The Soft Head
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Addo, the in-flight emergency back-up source of hydraulic fluid for DC-3s and other airliners in the old days was pee, from aircrew, then passengers!
Well, now I understand your idea Joe; pretty clever! Instead of cutting up manifolds, it might be neater and quicker to buy some U-bend tubing from J.C. Whitney and weld or braze them into manifolds that are angled and radiused exactly as you want them. Remember those real old-fashioned hot rod EXHAUST headers that curved down into a megaphone? Your intakes could look a bit like that, with a tapering plenum.
(More uninformed speculation and questioning):
What are you (or Vizard, Widmer, et al) trying to DO with these uniformly curved manifold runners? I understand that you are trying to get a uniform swirl, cylinder to cylinder. But the ports in the head are all the same, and I still wonder if a longer straight run into the ports is best for delivering well-mixed fuel/air. Since fuel is heavy, presumably it would tend to get centrifuged out of the airstream as it inters a curved section, and maybe the air would tend to pile up against the outside wall a bit farther around the turn. If you must make a turn, is it really any better to do it with a tight bend or a sweeping bend? A sweeping bend ought to give better dry airflow numbers, but is it any better for wet-flow, for maintaining a semi-homogenous mixture of fuel in the air? Isn't the point of swirl to homogenize the not-too-well-mixed fuel and air being pressured over the edge of the open valve? If a homogenous mixture, and not big airflow numbers, is the goal, then it would seem that the manifold and carburetion (or injection) that will deliver the most homogenous mixture to the valve pocket is the best one. In that case, a siamese manifold from a single carb into two ports should deliver the same uniformity of mixture to each valve.
There's a guy who sells very sophisticated flow-benches on one of the other engine-tech sites. We oughta ask him whether wet-flow in a Big Six is observably different between 1-2-3 and 4-5-6. I'll see if I can find him.
Well, now I understand your idea Joe; pretty clever! Instead of cutting up manifolds, it might be neater and quicker to buy some U-bend tubing from J.C. Whitney and weld or braze them into manifolds that are angled and radiused exactly as you want them. Remember those real old-fashioned hot rod EXHAUST headers that curved down into a megaphone? Your intakes could look a bit like that, with a tapering plenum.
(More uninformed speculation and questioning):
What are you (or Vizard, Widmer, et al) trying to DO with these uniformly curved manifold runners? I understand that you are trying to get a uniform swirl, cylinder to cylinder. But the ports in the head are all the same, and I still wonder if a longer straight run into the ports is best for delivering well-mixed fuel/air. Since fuel is heavy, presumably it would tend to get centrifuged out of the airstream as it inters a curved section, and maybe the air would tend to pile up against the outside wall a bit farther around the turn. If you must make a turn, is it really any better to do it with a tight bend or a sweeping bend? A sweeping bend ought to give better dry airflow numbers, but is it any better for wet-flow, for maintaining a semi-homogenous mixture of fuel in the air? Isn't the point of swirl to homogenize the not-too-well-mixed fuel and air being pressured over the edge of the open valve? If a homogenous mixture, and not big airflow numbers, is the goal, then it would seem that the manifold and carburetion (or injection) that will deliver the most homogenous mixture to the valve pocket is the best one. In that case, a siamese manifold from a single carb into two ports should deliver the same uniformity of mixture to each valve.
There's a guy who sells very sophisticated flow-benches on one of the other engine-tech sites. We oughta ask him whether wet-flow in a Big Six is observably different between 1-2-3 and 4-5-6. I'll see if I can find him.
Seattle Smitty":m0ok1a9m said:
Highly likely that I won't do anything with this myself, just had too much coffee one night and got to thinking....
But the big boys say it's supposed to work....
It sure seems to me that wet flow into 1-2-3 would have to be different than 4-5-6. Interesting thought.
gb500: Thanks for the link to the SU carbs. Is that the same as a "constant vacuum" carb or do I have my terms cross-wired?
Joe
