# Compressed Air V8 Cirrus



## cfellows (Jul 1, 2012)

Well, I seem to be back in the engine building mode. I want to pick back up on the compressed air powered Cirrus engine, but I decided to go with a V8 version. It will have a 3/8" bore and 1/2" stroke. I'm making it relatively small because I don't want it to use a lot of air and make the compressor start up every 30 seconds.

I started some tentative machining yesterday trying to make a cross-plane crankshaft. My first attempt didn't turn out very good.







It all went together OK, but when I chucked up one end in the lathe, the runout on the other end was abyssmal, like 1/4". So, I moved on to my second choice, a crankshaft turned from solid. 

Here's a picture of the raw stock. I turned a 1" diameter piece of 12L14 down to 13/16" and drilled center holes in each end. 






I had to noodle on it a bit to figure out the best way to do it. I decided in the end to turn it between centers. So the first problem was to drill center holes on each end, at 90 degree intervals 1/4" off center. I needed an identical set of holes on each end, and each corresponding pair of holes have to be exactly opposite each other. Luckily, I have a nice tool makers vice that is ground square and flat on all sides, so I was able to clamp the blank in the vice, then use my height gauge to find the center and scribe lines all the way around and a second set at 90 degrees to the first. I also scribed a center line on the face of Jaw #1 on my four jaw chuck. Using the 4-jaw chuck to offset the the work by .25" I drilled the holes, loosening the work and rotating it 90 degrees between holes, lining up the radial line on the end of the blank with the scribed line on the face of the chuck jaw. I think I got them pretty true.






I'm designing this engine as I go, so work may be slow at times. Just hope I can see it through to the end. Tomorrow I start turning the connecting rod journals, saving the mains journals until last.

Chuck


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## steamer (Jul 1, 2012)

I'll be watching Chuck!

Dave


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## Don1966 (Jul 1, 2012)

Ha! Chuck welcome back to the grinder. I quess you got tired of the honey do's. I be here watching bud.

Don


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## vcutajar (Jul 2, 2012)

Will be following also.

Vince


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## ShedBoy (Jul 2, 2012)

Welcome back Chuck, this sounds like a great idea.

Brock


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## gbritnell (Jul 2, 2012)

Hi Chuck,
I would try milling as much of the stock away as possible. Milling is a much smoother operation than trying to plunge in with some sort of necking tool. Naturally to finish the journals it will need to be turned on a lathe but I have found the less you have to do on the lathe the better. 
This should be a great project.
gbritnell


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## cfellows (Jul 2, 2012)

I took George's advice and milled away the bulk of material around the soon to be connecting rod journals.






Then I went back to the lathe and turned the journals down to their finish diameter of 7/32". This was done using my 4-jaw chuck, not between centers as originally planned. 






I still have to widen the gap which I will do next.


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## stevehuckss396 (Jul 2, 2012)

cfellows  said:
			
		

> I want to pick back up on the compressed air powered Cirrus engine, but I decided to go with a V8 version.




So is this going to look like a Whittle V8 only bigger!!


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## tvoght (Jul 2, 2012)

Hi Chuck,
 Did you re-chuck after each journal so that the journal you were turning was just beyond the jaws?

 I'll be watching your build,

--Tim


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## cfellows (Jul 2, 2012)

stevehuckss396  said:
			
		

> So is this going to look like a Whittle V8 only bigger!!



Hi Steve, yes I'm using the Whittle in terms of overall look. Don't know what the bore and stroke of the Whittle is, but mine is 3/8" x 1/2". The cylinder barrels will be 5/8" x 3/4" and the overall length of the crankcase will be about 3" or a little more.

Chuck


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## cfellows (Jul 2, 2012)

tvoght  said:
			
		

> Hi Chuck,
> Did you re-chuck after each journal so that the journal you were turning was just beyond the jaws?
> 
> I'll be watching your build,
> ...



Yes, I rechucked the blank in my 4-jaw for each journal. I used a live center on the outboard end, loosely applied mostly just as a guide. The spindle speed was low, around 600 RPM.


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## AussieJimG (Jul 2, 2012)

I watch, I learn. Thank you Chuck I am following.

Jim


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## cfellows (Jul 2, 2012)

I finished up the crankshaft this afternoon. Turned out really nice. Of course, it took me all day to make it. Quite a process!






Kind of hard to tell from the photo, but this is a cross-plane crankshaft. That means that the throws are 90 degrees apart as you proceed from one end to the other. 

Chuck


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## Don1966 (Jul 2, 2012)

That looks great Chuck, was it difficult to make? I only count 7 throws, how can that be since this is a V8? Anyway I am still following your progress.

Don


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## cfellows (Jul 2, 2012)

Don1966  said:
			
		

> That looks great Chuck, was it difficult to make? I only count 7 throws, how can that be since this is a V8? Anyway I am still following your progress.
> 
> Don



Thanks, Don. Actually there are 5 main bearing journals and 4 connecting rod journals. There is a main bearing journal on each end and 3 in the middle. There are 4 connecting rod journals and each will hold two connecting rods.

Chuck


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## Ogaryd (Jul 3, 2012)

Hi Chuck,

       That crankshaft sure looks pretty, Keep up the good work.

