.








I pressed the clamps in with red loc-tite for a lubricant. The new clamps were .6265" instead of .6255" for the oversized hole, they were fairly hard to press in so I think they should stay. I turned the flywheel on a mandrel between centers (or center and a collet) so it runs true to the shaft. The slowest speed on my lathe is 50 RPM which is faster than the chart says this should turn, but it cut reasonably well. I used a boring bar upside down with the spindle running backwards to cut the outside of the wheel. The second wheel is much the same, but easier because it is smaller.(5 1/2")



It will take about 2 1/2" of lift to clear the larger flywheel, or allow it to overhang an edge. Haven't got that figured out yet.
I've been making parts and mandrels to hold gear blanks, and that will be the next pieces.

Ski season is starting! I get to go work at the mountain a couple of days a week. Might slow my already slow progress here, but it's something I've done since I was in college and i don't know how to stop.
Any way, 
Thanks for looking!

Doug


----------



## a41capt (Nov 30, 2021)

I just found your build Doug, and this is some beautiful work.  Thanks for sharing!

John W


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## Sprocket (Nov 30, 2021)

Thanks John. It's been teaching me a lot.
Doug


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## minh-thanh (Dec 2, 2021)

*Sprocket !*
You weld and finish the surface is really nice
Soldering is part of a homemade engine, but I'm pretty bad at soldering silver


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## Sprocket (Dec 2, 2021)

Minh Than;
Thanks. That's a neat little diesel you made,
 Silver brazing is a really useful skill. It does take "Learn, Practice and Patience" as you know, I would add to that "plenty of heat". I don't know what you have used in the past, but I've tried some that was really hard to make work. I also think you have to distinguish between silver solder, and silver braze.
Silver braze is a higher temperature but should be much stronger. There are also different alloys of silver braze. My favorite has been Safety Silv 56. It is the lowest melting temperature of their brazes and flows very nicely. It is 56% silver. (1205 F.) Even the 45% silver is a noticeably higher melting point. (1370 F.)           I know some people will silver braze with propane, but I don't have the patience for that. Oxy-acetylene, or maybe acetylene -air, but propane has never worked for me except very light or small pieces.
It's definitely worth figuring out how to do as it opens up a lot of fabrication possibilities.
Thanks for looking!
Doug
(I have no idea what is available outside the US, but I'd assume something similar is.)
Safety-Silv® 56 | The Harris Products Group


----------



## Vietti (Dec 2, 2021)

Doug,

What silver solder do you recommend?  How much weaker is it and what is the melting temp?  I've tended to buy the highest silber content I can find and lowest melting temp.

Thanks, John


----------



## Sprocket (Dec 2, 2021)

John,
I really don't know much about silver "solder" I only use the braze. I really like the Safety-Silv 56 and the white flux that goes with it. That is their highest silver content, lowest melting point. Their Tech sheet says "solidus 1145 F. liquidus 1205 F." I don't see a tensile strength.  
Hope that helps.
Doug


----------



## Sprocket (Dec 4, 2021)

I had made a couple of gears for a Phil Duclos "Whatzit" engine. They were made with a single point fly cutter described in that article and while they worked, they were difficult cutting (thump! thump! thump!) and a little crude.
So, I decided to try to make these better. I had seen hob type cutters and directions for making them. Helicron has a good explanation for making this cutter and that's what I used.  (Making a gear cutting hob) I first tried this with mild steel and case hardened it to see if it was a reasonable thing to make. That one worked on brass OK, never tried it on steel. This one I made from O-1 and hardened and tempered it.
You start by making rings, spaced for your DP. mine was 32 DP, rings .098" apart, .106" deep




I used a hex collet block and made six teeth. I relieved the backs of the teeth with a stone and cleaned up the fronts, then hardened the hob part. I had the piece turning in the drill press as slow as it would go, then lowered it into the oil (ATF) while it was still turning. It seemed to heat evenly and stayed straight in cooling.




