Wyvernish Build

[kutzdibutz]

... so I put it in the jar of shame and made another, ...

LOL- brilliat!! The jar of shame! Hope you dont mind if I name my scrap bin like this as well...

Real nice work on the carb- I always sneak a peek every now and then...

Cheers, Karsten

 

[vcutajar]

Nice carb Gus. I enjoy the way you describe everything that happens. I went back to the beginning of your build and re-read it again.

Vince

 

[Generatorgus]

Pete, Karsten, Vince,
Thanks for the kind words and on my birthday (65).
Mike, I'll give the JB a go, not a lot to lose at any rate.

Karsten, the jar of shame has been on the window sill in my shop for some time now, somehow it never gets full, there is some good in most of my mistakes even if it's only a good lesson.

GUS

 

[Generatorgus]

Still wondering where my metal order got to, I'll have to finish the carb when it gets here.

What next? I decided to figure out what to do about the exhaust flange and the tight hole pattern.
Not only is the bolt pattern tight, but the carb and exhaust ports are very close.
The bottom of the carb is directly in line with the exhaust, meaning it will have to take a quick sharp turn.
I was thinking a simple flange wouldn’t do and started brainstorming (sometimes dangerous) a different approach, sort of a fitting, to make a very sharp turn, IE: right angle.
It will be a very modified flange.

Trying a slightly different approach to using the rotab for this, I put the 3 jaw chuck on and came up with this little fixture.

Then cut a small block from a square brass bar, did a bit of layout and drilled some holes and partially milled a hole for the outlet.

The holes I drilled and tapped in my fixture were intended for give center points so I could do all the radii on the rotab. I decided to do the big ones first, and the run straight down the predetermined angle to form the flats.

When I got that done I decided to abandon the table and hand file the small radii and avoid what would probably mess things up.
A quick trial fit and, although being shoehorned in, it should work quite well.

Then I turned the outlet tube and tapped it 1/16 NPT.

Temporarily assembled another quick looksee told me I should probably recess the screws a bit.

 

[Generatorgus]

Then off to the welding shop to fasten it together and a bit of cleanup.
Looks good to me.

The partially machined exhaust passage was connected by plunging a ball end mill.
I also plugged the center hole, which was unnecessary to begin with, and made a short length of exhaust pipe from brass round as I don’t have any 1/16 NPT nipples.

I couldn’t stand looking at the temporary screws so I decide to make a few more for the exhaust and the carb half flanges.
The screws I made for the carb mounting flange were made from a piece of ¼”,303 stainless, I turned down to make the 3/16” heads.
I found a 3/16” dia. length of SS rod I didn’t know I had so I decided to make these screws from it.

As soon as I started turning it I new it wasn’t the more user friendly 303, but life is not always a bowl of cherries, so I continued.
I got the first one turned and threaded, but just couldn’t get a decent finish turning it.

Still getting a pretty rough finish on the second, I had another little oopsie while threading it.

A while ago I broke the only 4-40 die I had when I jammed it into the underside of one of the short screws for the carb.
This replacement just arrived in the mail and I had to get the broken screw out.
My little Exacto jewelers saw to the rescue, I managed to cut thru it but it still took some doing to get the pieces out.

If I had ordered a split die it may have made things a tad easier.
At any rate I got the screws made and installed.

And yes, I know fillister head SS screws are readily available but I enjoy making them even though I have a little problem now and again.
　
Still no metal order recieved, I decided to get on the computer and find out where it got to.
On the Speedy Metals website I checked my "shopping cart" and suddenly figured out where the shipment got to, I didn't place the order. Then I finally remembered that "my account" wouldn't accept my password I got frustrated trying and shut the computer off. I got that starightened out and hopefully the metal is on it's way.

Although, having moved passed the carb for now, I'm thinking ahead about a cooling systen and fuel tank and have figured out I'll need more material fo them.

 

[Generatorgus]

I figured it would be best to start building the cooling system from the engine and work my way out to a cooling tank, and haven’t yet decided what the tank will be made of or how it will be constructed.

