testwest

Hi Russ You are doing it right my friend, investigate one thing at a time and share your results. If you could post what resistance values you found on your old plugs that would be great. RAM aircraft seems to think fines provide a "little" better efficiency, see here: http://www.ramaircraft.com/Maintenance-Tips/Spark%20Plugs-Fine-Wire-vs-Massive.htm But George Braly from GAMI disagrees. I would base your decision on your current economic situation....Tempest fines will be about twice as expensive. You do have an engine analyzer, right? Can you record the data and share it?

I-man you are correct. There are some folks not on this thread who aren't fully convinced about what LOP means. We don't have GAMIs on ours yet. Our plan when the JPI 930 is installed is to do the following: Check for any induction leaks, fix as necessary Do a GAMI Lean Check and LOP mag check at 8000' DA Pull our old Champion spark plugs, measure and record all resistances, then install new Tempest fine wires Do another GAMI Lean Check and LOP mag check at 8000' DA Determine if there is any change to the GAMI spread due to the spark plugs. There sure "seemed" to be an improvement on our Aerostar left engine when we did this, but I didn't do a good baseline first, so I don't have hard data. The steps above will be my atonement. We'll post the results. If our GAMI spread is more than .5 gph, we get GAMIs.

Parker is right....and I added him to my list above in an edit.

Hi Russ Byron (Jetdriven), Scott S (KSMooniac) and Parker know what they are talking about. There are others on this forum, who don't. Having said that, if you have been running 50-100 degF ROP with cylinders below "about" 380 degF you probably haven't messed up anything. If there is a lot of flying at 50ROP and 430 degF cylinders, you "may" have caused more wear on the cylinders than would otherwise be possible. Not damage, just wear. I am pretty sure (but don't know for certain) that diehard LOPers aren't having to top their engines every 600-1000 hours. We have 1100 hours on our old-skool chrome cylinders, and compressions are all above 70 still. Byron mentioned, "climb at target" in other words the Target EGT method - see the attached pictures from KSMooniac's airplane. This is a Target EGT climb at WOT/2700 from KAAO, up to 8000'. Folks, this is how you do it. Russ, does "Target EGT" have meaning for you? The other picture is what happens when you leave the mixture full rich. At top of climb at 8000' with Target EGT the fuel flow is 13.9 gph, at full rich the FF is 15.6 gph. You are much more efficient climbing at WOT/2700/Target at 115 KIAS in an M20J (and using 500 fpm climb when the performance drops to that level, around 6000-7000 feet or so) than you are at Vy and WOT/2700/Full Rich, or the dreaded 25 square. The flights whose data are shown below were flown back to back by KSMooniac, with me in the right seat. The first climb (called Vz, by the way) leveled off 19 miles down path. The second Vy climb leveled off at 12 miles, then Scott cruised at his absolute best 65%LOP capability to the 19 mile point. Fuel used to 19 miles - exactly the same. Average speed to 19 miles (actually, velocity made good), 20 knots faster for the Vz climb. This is the kind of performance improvement you can get when you STC Your Brain. Any other questions? We are glad to help!

Skyking You may want to find a friend with a Cessna who gets the Cessna owners magazine. There is an article in there by Mike Busch on spark plugs. One interesting set of pictures compares the insulator of Champion fines versus Tempest. Remember the issue with insulator cracking is currently limited to Champion fine wires, not Tempest. Have a look at those pictures and share your own conclusion here! We are getting ready to do a back-to-back comparsion on older Champion massives (with unknown resistances at this point) and new Tempest fines. We'll post any findings here.

+1, we really would like to see pictures!!!

Byron wrote (regarding the "lean 'til rough, then enrichen until smooth" can wind up LOP): Norm, can you comment on the Lycoming IO-540-S1A5? How does it behave? I sure can. It behaves as you say, it is quite smooth until well lean of peak, and enrichening back to smoothness parks the engine at least 100 deg F LOP on the richest cylinder. This is a high compression TN engine, basically 1.5 Mooney 200 hp engines held to 29.5" max all the way to FL230 or so. One has GAMIs, the other does not.

SOLD, thanks everyone for your interest!

D'oh, got my TITs and my CDTs mixed up! At any rate, those low-compression boosted engines just have a little more challenge when it comes to operating LOP, however....the fine wire Tempests may help. Check your spark plug center electrode resistances and replace any that are trending high. Good luck! Also, your mag timing may be a little on the late side, equally on both mags, so your combustion event is slightly delayed. This would explain both the lower CHTs and the higher TITs. Let us know what you find!