With management approval, I tempered the hob for one hour at 428F. in the kitchen oven. The color doesn't show really well, but it came out a nice dark straw color.



Now I have to try it!
Thanks for looking,
Doug


----------



## Sprocket (Dec 4, 2021)

I had a couple of gear blanks and mandrels ready. The smaller gear is 40 teeth and has a 7/16" hole with a little woodruff key. (#202 - it's tiny)
The cutter only makes a full depth cut on the center ring, and as you rotate the blank, it cuts facets to shape the teeth. There are sleeves on the mandrel to stiffen and deaden it, so it looks bigger than 7/16"- it's really 3/4"









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The smaller gear came out pretty well, and I probably will use it. Have to see if center distances work.
The larger gear has 80 teeth, and only a 3/16" hole. That mandrel also has the stiffeners, but I'm not sure they are enough. I cut an 80-tooth gear, but I think I can make a better one. I am going to try to anyway.



I had to touch up the cutter a couple of times, but it was 120 cuts to get around both gears. At least I think I have the process down, now I just have to touch up my execution.
Again, Thanks for looking!
Doug


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## Sprocket (Dec 14, 2021)

Sometimes you just have to do it a couple of times to make it work right. My first attempt at cutting these gears was OK, for a first try.
They weren't useable, but I had some idea of what to do differently. The smaller gear just needed to have the teeth cut deeper, but I decided to start over. I made the gear blanks from cast iron this time. Much easier cutting than the mild steel I used the first time. I also made a little hub in the center, so the gear was as wide as the Woodruff key. Cutting was much the same, but slower speed for the cast iron, it seemed to not dull the cutter as fast. I also found there was a little play in the dividing head which could be adjusted out.


The larger gear was also cast iron, but I silver brazed the hub into the center, and left it long to act as a mandrel as I cut the teeth. I wanted as much stiffness as I could get, and this also made sure the gear and hub were concentric. I couldn't drill the center hole until later.





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This also made it so I couldn't try the gears on the engine until I parted off the hub and drilled it for the cam shaft. After parting off, I tried the two gears together on the cam and crank, and while they went together it was a little tight. I tried running them on a mockup with some Clover compound, and that made it run more smoothly, but still too close. I had already taken the dividing head off the mill table and put the vise back on, but decided I really had to cut the teeth deeper. It was much easier to set the dividing head up the second time, and not nearly as much of a problem to re-align the teeth as I had thought it would be, so I cut the teeth on the smaller gear about .005" deeper. This made the fit quite a lot better, so I did the same with the larger gear. I had a mandrel from my first attempt that fit the 3/16" center hole and the cuts were very light. The fit was much better after trimming both gears.




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Somewhere in there I had drilled the six holes in the larger gear, which makes it look more finished. I'm happy with this pair and I think they will work well. It's becoming less of a mystery, at least for spur gears. The others will have to wait.
Thanks for looking!
Doug


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## kuhncw (Dec 14, 2021)

Nice looking gears, Doug.  Good work.

Chuck


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## minh-thanh (Dec 15, 2021)

Doug !
Nice gears !
The gear you made it is correct in diameter , angle .... ? 
Thanks !


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## Sprocket (Dec 15, 2021)

Chuck and Minh Than, Thanks! I like them.
Minh Than; I think they are. The cutter to make the hob was a 40-degree point which should make a 20-degree pressure angle. The outside diameter is set by the number of teeth and the diametral pitch (32 for these). I don't know how they would mesh with commercial gears, but they mesh with each other.


 The tool is just visible on the left, about to cut the fifth ring. It looks like a threading tool, but 40-degrees.
That was probably the hardest part to make and get square to the work. Where you'd use a fish mouth to square a threading tool, I made a 40- degree piece to square this tool.
Hope that helps,
Doug


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## minh-thanh (Dec 15, 2021)

Doug ! 
Thanks.


Sprocket said:


> I don't know how they would mesh with commercial gears, but they mesh with each other.



Anyway  your gear is look better than mine .


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## a41capt (Dec 15, 2021)

Doug,  I’m looking at the “Odds and Ends” by Phil Duclos as a build after “Pioneer”.  As I don’t have the required spur gear cutting tools, do you recommend going the extra mile and building the modified gear hob you built, or putting up with the thump-thump-thump of the Duclos profiled single tooth cutter?

Nice looking gears BTW!
John


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## Sprocket (Dec 15, 2021)

John,
Having done it both ways, I'd make the hob. I think the tooth profile is better when it is hobbed, and gentler on the blank. You can cut full depth in one pass, don't remember for sure, but I don't think I did with the single point cutter.
Doug


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## a41capt (Dec 15, 2021)

Sprocket said:


> John,
> Having done it both ways, I'd make the hob. I think the tooth profile is better when it is hobbed, and gentler on the blank. You can cut full depth in one pass, don't remember for sure, but I don't think I did with the single point cutter.
> Doug


Thanks Doug, I’ll have to give that method a try.
John


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## Sprocket (Dec 31, 2021)

In the past, when I've made a muffler, it's just been an expansion chamber, maybe another bit of pipe, and a flapper. This one is different.
This one is water cooled. I measured the distance for the exhaust flanges, and it is slightly different than the plans, so I made the muffler to fit.




The plans show a curved end on both the exhaust and coolant flanges. I left the ends square and made a hole to braze them into. 


 And the same for the coolant flanges.
There are holes drilled through the length of the muffler, one for exhaust, the other for coolant. The coolant channel is drilled on an angle from the center of the flange to miss the exhaust channel and hit the coolant. I started the hole with a ball end mill, then rotated the body and drilled in the side of the ball depression.







I made a mock-up of the cylinder to hold the flanges in the correct orientation. It held things well but was a pain to get apart.




end caps are bolted on with 1-72 hex head fasteners.

More in a little while. 
Thanks for looking,
Doug


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## Sprocket (Dec 31, 2021)

After a bit of silver brazing and a lot of cleaning up, I have a muffler. There are plugs in both ends of the coolant through hole, but not in the exhaust. I waited until the parts were together to drill and tap the 0-80 holes in the coolant flange rather than try to hold an alignment as I brazed.



The plans show a curve at the end of the exhaust pipe. It's thin wall 5/16" brass, and even when annealed, it didn't bend well.
So, I thought I would make a bend fitting. I sliced the tubing most of the way through a number of times, then flexed it and soft soldered it.





It looks better than my attempt at bending, but still a little rough. I may try slitting the exhaust pipe itself and not have a separate fitting or try one of the other methods I've seen in recent posts. I've used sand in larger tubes, but ice sounded like a cool idea. 

In looking back at pictures, I find the first parts I made were on 12/30/2020, so I have been at this a year. Pretty soon.
I'm getting down to the little things that connect it all together.
Anyway,
Thanks for looking and Happy New Year!
Doug


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## a41capt (Jan 4, 2022)

I like that transition piece Doug. Great workaround toward getting a smooth bend. I may steal that idea for future tubing bends!

John W


----------



## Sprocket (Jan 4, 2022)

John,
You're welcome to it. It felt a little flimsy sticking up like that, but I think if I had lowered it further in the V block it would be better.
I have used a similar method for bending angle iron, sometimes cutting out little triangles. I couldn't see that working here.
Doug


----------



## a41capt (Jan 4, 2022)

Sprocket said:


> John,
> You're welcome to it. It felt a little flimsy sticking up like that, but I think if I had lowered it further in the V block it would be better.
> I have used a similar method for bending angle iron, sometimes cutting out little triangles. I couldn't see that working here.
> Doug


One of my jobs during my time in the US Navy was sheetmetal work. Building sheetmetal transitions for everything ranging from 10 inch ductwork all the way up to 8 foot plenums for air supply to boilers. Geometric layout and construction required some careful work, especially on multiple angle transition (bends) to accommodate different shipboard applications.

