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AIRCRAFT TIMING

ONA540

Active member
I'VE BEEN TOLD THAT IF I ADVANCE THE TIMING A TAD I COULD GAIN SOME RPM'S THUS RESULTING IN PUTING MORE PITCH IN MY PROP (POWER SHIFT SIGNITURE SERIES ON A STRAIGHT VALVE 0540) IS THIS TRUE?
 
No I don't.. What is the best way to see what the timing is set at? How do I determine that? What should it be set at? Help Please
 
J.R, hows it going man? Bobby and a few other 540's i know of have there timing advanced to get more from the motor. The only bad thing is, when it gets hot and you try and crank it, most likely it wont. You have to let it cool.
 
http://www.lycoming.textron.com/sup...cePublications/serviceInstructions/SI1437.pdf

http://www.aircraftextras.com/LaserTim2.htm

Here's a couple of links that may help you check your timing.

You'll have to find #1 cyl tdc, and then check the mags to see if they are set properly.

Check it out.

You should know this though, aircooled engines may have pre-ignition problems if the timing is set to far advanced. If it gets too bad, it could hammer your engine.

Proceed with some caution on this.
At least I would.

JMO
 
Word to the wise if you raise the timing you should also raise your octane. If your running 93 now then go to a octane booster(for what their worth) or av gas 100 octane.


Geoff
 
If your running stock compression, Lycoming spec. is 25 deg. advanced. I set mine with a timing light. Mark the flywheel at 25, and at about 800 rpm's you can get it on the money. worn timing gears or the rubber bushings will cause the time to be off, if you set at the fire out hole in the side of the mag. If you bump the timing to 26,7,8..it will make the cylinders run hotter.
 
Well I don't have any problems now with high oil temps as far as I know compression is stock, and I have always run av gas.

Clayton I'm doing fine. I was always tought to turn your motor over with the starter and then flip the mags on,thus avoiding a "hot" start, it works great when you've been running shut it down and then try to start it a little later.
 
ONA540, As stated above get your #1 cylinder on top dead center on compression stroke use a screw driver or such to put in the plug hole until the piston comes up's and starts to rock back and forth..you will need a magneto synchronizer or buss box to tell at what degree your mags are firing. then on your flywheel you may have the timing mark's or may not if not you will need a degree wheel to put on your prop then back the prop up until you reach the degree of timing you are looking for and you will be able to tell what you timing is now.. you can also count the teeth on your flywheel and devide it by 360 and see how many degrees each tooth equals ie: 160 tooth flywheel = 2.5 degrees per tooth. the most important part is the synchronizer without it you dont know where your points are opening... I have the buss box and degree wheel if you need to barrow it ... hope this help... btw I set my 520 at 27 degrees
 
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