Crawfish

Also have a 231, no Merlyn though. Full power climb and pitch for 115-120IAS cowl flaps full open. Keeps temps cooler than pulling the power back.

@LANCECASPER CHT’s were somewhere in the mid to high 300’s (still rocking the stock CHT gauge, GI275 scheduled for install in January) TIT were sitting between 1530-1550. At 16,000 about 1500 at 13,000 Not sure how far LOP I was, as I do the “big pull” then verify I’m lean of peak by enriching to make sure TIT rises then pulling back to where I wanted to be at.

Little more data for anyone curious. M20K no intercooler no merlyn 4+29 hour take off to touchdown 16,000’ started at 165KTAS finished 175KTAS Total trip burn was 50.5 gallons. Was leaned to the mid 10GPH range in cruise. 4+36 T/O to Touchdown 13,000’ 155-160 KTAS. Total leg burn 51.7 gallons, same leaned to mid 10GPH range in cruise. Fuel burn was measured at the pumps by topping the plane back off. Reason I say mid 10GPH range is my fuel flow bounces a little bit in cruise .3 of a gallon or so.

Little late to the conversation but my 1979 M20K CG is 43.9 only real change is a GTN650 and added a fire extinguisher. No built in O2. She has been weighed twice in the past 10 years, came out to within .5# on both weights, done by independent shops. Although on the first weighing it gain 15 pounds from the calculated W&B from the factory. Cheers! Crawfish

@McMooney From what I understand it’s lead.

I thought embry riddle did some testing on G100UL back in the mid 2010’s?

Got my fuel system tweaked (so it doesn’t bounce around so much) while waiting on a couple parts for the EIS And took it on another trip! 11500 60% power 152 TAS 8500 63% 145 TAS both power values were LOP. Plane has a semi severe right turning tendency inflight so hopefully it will gain a few knots once that’s sorted out!

I only have about 7 hours in my Mooney now! Buutttt one of those flights was 4 hours literally 4:00, on that flight I set power at 2400 RPM 31” and leaned until rough and enriched just enough to smooth it out. At 6500’ it gave me 148TAS 8500 155TAS and 10500 160TAS and burned 12.3 GPH averaged over the whole trip which included a rejected Take off, and long taxi back. 135IAS at all three altitudes temp was 4°c at all three altitudes I don’t know what my percent power was as the fuel flow gauge was bouncing between 9.5 and 11GPH at constant power. But I was lean of peak so somewhere in the 60-70 percent power range I’d venture to guess I want to play around with more power settings but planes going into the shop to get an full engine monitor. So hopefully only a week or so.

I believe @kortopates meant was that if it was hotter than 1400°F at T/O power full rich it might be an indication your T/O fuel flow was set to low. Not that you were busting a limitation. Not that I want to put words in his mouth.

I’m not sure you realize you’re about to start a war in the comments. While this is not for the M20K specifically I think it’s better to understand why you’re doing things and this will definitely help you in that regard. turbocharged engines really make leaning simple. (I believe the MB is limited to 36” MP)

If you’re open too it I would suggest not overhauling your engine until it gives you signs it’s in need of overhaul, there’s a ton of really good information on what those indicators might be. To do that though you need to be looking for the signs. Which means having oil samples taken, looking at engine monitor data, inspecting the oil filter every oil change etc. I recommend several of Mike Busch's videos on the subject as well as books. (Side note a EIS is much cheaper than an overhaul) I see no point in overhauling a strong running engine. Poor use of money and time. Best of luck, Austin

@jlunseth thank you for the awesome explanation! I’ve read lots of your posts regarding 231 operations and it’s been a wealth of knowledge. I’m sure everyone appreciates the time and effort you put into your posts!

@hubcap that’s what my understanding of the wastegate did, but a couple mechs said it could help with the CDT as well. I couldn’t wrap my head around their reasoning of how it would lower CDT, because the compressor still had to compress the air thereby heating it up.

Reviving an old thread for a quick question! I was told that just the Merlyn UDC will help lower CDT due to more efficient Turbo operations, has anyone seen this in real world operations? (obviously an intercooler is the best way to lower CDT) Thank you! Austin

I really appreciate the write up on it @philiplane, PJ has it in his shop right now going through prebuy, and will also be doing a functional test flight on it as well. Beautiful paint job, but that could be a whole lot of makeup. Only one way to find out!

Holy cow! I’ve got plenty to read now! Good thing it’s a couple weeks until pick up the plane! (Once again assuming satisfactory pre-buy) thank you!

Thank you for the breakdown!

@1980Mooney Thank you!

Hello all! I have had my offer accepted on a 1979 231, with a LB engine no intercooler or Merlyn. Would someone share a PDF of their POH and MX manual if they have it? I want to start studying the POH before we pick up the plane. (assuming I still like it after the prebuy) I searched the downloads for both and could not find a 231 model one. Parts catalog yes, 252 mx manual yes but not the 231 POH. Thank you, Austin

I believe you are correct @ArtVandelay

Thank you @ZuluZulu, My thoughts are prebuy isn't something I'm going to go cheap on and want as good of an eye as possible. I just don't want to go somewhere that I can't trust. I was a little worried about people saying they think they create issues.... But I imagine every shop has had a client or two think that.

Hey guys, My partner and I have been looking at TN F/J models (fairly rare) and now found a 231 we like in south Florida, (PMP) and wanted some input on prebuy options. Going through the forums there seems to be a couple options solid options. What does the brain trust think? 1) Phil Jimenez (seems to be the most recommended) 2) Daytona Aircraft services (quality, but more of an avionics shop than Mooney shop) 3) Premier aircraft sales (Most expensive, even to the point some say they find some issues that might not be there. Might that be a good thing on a prebuy?) 4) Aviation Specialty services (quality but not mentioned often) Who am I missing, who would you absolutely not deal with, who would you run from? Thank you in advance, Austin

I'm curious where is the radar located?