However, cutting those transition angles in such a small piece of tubing would be damn near impossible. Your work around was a real high class job!

John W


----------



## Sprocket (Jan 16, 2022)

I decided that I'd better get the "peripherals " ready so I can run this thing soon. I think the only motor parts I have left are the crankcase doors, standing platform and handrail. So, other stuff. There is one water pump in the book for any of the motors.
I made it mostly per the plans but used a different lip seal as the specified one seems to be hard to find.
It starts with a pretty good chunk of aluminum.




Bearing side, and impeller side. Then drilled and roughed out the shape.




I made the inlet boss a little long so I could grip it in a collet and face the other side to thickness. When I drilled the mounting holes in the
cover, I went deeper into the parent stock so I could tap those holes and mount the cover back on it to shorten the inlet boss.


 Together, but nothing inside yet.

Going to run out of space.
More a little later.
Thanks for looking!
Doug


----------



## Sprocket (Jan 16, 2022)

The bearing is bronze, pressed into the case. There is an oil groove in the middle of the bearing, .020" deep and .12" wide. I don't have any boring bars that will fit into a 3/16" hole, so this is what I came up with. It took a couple of tries at different shapes, but this is the one that worked.




and I did get a groove in the middle of the bore. An oilcup feeds oilcup feeds oil to the groove.
The impeller is made with the four fins soft soldered to the hub. I made a little fixture to hold the fins in position while i soldered them in.
Then flipped the rotor over to solder it to the shaft.




I was a bit concerned about turning the rotor to size and thickness, but it worked out. None of the fins flew off, and nothing got bent.







I guess the next "peripheral" is the propane demand valve. And a coolant tank. And some pulleys for the pump. Yeah, a few more parts.
That's all for now. Expecting snow overnight.
Thanks for looking!
Doug


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## Sprocket (Feb 11, 2022)

Coolant tank and piping.
I had bought a piece of 2.5" DOM tube to make the coolant tank. It's a simple piece of pipe with ends soldered in.
I made the ends a little thick and over outside diameter so I can blend them and round the corners after soldering.


I wanted the legs to look as though they were cast, and so "mill whittled" them from pieces of 1/2 steel plate. Where I could, I used a 3/16" ball end mill to make fillets, and filed and sanded the edges to make a rounded corner.














That was a lot more cranking the rotary than I thought it would be, but I think they came out as I'd envisioned them.
There will be a brass strap for hold down with a clamp into the ears that stick out.
More later,
Thanks for looking!
Doug


----------



## Sprocket (Feb 11, 2022)

I don't plan to have an actual radiator, so there will be sections of brass fin tube in the coolant loop.
My plan is to have them mounted on the top of the tank. They are 5/8" brass, ends threaded for mode tapered pipe (1/4"-40)
and finned with .050" fins and .050" grooves. I ground a tool to make the grooves as I didn't have a parting blade that narrow. 




I still have to make stand offs to mount the "U" on the tank, and some tank fittings. Coolant will enter one end of the "U", and run into the tank
at the other.
Again, thanks for looking!

Doug


----------



## Sprocket (Mar 11, 2022)

It's been several busy weeks, but not in the shop. It has also been slow going because I am making the cooling system up as I go along. There
are no drawings for it, and sometimes using my imagination consumes a lot of time. (I get a little carried away) But here is what i came up with.
The standoffs to mount the fin tubes on top of the tank started out like making the big ends of a connecting rod




The mount holes end up being 90 degrees to each other. The tank ends were left thick so I could round them and blend with the tube after
they were soldered. Two straps/clamps attach the tank to the legs



There is a filler with venting on top between the fin tubes, an inlet fitting, and an outlet.



I guess I didn't get a picture of the outlet, but it's just a disc with a hole and a tube soldered in.





