WAFI Posted December 22, 2021 Report Posted December 22, 2021 I’ve noticed on takeoff, full power obviously, I reach 2750 RPM so just over redline. I have asked a couple of non Mooney A&P’s and they said that I shouldn’t worry about it. “It’s not going hurt the engine making an extra 50ish RPMs” Note: This usually happens more often than not because of the conditions. Hot South Florida days or time of day. Cool mornings it doesn’t seem to reach over the redline. I rectify this by pulling the prop back just a hair after gear and flaps up and climb out around 2600 rpm. This is before setting up my cruise climb. Should I have the prop “blue handle” adjusted slightly? Quote
N201MKTurbo Posted December 22, 2021 Report Posted December 22, 2021 There is a stop screw on the governor that is used to set the max RPM. 2 Quote
WAFI Posted December 22, 2021 Author Report Posted December 22, 2021 7 minutes ago, N201MKTurbo said: There is a stop screw on the governor that is used to set the max RPM. Gotcha, what’s your max RPM on takeoff? Quote
kaba Posted December 22, 2021 Report Posted December 22, 2021 My M20J on rotation inches toward 2800. I back off to 2700.My mechanics stated “ no problem”.Presently 1100 hours on reman.Runs greatSent from my iPad using Tapatalk Quote
WAFI Posted December 22, 2021 Author Report Posted December 22, 2021 5 minutes ago, kaba said: My M20J on rotation inches toward 2800. I back off to 2700. My mechanics stated “ no problem”. Presently 1100 hours on reman. Runs great Sent from my iPad using Tapatalk Well that’s comforting! Quote
N201MKTurbo Posted December 22, 2021 Report Posted December 22, 2021 33 minutes ago, WAFI said: Gotcha, what’s your max RPM on takeoff? Well, mine only goes to 2600. I need to re-clock the governor. A big PITA. I will get to it some day. Quote
takair Posted December 22, 2021 Report Posted December 22, 2021 For the anal amongst us, here is what Lycoming says. https://www.lycoming.com/sites/default/files/SB369S Engine Inspection after Overspeed.pdf The problem may be a simple tach calibration issue or not. There is also the case where the tach may read low and your overspeed is actually worse than you think. I suspect minor overspeed is not a big issue, race guys do it all the time…..but every so often the results are spectacular. I’m personally paranoid about it, but that’s just me and red lines. 3 Quote
WAFI Posted December 22, 2021 Author Report Posted December 22, 2021 31 minutes ago, takair said: For the anal amongst us, here is what Lycoming says. https://www.lycoming.com/sites/default/files/SB369S Engine Inspection after Overspeed.pdf The problem may be a simple tach calibration issue or not. There is also the case where the tach may read low and your overspeed is actually worse than you think. I suspect minor overspeed is not a big issue, race guys do it all the time…..but every so often the results are spectacular. I’m personally paranoid about it, but that’s just me and red lines. I don’t think its a tach calibration issue because my JPI reads the same RPM. I to get paranoid over any red lines regardless how quick they come and go. Quote
N201MKTurbo Posted December 22, 2021 Report Posted December 22, 2021 So, for all you guys that have momentary overspeed events, are you logging every event in your maintenance logbooks? It is mandatory according to Lycoming. Quote
Guest Posted December 22, 2021 Report Posted December 22, 2021 My blood pressure is a little over redline, my local undertaker says not to worry. I'm happy with that Clarence Quote
takair Posted December 22, 2021 Report Posted December 22, 2021 43 minutes ago, N201MKTurbo said: So, for all you guys that have momentary overspeed events, are you logging every event in your maintenance logbooks? It is mandatory according to Lycoming. What overspeed? I had a friend who had an overspeed…. 1 Quote
takair Posted December 22, 2021 Report Posted December 22, 2021 46 minutes ago, N201MKTurbo said: So, for all you guys that have momentary overspeed events, are you logging every event in your maintenance logbooks? It is mandatory according to Lycoming. Does Mooneyspace count as a log entry? 1 Quote
Igor_U Posted December 22, 2021 Report Posted December 22, 2021 2 hours ago, N201MKTurbo said: So, for all you guys that have momentary overspeed events, are you logging every event in your maintenance logbooks? It is mandatory according to Lycoming. Off course. Actually, Lycoming SB says: 1. When the overspeed occurrence is less than 5% of the rated engine speed, the recommended corrective action for all engines is as follows: a. Identify and correct the cause of the overspeed. b. In the engine logbook, record the overspeed incident, any inspections, and corrective action. So, they say recommended, for 5% (or less) overspeed. OP had overspeed of only 50 RPMs... YMMV. On my old engine, my max RPM would reach 2700-2710 on a takeoff . The new engine/governor is set to 2670. I need to tweak it and gain those 20-30 rpms on a takeoff. I really hate going over the redline as my CGR30P monitor has warning lights that start flashing. 1 Quote
A64Pilot Posted December 22, 2021 Report Posted December 22, 2021 It’s extremely common for guys on floats to turn 100 RPM over, they have been doing this for decades with no issue. I had my Maule set 100 over. Those of us that add 100 RPM, reduce to redline soon after TO though, we don’t do long climbs over redline Its surprising how much 100 RPM helps get a floatplane on step. I wouldn’t bother with 50. My Mooney won’t quite make 2700, but I’m not going to bother with it either, but all I have is the factory 40 yr old tach too, so who knows what it is exactly. These engines were designed long before digital accuracy existed, they don’t necessarily require it Quote
PT20J Posted December 22, 2021 Report Posted December 22, 2021 The procedure for setting this is in the McCauley manual available on McCauley's website. First thing of course is to verify that the tach is accurate. Then you fly at cruise and set the rpm to redline with the prop control. Then land without touching the prop and adjust the governor set screw so that it just touches the control arm. Then fly it again to check. I understand that some McCauley governors had plastic backs and the screw threads could strip, so it's worth checking that the stop screw is secure. Skip 1 Quote
RobertGary1 Posted December 22, 2021 Report Posted December 22, 2021 Pretty common to set them that way. some say it helps with short field take offs. -Robert Quote
jaylw314 Posted December 22, 2021 Report Posted December 22, 2021 Mine seems to vary by season--I can only reach 2670 during the summer and hit 2730 in the winter. Seems like the reverse of what I might expect, unless it's just my imagination. If it breaks 2700, I do dial it back a bit, because the most serious outcome is that it freaks out the wife. She never seems to remember when I explain it. "WHAT'S THAT FLASHING RED LIGHT????" 1 Quote
cujet Posted December 24, 2021 Report Posted December 24, 2021 On a 2700 RPM engine, 5% over is 2835 RPM and 10% over is 2970. We've run our aerobatic AEIO 540's at 2800 for the last 25 years. Never an issue. Of course, they twist and turn, fly knife edge without oil pressure for up to 30 seconds and go straight up right after takeoff, so they are subject to more than just a momentary overspeed. They are subject to intentional abuse. 1 1 Quote
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