                                    :bow: Gary


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## cfellows (Jul 3, 2012)

Ogaryd  said:
			
		

> Hi Chuck,
> 
> That crankshaft sure looks pretty, Keep up the good work.
> 
> :bow: Gary



Thanks, Gary. I showed the crank to my wife this morning. Usually all I get is a grunt or something like, "Oh, that's nice". This morning she said, "Wow, that's cool. Looks like a piece of jewelry".

Chuck


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## kutzdibutz (Jul 4, 2012)

Hi Chuck,

Haha- another common reply would be: 'What? And that small thing took you all day??' :big:

But sure the part looks great! 
I would have big respect making a crankshaft from one piece, I'd rather build the crankshaft with big diameter and thin ring ball bearings, center pieces and bolts. Mainly because I could correct small mistakes by re-doing comparably small and easy pieces, not the entire shaft. Hmm- I guess thats part of the 'growing with the experience' what challege one seeks...

... and certainly the bling-effect is much higher with your approach! :bow:

Cheers, Karsten


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## cfellows (Jul 5, 2012)

Got some more done on the engine today. I started roughing out the top part of the crankcase. 

Here is a picture of the block I'm using. It's magnesium and was cut from a 1" thick piece that I've had laying around for a long time. The overall dimensions of the block is 3" x 1.7" x 1" thick.






Here is the block mounted in my milling vise read to surface one of the sloping sides. I'm using a 1.25" indexable face mill to form the 45 deg angled faces. 






This is the block with one of the angled faces finished. This magnesium machines really nicely. I was able to mill away .100" on each pass.






And here is the piece with both angled faces milled, along with crankshaft for size comparison.






I was careful to vacuum up all the magnesium swarf after I finished. It's not likely to catch fire since the kindling point is around 700 degrees, but didn't want to take any chances...

The next step will likely be to hog out the underneath side of the crankcase. Not entirely sure how I will do that, probably with an end mill.

Chuck


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## cfellows (Jul 6, 2012)

This is iteration #2 of my crankcase, top half. The first one would probably have worked, but I missed a lot of the dimensions, by a lot, so couldn't in good conscience continue with it.

With this iteration, I've mounted the crankcase half in my dividing head. I will use the rotating motion and lower the end mill a bit at a time to achieve a semicircular, concave cutout in the metal. I think this will give me a lot more consistent result. The metal cuts really nicely so I don't think the long overhang will be a problem. I plan to go slow. Could really use a CNC mill at this point, but this will have to do.






I may shoot a video of part of the process to show how it works. This is work for tomorrow.

Chuck


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## gbritnell (Jul 7, 2012)

Hi Chuck,
Nice work as always. I worked with magnesium in the shop many years ago. Every time we cut it we had the proper extinguisher and sand bucket available. Although I never saw an accidental fire I saw a few that were demonstrations and it's nasty stuff once it catches. 
gbritnell


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## cfellows (Jul 7, 2012)

Thanks for the kind words, George, although my work pales in comparison to yours!

I got the crankcase top, 2nd version pretty well finished today and I'm quite happy with the process and the results. I'll be uploading a video showing how I used my dividing head to position the work for hollowing out the inside. 












I'm hoping these will have been the most difficult pieces and having them out of the way should make the rest of the project go pretty smoothly (famous last words!).

Chuck


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## ShedBoy (Jul 7, 2012)

Looks good Chuck. Do you plan on running the crank in bushings, bearings or can it just run in the magnesium? 

Brock


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## cfellows (Jul 7, 2012)

ShedBoy  said:
			
		

> Looks good Chuck. Do you plan on running the crank in bushings, bearings or can it just run in the magnesium?
> 
> Brock



Thanks, Brock. Current plan is to run ball bearings on each end and a 2 piece bronze bushing in the middle.

Chuck


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## cfellows (Jul 7, 2012)

Here's a couple of videos. The first shows how I formed the semicircular cavity in the underneath side of the top crankcase half.

[ame]http://www.youtube.com/watch?v=gqCRwGf8EtI[/ame]

The second video shows it finished.

[ame]http://www.youtube.com/watch?v=yZNTW789r9g[/ame]

Chuck


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## Don1966 (Jul 7, 2012)

Great video Chuck thanks for showing how you did the inside of the crankcase. I have never done this but will give it a try. Love the progress you have done so far and interested in seeing more. Great work as usual.

Don


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## gmac (Jul 7, 2012)

Chuck;
Great work, as always. I appreciate these types of videos because as a beginner, it helps me to get a feel for depth of cut and feed rates. The by the book numbers are fine but I guess I'm old fashioned - I like to feel, hear and smell things.

Cheers Garry


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## steamer (Jul 7, 2012)

That works slick Chuck!

Dave


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## cfellows (Jul 9, 2012)

Here's a pile of cylinders in the rough...






And here's the first prototype.






I decided to make the head integral with the cylinder. Simpler and easier to make. Sigh, 7 more to go!

Chuck


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## cfellows (Jul 14, 2012)

Been working on the cylinders. 






Part of the task was to use a slotting or cutoff tool to form the cylinder fins. I needed something that would cut a .050" slot and I didn't want to buy or use a standard parting tool, so I decided to make my own from a 1/2" square HSS tool bit. Here you can see the finished tool ready to cut a slot.






I didn't want to grind away the large chunk to to bring it down to .050" so I used a dremel with an abrasive cutoff blade to cut out the corner piece. Didn't take as long as I thought it would. Here's a picture of the partially cut out piece.