So this is the cooling system. I guess I'll make pulleys to drive the pump next. I got 1/8" timing belts, and I'm trying to figure out if I can cut slots in the pulleys 
to drive the belts or just depend on friction. 
Thanks for looking,
Doug


----------



## kuhncw (Mar 11, 2022)

Doug,

Nice work on your cooling setup.  That is an interesting design.

Chuck


----------



## Sprocket (Mar 11, 2022)

Thanks, Chuck. I hope it fits with the era of the motor. I have no real idea what the original was like.
Doug


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## gbritnell (Mar 12, 2022)

Great looking cooling setup! I don't know that it's period correct but as nice as it looks, who cares.


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## Sprocket (Mar 12, 2022)

Thanks, George. 
It was kind of fun to try to imagine what it might have looked like in 1898, with maybe a little "steam punk" thrown in.
Doug


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## kuhncw (Mar 12, 2022)

Doug,

Since the Nash is a stationary engine and would be in an engine house, I suspect it was cooled by a cooling tower of some sort mounted outside.  The Steampunk look is always interesting.

Chuck


----------



## Sprocket (Apr 3, 2022)

There were some other parts I needed before I could start to assemble the engine, Like doors so the oil doesn't fly out of the crankcase.





And doors need handles





A little tool to hold them for filing and sanding





And screwed to the doors. 
Little parts seem to take a lot of time! 
More in a little while,
Thanks for looking!
Doug


----------



## a41capt (Apr 3, 2022)

Fantastic work Doug. Looking forward to the first pop!

John W


----------



## Sprocket (Apr 4, 2022)

Thanks, John.
I'm really looking forward to the first pop too.
Soon I'll run out of little pieces to make and have no excuse but to put it all together!
Doug


----------



## Sprocket (Apr 11, 2022)

This engine uses a wasted spark ignition, with two magnets on the flywheel. The ignition came from Roy Sholl at cncengines.com. It uses a wasted spark, so both plugs fire at the same time (as I understand it) and two magnets so they fire every 180 degrees. I put brass sleeves in the smaller flywheel and will glue the magnets in after I'm sure of polarity.



I had decided to make all the coolant piping from PMR fittings and pipe. I think it made for a lot of extra, very fiddly work. I also had to drill and tap the fittings. The "Ts" and elbows weren't so bad, but the 45s were a real pain to hold.





The wood mounting is just to get it running, I'll make something more permanent when I've figured out where things will go.
I'm not sure I like where the coolant feed line is running right now, so that may change.



Need to figure out the demand valve and fuel (propane) feed.

Thanks for looking!
Doug


----------



## kuhncw (Apr 11, 2022)

Doug,

Nice work on the piping.  Not an easy task.

Chuck


----------



## Sprocket (Apr 15, 2022)

Because this will run on propane, it needs a demand valve. The demand valve opens on the piston's intake stroke (suction) and otherwise keeps gas from leaking. I used the plans and parts from www.jerry-howell.com .  There are really only two parts  to make, the body and the cap, plus whatever adapters are needed to connect the gas. These are all the parts.



and the demand valve assembled


It seems to allow flow when I suck on the outlet side, and not allow flow when I blow on the inlet side, so I think it is working. Only supposed to have 4 or so PSI on the inlet.
I have everything apart, ready to assemble and try running.
I'll be back as soon as that happens.
Thanks for looking!
Doug


----------



## ignator (Apr 15, 2022)

Sprocket said:


> Because this will run on propane, it needs a demand valve.


I assume the diaphram and needle valve  and other parts were included in the kit?


----------



## kuhncw (Apr 15, 2022)

Doug,  I built the same demand valve recently and found it would not completely shut the propane flow off.  I found this by submerging the outlet tube in water.  Propane was leaking past the threads on the needle valve housing.  Some teflon tape fixed the leak.  You probably won't have this problem but I wanted to mention it just in case.

