Tom @ N269CP
Well Known Member
We've finished installing one Pmag 114 (v.40) to replace the right Slick magneto in my RV-8, leaving me with one IC Slick on the left and the PMag on the right. So now its time to finish setting timing and other parameters suitable for my airplane and flying conditions. I'm reluctant to test fly it until I have confirmed/finalized settings with EICAD.
Plane Specs:
RV-8 with O-360-A1A (8.5:1) carbureted engine with Hartzell CS prop running on 100LL. Aviation plugs on top, auto plugs on the bottom.
Home airport: Durango, CO (KDRO).
Field elevation: 6,689 Ft.
Typical summer DA: 9,000-10,000 ft
Engine Monitoring Eqpt: EI UBG-16 analyzer and FP-5 fuel flow computer
Baffling is in good shape and blast tubes installed for PMag and Slick.
Installation details:
Advance shift: -1.4º ATC (set manually...~1.5 gear teeth ATC)
Advance curve: "A" (jumper in)
MP restriction orifice: Installed
Questions/Comments:
1. What is the factory default "max RPM" setting for the PMag? Did not see in PMag manual.
2. Before using EICAD, should I first reset PMag timing to TDC (zero advance shift) instead of the current "manually-set" -1.4ºATC?
3. The EICAD serial cable connects to PMag terminals 2 & 3 where the "A" curve jumper normally goes. If I run a permanent serial cable from the PMag back to the cockpit, will I have to install the "A" jumper in the DB9 connector (in the cockpit) in order to use the "A" curve? Or do EICAD-entered settings obviate the need for a jumper?
4. What kind of RPM drop should I expect during run-up at 1700 rpm (leaned) when switching from "both" to the left magneto? Saw some big drops at lower RPM's. I've installed a Flight Data Systems T-30 tach with speed signals coming from both the Slick mag p-lead and PMag 12v tach output.
5. My normal high-DA pre-takeoff runup procedure is to lean for peak RPM at 2000 rpm and then move the mixture lever halfway from there towards full rich for WOT take-off. Once airborne, I then climb to cruise altitude at WOT, 2500 rpm and 120-130 mph IAS. (I normally cruise LOP circa 10k-12k feet at 20" MP and 2200-2300 rpm). I very much wish to avoid CHT's above 400ºF during T.O. and climb. FWIW, I've been told that full power run-ups for leaning (to peak RPM) at high DA should be avoided in the RV-8...not sure if this is just "mythology". Any suggestions?
I'd be grateful for any and all comments/suggestions.
Thanks!
Tom
Plane Specs:
RV-8 with O-360-A1A (8.5:1) carbureted engine with Hartzell CS prop running on 100LL. Aviation plugs on top, auto plugs on the bottom.
Home airport: Durango, CO (KDRO).
Field elevation: 6,689 Ft.
Typical summer DA: 9,000-10,000 ft
Engine Monitoring Eqpt: EI UBG-16 analyzer and FP-5 fuel flow computer
Baffling is in good shape and blast tubes installed for PMag and Slick.
Installation details:
Advance shift: -1.4º ATC (set manually...~1.5 gear teeth ATC)
Advance curve: "A" (jumper in)
MP restriction orifice: Installed
Questions/Comments:
1. What is the factory default "max RPM" setting for the PMag? Did not see in PMag manual.
2. Before using EICAD, should I first reset PMag timing to TDC (zero advance shift) instead of the current "manually-set" -1.4ºATC?
3. The EICAD serial cable connects to PMag terminals 2 & 3 where the "A" curve jumper normally goes. If I run a permanent serial cable from the PMag back to the cockpit, will I have to install the "A" jumper in the DB9 connector (in the cockpit) in order to use the "A" curve? Or do EICAD-entered settings obviate the need for a jumper?
4. What kind of RPM drop should I expect during run-up at 1700 rpm (leaned) when switching from "both" to the left magneto? Saw some big drops at lower RPM's. I've installed a Flight Data Systems T-30 tach with speed signals coming from both the Slick mag p-lead and PMag 12v tach output.
5. My normal high-DA pre-takeoff runup procedure is to lean for peak RPM at 2000 rpm and then move the mixture lever halfway from there towards full rich for WOT take-off. Once airborne, I then climb to cruise altitude at WOT, 2500 rpm and 120-130 mph IAS. (I normally cruise LOP circa 10k-12k feet at 20" MP and 2200-2300 rpm). I very much wish to avoid CHT's above 400ºF during T.O. and climb. FWIW, I've been told that full power run-ups for leaning (to peak RPM) at high DA should be avoided in the RV-8...not sure if this is just "mythology". Any suggestions?
I'd be grateful for any and all comments/suggestions.
Thanks!
Tom
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