I had started grinding the tool bit to final shape using my tool and cutter grinder, but found that the cup wheel was just glazing over and heating up the tool bit too much. So I decided to make an attachment for my belt grinder and use that.






Here's a series of pictures showing how the fixture lets me swing the tool bit up to the belt, applying light pressure and pulling back briefly to let things cool.
















The attachment allows me to adjust the bottom and side relief on the tool bit. It also cuts much faster and cooler than a grinding wheel. And, of course, the fixture keeps the angle constant, makes it easy to lift off the tool bit to inspect it and immerse it in water to cool it off. And, the finished cutoff tool did a very clean and fast job of shaping the fins and base of the cylinders.

Chuck


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## kustomkb (Jul 14, 2012)

Your project is looking great Chuck.

That's a pretty neat way of scalloping out your case.

Your grinding attachment looks well thought and made too. I like the clean finish you get when touching up your tools on a sanding belt. Gotta make me one!


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## cfellows (Jul 14, 2012)

KustomKB  said:
			
		

> Your project is looking great Chuck.
> 
> That's a pretty neat way of scalloping out your case.
> 
> Your grinding attachment looks well thought and made too. I like the clean finish you get when touching up your tools on a sanding belt. Gotta make me one!



Thanks, KB. I'm thinking about making a video to show the fixture and how it works.

One of the problems, particularly in multiple cylinder engines, is to make all the screw holes the same so the cylinders are interchangeable. I'm not particularly skilled at locating holes, so I made a drilling guide.






The guide has a spigot on the bottom which is a close fit in the hole in the crankcase. In the picture, I have a 1/4" cutting bit wedged in the back to hold the guide square to the vice and the case.

The drill guide has a recess on the top that is a close fit for the spigot on the bottom of the cylinder. The cylinder and the guide are held together square and tight in a vice to drill the matching holes in the cylinder.

Here are a few pictures of the crankcase with all the cylinders attached.
















Chuck


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## ShedBoy (Jul 14, 2012)

Moving along pretty quick there Chuck. Drilling jigs are great and if made thicker they are good for a tapping guide also 
Brock


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## gbritnell (Jul 14, 2012)

Hi Chuck,
Man, you're really ripping through this engine. At this rate you'll have it running in no time. Great work as usual.
gbritnell


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## steamer (Jul 14, 2012)

Looks great from here Chuck!

I always liked the Cirrus 4

Dave


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## cfellows (Jul 16, 2012)

Now here comes the connecting rods. 






Kind of entering new territory with the size of these things. The blanks are 1.4" x 0.46 x 0.125. The big end screws will be 0 x 80 and they fit around a journal of 3/16". I'm going to have to come up with a fixture and a process to have any hope of making these things uniform in size and shape and completing them before before dementia sets in.


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## cfellows (Jul 26, 2012)

There's a few postings that are missing from the change over of the website.  I had finished the the connecting rods, then had to remake them because of a screwup!

I managed to reclaim my shop from the missus who was using it to paint a large piece of furniture.  Here's 8 new connecting rods.  Not perfect but good enough.  I need to leave well enough alone or I'll wind up making a 3rd set! :hellno:






Next I think I'll give the pistons a go.  I'm planning on using steel since they will be riding in aluminum cylinders.

Chuck


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## Don1966 (Jul 26, 2012)

Hi Chuck, still following here and you are moving pretty fast to me. You always amaze me with your fixtures and jigs. Great work as usual, remaking is just another step to learning.

Don


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## kuhncw (Jul 26, 2012)

Nice work, Chuck.  It wil be interesting to hear this one run.  You get some pretty good sound out of your air engines.

Regards,

ChuckKuhn


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## rhitee93 (Jul 26, 2012)

I'm glad to see this build is still going.   I am also looking forward to following along.


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## cfellows (Jul 26, 2012)

Thanks, Don, Chuck, Brian.

Here is a picture of the first piston.  I decided to make them from brass since it's easier to machine than steel.







Chuck


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## rhitee93 (Jul 27, 2012)

Well now, that gives me a whole new appreciation for the scale of this engine


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## cfellows (Jul 27, 2012)

I got the pistons all made today.  Still need to drill the wrist pin holes, but other than that, they are finished.  I decided to make them out of steel rather than brass, mostly cause I hate using my brass, but also I figured the steel would wear better.  Turns out they weren't all that hard to machine.
I first cut 8 blanks from 3/8" OD drill rod.  The blanks are are about 7/16" long which is 1/16" oversize.  The first lathe operation after skimming the end is to drill a 1/8" center hole that is 5/16" deep.  This will leave a 1/16" thick top on the finished piston.






Next I used a 5/16" end mill to bore out the bottom 1/16" deep, forming the skirt.






Here's 7 of the pistons after drilling the bottoms...






Unfortunately I didn't take any pictures of the slot milling operation.  All I did was chuck each of the pistons in an ER20 collet chuck that allowed me to hold the piston vertically in my milling vise.  Then I made multiple passes with a 1/8" end mill to form the slot.  After milling all the slots, I then trimmed off the tops of the pistons in my lathe to bring the finished length down to 3/8".

Here's the finished pistons along with all the other parts I have todate.






Next I'll be figuring out the details of the valve and air supply assembly.  This could take a few days...

Chuck


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## Don1966 (Jul 27, 2012)

Looking good Chuck, I am partial to the brass pistons. Never realized how small they were till you had it on your finger. 

