Slagergren
Active Member
Ive got a new RV7 (just 10 hrs on it) with an 0-360-A1D rebuild Lycoming w/new cylinders & more from Lycon. My ignition system is the Dual Plasma III from LSE (Light Speed Engineering) (no mags) and my carb is an Ellison Throttle body (no carb). My buddy has the same setup/plane except his is 5 yrs older and has 700 hrs on itand it runs incredible smooth and cool. In my 10 hours I have been dealing with higher than normal CHTs (ie upto 430?F) and a rougher running engine. I even loaded up and fowled some of the plugs on the bottom of the cyclinders by running too rich. Anyhow today my buddy noticed that at idle my engine drops in RPM when pulling out the mixture from full rich to say the halfway before cutoff point. On his airplane doing the same thing the RPM increases and runs smoother. Another very noticable item is my exhaust pipes have a very black soot on the insides vs his which are fairly clean and have maybe a little grey colored soot. Using a timing light per LSE's (LightSpeed Engineering) instructions, I checked the timing and found it met spec (ie 20+/-2?off TDC) w/o the manifold pressure connected end but out od spec with manifold pressure lines connected (I measured 37.5? vs the spec of 40+/-2? off TDC w/MP line connected). Note: these iginition modules measure both MP and RPM and than adjust the timing accordingly. I ran these numbers by LSE and they stated my timing was good and that the more important spec was the w/o MP at 20+/-2? off TDC and to continue engine break-in. Im still running straight SAE 50 Mineral oil, could I still be breaking this motor in after 10hrs? Could my timing be off enough such that my spark occurs too late in the cycle and thus is trying to burn the fuel as it leaves the engine? I trimmed my bottom cowl exit today to match my buddies cowling and thus have brought the CHTs into the 360-380?F region so Im a little safer. Anyone have any ideas or thoughts?
Thanks Steve,
Thanks Steve,