231 Engine Upgrades?

[panther1400]

I have an almost new tsio-360 took a few trips with it some high altitude and some low and hot.  Some the temps I am seeing is 190 on the oil and about 1425 tit and 350 cht that was on a trip to Arizona cruising at about 12500.  At low altitudes in 90 degree weather tit seemed a little lower and oil temp still the same and cht and get seemed a bit higher about 360 cht.

 

Bottom line is what upgrades if would you look at and in what order would you put them on?

 

[panther1400]

With a little checking and approximate numbers 

 

4000 automatic wastegate

6000 intercooler

Not sure if these will be on anyone's list?

[jlunseth]

Where are you in MN, I have a 231 with intercooler and Merlyn wastegate and am based at Flying Cloud.  Would be glad to talk, but those are the two major engine options, nothing else of significance can be done except maybe GAMI's and some tuning so you can try LOP, but it is a difficult engine to run LOP.

[panther1400]

Sleepy Eye MN, when I setup to cruise it seems like the more I lean it the closer the egt's get together.  100 ROP egts are about 50 from high to low.  The engine has position tuned injection nozzles, don't know what that means compared to GAMIS but seems to run good but never tried LOP (yet?) I am based out of D42.

 

I'm just not thinking it will pay to upgrade for the fuel savings because I run very low power setting 65-70% so heat doesn't seem to be a problem yet, but only been to 14k so far not sure how much I will be above 18k?

[231LV]

I've been flying my 231 for almost 10 years out in the west where high altitudes are the norm....here are my thoughts (for what they are worth). Intercooler....absolutely yes...a must on a turbocharged engine

wastegate...you can spend for an automatic but it won't completely remove the workload...probably better than a fixed (which I have)

Gami's....nice to have but if your injectors are nicely balanced (which it sounds like they are)....keep what you have...do the "Gami test"

LOP...absolutely...my engine runs great LOP (with Gami's) and I have the old, hot running GB engine. I keep the hottest CHT at 380 and save 3-4 gph

TAS at 18k is 175kts on 10.5 gph running LOP...if that doesn't get your attention..don't know what will...this is why the 231 is so efficient

up high....absolutely, the turbo works harder the higher you go and the engine gets much hotter...at 22k, it is glowing cherry red...(at least it's hot)

speed brakes...I have them, I love them and need them when a controller slam dunks me from 18k to 6k in 10 miles

Overall...the 231 is a high altitude machine...it is optimised for flying high where speed on low fuel burn makes it pretty tough to beat in the dollars dept. Dont fly it below 12k (on cross country) or you are wasting it...a 201 will outrun you due to lighter weight. I routinely fly between 16k and 18k. Only downside is lack of pressurization,,,,sucking O2 for several hours on a cross country gets old fast but worth the hassle for the most efficient airplane (around $100k) you can buy!

[M20Kid]

231LV - I am new to the 231 having had one just a few months. I have a merlyn wastegate and GAMIs but no intercooler. I recently installed an EDM700 so I could safely explore LOP operations. My question concerns you LOP fuel burn - I was down around 9~9.5 before all the cylinders were peaked and headed back down. I was flying briefly on an indicated 8.8 gph! I need to do a GAMI check to see how all the cyliders are actually doing but I was amazed that the engine was running smooth and I had only lost about 10kts indicated.

Where "out west" are you flying? I'm in the Phoenix metro area.

[CAMooneyPilot]

I have been flying my 231 for around 18 years now and have around 2500 hours in it, almost all cross country of 800nm or more. I bought it with the intercooler already installed, and added the Merlyn automatic wastegate about 8 years ago. The wastegate added around 7kts to my cruse speed above 18K ft. It made some difference below 18K, but not as significant. I routinly fly in the lower flight levels, and routenly see 180 to 185 kts true. (Highest groundspeed i've seen is 275kts) Another change that added around 3kts cruse and 200 to 300 ft per minute climb rate was the MT prop. The 231 is definatly a high flying machine. I usually see 20Kts faster speed in the flight levels over 12K. I almost never fly lower than 10K if the trip is an hour or more. Heat at altitude is not a problem. There is a partial open position for the cowel flaps, and it does not impact speed at the thin air at altitude. My highest cht at FL 210 is 280. I keep TIT below 1600 and run ROP to keep TIT at or below 1600. So far, 1600 hrs on my current engine and compressions are all 70 or above. I am not a believer in ROP in a turbocharged airplane. therefore GAMI has little value to me. Adjust the stock injectors if temps are out of line. Just my two cents.

