Original Posted By: "Douwe Blumberg"
My Uncle Tony says no Teflon tape in fuel system plumbing but recommends this "beeswax-like" substance and it works great. (as long as you don'tget any in the ID of any fittings.)Mike C.[cid:image001.png(at)01CE941A.080F3D00]________________________________________________________________________________
Pietenpol-List: fuel component thread sealing compound
Pietenpol-List: Re: Speed
Original Posted By: "tools"
Hey Dan,Years ago, I delved into this subject when coming up with ways to replicatethe performance of WWI type engines.While the Ford is much closer in performance to these older engines thanmodern aircraft engines, there are still some major differences whichaccount for the Gnome's ability to spin that large paddle prop while theFord struggles with your four-blader.First off, the 50hp Gnome is a 488 cubic inch capacity engine while yourFord is around 200...Secondly, it is producing all of it's torque at 1200, while yours needs tospin up closer to 2,000 to produce max torque. Since drag on these propsincreases exponentially, one can see how much more power would be requiredto spin that prop even a few hundred rpm more.With old engines, airplane guys always get confused with HP and torque,assuming that a modern 180 Lycoming can spin the same nine foot prop a 180mercedes of almost 900 cubic inches did. IT can't, they are two differentanimals.It's like the old 35hp tractors which can pull three plows behind them whileyour 500hp mustang never could.I think it's a great experiment, but my guess is that you'll need togradually thin those blades down until you can turn up a bit more.Good luck!Douwe________________________________________________________________________________Subject: Pietenpol-List: Re: Speed
Hey Dan,Years ago, I delved into this subject when coming up with ways to replicatethe performance of WWI type engines.While the Ford is much closer in performance to these older engines thanmodern aircraft engines, there are still some major differences whichaccount for the Gnome's ability to spin that large paddle prop while theFord struggles with your four-blader.First off, the 50hp Gnome is a 488 cubic inch capacity engine while yourFord is around 200...Secondly, it is producing all of it's torque at 1200, while yours needs tospin up closer to 2,000 to produce max torque. Since drag on these propsincreases exponentially, one can see how much more power would be requiredto spin that prop even a few hundred rpm more.With old engines, airplane guys always get confused with HP and torque,assuming that a modern 180 Lycoming can spin the same nine foot prop a 180mercedes of almost 900 cubic inches did. IT can't, they are two differentanimals.It's like the old 35hp tractors which can pull three plows behind them whileyour 500hp mustang never could.I think it's a great experiment, but my guess is that you'll need togradually thin those blades down until you can turn up a bit more.Good luck!Douwe________________________________________________________________________________Subject: Pietenpol-List: Re: Speed
Original Posted By: "Dennis Engelkenjohn"
As Piet folks, we really don't spend much time rigging our planes. Most Pietsfly around with the elevator not in line with the stab in normal cruise flight.The Piet tail is not a lifting tail like a bleriot (spelling) or something. Eventhough the elevator is deflected down in level stable flight, the tail is holdingthe nose up. What that would indicate is that the stab should be trimmedout to eliminate that extra drag.Struts and washout should be trimmed for fastest cruise. Incidence should be trimmedfor minimal drag...When I rebuilt my Piet, which included making new wing struts, I'm sure the planewas rigged differently than before. However, it felt the same so I let itgo at that. However, it was faster than before, I attributed it to finally beingcomfortable enough in the plane, and by myself (before always instructingmy son) to realize it went faster with the ball 3/4 out to the right, meaningthe plane wasn't rigged right, the ball indicator wasn't rigged right, or thenew struts just happened to rig the wing in a way that was faster.While airfoils obviously make a difference, in our performance zone, I'm thinkingstuff like I mentioned is simply more likely than the trailing edge difference.Larry Williams thought maybe his leading edge half ribs slowed his plane down significantly...who knows?!Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________
As Piet folks, we really don't spend much time rigging our planes. Most Pietsfly around with the elevator not in line with the stab in normal cruise flight.The Piet tail is not a lifting tail like a bleriot (spelling) or something. Eventhough the elevator is deflected down in level stable flight, the tail is holdingthe nose up. What that would indicate is that the stab should be trimmedout to eliminate that extra drag.Struts and washout should be trimmed for fastest cruise. Incidence should be trimmedfor minimal drag...When I rebuilt my Piet, which included making new wing struts, I'm sure the planewas rigged differently than before. However, it felt the same so I let itgo at that. However, it was faster than before, I attributed it to finally beingcomfortable enough in the plane, and by myself (before always instructingmy son) to realize it went faster with the ball 3/4 out to the right, meaningthe plane wasn't rigged right, the ball indicator wasn't rigged right, or thenew struts just happened to rig the wing in a way that was faster.While airfoils obviously make a difference, in our performance zone, I'm thinkingstuff like I mentioned is simply more likely than the trailing edge difference.Larry Williams thought maybe his leading edge half ribs slowed his plane down significantly...who knows?!Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________