Manifold for DIY bottle Manometer (Updated!)

thingiverse

A multi-cylinder model is now live! When setting up a bottle chain, you'll want to use three-port manifolds for the middle bottles and two-port manifolds for the bottles on the ends. Each bottle should be connected to every bottle next to it in the chain. For a four-cylinder engine, the order would be 2-3-3-2, while a six-cylinder engine would be 2-3-3-3-3-2. Make sure that the connecting hoses reach all the way to the bottom of each bottle, and only just poke through the top for the intake hoses. The more bottles you run, the lower the overall fluid level will need to be - do not run more than 3/4 of a single bottle of fluid. Excess fluid in the chain can cause one cylinder to suck everything into one bottle, then up the hose and into your engine, resulting in hydro-lock. Similarly, running only two bottles can cause all the fluid to get sucked into that one bottle, drowning your engine and bending or shattering the connecting rods. Throttle body/carburetor balancing is probably the most neglected part of motorcycle maintenance, and when people find out how much the tools cost, they "nope!" right out. Here's the secret: no expensive tools are required. All you need are a few sealed containers, some flexible hose that won't collapse under vacuum, and a way to connect them so each pressure bottle is linked to all the others. These manifolds are sized to fit 1/4" O.D. clear vinyl tubing, just fitting into the cap of a typical bottle. Bottles of Jack were used for this example because they are squared off and fit together neatly into an array. Round bottles will work just as well, as long as everything sits flat on the bench. To ensure no leaks, gaskets can be made from old inner-tube, silicone sealing tape, cork, or even a schmear of RTV on the underside of the manifold itself. The holes in the manifold are just small enough to grip the tubing snugly and should hold a seal without any help. If you're using RTV, it's a good idea to double-check for leaks. If you find a slight leak where the hoses pull through the manifold, this can be solved with a few drops of oil or even a dollop of RTV. Manifolds pictured were printed using nylon 6,6 weed-whacker line because that's what I had on hand that could handle heat and chemical exposure. I believe ABS/ASA would actually be a superior option, as you could use acetone to seal and fix the tubing in place, creating a form-fitting seal against the mouth of the bottle. You'll need the original bottle caps to clamp the manifold onto the bottle mouth. Just cut a 20mm diameter hole in the center of the cap, and the manifold will slot right in. The hole needs to be circular so that the bottle cap can spin independently of the manifold, just like mason jar lids work. Be aware that while any liquid can be used in the bottles, if an organic fluid is used, you'll need to open and clean out the bottles after use - mold doesn't make for good sighting fluid. Also, note that it's diluted coffee in the bottles, not liquor!