Don


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## cfellows (Jul 28, 2012)

Thanks, Don

A bit of an aside today.  Actually, building fixtures and improving the work area, all related to building this engine.

For the air delivery system, I'm using 3/32" brass tubing.  Because of the engine design, I'll be needing a 90 degree bend in each tube that will have to be pretty tight.  I have a nice tube bending set, but it won't achieve the radius I need.  So I set out to make  a special jig.

I needed to turn a 3/32" wide groove with a radiused bottom 3/64" deep.  So, I ground a semicirular (more or less) tip on a 3/32" cutoff blade.






Then I chucked a 3/8" diameter length of drill rod in the lathe and cut the groove.  Well, I actually cut two grooves because I originally planned to make a two-piece bending jig.  I later decided it didn't need to be that complex.






Next I milled an axial notch on the center line of the rod and silver soldered a rectangular piece of cold rolled steel into it.






Finally, I drilled a 3/32" hole though the cold rolled steel, positioning the drill bit in the groove in the rod.






To make the bend, I insert the tubing into the hole...






Clamp the jig into my bench vice and make the bend using my thumb











Chuck


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## cfellows (Jul 30, 2012)

I'm getting into what is arguably the most tedious part of the project.  I've more or less settled on the air valve and delivery system.  This part is hard because I want to keep the engine looking as much as possible like an IC engine which means keeping the air plumbing as inconspicuous as possible.

Here's a picture of where I am so far...






First I drilled the 7/32" axial hole along the top of the block.  The brass tube with the air connection on the end will be Loctited into place later.  The rotary valve will be a 3/16" length of drill rod with a 3/32" hole drilled lengthwise most of the way (but not all the way) through from the back.  A flange will be soldered onto the back of the tube.  This tube will then be inserted into the brass tube from the back of the engine.  The flange will fit inside the air connector and will ride on a shoulder inside.  This is the stop that will keep the valve tube from just sliding out the front of the engine when air pressure is applied to the back.  The secondary cam gear will be mounted on the front side of the air tube and turn it at 1/2 the crankshaft speed.

Radial holes will be drilled through the side of the brass tube and the valve rod.  These holes, which can barely be seen just below the ridge of the crankcase will then supply air through 3/32" brass tubes to the top of the cylinders.

The hex pieces are made from 3/16 hex brass.  They will be threaded, cone side up, into the holes along the ridge of the crankcase.  A 1/16 axial hole will be drilled through the center of each one.  The brass tubes will have a flange and threaded caps to hold them onto the brass hex pieces.

OK, so is everyone thoroughly confused now?

Chuck


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## Don1966 (Jul 30, 2012)

Sure Chuck the brass tube will supply air to the engine right. Nothing confusing about that. Just how it gets to each cylinder is confusing. 

Confused Don


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## cfellows (Jul 31, 2012)

Don1966 said:


> Sure Chuck the brass tube will supply air to the engine right. Nothing confusing about that. Just how it gets to each cylinder is confusing.
> 
> Confused Don



Thanks, Don, maybe this will start to clear things up...

I think I've got the details of hooking up the air tubes worked out.  I made a prototype today.  It's fiddly work and the prototype doesn't look very professional, but maybe I can do better on the rest.

I think the pictures will tell the story...











The end that threads into the crankcase is a 5-40.  The other end is an 8-32.  The through hole is 1/16" and the OD of the brass tube is 3/32", ID is 1/16".  I'll take a picture of the fixture I made to flare the end of the brass tube.  

I'll probably be tearing my hair out by the time I get these air tubes all done.  Gonna be a challenge!

Chuck


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## rhitee93 (Jul 31, 2012)

Holy smokes!  The next thing you will tell us is that you will be making double flares.

Very impresive scale :bow:


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## dreeves (Jul 31, 2012)

Chuck what a great looking engine you have going on there. Im always impressed with the detail you have in your engines.  Thm:

Dave


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## Don1966 (Aug 1, 2012)

Very nice Chuck, I am wondering where the end of those tube are going to go...

Don


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## cfellows (Aug 2, 2012)

Don1966 said:


> Very nice Chuck, I am wondering where the end of those tube are going to go...
> 
> Don


 
Here's  drawing of what the engine will look like with all the air plumbing done.


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## Don1966 (Aug 2, 2012)

Awesome Chuck, I like it already. A rotory air valve and ball check, I like.....A Karma from me.


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## cfellows (Aug 6, 2012)

Don1966 said:


> Awesome Chuck, I like it already. A rotory air valve and ball check, I like.....A Karma from me.



Thanks, Don.

I finished up the flared tubing connectors this morning.  






The female caps and the male part has an 8-40 thread on the flare end and a 5-40 thread on the smaller end which will screw into the crankcase.  There is a 1/16" center hole drilled all the way through






Both the female and male parts are made from 3/16" brass hex rod.  Chucking this small stuff in even a 3" 3-jaw chuck is troublesome and can come loose when trying to cut threads.  So, after noodling on it for awhile, I rummaged through my socket drawer and found a nice 3/16" socket with a depth that was suitable for my work pieces.






I used this to hold the male part for both threading operations and for drilling the 1/16" center hole.






I also used the socket to hold the female caps for chamfering the top end and cutting the bottom end to uniform length.

Chuck


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## rhitee93 (Aug 6, 2012)

K point for the socket idea.  This solves a problem I have that I was about to buy a hex collet for.

