Update:
The engine is doing very well with about 6 hours now. Im fiddling with flow matching injectors, and even cht distribution. I also have one pesky mag cover bolt oil leak. One of the items that took some fiddling was the timing.
I run dual LSE ignitions with a direct crank pickup. As a result of increased compression, the timing needs to be adjusted a bit. The bad news it that in order to do this, its a complete prop pull. Which on a fixed pitched prop, no problem. But these c/s props, well, its a finger chore. Since the original 8.7:1 compression was a 25deg timing, and the new timing needs to be 20, this required either a set of computer swaps, or a board adjustment. I choose the later.
In the picture below, taken from above the engine, looking down and fwd on the case at the nose, crank flange is at the top of the picture, you can see item mark A is the case split. Normally you line up the case split with the arrow on the board marked B. These 2 were lined up in the original set up. To retard the timing from 25 to 20 (make it fire later in the stroke, Later equals retarded and earlier equals advanced. Why they make this verbiage so confusing is beyond me), simple move the board in its mount slots. Thats the good news. The bad news is that its not that easy to know exactly how much movement there needs to be to capture the timing you want. Its a swag. And the only way to know exactly what timing you have is with a timing light. Thats a prop off, board move, prop on, test, prop off, board move until done activity.
In this picture I went from 25 to 18. Rats. Went to far. I settled in on half the distance.
NOTE: measuring the timing with a timing light is rather difficult on a tail dragger. Your up on a step stool behind the prop with the engine running pointing your timing light fwd to the aft side of the ring gear, looking for the case split and the ring gear marks you marked with white paint, doing the best you can trying to eyeball a line up. Praying that you don't slip and fall and kill yourself. I ended up making a pointing device out of scrap aluminum that bolts to the case and gives me a physical pointer right up to the ring gear face markers so that I know EXACTLY what the timing is. I should have made one of these long ago. It makes the entire effort safer, and more accurate. With this I can stand along side of the engine with the timing light and get very accurate readings. Remember, with these electronic ignitions, there is only ONE way to know that the timing really is, and thats with a timing light on the ring gear.
