Without a question this creation is an engineering marvel with a blend of new original designed components and some tried and true Mercury items. When the creation comes to life it surely will bring a smile to everyone's face. The machining of the components has been a slide show worth seeing. It would be cool to make a CD with all the photos along the way. Can not wait to see this beauty standing tall.
Again Well Done!
Alan
Still waiting on the main bearing races, so work continues on the carbs conversion to alcohol. Added some pictures of the small parts being made for the conversion. Probably not as interesting as the engine work, but work that is still required to complete the project.
The conversion requires new main nozzles to eliminate the atomizing air from entering the tube. Just solid fuel flow. The main fix jet is removed and replaced by an adjustable needle valve that seats into the jet hole.
The carb bowl had a 1/4 in pipe plug for access to the main jet. That was removed and drilled and taped to 9/16" X 18 thread which is the thread and size of the pipe plug, just straight and not tapered. An aluminum adapter is made to screw into the bowl to accept the needle valve which will include o-ring seal and spring loaded for adjustment friction to hold adjustment.
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As usual very impressive , I'm waiting to see your main bearing solution . Final assembly must be in sight now. Glen
Dam you're a geniusYou are a very rare breed, there just isn't that many that skilled around like you.
None of this is boring at all. In fact these little details make it all the more entertaining, let alone amazing.
Are those adjustables a mercury part or did you fabricate them from stock. All my adjustables for the Carter N's I have for my two loopers are missing. Just curious.
As the projects 2nd year end mark approaches, I am still working on the carbs and waiting for the main bearing shells.
The existing needle and seat will not supply the required amount of fuel so I pulled the pressed in float valve seats and have found an auto valve set that can replace the existing setup. It requires tapping the hole for the new seat. I aligned the carb with a pilot shaft that fits the stepped bore. The float valve has a 3/8 fine thread body and the casting with the seat removed is the right size for tapping with out drilling. First a starter tap followed by a plug tap and finely to a depth of 1/2 inch with a custom ground bottom tap to the bottom.
Then the excess was milled down to the base of the float hinge tower to allow for shortening the body and the valve far enough below the float hinge center line.
The idle/low speed fuel supply was from a tube that ran down the center of the high speed nozzle. This reduces the flow thru the high speed circuit and the flow thur the high speed jet. All fuel with this setup had to flow thru the high speed jet. So, to improve fuel quantity to both circuits, I removed the central idle circuit tube and relocated under the idle speed screw passage with a new tube. The hole in the top that the tube was removed from is tapped and plugged with an aluminum 6/32 stud. Now both the high speed and low speed circuits are clean, independent and can flow more total fuel. Just like the Model N Carters.
That of course required making new supply tubes. Taking a brass rod and drilling and reaming to the tube O.D.,to keep the tube from buckling or bending. Then grinding a taper with a smooth radius on the shank end of the correct size drill, I clamped the drill securely in a large vise with the drill exposed the length of the expansion. I then set the tube on the drill point and drove down with a hammer forming the expanded end to seat in the tube bore to complete the seal below the low speed idle screw and lock in place.
For those of you following this project, I wish you a Safe and Joyous Holiday Season.
TO BE CONTINUED NEXT YEAR.
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Outstanding attention to detail! The engine will be to nice to run hard and risk a failure. Hopefully the engine will be sound and set the standard for scratch built projects.
Alan
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