Thanks


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## Ogaryd (Aug 6, 2012)

Hi Chuck,
           Just wanted to drop in and let you know how much I appreciate the the time you take to share your builds with us. You better be careful, as much as your wife liked that crankshaft, she's liable to take that hole engine.
                                                                                                                      Regards Gary


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## cfellows (Aug 7, 2012)

rhitee93 said:


> K point for the socket idea.  This solves a problem I have that I was about to buy a hex collet for.
> 
> Thanks



Thanks Brian, glad you found something you can use!



Ogaryd said:


> Hi Chuck,
> Just wanted to drop in and let you know how much I appreciate the the time you take to share your builds with us. You better be careful, as much as your wife liked that crankshaft, she's liable to take that hole engine.
> Regards Gary



Thanks, Gary, for showing your appreciation!  I'll make sure the engine has some oil smeared on it which will totally turn her off!

Chuck


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## cfellows (Aug 7, 2012)

I thought I'd post some pictures of the new jig I made for bending the 3/32 brass tubing...
I started with this... it's turned from 3/8" drill rod and has a 3/32" wide, 3/64" deep radiused groove turned in it.  It's screwed to the aluminum block with a 10-24 SHCS.






This is clamped in my vise, about 5/16" down from the top of the jaws.






Next I place the brass tube into the groove in the bushing






... and hold it there while I slide a stop block between the bushing and the vise jaw.  The stop block has a 3/32" radiused groove in it so the brass tubing won't kink.






Then I take a second block, also with a 3/32" radiused groove in it and use my thumbs pushing on it to force the tubing around the bushing.





As the Brits would say, it works a treat!
Chuck


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## SilverSanJuan (Aug 7, 2012)

Clever stuff Chuck.  Thanks for sharing your methods with us. 

Todd


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## Don1966 (Aug 7, 2012)

Very nice Chuck, I like that. You coming right along with your engine. I want to see the rotary valve when you make it.

Don


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## rhitee93 (Aug 7, 2012)

I'm impressed.  I haven't had much luck bending small diameter tubing.  I'll have to try your approach!


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## cfellows (Aug 8, 2012)

Thanks Todd, Brian, Don...

Did some more work on the air inlet tubes today.  I made the flanges that will be soldered to each tube.  

I first chucked a length of 7/16" brass rod in the lathe and center drilled a 3/32" hole about an inch deep.  Than I used a parting tool to part off 9 disks, each .080" thick.  I made an extra one since I usually manage to screw up at least one.   oh:







After running each face over some 220 grit sandpaper to remove the flashing I clamped each one individually in my milling vice and milled opposing flats, resulting in a piece 1/4" wide and 7/16 long.  






Got one piece in the picture mocked up with the air tube sitting in the flange.  When soldered, the top end of the tube will extend through the flange by about 3/32" and extend into the head by that amount.

Next I'll drill the holes on either side of the center hole.  These will be used to screw the flange to the cylinder head.

Chuck


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## kuhncw (Aug 8, 2012)

Chuck, nice work and interesting detail as usual from you.  I like your tubing bending fixture.

Regards,

Chuck Kuhn


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## cfellows (Aug 10, 2012)

kuhncw said:


> Chuck, nice work and interesting detail as usual from you.  I like your tubing bending fixture.
> 
> Regards,
> 
> Chuck Kuhn


 
Thanks, Chuck

That tubing bender does work nice.  You might pay particular attention to the little block that fits between the spool and the vice jaw.  I purposefull made it that size so it would be a firm fit... Didn't want to have to permanently fix it to the jig.

Got some more work done on the engine today.  I had kind of convinced myself not to make an oil pan for the crankcase, that I would just leave it open.  I like looking at the crank and rods and it also makes it easy to oil them periodically.  However, I decided the engine would look better if it had a pan, so today I got to work and made one.

I started off with a piece of 3/4" thick magnesium 3 inches long and 1.7" wide.






Here I've milled 3/16" of each side to form the bolt flanges for the screws which will attach the pan to the upper crankcase half.






Next I milled out the inside of the pan and rounded the inside edges along the sides.






Finally I rounded over the outside bottom edges.





And here's a picture of the two halves placed together.






Chuck


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## RonGinger (Aug 10, 2012)

Chuck, how did you keep those brass pieces in the hex socket? Ive always found sockets to be a bit over the stated size. Ive tried to stick bolts in them as a holder to reach down into tight places, but never found anything that held well enough to work, but then would release the part.


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## Don1966 (Aug 10, 2012)

Great work Chuck, love the pan. How will you mount it, will you be putting feet on the pan? I also liked you bending jig, but I use glass beads in the tubing just in case.

Don


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## dsquire (Aug 10, 2012)

Chuck

I haven't been saying much but thought that I better let you know that I am watching your progress. I like some of the ideas that you have came up with to solve some of the problems that have came up. You are doing an excellent job. Thanks for continuing to share it with us.

Cheers 

Don


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## cfellows (Aug 10, 2012)

RonGinger said:


> Chuck, how did you keep those brass pieces in the hex socket? Ive always found sockets to be a bit over the stated size. Ive tried to stick bolts in them as a holder to reach down into tight places, but never found anything that held well enough to work, but then would release the part.


 
Hi Ron,

The socket I used actually had a pretty close fit with the hex rod.  And, of course, the drill bit was pressing the hex rod into the socket against a shouldered down diameter inside.   I think rather than sockets typically being oversized, that nuts and bolts tend to be a little bit under-sized.  Maybe I just got luck on this one..