I chose a piece of the 1” dia. brass door push bar for the flanges. This piece was just at the bend and I turned the bent part down to reveal valuable useable material, kind of oval but big enough for the flanges. I scratched a rough centerline with the lathe tool.

Using the same method I used to make the exhaust flange shape, I laid out the material and went to the rotab, this time slicing off two slabs at the appropriate size with my cheapa…. slitting saw. The blades work nice but the arbor is a nitemare.

The first time I used the slitting saw(some time ago), I was wondering why they included a second holding screw, but when I went to change the first blade I ruined I found that the screw was seized into the arbor to a point that I ruined it getting it out.
Remembering that experience, the next time I used it I figured that I had nothing to lose by reversing the rotation(CCW). The arbor has no locking lug for the blade so, maybe the torque load is what locked it up.
Not so, that also resulted in seizing the screw. When this blade goes, so does the arbor, and good ridence:rant:I’ve got to get something better.


The stems were turned, drilled and tapped ¼“-40T. You may ask “why that size thread?”, because I had the tap and it seemed appropriate. I got the tap with a lot of new taps I flea market purchased a few years back and found a die when I was searching for a 1/16NPT die. Thought process was I already had the tap and no way I’m ever going to single point turn that thread, not one of my better machining skills.

Stems inserted in the flanges, silver soldered and cleaned up and a couple of lengths of “long enough to do the trick” ¼” dia. SS tube threaded with the 1/4-40.
I’ll rely partially on the tapered end of the tap and to help form a seal, and Loctite will really seal the deal.

Screws made and gaskets cut

and installed on cylinder.

And a piece of swarf art added for a garnish.

 

[Generatorgus]

Bumping around a bit, material not in hand to finish the carb, I’ve made the cylinder water outlets, now what?
Muffler? OK A pot muffler should look right on this engine.

Poking around trying to get ideas, I found not much in the way of pictures. Fairbanks Morse used a two piece muffler, but it was not quite what I wanted.
I found this over on Smokstak : http://www.smokstak.com/forum/showthread.php?t=112545
Wayne Grenning restoring a 10 HP Schleicher Schumm Slide Valve Engine, bottom of page, just what I wanted. Pretty interesting stuff, recommended reading.

Material? Cast iron. Yes, I have a couple pieces about the right size.
I chose the smaller 1” dia. to make the body.

Hollowed out,

Parted off and flipped around, rounded a bit and inlet hole drilled.

I decided it would look good on a base.
For that, a larger 1 ½” diameter iron bar from the Wyverns cylinder liner was used.
A lug was turned to fit the ID of the body and then a larger step turned to match the OD and trial fitted. I left a small fillet where the base and body meet.

Now held by the lug the base was shaped.

Then a simple round flange cut a parted from a small piece of iron bar.

That piece of iron used up, for the next flange I resorted to an alternate material source,

A one piece flange and boss was turned and the rounded out to the body dia. on the mill with the boring tool.
A couple of short alignment pins cut from a dowel to hold the parts in place until the glue dried.

I wasn’t intending Loctite to be used to permanently hold the muffler together, just to keep the parts in place while they were drilled and tapped 2-56. The lower screws in the side outlet actually screw into the base lug.

 

[Generatorgus]

Not at all wanting to attempt making the 2-56 screws I raided my salvaged screw collection and found just enough.

Horizontal alignment for the lower flange accomplished with a homemade tool,

Holes drilled and tapped.

Wood dowels drilled out,

Almost finished.

Only then did I notice that brain fade had kicked me in the pants.oh:

Wrong size pipe. :wall:
These are ¼”-40, same size as my water piping. The exhaust is 1/16NTP.
The flanges are not big enough to redrill and tap, this muffler will not work.

I was really disappointed with myself for goofing up on something this simple but, I decided it was too nice to put in the jar and went on and finished work on the base.

I rounded out the feet with a file, and stepped back to admire this orphaned muffler.