Chuck


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## Sprocket (Apr 16, 2022)

Ignator,
Yup, all the internal parts came with the kit. They are Tecumseh carb parts I believe. Connections are to suit your purpose.
Doug


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## Sprocket (Apr 16, 2022)

Chuck, 
Thanks for the heads up. I’ll seal it well. That bored hole for the 3/8-24 thread was a bit of a challenge.
Doug


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## Sprocket (Jun 7, 2022)

It's been a while, but Spring came to Vermont, and all that comes with it. (mud, yard work, other outdoor stuff) I've been working, but not looking like I accomplish much. There were a few more parts to make and start to assemble:




Wrist pins, handrail stanchions and rail, 






 and the step to reach the cylinder heads.
I started to assemble the valve train

 Lifters, rocker arms and wheels,  

 and all together. there is a "faux governor" you can see in the middle.


Someday I'll learn how to make those gears, but for now they're plastic.
 I got the valves in the heads, the cams set and the pistons assembled in the cylinders. Piston vacuum and compression felt ok, hand-over-the-hole test,
but the valves were not as well sealed as I thought they were. So I took it apart again, made a valve seat cutter and re-seated the valves.
I think that's all for right now, more tomorrow I hope.
Thanks for looking,
Doug


----------



## kuhncw (Jun 7, 2022)

Very nice work.

Chuck


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## Sprocket (Jun 8, 2022)

I had it all together to check compression, got the valves adjusted and the cams timed, and the compression was pretty bad. I had seated the valves before the valve cages were pressed in, and I think they may have changed shape.




 In the past, I had made a valve seat cutter from a drawing in one of Upshur's plans, and it didn't work very well. This time I used the same kind of technique as for a gear cutter. I turned the cutter to 46 degrees and the original seats were 45 so it would cut near the top most. I cut six flutes then relieved the backs with a small end mill. I was figuring out how to do this on a piece of 12L14 before I went to O-1.
It came out well enough that I just case hardened the 12L14 stoned the edges and tried it. It only had to cut bronze, and it worked! so next time I'll make it more permanent.




I lapped the valves with Clover and a little extension that threaded onto the end of the valve. It took a couple of tries, but I got them to seal reasonably well.
I had seen this method of testing valves somewhere here, so thank you to whoever this came from. It worked nicely.



 an inexpensive brake bleeder for vacuum and silicone plugs for connectors.




While everything was apart, I started painting the parts that shouldn't need any more work. The color got much grayer as it dried, it looks a bit beige here.
That about catches up. the finish work always seems to take a long time with little visible progress. Time to get it together!
Thanks for looking,
Doug


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## Sprocket (Jun 18, 2022)

I had been thinking about a mount for this engine. Because the flywheel protrudes past the bottom of the crank case by over two inches, it needs to sit up on something. Or have the flywheel go into a cut out in the base, and I didn't want to do that. I made a "plinth" for the motor to sit up on. It's riveted steel angle and sheet. The rivets are 1/16" round head brass. I first tried gluing the parts together with JB Weld so I could drill them It sort of worked, but some of the joints were too small to be strong.




I made some little tools for riveting.  the one on the left fits in the hole in the anvil (pritchel) or could go in a vise. this has the shape of the rivet head in it, so the head doesn't get flattened out when you pound on it. the center one sets the rivet tight in the hole, and the third has a rounded dimple in the end to form a head on the inside. I know that it can be done to buck the inside and hammer from the outside, but this is kind of small, and strength shouldn't be a problem.





 In these pictures, the first was glued and drilled, the second with rivets just dropped in the holes, the third with rivets set, and the last, from inside. Riveting the final edges was a bit difficult. I drilled them all with the parts together, then riveted just the top on, slid that in and did the two vertical ends of the long sides. Also, hard to keep square.





