Stephens knuckle head build

[driller1432]

It's a twingle I started to work on cam to crank timing after I made the flywheel and engine stand so I could roll the engine over so I focused on one cylinder piston going down intake open piston up fire then exhaust normal cycle then looked at other cylinder and it's almost right on the same combustion cycle! What this can't be right-----or can it after researching on the Internet for a while I found it will work it's called a Big Bang or twingle instead of the normal 315-405 firing interval it fires at 45-675. So both cylinders fire the at the same time or pretty close to the same time. I never worked on V twins so all this is new to me. So Hera are more pictures of mock up. Oil pump installed
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Starter/ generator
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Flywheel complete it was fun rolling the bar for the rim
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Pushrod tubes and push rods
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Distributor
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Die for making head gaskets
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The engine rolls over so smoothly with so little effort (no rings on Pistons) I can't say it enough what an amazing set of plans Jack Draw-Tech has created. Back to the shop need to get some fuel & fire going, see if I can get it to backfire or run. Still lots of small parts to make! Happy New Year to all.
Steve

 

[gbritnell]

I don't know if the design intent was to make it a "twingle" or not but a Knucklehead engine doesn't fire both cylinders at the same time. At one time Harley went to what you're describing but it was only for racing. All Harley V-twins fire at 315 and 405 degrees. They have a waste spark for the cylinder that isn't under compression.
gbritnell

 

[Hopper]

Twingle? sounds bizarre. Probably worth checking with the designer on that one. Usually only works on twin-carb engines for racing. Otherwise the second jug starves for fuel mix.

The engine is looking beautiful now. Awesome how quickly you have done all that work!

Keep us posted.

 

[driller1432]

Checked with Jack on firing interval and that's how he designed it to fire so I,m going with it. If it don't work I will make cam with conventional firing interval 315-405 which will be very easy to do with the design of cam i.e. Unsolder lobes make new shaft install lobes in new positions modify the dizzy What could possibly go wrong💥 Thanks guys

 

[Hopper]

I might have to get my old Harley 45 out and retime the cams to run as a twingle. could be kind of fun. It has four separate cams on four separate shafts and gears so would only take an hour or so to do. Hmmm....

 

[driller1432]

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Camshaft redesign, well folks after getting the distributor put together and installed and rotating engine and taking a hard look at valve timing and ignition timing I'm not liking this twingle idea, so ( hopefully today) I am going to remake cam with conventional firing interval which will also make engine run opposite of what it is now. Then the flywheel will push air to engine and the little rope starter will be going in right direction.View attachment ImageUploadedByModel Engines1452956982.785333.jpg

 

[driller1432]

Oops hit reply button before I was done. I will make cam lobes slightly larger which will move (angle) the lifters away from each other for more clearance between them. The way the cam is designed with keyed on lobes will allow me to move them around before soldering into place.
So it's time to get out the degree wheel and dial indicators. The engine has a long stroke of 1.250 so I should be able to increase duration of valve opening. I'm not an engineer so I can't figure out on paper so I'll have to make a single lobe put on shaft and use degree wheel and indicators to check opening closing and duration. I
found a cam card for a full size knucklehead that gives me lobe center lines that helps a lot.

 

[dethrow55]

awsome im thinking of this build.will follow looks great.

 

[t.l.a.r. eng]

Are the belts used for the starter designed to run in oil?

Everytime I get oil next to one of those little toothed belts it turns into a disaster.

I boldly assume there is going to be oil in the crankcase.

 

[driller1432]

Yes there will be oil in crankcase belts are polyurethane with Kevlar cords oil resistance and 130# per 1/8 inch width breaking strength according to manufacture

 

[Hopper]

That engine looks flat-out beautiful! True craftsmanship.
Here is a link to Andrews cams specs for Knucklehead cams, might be some help to you.
http://www.andrewsproducts.com/sites/www.andrewsproducts.com/files/catalog_pdfs/2014-page14.pdf

 

[driller1432]

Hopper thank for your kind remarks and the cam chart will help to figure out new cam I truly appreciate your help. I did not work on cam yet as I received tungsten rod to finish spark plugsView attachment ImageUploadedByModel Engines1453041497.693761.jpg
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[Bowtie41]

I just dl'd the drawings.Thanks Jack!
Driller,I noticed in the first photo of your post that some of the holes "broke out".Is there a problem with the dimensions of the holes,did your drill/tap walk,or is the pocket oversize?I will start mine when the shop gets warmer.I haven't had a chance to peruse the dimensions.It will probably still seal fine,just be careful when assembling,but I wish to avoid the same dilemna.Thank You.

 

[driller1432]

Bowtie if your talking about the rocker box covers witch I think you are dimensions are very close so a little drill walk or flex could have cause that. The pocket curves in as it goes down so further down I have full thread so no concern to me. Also when I made those parts I had A HF round column mill not the best as quill was a little sloppy on extension.

 

[Bowtie41]

I was.Thank You for clearing that up.When I get to that point,I may centerpunch before the centerdrill.

 

[Rozlo]

Diller,
Where did you get the porcelain for your plugs? Very good work on these, I've tried to get information on building plugs from others and they really dont want to help out.

Thanks
Bill

 

[Draw-Tech]

Hi Guys

Been offline for a while, Steve perfect as usual. Bowtie41, are you using a milling machine with an edge finder to drill the holes? Rozio, if you drop me a PM I can send the files for the plugs. The ceramic is coreian counter top material, it burns but bvery slowly, nd easy to machine. Seals by compression
Jack
Draw-Tech

 

[driller1432]

Camshaft redesign completed and done installed in engine started on fuel system manifold and carb body in lathe
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Got side tracked installed VFD on southbend 9 I like it
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Good to hear from you Jack
I'll try your method for making carb float i.e. Filling tube with sand or solder wrapping around rod a couple of wraps and cutting out best part thanks for the tip.

Thanks to everyone for nice comments

 

[Rozlo]

Very cool never thought of that.

 

[Parksy]

Amazing work driller. I hope one day I can achieve similar results in my future projects.

I have a question about a picture of your flywheel in post #42. What is the ring with the cut out? I see many people use this, but I don't understand how it works or what it actually is.

Cheers