Chuck


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## cfellows (Aug 10, 2012)

dsquire said:


> Chuck
> 
> I haven't been saying much but thought that I better let you know that I am watching your progress. I like some of the ideas that you have came up with to solve some of the problems that have came up. You are doing an excellent job. Thanks for continuing to share it with us.
> 
> ...


 
Thanks, Don.  I have to use every advantage I can think of since I don't always have the right tools and I sure don't have near the talent of a lot of you guys!

Chuck


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## cfellows (Aug 13, 2012)

Here's a couple of photos of the engine partially assembled.  I rounded the vertical edges of the oil pan and it looks better that way!  Had to use a file since I couldn't figure out any other way to do it...











Next I'm laying out the lines and drilling the holes in the head to accept the air supply tubes and the slave valve assemblies.

Chuck


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## Don1966 (Aug 13, 2012)

Awesome Chuck, I really like the look of it. Still waiting to see how the rotary valve will look like. Please give us details on it when you start?

Don


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## cfellows (Aug 14, 2012)

Don1966 said:


> Awesome Chuck, I really like the look of it. Still waiting to see how the rotary valve will look like. Please give us details on it when you start?
> 
> Don



Thanks, Don, I hope that part will be coming up soon!

One last picture for the day.  I finished soldering the bolt flanges onto the inlet air tubes this evening.  






The flanges are a little bulkier than I'd like, but I'm not inclined to try to slim them down at this point.  Next I'll have to assemble the flange nuts and then put the flange on the bottom end of all the tubes.  I hate it when I get to this part.  One little misstep can flush a lot of work down the drain!

Chuck


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## rhitee93 (Aug 14, 2012)

Looking great Chuck


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## cfellows (Aug 14, 2012)

rhitee93 said:


> Looking great Chuck



Thanks.  I'll be mightly glad to get past all this fiddly work and get back to parts that are less susceptible to error!

I managed to sneak in a little more shop time this morning.  I got the air inlet tubes all flared with the flare nuts in place.  It was really pesky getting the length on those tubes correct.  There is very little margin for error.  I used a piece of 5/8" thick cold rolled steel plus an .008" feeler gauge blade clamped in the vise as a gauge and filed the tubes to length.  I would have used 3/32" compression fittings if I'd been able to find any, but didn't have the patience to search the internet for them.  I might have gotten by with using a short length of 1/8" tubing as a compression fitting.  Need to try that some day, it would be a simple solution.






Chuck


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## SilverSanJuan (Aug 14, 2012)

Sure looks great Chuck.  It is coming along nicely.

Todd


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## vcutajar (Aug 14, 2012)

It is really shaping up nicely.  Keep it up.

Vince


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## cfellows (Aug 15, 2012)

Thanks for the support and the comments.  Keeps me plugging away at times I'd rather be doing something else!   

Here's a video of me using my new Arduino dividing head, built and programmed by yours truly, to cut the small timing gear.  Kind of boring for you guys to watch, but I found it very exciting to do!  That electronic dividing head makes gear cutting a breeze.  I also have a video of me cutting the larger timing gear out of brass, but I haven't loaded it yet.

[ame]http://www.youtube.com/watch?v=A6CrFMwxbxQ[/ame]

Chuck


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## cfellows (Aug 15, 2012)

Here's a picture of the gears (so far).




Chuck


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## Don1966 (Aug 15, 2012)

awesome Chuck, you mill makes short work of those gears. I like it got to maske me one of those.

Don


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## dsquire (Aug 15, 2012)

cfellows said:


> Here's a picture of the gears (so far).
> 
> 
> 
> ...



Chuck

Are you making invisible gears now. If you are, then that explains why I can't see them. :hDe:

Cheers 

Don


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## cfellows (Aug 16, 2012)

dsquire said:


> Chuck
> 
> Are you making invisible gears now. If you are, then that explains why I can't see them. :hDe:
> 
> ...


 
Don, are you suggesting the gears are a bit imposing???   They are pretty big but I didn't particularly want to make smaller gears and have to use an idler in between.  I'm going drill holes or make spokes in the larger gear so it will be less bulky looking.

Chuck


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## rhitee93 (Aug 16, 2012)

Hi Chuck,  I don't want to speak for Don, but I think there was a period yesterday evening that the gear photo wasn't showing in the posts.  At least it didn't show up on my tablet last night.  It may have just been me.

I'm loving the engine.  Your design skills are impressive


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## Maxine (Aug 16, 2012)

Nice application for the Arduino.  Cool!


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## mulac321 (Aug 16, 2012)

Hi chuck very impressed with your work, can't wait to see it run. i've got a bit of a way to go before i could make 8 parts all the same   . I've been working on an arduino Indexer for my rotary table, would be interested to here more abouts yours, was there a thread for it I missed? 
Calum


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## dsquire (Aug 16, 2012)

cfellows said:


> Don, are you suggesting the gears are a bit imposing???   They are pretty big but I didn't particularly want to make smaller gears and have to use an idler in between.  I'm going drill holes or make spokes in the larger gear so it will be less bulky looking.
> 
> Chuck



Chuck

Honest. When I wrote that reply there was no hint of a gear in your post. As you know we are both moderators so we have editing privileges. I looked at your post and couldn't see anything that could link to a photo. It must be that gremlin at work again. 

