What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Electric prop and EI combo

deej

Well Known Member
I have a solid crank 150 hp O-320, and am using an older FlyEFII/SDS electronic ignition that replaced the right mag. The EI system is using magnets embedded in the flywheel for timing info.

I would like to replace my solid metal prop with an electric variable pitch prop (GT or AXSport). The e-props use a plastic ring supporting the electric slip rings to get the electric power to the prop, and this is mounted in the inner section of the flywheel, which is also where the magnets are mounted for the SDS system.

Here is a pic of the magnets in the flywheel:
https://deej.net/glastar/pics/efii/unpacking5.jpg

Here is a pic from AXSport showing their slipring setup:
https://deej.net/glastar/e-prop/pics/AXSport-slipring.jpg

Thoughts on how to solve this?

-Dj
 
Talk to Ross, the magnets most likely could be relocated to the face of the flywheel.

I seem to recall that some of his automobile setups do this.
 
Hi Deej,

Here are some photos of what one of our customers did with a small ID Lyc flywheel to mount magnets on the rear face. These might give you some ideas.


Tapped 8-32 holes for magnets


Custom Hall sensor mount



The Hall sensor can be mounted anywhere around the engine that you have room and that position determines where the magnets are placed in the flywheel. Aim for about .060-.090 air gap.

Drill magnet holes with #29 drill and tap for 8-32 Allen set screws. We can provide you with the set screws and new magnets if required.

You can find general info on how the magnets should be arranged here: http://www.sdsefi.com/faero2.pdf
 
Looking at the pics, Im not sure you do have a conflict there yet. Id set it up and see what you have.
Tim Andres
 
The distance from the front edge of the sensor and the centerline of the Hall Effect transistor is about .220.
 
Hi Tim,
There is definitely a conflict. If there were a way to shrink the thickness of the plastic ring behind the slipring, it might be possible to make it work, but I'm not quite sure how to accomplish that.

Ross, is there another method for timing other than using magnets on the flywheel? I'd much rather have a "bolt on" solution rather than trying to fab something due to the critical nature of this item... :)

Thanks,

-Dj
 
Ross, is there another method for timing other than using magnets on the flywheel? I'd much rather have a "bolt on" solution rather than trying to fab something due to the critical nature of this item... :)

Thanks,

-Dj

No, we need to have the magnets spinning at crankshaft speed and we feel there are more potential points of failure with Hall sensors mounted inside the mag housings- temperature, gear and bearing failures.

I think you're stuck with fabbing a new mount unfortunately unless you can thin down the slip rings somehow and perhaps machine off some of the material at the tip of the sensor.
 
Thanks Ross. Thinning the slipring is my preferred option I think. I haven't purchased a prop yet so maybe the manufacturer will work with me on this.

-Dj
 
Ross, is there another method for timing other than using magnets on the flywheel? I'd much rather have a "bolt on" solution rather than trying to fab something due to the critical nature of this item...

On the plus side - magnet placement on a 4 banger is pretty easy, and the mount for the hall pickup should not be very difficult. As long as everything stays in place, the alignment can be taken care of during the initial setup process.

I certainly understand the desire to stick with the existing setup, but think it through and talk it over with some other people experienced in fabrication. Might not be as hard as you think.
 
Back
Top