Very tempting to use the reduced pipe size, but it would probably affect the way the engine runs.
I’ll have to start over. Maybe someday I’ll build an engine just for this muffler, but for now it will be a shelf pet. It wasn’t time wasted.

More to follow
GUS

 

[Generatorgus]

“OK, get over it and build a new muffler, only this time get it right!!” said my little shop buddy and all around good friend.
At least that was what I think that look was for.

Starting at the flange size I would need, I scaled the bungled muffler to the new size, only about 5% bigger.
The 1 ½ iron bar would do for the body, but I had nothing big enough for the base.
Back in the pipe fitting bins, I dug out a donor.

In the lathe, holding the pipe cap by the rim I turned the top flat and cut the dia, to the approx. radius of the feet. Then drilled and tapped it for a ½” hex bolt. Loctited in the hole this would become a machining lug.

The threaded end was then cut flat to the bottom surface. Then to the rotab to make do the rest of the base machining.

The base completed.

Not a lot bigger than the blunder muffler, but big enough.
Though there were a few differences in construction, the rest of the muffler was done pretty much like my first try. Finished product.

Now I have to start thinking about the rest of the cooling system.

 

[gus]

Hi GUS

You are doing fine there. Will be monitoring this engine thread.You have a great machineshop.

Gus Teng from faraway Singapore.

 

[idahoan]

Gus

The Muffler is a work of art! and kudos to you for not just putting a stright pipe on it; its the little details that make all the difference.


Dave

 

[Generatorgus]

Gus, Dave,
Thanks for stopping by and the kind words. I really like working on the smalls and/ or accessories, probably more so than the engine itself.

I have a few things in mind for this engine, a governor would be nice, I'll delve into that more when, not if, I get it running.

GUS

 

[vcutajar]

Gus

Sorry to see that you had to do the muffler twice but as Dave said it is these details that make a model stand out.

Vince

 

[Generatorgus]

Hi Vince,
Making a second muffler was fun, having to make it was not.
Brain farts are way to common in my world.

I’m about two weeks behind the actual build in my posts, catching up seems to be impossible so I won’t even try. I’ll just try to keep posting in the order I did things.

The lost metal order finally got here about then, meaning I could finally finish the carb.
Not rocket science, the carb valve was made

and the elusive 1/16” stem was Loctited in place, and cut to length.
Valve finished, it took about a half hour after waiting weeks for the 1/16” rod for the stem.

Now to repair the buggered up fuel inlet hole in the middle of the valve seat.
I chose to copy Mike’s repair and try the JB weld method.
Not wanting to plug the fuel inlet hole or leave a big gob of JB to have to tediously lap flush, I decided to try to limit the amount I had to remove.
First was to wrap the valve face with plastic food wrap and stretch tight enough to remove as many wrinkles as possible.

Then with a drill shank inserted in the hole the JB sparingly applied and the bit removed. This would help eliminate the possibility of stuffing the hole.

At this point I realized that the leftover JB mix should have been removed from the immediate work area.

JB cleaned from hand, the valve was inserted in the carb body, weighted down to and left to set overnite.

It worked pretty well, but I probably could have gotten a the same or result by sooting the valve face to prevent sticking.

The seat lapped in really nice, the pic was blurry, but the carb got reassembled and installed on the engine.


I guess I skipped ahead a little. I forgot the part about making A George Britnell valve seat cutter, not nearly as pretty as George’s but it did the trick.

Valves lapped into the housings and installed in the head, head gaskets made (there are two) and installed, I wrapped the flyweel with masking tape and marked off and set the valve timing.
I’ve finally got COMPRESSION.

Not just a little, the engine turns freely and bounces off the compression quite nicely. I think in that respect and if the carby works, I’ll have no problems getting it running. I hope!
At any rate I can see the end of the carb valve stem lift on intake so that part is apparently working.

I'm not in a real hurry to get into the usually frustrating chore of getting the engine running and there are a few more accessories such as the cooling system and fuel tank to build.

