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  1. R

    Making cast iron piston rings

    Mauro, Using your method how is the relaxed gap dimension determined, or did I miss something? Jeff
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    Santa's vintage generator

    Has anyone noticed the huge vintage steam or diesel 4 cylinder open crank generator in the current seasonal ServiceNow TV ad? Merry Christmas... Jeff https://www.ispot.tv/ad/tTzO/servicenow-chief-holiday-officer
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    fuel mixture issues. stuart 400 replica build.

    You do need a throttling carb, a barrel throttle type RC carb will work fine with about a .188" bore in the barrel. To reiterate, you need a propane regulator of about 4-5" water column output pressure (Weber Go Anywhere portable gas grill), a JH demand regulator (DR), and a throttling type RC...
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    Ignition question

    Lot of good discussion here, but like Gordon, over my head also. All I really know is that the 3 single coil waste fire CDI ignition ignition systems that Roy Sholl built for me have worked flawlessly for many, many, many hours on twin's with both 360 degree and 180 degree crankshafts. The video...
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    fuel mixture issues. stuart 400 replica build.

    Jasonb I assumed the 400 was H&M due to the first plan publication of the 1915 era and the hot tube ignition. With spark ignition it just means the fuel mixer can be changed to a simple carburetor with a throttle for speed control. Preferably a self compensated RC carb that maintains a...
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    fuel mixture issues. stuart 400 replica build.

    miss_emma_jade A propane fuel system for a hit & miss engine is one of the simplest fuel systems in use and lots of good suggestions here. But it depends on whether you are trying to duplicate the "original" fuel system for this Stuart engine or just want to get it running for now. I cannot help...
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    My Improved Snow Engine

    Colin, Glad to hear you continue making progress. I used a piston rod connector that another Snow builder designed which takes careful close tolerance machining of the coupling and the rod ends. I machined the coupling completely in one piece before cutting it in two with a .010” slitting...
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    Snow engine thoughts

    The intake manifold was made by soldering two 3/8” x 3/16” rectangular cross section brass tubes back to back. See photo of the open end cross section before closing it up. The center carburetor cross section sketch shows the coolant water path at the carburetor. I suggest you put a drain...
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    My Improved Snow Engine

    Colin, You have been busy. Glad you are getting positive results. Jeff
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    Another Water-Cooled Twin

    John, The article is copyright protected so I cannot copy it, but Dave Bowes article is well worth the cost of a back issue. I suggest you contact MEB at www.modelenginebuilder.com Jeff
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    Another Water-Cooled Twin

    John, I highly recommend that you read Dave Bowes article A Few Thoughts on Valve Timing in issue 12 of the Model Engine Builder magazine. It has everything you want to know including the timing diagrams for low, mid, and high speed engines. Jeff
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    Another Water-Cooled Twin

    John, Yes, the S/S wasted spark version of the S/S CDI ignition will reliably fire both plugs simultaneously. See two links below: the first is a 180 crank engine and the second is a 360 crankshaft. Both are using the smaller 10-40 thread Rimfire spark plugs. Someone else on this site may have...
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    Another Water-Cooled Twin

    John, With a twin cylinder engine you can use a single coil waste fire ignition for either 180 or 360 degree crankshaft design engines. Use a Hall sensor for timing and just add one more magnet for 180 degree crankshafts. S/S offers a very compact CDI waste fire ignition using 4 AA batteries. I...
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    Another Water-Cooled Twin

    John, It could be the carb. My guess is too large. What is the carb throat dia? Have you tried this carb on propane? I use RC carbs with a demand regulator on most of my engines. I use a 3 mm throat size carb on a 4 cylinder 1"b x 1.125"s. I don't run it that fast, but it will go faster if...
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    My Improved Snow Engine

    Colin, With a new untried engine you have to know for sure that you have good sealing piston rings and valves. An absolute must on the Snow. Your pistons should not contact the cylinder walls. The pistons should float between the two piston rod bushings on each cylinder head. If all is good, you...
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    My Improved Snow Engine

    This is the proverbial Snow tandem double acting gas engine designed by Doug Kelley that I built in 2008. It is my favorite model engine. I never took any video of it at the time. Over the years this little engine and I have had our ups and downs and finally last year we had a bit of an...
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    reamed hole vs. drill rod size

    Petertha, Steamchick Watch this How Its Made video on manufacturing light aircraft engines. In the very beginning they show similar use of the tools you discuss for polishing their aircraft engine crankshafts. The outside cylindrical hone does much the same thing and we are now discussing the...
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    reamed hole vs. drill rod size

    Silver brazing SS head on the stem is fine. Turn a shoulder on the stem to keep the SS head square. Chamfer the stem hole in the head piece. Put a small dab of flux and small piece of braze wire in the chamfer. Stand the stem on end in a vise and heat from the stem side with a butane hand torch...
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    reamed hole vs. drill rod size

    Petertha, Yes, that is the hone I made and use. Jeff
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    reamed hole vs. drill rod size

    John, Yes, phosphor bronze is much harder than brass. It holds a good seat and should wear better than brass. Machine the valve cages on one setup on the lathe to maintain concentricity. After drilling for the valve guide, and before reaming, make a light pass with a carbide boring cutter...
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