Pietenpol-List: impulse mags

[matronics]

Original Posted By: "Clif Dawson"
I flew 41CC behind the A65 with two different mags (left and rightmags were different). Neither had impulse couplers and the olderone was a Scintilla "lunchbox", probably as old as the engine.Still threw a great spark.The A75 on the airplane now has matched, brand-new Slicks andthey both have impulse couplers.Honestly, I don't notice any difference in ease (or difficulty) ofstarting, probably because the compression is so low, the prop isso long, and I try to keep everything in a good state of tune. Ican't comment on starting a Ford without impulse coupling, but myexperience with my Continentals has been fine with or without.That plus the key to hand-propping these engines is finding theright starting routine and following it exactly, every time, andincluding whatever types of sprinkling pixie dust in the air orswinging a dead chicken make it work for you. There is also animportance to what you do when you shut the engine down, too. Ifyou shut off the fuel valve as you taxi up to your hangar and thenlet the engine sputter and die as it runs out of fuel before youkill the mags, it will start differently than if you leave fuel onand shut it off with the mag switch, leaving fuel in thecarb bowl. It will also start differently if after you turn offthe mag switch and as the engine is spinning down you roll thethrottle forward (open) instead of leaving it at the idle stop.I do not have a fuel primer; I pull it through a couple of bladeswith the throttle back at the stop so it will pull fuel throughthe idle circuit (Stromberg carb). It will usually start on thefirst or second blade after I go through the proper motions.Sprinkling the pixie dust works for me ;o)Oscar ZunigaAir Camper NX41CC "Scout"Flying Squirrel N2069Z "Rocket"Medford, OR website at http://www.flysquirrel.net ________________________________________________________________________________

[matronics]

Original Posted By: Ben Charvet
I remember reading somewhere that two impulsemags was a bad idea. I can't remember exactlywhy but I think it had something to do with someform of engine damage on startup.I thought it was one of the Skyranch articles I'vegot but it's not there.Both O-290's I've got have one impulse, on theleft. Also the parts book and repair manual saythe same.Clif> The A75 on the airplane now has matched, brand-new Slicks and they both > have impulse couplers.> Oscar Zuniga________________________________________________________________________________Date: Fri, 10 Feb 2012 09:33:49 -0500

[matronics]

Original Posted By: BRETT PHILLIPS
Thinkin' 'bout puttin' the Continental in the Ford? Think it'll cool alright?Seriously, need a cool oversized warbird style towbar to use your new accessoryto move the Piet into and out of the hangar! Ok, maybe that's not so seriouseither...My dad is finishing up a Model A restoration, would be cool to get a pic like that.ToolsdnaRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Fri, 10 Feb 2012 11:27:10 -0500Subject: Re: Pietenpol-List: impulse mags

[matronics]

Original Posted By: Michael Perez
One important difference to remember in this whole discussion is that the headmounted mag is turning at cam speed whereas the crank mounted mag will be mucheasier to coax a good spark out of.--------PAPA MIKERead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Fri, 10 Feb 2012 13:01:29 -0800 (PST)

[matronics]

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Looks good. How much will it hold?Jack PhillipsNX899JPSmith Mountain Lake, Virginia _____