Mag timing

[pistoncan]

Is there any way an uneducated person can time the mags on a O290D2 without buying the expensive tools?

Thanks

Gary

[Vagabondblues]

Build your own http://www.magnetotimer.com/

$19.00


Rotate the engine to fixed firing position compression stroke #1 cylinder..

You can cut a piece of scrap metal 1" wide by 10" long. The straight edge can then be laid at the case half split at the nose case section. Normally the flywheel gear is marked on the backside with the 25 degree BTDC mark so you can time mags without removing the nosebowl. If is not marked you can line up the 25BTDC mark with the dot on the starter housing and transfer the timing mark to the back of the starter ring which will allow the case split method again in the future.

Pin or lock mags at firing position. Distributor finger should be on the number 1 tower.

install mags and synch both to firing position, plus or minus 2 degrees.

Remember to make sure the Impulse coupling is released first and always turn the prop direction of rotation to remove backlash.

[Glen Geller]

Hi Gary,
Your A&P should have checked this at the last annual. If you are building a plane this might be a tool worth investing in.
Can you give some additional background on what you think the problem is, what tools you think you need, and why you think you need to adjust mag timing?

Reach out to members of the local Shortwing Piper Club or EAA chapter and ask if they can help.
Most EAA and similar aviation clubs have tools that can be rented by members.
Lots of links on the interwebs: https://www.google.com/?gws_rd=ssl#q...=1495235825209
This one in particular you should look at, see Steve's post #24:
http://www.shortwingpipers.org/forum...o-timing/page3

The tools are not very expensive, a magneto timing light is only ~$75 and lasts many years.
http://www.pilotshop.com/catalog/top...FQxofgodQIkJfA

[pistoncan]

Glen, my tandem wagabond project (Wagzilla) is powered by a 100hp Corvair engine, which I built in 2008. (We are into our 12th building year). Last year I did some horse trading and got a O290D2 less mags and carb. I was able to buy a pair of Bendix mags and new harness from my friend Marty in California who is upgrading to the new electronic mags so I have to time them from scratch. I have them mounted on the timing marks, but I have to do the final timing.

Hi Gary,
Your A&P should have checked this at the last annual. If you are building a plane this might be a tool worth investing in.
Can you give some additional background on what you think the problem is, what tools you think you need, and why you think you need to adjust mag timing?

Reach out to members of the local Shortwing Piper Club or EAA chapter and ask if they can help.
Most EAA and similar aviation clubs have tools that can be rented by members.
Lots of links on the interwebs: https://www.google.com/?gws_rd=ssl#q...=1495235825209
This one in particular you should look at, see Steve's post #24:
http://www.shortwingpipers.org/forum...o-timing/page3

The tools are not very expensive, a magneto timing light is only ~$75 and lasts many years.
http://www.pilotshop.com/catalog/top...FQxofgodQIkJfA

[pistoncan]

Thank you Vag, that is just what I need. I ordered the 25 dollar kit.
Gary

Build your own http://www.magnetotimer.com/

$19.00


Rotate the engine to fixed firing position compression stroke #1 cylinder..

You can cut a piece of scrap metal 1" wide by 10" long. The straight edge can then be laid at the case half split at the nose case section. Normally the flywheel gear is marked on the backside with the 25 degree BTDC mark so you can time mags without removing the nosebowl. If is not marked you can line up the 25BTDC mark with the dot on the starter housing and transfer the timing mark to the back of the starter ring which will allow the case split method again in the future.

Pin or lock mags at firing position. Distributor finger should be on the number 1 tower.

install mags and synch both to firing position, plus or minus 2 degrees.

Remember to make sure the Impulse coupling is released first and always turn the prop direction of rotation to remove backlash.

[Glen Geller]

I see, sorry I didn't know all the background. Sounds like an interesting project.
I think the EAA may have some resources since this has been popular on Peitenpol Air Camper etc for the last 50 years.
https://www.eaa.org/en/eaa/eaa-chapt...an-eaa-chapter

And I never thought about it before, but of course there is a Corvair aircraft club:
Flycorvair.com

Good luck,
GG

[pistoncan]

Glen, I never figured I would ever be lucky enough to have a real airplane engine, so it becomes plan B in case I don't have enough power with the Corvair.

I see, sorry I didn't know all the background. Sounds like an interesting project.
I think the EAA may have some resources since this has been popular on Peitenpol Air Camper etc for the last 50 years.
https://www.eaa.org/en/eaa/eaa-chapt...an-eaa-chapter

And I never thought about it before, but of course there is a Corvair aircraft club:
Flycorvair.com

Good luck,
GG

[Steve Pierce]

I use this tool to lock the magneto while installing it on the engine. http://www.aircraftspruce.com/catalo...clickkey=27328

[gliderman]

Build your own http://www.magnetotimer.com/

$19.00


Rotate the engine to fixed firing position compression stroke #1 cylinder..

You can cut a piece of scrap metal 1" wide by 10" long. The straight edge can then be laid at the case half split at the nose case section. Normally the flywheel gear is marked on the backside with the 25 degree BTDC mark so you can time mags without removing the nosebowl. If is not marked you can line up the 25BTDC mark with the dot on the starter housing and transfer the timing mark to the back of the starter ring which will allow the case split method again in the future.

Pin or lock mags at firing position. Distributor finger should be on the number 1 tower.

install mags and synch both to firing position, plus or minus 2 degrees.



Remember to make sure the Impulse coupling is released first and always turn the prop direction of rotation to remove backlash.

just one quick change- Mag timing on A 0-290-d2 is 18 Degrees BTDC...

AD:54-02-01 LYCOMING: Applies to All Model 0-290-D2 Engines.

Compliance required by February 1, 1954, and at each subsequent 100-hour inspection.

In order to preclude the possibility of serious engine damage from incipient detonation under certain atmospheric and altitude conditions, the magneto timing of all Lycoming O-290-D2 engines must be set at 18 degrees BTC. To insure that the magneto timing does not change substantially from this setting, it should be checked and reset, if necessary, at each subsequent 100-hour inspection.

(Lycoming Service Bulletin No. 169 covers this same subject, but recommends that the timing be checked every 50 hours.)

however i have advanced the timing to about 21-22 degrees and no problems as the fuel today is a whole lot better than it was in 1954. your and your mechanics' call

Shane-o

[wyandot jim]

"AD:54-02-01 LYCOMING: Applies to All Model 0-290-D2 Engines."
Not quite true of all O-290-D2s Our O-290-D2B is set at 25 degrees. It also has a little less compression than the O-290-D2As