[231LV]

231LV - I am new to the 231 having had one just a few months. I have a merlyn wastegate and GAMIs but no intercooler. I recently installed an EDM700 so I could safely explore LOP operations. My question concerns you LOP fuel burn - I was down around 9~9.5 before all the cylinders were peaked and headed back down. I was flying briefly on an indicated 8.8 gph! I need to do a GAMI check to see how all the cyliders are actually doing but I was amazed that the engine was running smooth and I had only lost about 10kts indicated.

Where "out west" are you flying? I'm in the Phoenix metro area.

California.....the "left coast"....to travel north or east, I have to clear some pretty high rocks.....sounds like you were running pretty low power with that fuel burn...I typically level out for cruise, pull the power back to 75 percent running full ROP, close the cowl flaps, dial down the prop rpm to 2500 and click Find L on my JPI 800 and then do " the big pull"....fuel burn drops from about 12.5 to 13 gph down to about 10 to 10.5 gph. Using the formula to calculate power when running LOP (14.95 x fuel flow/engine horsepower) Gives me about 68 to 69 percent running LOP. At 8.8 gph, you are only running about 64 percent power. Nothing wrong with that and your endurance is way up.

[M20Kid]

California.....the "left coast"....to travel north or east, I have to clear some pretty high rocks.....sounds like you were running pretty low power with that fuel burn...I typically level out for cruise, pull the power back to 75 percent running full ROP, close the cowl flaps, dial down the prop rpm to 2500 and click Find L on my JPI 800 and then do " the big pull"....fuel burn drops from about 12.5 to 13 gph down to about 10 to 10.5 gph. Using the formula to calculate power when running LOP (14.95 x fuel flow/engine horsepower) Gives me about 68 to 69 percent running LOP. At 8.8 gph, you are only running about 64 percent power. Nothing wrong with that and your endurance is way up.

Thank you for the information! I was surprised to find the fuel flow so low but it took that to get all the cylinders to peak and reverse. I suspect some of the GAMI injectors need adjusting and I still need to do the GAMI lean test, so that will tell me something.

[KSMooniac]

California.....the "left coast"....to travel north or east, I have to clear some pretty high rocks.....sounds like you were running pretty low power with that fuel burn...I typically level out for cruise, pull the power back to 75 percent running full ROP, close the cowl flaps, dial down the prop rpm to 2500 and click Find L on my JPI 800 and then do " the big pull"....fuel burn drops from about 12.5 to 13 gph down to about 10 to 10.5 gph. Using the formula to calculate power when running LOP (14.95 x fuel flow/engine horsepower) Gives me about 68 to 69 percent running LOP. At 8.8 gph, you are only running about 64 percent power. Nothing wrong with that and your endurance is way up.

FYI, the multiplier for your TSIO-360 engines is 13.7, not 14.9 due to the lower compression pistons! 10.5 GPH while LOP in a K = 10.5 * 13.7 / 210 = 68.5% power. 8.8 GPH = 57.4% power.

I'm not a K owner, but I would value an intercooler much more so than the Merlyn, and an engine monitor above all other extras.

[jlunseth]

I routinly fly in the lower flight levels, and routenly see 180 to 185 kts true. (Highest groundspeed i've seen is 275kts) Another change that added around 3kts cruse and 200 to 300 ft per minute climb rate was the MT prop. The 231 is definatly a high flying machine. I usually see 20Kts faster speed in the flight levels over 12K. I almost never fly lower than 10K if the trip is an hour or more. Heat at altitude is not a problem. There is a partial open position for the cowel flaps, and it does not impact speed at the thin air at altitude. My highest cht at FL 210 is 280. I keep TIT below 1600 and run ROP to keep TIT at or below 1600. So far, 1600 hrs on my current engine and compressions are all 70 or above. I am not a believer in ROP in a turbocharged airplane. therefore GAMI has little value to me. Adjust the stock injectors if temps are out of line. Just my two cents.

I just flew KPIA to KFDK this past weekend, and had a long period where cruise GS was 275. TAS was around 175, so I was picking up a 100-105 kt. tailwind at 210 . Peoria to eastern Maryland in about 2 and a half. I also have cool CHT's in the flight levels, I manage them so the highest CHT is not over 400, which puts most of them in the 380 or less range. CHT 2 is always a little hotter (rear cylinder).

I do have some flights under the 12k level though. Sometimes winds aloft are just too strong if you get over 6k. So I came back from MD at 6000, still had a strong headwind and was making about 140 over the ground. Its sort of like sailing, you take every advantage of the winds that are available. Averaged out between the outbound and inbound trips, my GS was around 200 kts. at slightly less than 13 gph. Hard to beat that.

[kortopates]

Bottom line is what upgrades if would you look at and in what order would you put them on?

