Original Posted By: "Greg Yotz"
I would also like information on the Russian Engine, anyone found a website?Also...Here's one for you Model-A engine gurus, which engine stud is the ignitionstud (the stud that is 1/4" longer than the rest). Also, why is it longer?Robert HainesMurphysboro, Illinois________________________________________________________________________________
Pietenpol-List: A-engine
Re: Pietenpol-List: A-engine
Original Posted By: Robert Haines
The center stud just behind the distributor held the armoured primary cablewith a clip of various design depending on the factory and year. It wouldhave no bearing on a magneto fired engine.A bit on the mag firing problem.Aircraft mags are usually run at 1/2 crank speed. and the older tractor typemags that Bernies plans show driven fron the crank have a geared distributorand they then fire two cylinders per rev.The use of carbon core wires on a mag may lead to misfires as the increasein secondary circuit resistance causes a higher voltage. Some mags have a"safety gap" that allows the secondary winding , mag output, to fire toground above a predetermined voltage. This protects the insulation of thesecondary winding. Solid core wire will fire the plug at a lower voltage.The missing cylinders could be a result of un even mixture distribution anda marginal spark.One trick I use to find out if a cylinder is firing is to slide the point ofa grounded twelve volt incandescent test light between the plug wire and theboot until it touches the HT terminal. the cylinder then misfires if it wasproducing power. No change indicates a dud cylinder.The High secondary voltage only builds high enough to over come circuitresistance. lower the resistance lower firing voltages. This method preventscoil damage from trying to fire an open secondary lead. It also reduces thechance of me being on the receiving end of mag.John Mc----- Original Message -----
The center stud just behind the distributor held the armoured primary cablewith a clip of various design depending on the factory and year. It wouldhave no bearing on a magneto fired engine.A bit on the mag firing problem.Aircraft mags are usually run at 1/2 crank speed. and the older tractor typemags that Bernies plans show driven fron the crank have a geared distributorand they then fire two cylinders per rev.The use of carbon core wires on a mag may lead to misfires as the increasein secondary circuit resistance causes a higher voltage. Some mags have a"safety gap" that allows the secondary winding , mag output, to fire toground above a predetermined voltage. This protects the insulation of thesecondary winding. Solid core wire will fire the plug at a lower voltage.The missing cylinders could be a result of un even mixture distribution anda marginal spark.One trick I use to find out if a cylinder is firing is to slide the point ofa grounded twelve volt incandescent test light between the plug wire and theboot until it touches the HT terminal. the cylinder then misfires if it wasproducing power. No change indicates a dud cylinder.The High secondary voltage only builds high enough to over come circuitresistance. lower the resistance lower firing voltages. This method preventscoil damage from trying to fire an open secondary lead. It also reduces thechance of me being on the receiving end of mag.John Mc----- Original Message -----