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Scott,
I have the Cont TSIO550 with LightSpeed, so is most of what you wrote applicable? Seems like it, except I believe that Klaus does not have a rear crank pickup for my engine. As it is, I have his circuit board in the front end where it is oh so close to the AC pully system and the yet-to-be- de-iced prop. The Simpsons vary widely: at idle (Chelton says 1050 rmp) the LSE readout varies from 650 to 1000. I have three of the units in the panel so I do not have to switch from one to the other - there is always a display of firing angle, RPM, and MP. I get to watch all three dance at the same time.
Still working on a very low oil pressure problem. Pressure tested the gauge and it is correct. Startup is 45-50 psi, idle at 1,000 shows 40 psi at 110 F, 35 at 120 F, 30 at 130 F, 25 at 140 F. In cruise it stays at about 22 psi and 185-190 F. On landing and pulled back to idle pressure dromps quickly to 5 psi and if I do not goose it quickly, down to 2 psi! To get back to the hanger or for another TO I have to keep the RPM at 1,000 and ride the brakes.
I screwed the pressure controller all the way in and got no change. I pulled it and gave it the old evil-eye (no obstruction seen), put it back, and no change. Ron Munson at Performance said that they had no problems on testing so it leaves me scratching my head. Today we'll pull the aux oil pump out of the system, cap the ends, and see what happens.
Robert M. Simon
ES-P N301ES
________________________________
From: Lancair Mailing List on behalf of Sky2high@aol.com
Sent: Thu 8/10/2006 2:13 PM
To: Lancair Mailing List
Subject: [LML] Re: Wing Twist and EI observations
In a message dated 8/10/2006 11:57:25 A.M. Central Standard Time, lancair@USTEK.COM writes:
I am still flying off hours and playing at low altitudes, but running way lean of peak at 12k ft I am burning 15.5 gph and seeing about 205 kt TAS. These investigation hours are a mix of fun and frustration. The EI readouts are all over the map and do not agree with the RPM and MAP displayed on the Grand Rapids EIS. If the firing angle readout is correct we are at 40 degrees on take off, 32 degrees when cruising ROP but that drops off as we go LOP - and that seems strange. Could anyone enlighten me on this?
Robert,
You are using Light Speed EI, right? And a Lycoming engine, right? If it is a Continental engine or not LSE, ignore most of this e-mail.
Otherwise, remember that the timing is tied to power as represented by RPM and MAP. At idle (lo MAP, lo RPM), the timing would be quite advanced (35-38 DBTDC). At takeoff power (hi MAP, hi RPM), timing advance is minimal, i.e. 25 DBTDC. As power declines by an increase in altitude (lower MAP) and cruise RPM (2300-2500), the advance should increase towards 35 or so DBTDC. If running LOP causes a reduction in RPM or MAP, the advance should increase a bit further. Reduce all the timing numbers by 5 degrees if the compression ratio (CR) is greater than 8.7:1.
If mag hole timing sensors are being used along with a hi CR, the sensors are offset and the indicator readouts are 5 degrees higher than actual. However, if a big engine (6-cyl, >200 HP) is being used, the very accurate crank sensor should be installed. Once again, if a hi CR, the sensor magnets imbedded in the flywheel are offset by 5 degrees and the timing indications are accurately reported.
In my airplane, the MAP and RPM are low by .5" and 60, respectively as against those displayed by VM instrumentation. There is no damping of the display so the numbers can jump around quite a bit.
Finally, if the above doesn't explain what you are seeing, re-check the actual timing with a timing light. If that is good, check the wiring and connections. The display is a Simpson volt meter showing hundredths of volts. The selector switch not only connects the appropriate source, but adjusts the display decimal point location.
Good Luck,
Scott Krueger AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)
Abnegate Exigencies!
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