I can only tell you I started with a stock 231 and was dissatisfied with its high altitude performance. Rather than spend $ on engine upgrades to improve, I had an opportunity to upgrade to a 252 a year later and took it. 10+ years in a 252 and I am very glad I did. Besides a very improved MB engine with full turbo configuration with infinitely adjustable electric cowl flaps, I picked up 10 kts over the 231, got 4x times the electrical system capacity (12v 1 alternator to 24v dual alternaors), speed brakes included as standard, and enjoy the flexibility of rear bucket seats that fold down entirely (or easily removable). Plus the 252 is eligible for the Encore gross weight increase conversion to SB configuration and adding FIKI - unlike a 231.

[231LV]

FYI, the multiplier for your TSIO-360 engines is 13.7, not 14.9 due to the lower compression pistons! 10.5 GPH while LOP in a K = 10.5 * 13.7 / 210 = 68.5% power. 8.8 GPH = 57.4% power.

I'm not a K owner, but I would value an intercooler much more so than the Merlyn, and an engine monitor above all other extras.

whoops...you're right...I was copying the wrong formula!

[231LV]

I can only tell you I started with a stock 231 and was dissatisfied with its high altitude performance. Rather than spend $ on engine upgrades to improve, I had an opportunity to upgrade to a 252 a year later and took it. 10+ years in a 252 and I am very glad I did. Besides a very improved MB engine with full turbo configuration with infinitely adjustable electric cowl flaps, I picked up 10 kts over the 231, got 4x times the electrical system capacity (12v 1 alternator to 24v dual alternaors), speed brakes included as standard, and enjoy the flexibility of rear bucket seats that fold down entirely (or easily removable). Plus the 252 is eligible for the Encore gross weight increase conversion to SB configuration and adding FIKI - unlike a 231.

I would love to upgrade to the 252 for all the reasons you quoted....except the nearly doubling of the price from $100k to almost $200K!

But back to the original posters question....I agree with one of the earlier posters....the single most important thing to get is an intercooler ...

[kortopates]

I would love to upgrade to the 252 for all the reasons you quoted....except the nearly doubling of the price from $100k to almost $200K!

But back to the original posters question....I agree with one of the earlier posters....the single most important thing to get is an intercooler ...

Its really a very tough call in my opinion, without the Merylyn you still have a critical altitude of around 17.5K, not terrible, but climb rate will really suffer climbing above the wx to clear air in the flight levels. But a Merlyn without the intercooler will get you up higher faster yet you'll have even bigger temperature issues (CDT) to manage without the intercooler. All trade offs of course.

Jimmy Garrison's latest pricing from the MAPA Log is showing 252's starting at $139K now,

[Parker_Woodruff]

I would love to upgrade to the 252 for all the reasons you quoted....except the nearly doubling of the price from $100k to almost $200K!

You should be able to purchase a decent 252 for about $150,000 or less these days....just depends on what you want in the plane! There are a few that really need some work, and those airframes are likely the ones that languish on the market, even at low prices. There are also quite a few nice examples out there.

Mine has the Encore conversion and therefore an excellent useful load. There have been a few kinks in the first year of ownership, but I cannot be happier with this airplane's performance, especially in relation to fuel burn!

[231LV]

You should be able to purchase a decent 252 for about $150,000 or less these days....just depends on what you want in the plane! There are a few that really need some work, and those airframes are likely the ones that languish on the market, even at low prices. There are also quite a few nice examples out there.

Mine has the Encore conversion and therefore an excellent useful load. There have been a few kinks in the first year of ownership, but I cannot be happier with this airplane's performance, especially in relation to fuel burn!

well, the last time I did any serious work on this the value spread between a relatively good condition and well-equipped 231 and 252 was about $70k. Here in California, you get to pay 10% on top of that for sales tax and then you start to spend for any unknowns that the pre-buy missed. If you can find a 252 with a serial number between 25-1000 and 25-1230(they do carry a price premium), you can get the Encore upgrade which gives the gross weight increase and the SB engine BUT with the SB engine comes the mandatory airframe landing gear kit (which strengthens the gear due to the gross weight increase) which cost $16k and the dual alternator kit with mount, electrical, ect which was quoted at $20k...all in the upgrade to an SB engine with a 252 in the serial range was an additional $36k above the engine cost...according to the Mooney factory about 3 years ago

[fantom]

There are also quite a few nice examples out there.

Mine has the Encore conversion and therefore an excellent useful load. There have been a few kinks in the first year of ownership, but I cannot be happier with this airplane's performance, especially in relation to fuel burn!

Ok, Parker, you talked me into it...I'll swap you even for my pristine MSE, but you have to change that to a red stripe, and switch the N# to 17K