The top was riveted on and used to square the base to the top. The top was flush riveted because the crankcase had to sit over the rivets. The top is drilled and tapped for studs to bolt the crankcase down. I plan to mount the water pump on the side of the plinth, and probably the hall effect pick up also.
The rivets came from Godshall's Custom Machine/ American Model Engineering.
That's all for now.
Thanks for looking!
Doug


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## werowance (Jun 19, 2022)

that looks really fancy and nice.  good job


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## Sprocket (Sep 4, 2022)

It's been quite a while. Seems as though I worked a lot and had little to show for it. Making an engine is one thing but making it run is another. 
Anyway. A lot of finish work, painting and fitting.



The base, painted with attachment feet, and the Hall Effect pickup




assembled enough to set the valves.


The little brass piece replaces a spark plug, then if you put compressed air into the cylinder, you can hear when the valves open and close,
or where you may have leaks. It verifies what you have done in setup.

 I tried with a bike pump, but I really don't have enough hands. I used a small
compressor and set the output for about 15 psi and that worked pretty well. There is also a probe that fits in the through hole that I used to measure TDC.



I mounted the water pump on the base for a belt drive next to the timing gears.



 I also made a "Hucks Starter" for it. 

Next time I'll tell you about trying to start it.

Thanks for looking,

Doug


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## Sprocket (Sep 5, 2022)

This engine is to run on propane. I built the demand valve. I had gotten a propane hose with an adjustable regulator.
Rustkollector had said you need to open the needle valve quite a lot more than for liquid fuel. Also, the carburetor that was recommended
isn't made anymore, so I made one to GBritnells plans. When I first tried to start it, I would get some pops, but only with my thumb choking the air intake almost fully. Seemed like it was way too lean even with the needle valve way open.
Sometime in here, I found I had a weak joint in one of the connecting rods. It separated from the big end. Grrr!
So, a bunch of disassembly, clean up the parts and re braze. This time I drilled a tiny hole in the side of the big end to meet the hole the shaft of the connecting rod as a vent, because I wondered if pressure buildup had kept the silver from penetrating. There was plenty of heat.

In reassembly, I changed a few things about the cams. The cam carriers have 4-40 set screws and I milled a flat for those to sit in.
The cams themselves had 2-56 x 1/16" set screws which use a .035" Allen key. They didn't feel like I could get them tight enough to prevent slipping, so I replaced them with 3-48 x 3/32" set screws which use a .050" key. Not much bigger, but they feel a lot stronger.

To solve the lean mixture, I made a restrictor for the air intake:






And made a new jet with a larger hole, larger needle, and larger feed line:



I was trying not to do anything I couldn't undo if it didn't work.





I had gotten short runs with no coolant in case I had to take it apart again, so yesterday I filled it with coolant and got it running!
 

It runs. I think it will need a larger cooling system as it heated up fairly quickly. Right now, I'm just happy to have it running.
I guess the next thing is to make a more permanent wooden base for it and eventually figure out a generator.
That's all for now.
Thanks for looking!

Doug


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## kuhncw (Sep 5, 2022)

Doug,

Congratulations.  Your Nash looks great and has a good exhaust note.  Thanks for taking time to post an interesting build thread.  

Regards,

Chuck


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## Sprocket (Sep 5, 2022)

Thanks Chuck. 
It's quite a relief to hear it run.
Doug


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## minh-thanh (Sep 5, 2022)

Hi Doug !
Nice engine and runs great.
  Congratulations !
Although I have done welding and surface finishing on aluminum, iron, stainless steel, brass,  But I am really impressed with how you handle the welds and surface finish,  .


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## stanstocker (Sep 6, 2022)

Greetings!