A temporary fuel tank I have, but the cooling system will be important as I feel that this engine, not being hit and miss, will heat very quickly.
I might as well make a permanent solution, which will be a cooling tank.

 

[Mike1]

Gus. Good to hear that the JB Weld repair worked on your fuel inlet, and I can say that the same repair job on my Wyvern is giving no problem.

Mike.

 

[Cogsy]

At this point I realized that the leftover JB mix should have been removed from the immediate work area.

I'm glad to see I'm not the only one to do stuff like that. Just last night I managed to stick the palm of my left hand to my vise with some gel CA I hadn't bothered to clean up...

Great work on this build. I'm enjoying every post.

 

[Generatorgus]

Cogsy, thanks. We all suffer from the "human condition", some more than others.

Mike, I couldn't quite glean this info from the drawings, does the throttle drum completely cover the inlet hole when in the closed position?
Also, about how much travel is allowed on the inlet valve adjustment?

Just trying to stay ahead of it when I do decide to put fuel and spark to it. My experience, so far, has been with simple mixers.

GUS

 

[Mike1]

Gus. I made the slot length in the throttle barrel just to give a 1/32" opening at the slow running position, this opening was just a guess on my part, and my engine runs slow at that setting.

However a better way may be to allow the throttle barrel to fully close the port and arrange a adjustable stop on the throttle arm.

Again the inlet valve travel is a guess, I have no more than a 1/16" on my engine and as you say there is no detail on the drawings.

Mike.

 

[Generatorgus]

Thanks Mike, That's about the same as I guessed and did, maybe a tad larger on the intake opening.


More of the cooling system.
Ignoring the fact that I hadn’t considered what I would use for a cooling tank, I proceeded to make some plumbing fittings.
I rummaged through my fitting bins and came up with one older style brass elbow, and an iron tee plus two unions.

The unions looked easier to start with, so I measured the models up and scaled them down to my chosen ¼” OD pipe size using the OD of the NPT fittings for ratios.
Surprisingly they came in pretty close to each other in what would be the final size of the components I had to make.

Hardest thing I could see would be the threads that join the union, ½” OD.
Standard ½-13 and ½-20 seemed to be too course and single point threading has been something I don’t handle very well, especially internal threads.

I found I had an old ½-24 NS tap in a box of old taps I bought. Standard plug style, maybe I could cut it down and make it a bottoming style.
I took a shot at cutting tapered in off using my HF mini cutoff saw. Touched up on the grinder it looked like it might work, meaning if it did work I would only have to cut the external thread on the lathe.

A sample hole proved it would do the job.
So, I proceeded to make a couple of joiner nuts.
Starting by plunging an end mill in the bar, the same size as the inserted seat, then opening up to the tap size with a small boring tool. And threading.

Then in the hex collet block, the hex cut,

And then back in the lathe to pretty it up and part it from the bar.

Cleaned up, these will do nicely.

 

[Generatorgus]

The other two parts.

Now to go back and refresh myself on single point threading 101.
Maybe I should have done this before making the nuts but I sometimes get to thinking failure is not an option.
After about four or five failed attempts, the same problem.

One side of the thread seemed too steep and the other not steep enough.
I was starting to wonder about the failure option.
Thinking maybe my cutting tool wasn’t ground at quite the proper angle, I dug this bit out of the box, seems to be brand new and at the proper angle. Set square to the work.

I didn’t know if it was intended for threading, but took a crack at, it cut well but still the same problem.

I thought I took a picture of that, but I guess I just cut them off and tossed them in the trash.
The sample cuts would thread into the hole I previously tapped, but I had to cut the thread undersize on the diameter. Not what I wanted to settle for.
Maybe the angle setting on the cross feed?
Moved it one degree and got a better result. Two degrees better and three was the magic number.
Great, I found the problem but also found I can no longer trust the angle I set.
　
Having kind of stumbled over that hurdle the rest was EZ, .
The only exception from the real fitting was to make the joining surfaces flat and depend on an o-ring or Teflon seal.

Next the elbow.

GUS