[phil finlayson]

Hi I had a fadec acis running super rich 9-1 and 10-1 fouling plugs, had a chat to a drag racing guy, ours are a memory ecu as they dont take afr readings and respond accordingly , east to tune though, put a mechanical fuel pressure gauge on rail after last filter (electrical pressure gauge are not acurate enough) change the fuel regulator to an adjustable (30-70 psi), fit or use an AFR Air Fuel Ratio gauge, our ecus can run as low as 30-35 psi fuel pressure up to 70 psi , so now tune your engine to 12.5-1 to 13-1 fuel ratio at operating rpm on both pumps, IF YOU ARE UNDER 40 PSI YOUR BASE MEMORY TUNE IS SHIT AND OVER 60 , mine is turbo and am running 46 psi with both pumps on one pump is 43 psi and alters AFR. EASY PEASY

[Lyle Swallows]

what i'm taking away from this is DO NOT ATTEMPT UNLESS, you have a means of monitoring your Wideband Airfuel ratio. lean conditions and detonation can have deadly consequences. that being said i will be doing this with an AFR indicator on my panel. will not be turbo'd as i'm at sealevel in cold conditions but doing this in the name of fuel economy/endurance, and minimize carbon build up in the engine which could lead to sticky valves.

thanks for the informative post!

[phil finlayson]

Fit fuel pressure gauge to your rail first and get a psi with both pumps running on yoour fuel reg to use as a base line. Yes definitly need AFR gauge in dash.

[Orv Neisingh]

Over the years I have experienced several failures related to the ACIS system on the Rotorway. Dave W. in California is one of my former students for both hover and altitude training. He had just completed his 100 hour inspection and asked me to give him some more autorotation training. I informed Dave that the ACIS engine often burns through a piston around the 100 hour mark due to detonation. I went out to CA and on our second auto the engine started to run rough, as we set it on the ground we noticed a huge puddle of oil pouring out of the oil tank vent tube. Piston number one had a hole burnt through it causing combustion gasses to pressurize the crank case and force the oil out of the engine and tank.