Timing the Magnetos

[AZSteve053]

Have you ever just used rubber bands to attach your digital precision level to a prop blade - then rotate the engine the proper number of degrees after you found TDC by previously described methods.

[gasman]

Originally Posted by AZSteve053

Have you ever just used rubber bands to attach your digital precision level to a prop blade - then rotate the engine the proper number of degrees after you found TDC by previously described methods.

Yes. I used a yogurt container taped to the spinner and used an app on my phone taped to it. You can also confirm TDC by using a timing plug....https://www.aircraftspruce.com/catal...iming_ind1.php

[C. Brenden]

I have a box of brand new piston pins left over from a business I had selling timing disk kits to A&P Schools. I'll send you one (no charge) if you mail me a prepaid mailing envelope.

[Two sheds]

I’ve found it’s easy to use a mirror and sight along the case parting line to the back of the flywheel timing marks. My installation doesn’t have a baffle blocking the view.

[snopercod]

Here's how I did it:

My flywheel (probably off an O-320) has both #1 TDC and 25 deg stamped on the front of the flywheel. I didn't have to use the case part line at all:


A 1/16" drill bit fits perfectly into the hole on my Sky-Tec starter. Don't let the bit stick out too far or the teeth on the flywheel will break it off. You can't see it in this photo due to parallax, but at #1 TDC, the drill bit is aligned with the center of a tooth. I added a short piece of blue tape along the TDC mark to extend the line down onto the tooth:


I used double-sticky carpet tape and painter's tape to fasten the digital gauge to the prop extension. I just zeroed it out at #1 TDC and could read the mag settings directly: