automan1223

I can understand why, the crank and cam sprockets have points for the pickups for the sensors and moving them might negate any improvement unless you compensate. For now I am stuck with 4 degrees max before or after. To mfg such a part is more involved than the hondas or toyotas.

Gyros are draggy rotorcraft, and they take A LOT more power to keep going than any fixed wing aircraft. I have been a gyro enthuiast since 1998. Believe me when I say good old boys just yank em from the junk yard and swap some parts and go flying. I am an ASE Master certified tech since 1990. Some of the stuff I have seen some do gave me chills. I am not going to argue with someone elses data, or facts, you do what you want to. but I can tell you what I know from 1st hand experience not some writing on a wall....... and that is if you dont run them too lean, or to agressive a timing curve, they run like timex watch. Now you can overheat them on a summer day with a poor cooling system or too small a radiator but as long as your egt stay below 12-1300 deg I dont care what you turn. He might have them set up for max power at 4500, I dont know I can only tell you what the gyro crowd runs them at. I am curious what failures he has had. I guess nobody has messed with cam timing.

I am using a EJ 2.2 l . But it has been fitted with a custom manifold for a holley carb and an electronic distributor.

I got news for you guys. Experimental aircraft builders use subs going back to the ea 81, 82, ej 18, 22, 25, & eg 33. There are great little engines and they run full open all day long. If they do go its because the aircraft builder took the easy way out and got a bit too high mileage one out of a junkyard and just bolted it up and away they went. Never checked anything and either the mix was so off it burned it up after hours of abuse or they ran really bad gas or av gas thinking they were doing it a favor. I have pulled apart engines from running junk yards donors with 110,000k miles and the insides look brand new except for some burned oil here or there. The weak spot with the 2.2s seem to be the exhaust valves. Pitting, some metal transfer from the valve seat to the valve ! Once in a while an oil pump will let go, or act funny enough to get replaced. These engines are a lot better than they get credit for. While most blow head gaskets after years of cooling system abuse, they can and do run for years happily at 5500 rpm. usually 5200 with stock cams, 54-5500 with high po regrinds. Except for vw & corvair engines, subaru is the most popular auto conversion out there.

Ok, this engine is in a gyro, and turns a Propeller a steady 5000-5500. I forgot to mention that the cams are a slightly high po stratus grind, which I figure due to their low cost is just a simple base lobe regrind. The motor does have a slight lope at idle, but turns no less than 1200 rpm. Head work will be done, currently working on a mild port, polish, and 5 angle valve job. I think that might wake it up but I feel there is more to be had with a more agressive cam profile. Jonathan

Curious if any of you tune'rs out there have messed with valve timing. I am concerned with increasing power in the upper rpm range as engine is on aircraft. 5000+5500 range. I know most tuning books recommend 8 degrees max before or after but I am wondering how much improvement can be had. Any thoughts ? Automan