Whatever was the case I am glad to see it now and as usual it is more outstanding work from you. The whole project is imposing but in a good way. Thanks for continuing to share it with the HMEM members.






Cheers 

Don


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## cfellows (Aug 16, 2012)

Thanks to all for your support and kind words.

I thought for sure Don was poking fun at the fact that the two gears look particularly imposing in the photo I put up.  Photobucket was doing some maintenance last night and none of the photos from there were displaying.

Chuck


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## cfellows (Aug 16, 2012)

mulac321 said:


> Hi chuck very impressed with your work, can't wait to see it run. i've got a bit of a way to go before i could make 8 parts all the same   . I've been working on an arduino Indexer for my rotary table, would be interested to here more abouts yours, was there a thread for it I missed?
> Calum



Thanks, Calum.  Here's a link to the build thread for the dividing head:

http://www.homemodelenginemachinist.com/f39/electronic-dividing-head-using-arduino-17896/

I plan to rebuild the electronics using an Arduino Nano, and replacing the display/keypad combo with a new display and and infrared remote for issuing commands.  I'll start another thread when I start work on that.

Chuck


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## Aydelott (Aug 17, 2012)

I just made a similar crank but its only there pieces I have a few ideas on indicating it in true but I  would like to know how you are going to do it ? Are you silver soldering it together ? Or press fit? it looks great!!!


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## cfellows (Aug 17, 2012)

Aydelott said:


> I just made a similar crank but its only there pieces I have a few ideas on indicating it in true but I  would like to know how you are going to do it ? Are you silver soldering it together ? Or press fit? it looks great!!!



My crankshaft was made from one solid piece of 12L14 steel rod.  Luckily, it turned out about as true as I could expect.

Chuck


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## cfellows (Aug 17, 2012)

I am so tired of tapping.  So far I count 106 holes drilled and tapped plus the 8 flare connections threaded on each end.  But, I think the worst is done.  

These are 8 pieces of brass turned from 7/16 rod.  They are destined to become exhaust flanges that will hold the slave valve and spring inside the head.






I used my square 5C collet block to hold each flange while I milled a flat on opposite sides.






Here's 9 of them ready to drilled.  I save the exhaust hole in the middle until the very end since it really weakens the piece.






And here's a few teaser pictures.  Still got a few more things to complete before it's ready to run, but this gives you an idea of what it will look like.





















Might have this thing running in a few days!

Chuck


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## rhitee93 (Aug 18, 2012)

Aesome!


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## ozzie46 (Aug 18, 2012)

Looks fantastic, Chuck. Can't wait to see and hear it run. Excellant build log.

  Ron


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## Don1966 (Aug 18, 2012)

Wow! Chuck that is looking great, almost looks like a real Car engine.

Don


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## SilverSanJuan (Aug 18, 2012)

Chuck, this engine is so cool!  A really neat design.  And, some really nice work by you.  I'm looking forward to seeing it run.

Todd


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## cfellows (Aug 18, 2012)

Thanks everyone, for the kind words.

I need 8 springs for the slave exhaust valve assemblies, well maybe 10 if you count the 1 or 2 that will almost certainly get dropped and disappear into another dimension or at least into the neighbors yard which at it's closest point is at least 50 feet from my workbench (they are springs, after all!).

So I found a smokin' deal on ebay for exactly the right sized springs...






I didn't count, but there are supposed to be 250 springs there.  Guess I'll be building a few more engines...

Chuck


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## cfellows (Aug 19, 2012)

Actually beginning to feel like an engine now.  I installed the crankshaft, rods and pistons.  I had to turn it over a few times with the drill, but that was probably just to remove bits of metal and dust.  Turns over with my fingers now with little very little detectable slop anywhere.  I'm sure there is slop, but I guess the misfits are in random and opposing directions making the overall assembly feel pretty snug.






Next I guess I'll decide on a flywheel.  I could make another steel propeller, but that is a fair amount of work and I managed to get smacked by them quite a bit on the other two engines I build with propellers.  Maybe a small, thick sectioned steel or brass flywheel, like those found on older marine engines?  I'd gladly entertain any ideas...

Chuck


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## kuhncw (Aug 19, 2012)

That is really looking great, Chuck.  Very nice work.

Regards,

Chuck Kuhn


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## Brian Rupnow (Aug 20, 2012)

Chuck---what a marvelous build!!! I've noticed it on the forum but didn't realize it was you building it. I have a sore back from too much machining today, so I'm taking some time to read through the various posts, and just discovered yours. Beautiful work as always.----Brian


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## cfellows (Aug 20, 2012)

Thanks, Chuck.  Thanks, Brian.

Here's the process of building the rotary valve tube.

The rotary valve tube actually starts out as a 3/16" length of drill rod.  The first step is to press a small flange onto the back end.  






I made the flange from 5/16" drill rod and drilled the center hole with a #2 drill bit which is about .002" smaller than the 3/16" diameter of the valve tube.  I deliberately made the flange over-sized on both the diameter and length so I could turn it to finish dimensions after it was fixed on the valve tube (which is still a solid rod at this point).  Here's how the valve tube will fit in the engine once finished.






Next I had to drill a 3.5" deep center hole in the rod.  The only bit I had which was long enough was 1/8" so that's what I used.  I had to back out of the hole, clear the chips, and add oil about every 1/8" to keep the drill on center and to keep the chips from piling up and seizing the bit.






