Stephens knuckle head build

[Hopper]

@ Parksy -- looks like a taper-lock fitting that clamps the flywheel to the shaft as you tighten those three socket head screws. But I may be wrong. The drawings are available to download in the plans section of this site and should reveal all.

 

[driller1432]

Hopper you are correct it's a split taper bushing in a hub and uses 6 screws, I only have 3 in for mockup
Steve

 

[Parksy]

Thanks for that! I tried having a look for those plans but I couldn't find them. I don't suppose anyone has a link to them?

 

[Brian Rupnow]

Try this
http://www.homemodelenginemachinist.com/downloads/draw-tech-297.html

 

[driller1432]

Carburetor main body all machined and silver soldered together now have to make adjusting needles and needle seat for float. Tried to bend brass tube for float in circle no luck too tight of circle 1/4 inch inside of float filled with sand and another with solder. I will make die and stamp out float in 2 halves and solder together hope that works
View attachment ImageUploadedByModel Engines1454907750.355509.jpg
View attachment ImageUploadedByModel Engines1454907767.508502.jpgView attachment ImageUploadedByModel Engines1454907783.609574.jpg
Thanks guys

 

[10K Pete]

That's a great looking carb body. Excellent and very tidy fabrication work.

Pete

 

[Swifty]

Great job, looking very impressive.

Paul.

 

[Hopper]

Awesome work, again. Can you get some of those tiny stick-on letters the locomotive modellers use to put the "LINKERT" on the side of it?

On the full size Linkerts, most of us have given up on the hollow brass floats and go with the "Rubber Ducky" floats made from Nitrophyl M, the plastic foam material that modern car floats are made from.

More info here
http://www.rogerscorp.com/ec/nitrophyl.aspx

Those guys apparently will sell you a sample piece for $40 big enough to make 8 full size Linkert floats. But I reckon your local car wrecking yard might be able to sell you an old float big enough to cut one model size float out of.

The brass floats are notorious for leaking, either from the get go or after some use and corrosion takes place.
The original Linkert floats were cork and lasted for many decades. I still have one in use today, but it has been dried out and coated with expoxy since it got " waterlogged" in the 1970s.

 

[dethrow55]

that a great looking job. making the float in two halves should work well. Thm:Thm:Thm:

 

[driller1432]

Hopper thanks for the tip I suppose you could epoxy float hinge to nitrophyl and do you have to coat the nitrophyl with something after cutting and shaping? Thanks to the other guys for the compliments on work.

 

[Hopper]

Driller, you would have to ask Rogers, the makers of Nitrophyl about that to be certain. I buy my Rubber Duckies already made up and the hinge bracket is already moulded into the float.

If you could get hold of an old car float made from Nitrophyl you could play about with it and see how it reacts to gasoline if cut, and if epoxy will stick to it.

Or you might be able to buy a new float like this for $15 or less,
http://www.ebay.com/itm/Holley-116-...ash=item58c1c130af:g:xD0AAOSw34FVFfie&vxp=mtr

and play around with it.

 

[gbritnell]

Great looking work on everything so far! Here's some information I have found about making carb floats. Many years back I built a carb that was featured in SIC magazine. That particular float was a hinged type and made from brass shim stock. The construction wasn't a problem but given the small size it really didn't have the leverage to seal the needle consistently.
My next float experience was when I built the Holt engine. The drawings recommended cork so I tried it but it was a real pain
mounting and sealing it so I ordered an automotive float made of whatever synthetic plastic material they are made from. It was easy to carve and shape but I had the same problem as with the brass float, it just didn't have enough surface area to provide enough leverage to seal the needle. What I'm getting at is with the small size of your carb you might have a lot of tinkering ahead to get the float to function properly.
Gbritnell

 

[driller1432]

The float dilemma will definitely take some experimentation on my part, I could see where it wouldn't have enough bouyancy to hold needle on seat. Thanks guys for sharing your solutions

 

[driller1432]

This might work, fuel sender I replaced on jet ski has small round floats about the right diameter

View attachment ImageUploadedByModel Engines1455114564.407271.jpg

 

[Hopper]

That looks like the perfect set up to play around with.

 

[Bowtie41]

I was thinking of a flat "torroid"?? shaped Float?Soldered up from 4 strips of thin brass or SS shim stock.Ultralight,and way more bouyant than copper tubing,as it's too thick.Here's a drawing I whipped up in paint.Hope it helps!

 

[driller1432]

This is a great idea and very doable thanks bowtie I'll make a float like this and let you know how it works out!
Steve

 

[dnalot]

Hi

When I had a boat building shop I used microballoons ( tiny hollow glass spheres ) to make very very light weight fillers for filling voids in fiberglass. It was extremely strong when mixed with epoxy or fiberglass resin. It would make a very durable material to make floats with.

I am watching this build closely, as I would like to build this engine. I have to say your work is impressive, as I am impressed.

Mark T

 

[driller1432]

Microballons I think I have some from R/C boat I built thanks for compliments on work

 

[ddmckee54]

Could you fill a built-up float with loose micro-balloons? That way even if a seam leaked you couldn't lose much floatation. As long as you didn't use any binder when installing the micro-balloons you wouldn't be adding that much extra weight to the float. Of course if the seam split open wide enough you'd have micro-balloons throughout your carb/engine.

Just wondering,
Don