It's been a pleasure following this build, congratulations on getting it running so well.  It looks great.  Thanks for all your effort to share the build with us.
Stan


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## Sprocket (Sep 6, 2022)

minh-thanh;
Thanks!
If you haven't tried silver brazing, it's a really good way to join a lot of metals. (but not aluminum)
The braze flows into the joint with little buildup on the surfaces, so not so much to finish.
Also, I think you were considering a sand/bead blaster, and that's another big help for surfaces and paint prep.
Doug


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## Sprocket (Sep 6, 2022)

Stan;
Thanks! 
I keep learning from people and projects here, so it's nice to show what I've learned.
Doug


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## Rustkolector (Sep 7, 2022)

Doug,
You have an excellent runner. Congratulations. May I suggest that you don't forget to add a gear guard to your engine before too long. I couldn't tell the rotation direction of your engine, but accidents can happen in the strangest ways.  

Your carburetor problems with propane are common. A restrictor plate often works well because the needle is working only 1 or 2 turns out. When using methanol carbs without restrictor help the needle needs to be way out on the threads with propane. This normally creates air to leak back through the threads upsetting the fuel air ratio. Depending on the carb used, a fix is to stack small silicone O-rings on the needle threads to prevent air from getting sucked through the threads. 

Let us know your generator/alternator thoughts for your Nash. 
Jeff


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## Sprocket (Sep 7, 2022)

Rustkolector Jeff,
Thanks.
You helped a lot with the propane fuel.
I had looked at your model and the gear cover and thought that looked like a good idea. My gears are behind the large flywheel and so not as exposed as yours but should be covered. I'll work on that.
Rotation direction was hard to figure. Which way should it rotate? or maybe it doesn't matter, but I finally found in "Full assembly, Figure 2"
an arrow that looks like rotation is clockwise looking at the end opposite the gears, so that's how mine rotates. I was sure I'd seen it in the writeup somewhere, but never found it again. That arrow was my only clue.
What I'm planning for a generator is to use the winding from a fan motor and make a new shaft and rotor with magnets and build a case for it. I have the fan motor and the shaft needs to be longer. I figured an aluminum core for the rotor with magnets glued in. I need to do some more poking around in the windings, it was a three-speed window fan. Should fit in a 4" tube for the case, then build up the ends to look like castings.
I'm just beginning on that, so any suggestions are welcome.
Thanks again,
Doug


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## Sprocket (Sep 23, 2022)

It was suggested that a gear cover would add to safety around the engine. There are no plans for this, so, I made it up.
At first. I thought I could make the vertical part and mounting tabs from one piece.





But after several iterations of paper pattern, it just wasn't going to work. So, the tabs were added to the vertical part of the cover.
I cut the brass to shape with a scroll saw and finished with a die filer.




The die filer was a project I did a few years ago in an attempt to get more comfortable working with castings. It came from Martin Models and was a
good casting set to work with. Replacement parts are available but weren't needed, and it has been an occasionally useful tool. (The 1/4 scale 5 HP
Galloway castings are still "aging" under the bench)




Rather than have to drill more holes in the crankcase, I used one of the cylinder mounting bolts, and one of the crankcase joining bolts.
Fit looks good with about 1/16" clearance all the way around.



These two are the parts set up to silver braze (no flux yet) and the parts all brazed together.





Last fit check before filing, sanding and bead blast. I had added another handrail on the opposite side to the left of the crankcase doors for "operator safety". I know the step up onto the base is a bit high, but maybe he gets a step stool.
 I got a computer radiator with a fan for better cooling. There is only 12 oz. of coolant or so in the system as it is now, and it heats up after a few minutes running. 
 That's all for now,
Thanks for looking,
Doug


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## kuhncw (Sep 24, 2022)

Doug,

Nice design and well done.  Looks great on the engine.

Chuck


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## rcflyer (Oct 18, 2022)

It amazes me how you do that! Your work is truly magnificent. One day I will see it in person.

Steve


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## Sprocket (Oct 18, 2022)

rcflyer,
Thanks, I'd like to show it to you.
Different models, different materials, different techniques, but it's all kinda the same. 
If you can make things, you make things and figure out the differences.
Good thing mine don't have to fly!
Doug


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