Once the center hole was drilled, I inserted the valve tube into the crankcase from the back.  Here's a picture of the valve tube fully inserted after I had drilled the center hole.






I then attached the larger timing gear to the front part of the valve tube where it extended out of the crankcase.  Notice that the center hole does not go all the way through the valve tube.  Here's what it looks like with the valve tube installed and the two timing gears attached to the valve tube and crankshaft, respectively.  The crankshaft and the valve tube are now geared together and the valve tube will rotate at 1/2 the rate of the crankshaft giving the engine 4 stroke operation.






Here I've turned the crankshaft so that the first cylinder in the firing sequence is at top dead center (far right cylinder).






Next I attached a disk which has 4 lines scribed 90 degrees apart to the crankshaft.  These lines are used to measure exactly 1/4 turn of the crankshaft.






Here I'm ready to start drilling the holes in the valve tube.  I've already center drilled the holes in the flare fittings so it's just a matter of running the drill bit down until it hits the valve tube and drilling through to the center hole.






After drilling the first hole, I rotate the crankshaft 1/4 turn and proceed to the next cylinder in the firing sequence where I again drill a 1/16" hole through the side of the valve tube into the center hole using the cylinders flare fitting as a guide.  This operation is repeated until holes have been drilled for all 8 cylinders.  This results in 8 individual holes in the correct position for each cylinder.  Note, however, that after I finish drilling all the holes, I have to retard the valve tube timing.  As drilled, the holes are fully open when the piston would be at top dead center and in fact you want the piston to be half way through it's stroke before it's valve hole is fully open.

I hope this is a little clearer than mud.  Let me know if you have any questions.  I expect to have this engine running by the end of the day.  Or perhaps I should, ready to run by the end of the day.  Whether it actually runs remains to be seen!

Chuck


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## rhitee93 (Aug 20, 2012)

That is a clever way to position the valve holes.  I am afraid I would have done it with an indexing head and a lot of calculating, and I would have messed it up a few times before I got it right! K-point from me.

Nicely done


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## cfellows (Aug 20, 2012)

It Runs!!!! And does it sound sweet.  I'll get a video up pretty soon...

Chuck


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## cfellows (Aug 20, 2012)

Here's the video...  Couldn't be more pleased with the way it runs.  Do wish it was a little louder on the exhaust note.  Any body know where I can get some miniature glass-packs?

[ame]http://www.youtube.com/watch?v=f0VIV4CVl-U[/ame]


Chuck


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## Maryak (Aug 20, 2012)

Beautiful work Chuck 



Best Regards
Bob


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## dreeves (Aug 20, 2012)

Great job on the engine Chuck. woohoo1

Dave


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## Brian Rupnow (Aug 20, 2012)

Great work Chuck, as we've came to expect from your creative builds. Congratulations.---Brian


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## picks27t (Aug 20, 2012)

Nice Job Chuck i started you four cly. boxer last winter hope to finish this winter and start this V-8 sure hope you can share your plans on this one again Wow that is Great 

Thanks


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## GailInNM (Aug 20, 2012)

Very nice Chuck.
Gail in NM


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## dsquire (Aug 21, 2012)

Chuck

Very impressive engine. Looks, sounds and runs very nice. Another one that you can be proud to add to your collection.

Cheers 

Don


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## vcutajar (Aug 21, 2012)

Great work Chuck.  Another beutifull build.  Thm:

Vince


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## SilverSanJuan (Aug 21, 2012)

WOW!!!  That is beautiful Chuck.  She sounds sweet at idle.  Has a nice lope to it like a V8 with a hot cam in it.   Sounds nice revved up too.  What's the next step?

Todd


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## rhitee93 (Aug 21, 2012)

That is way cool


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## melw44 (Aug 21, 2012)

I have to chime in here. That is one nice engine. 
Mel W.


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## cfellows (Aug 24, 2012)

Here's another vido.  This one is several videos combined, with a small flywheel, no flywheel, a propeller, and one with the oil pan removed to show the rods and crankshaft.
http://www.youtube.com/watch?v=NSFASUx_NkY&feature=youtu.be
Notice the sound is amplified by the board it's sitting on.  I'm going to make a sound box to run my engines on.
Chuck


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## Maxine (Aug 24, 2012)

Nice, real nice!

Maxi


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## SilverSanJuan (Aug 25, 2012)

That's awesome Chuck!  I love the sound on the board.  And, the start up sounds with the propeller are really cool.  It sounds just like a plane starting up when the momentum of the propeller is overcome.  Nice work.  I would love to build one of these some day.

Todd


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## rhitee93 (Aug 25, 2012)

I love the piece with the crank shaft exposed.  I could watch that all day


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## cfellows (Dec 11, 2012)

I have just uploaded the full set of drawings for this engine.  The drawings were done by John McClelland.

Chuck


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## johnmcc69 (Dec 11, 2012)

I hope everyone enjoys the plans. This
 was an enjoyable project.

Would love to see your builds of it here..

Chuck did a great job on this engine.

John


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## idahoan (Dec 11, 2012)

Hi Chuck

I some how missed this when you got it running a while back.

Nice Job!

Dave


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## lensman57 (Dec 12, 2012)

Hi Chuck,

Congratulations, excellent looking engine with a sweet sound. Where did you get the plans from if may ask?


Regards,

A.G


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## lensman57 (Dec 12, 2012)

Sorry Chuck, Found the drawing in the plans section. 

Regards,

A.G


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