Hangar Flying => Hangar Flying => Topic started by: ramachandra on February 14, 2005, 05:08:40 AM
Title: rpm pickup
Post by: ramachandra on February 14, 2005, 05:08:40 AM
I am using Lycoming O-235 on Long EZ. I want to take engine rpm pick up from the slick magneto instead of using mechanical tacho generator. My analogue engine rpm gauge has a 5 pin plug. Could some one please let me know how to connect it with the magneto. Magneto has two hexagonal nuts with six holes in each. Is it for any electrical connection or only for cooling.
Thanks for the help.
Regards Ramachandra
Title: rpm pickup
Post by: Anonymous on February 14, 2005, 12:03:22 PM
Venting
Title: rpm pickup
Post by: Waiter on February 14, 2005, 12:29:58 PM
Dah :? I was trying to picture what Ramachandra was describing, Of course the vent plugs!!!
I think there's only two ways you can get a tach signal from the Mag, P-Lead or Spark plug.
There are a couple inexpensive Tach's (WestTech) that run off your P-Lead, but they do leave a little to be desired as far as accuracy. I think some of the newer electronic guages can also read the P-Lead with good accuracy. There was a post here not long ago "StratoMaster" or something like that.
Good Luck
Waiter
Title: wire up RPM gauge
Post by: one guest on February 14, 2005, 05:30:27 PM
Like everyone said the six holes are the vent holes. your P lead should go to the number 2 pin on your rpm gauge and the number 5 pin on your gauge should go to the aircraft ground.
Title: rpm pickup
Post by: easyrider on February 15, 2005, 12:43:46 PM
I am running a Jeff Rose Tach with Jeff Rose Electronic on the bottom plugs and Slick impulse on the top. The Tach runs fine. It is also accurate, I ran the original mechanical tach in parallel for several hours and the readings were the same. Easyrider
Title: rpm pickup
Post by: hewlett on February 16, 2005, 11:08:03 PM
Attaching ANYTHING to P Leads can cause problems. Accidental grounding kills the mag.
Title: rpm pickup
Post by: ramachandra on February 23, 2005, 03:49:02 AM
thanks for all those replies. I tried to use handheld electronic tachometer near sparkplugs. The display was nil. From the suggestion regarding connecting tachometer, I understood that the cable going from magneto to rotory switch (in cockpit) which switches the magneto ON & OFF, is to be tapped and connected to the tachometer pin no.2 and the ground of magneto and pin no 5 of the tachometer are to be connected to A/C ground. Am I right ? Is there any restriction on the magneto to be used for rpm pickup ? i.e. left or right etc. What about connections to other pins of the tachometer? So many doubts!
thanks Ramachandra
Title: rpm pickup
Post by: Gilbert DRIEUX on February 23, 2005, 01:41:19 PM
Have alook at : Aircraft Spruce / Westach Tachometers