Some very good information on intercoolers here: http://www.cirruspilots.org/blogs/braly/archive/2009/02/13/intercoolers-are-wonderful-devices.aspx

Actually, this thread may turn into a thread on intercoolers......which, if you want to gain any economy of operation with your low compression ratio engine, may be the only alternative. Also, check your spark plugs for high resistance on the center electrode. There is an encyclopedia's worth of information on that subject here, and on Beechtalk. BTW, I would suggest lurking on Beechtalk for anyone who has any interest in this subject. The APS guys (Deakin, Braly, Atkinson) hang out there and post all the time.

Edited the post since it has not sold yet, now $175 + shipping OBO. Come and get it!

That is fantastic news, I will be emailing them ASAP. KSMooniac will probably beat me to the punch though.

Take a look at this KX-175B, it is over on the Vans Air Force Forum.....this is a very good price for a y/t KX-175B outright. http://www.vansairforce.com/community/showthread.php?t=86474

Please check out my ad for this yellow-tagged Aerosonic encoding altimeter - $950 OBO. View My Ads on Barnstormers

Edit - this unit has been sold, thanks! Was: Up next from us is a Whelen tail light/strobe combo, the Whelen part is A500A-V-14 (14 volt). This is a new-in-the-box light, they normally go for $158 or so from the usual suppliers. We are asking $99 + shipping, if we use USPS Priority Mail Standard Box, shipping will be only $10.85 to anywhere in the US. We prefer PayPal! PM if interested, thanks.

Hi Skybrd Check with JimR, he might sell you one of the flash tubes in this lot. The Whelen flash tube base is smaller than the Hoskins, so it would "fit", but it would not be a great fit.

For sale is a lot of Hoskins strobes from a Mooney 201. Of note in this lot is one NEW (old stock) Hoskins flash tube, perfectly clear, perfectly bright. These are impossible to find in unused condition, this was manufactured in 1986 and still has the original box. Also included are two NEW strobe tube clear glass domes ($65 value all by themselves) and the strobe housings, restored and ready for paint. Also there are the old strobe dome covers (they are kinda yellow) and two older strobe flash tubes, they do flash but are not the greatest in appearance. Sold as a lot only. $150 plus shipping. Paypal accepted!

Hi everyone We have decided to sell our old strobe system from our M20J. First up is this Hoskins strobe power supply, works very nicely. Part # 701295-3. The red wire is power in, the yellow wire is a synch wire for those airplanes so equipped, and black is ground. And the Molex receptacle on the top that has the B+, TRIG and GND labels, plugs right in to your existing Hoskins strobes. These don't come on the market too often so I would like $175 plus shipping, OBO. PM me with your information, first Paypal is first served. Thanks!

Hi everyone Here is the diesel aero engine you should keep an eye on. You probably have not heard of it before. It is the Engineered Propulsion Systems (EPS) Vision 350. The company is in New Richmond, Wisconsin. It is a similar size and weight and cost as a new turbo Lyc IO-540 (angle valve) or a new turbo Cont 550. It's a horizontally opposed 8, with shared crank throws, geared, with a powerhead similar to the latest Mercedes 4.4L diesel. Also, here is a drawing of the engine installed in an Aerostar nacelle. Right now, I can go about 205-210 knots at altitude on 26 gph total (65% power), that is on TN 540s...AFAIK the 601P is the only TN pressurized airplane on the market. With the 350 diesel that becomes (roughly) 220 knots at 22 gph total (65%)....or 242 knots at 32 gph total (85%). Looks like 65% is a good place to run a compression ignition engine, too. This engine as a retrofit to Malibus will be a world beater. Ooops, Alan Klapmeier has already figured that out, but hasn't told anyone yet, http://www.kestrel.aero/aeroworks.html A Gippsaero GA8 Airvan with one of these will be a world beater as well...not to mention a heavy fuel UAV engine the perfect size for a new Predator with excellent range. Retrofit Zezzna 421s! The end of the schitzo-GTSIO 520..... Anyway, take a look.

You could try Advanced Aircraft in Troutdale. They are a Mooney Service Center. We use them for our annuals.....good folks.

Yeah, no joy with Safari either. I wound up using Firefox for Mac.

Also I see on the chart that you just posted the GAMI spread is more like .6 gph. So, when you are optimizing your injectors with GAMI, be sure to check WOT/65% power and use those data as the reference. By the way, are you using EZtrends to post your data, or importing to Excel or Numbers? I am a Mac guy too.

Hi Kris If you want, just repeat the same test except at wide open throttle (and 2300 RPM)...you should get about 25" of MP under those conditons. If you have ram air, you can open it up and gain back (some) manifold pressure. Of course, for a trip your choice of power settings for most efficient operation is completely dependent upon winds, so you may be at 2700 RPM WOT at 11,500 (~65%) for increasing tailwinds at altitude, or 2200' WOT at 5500' for the same power if the winds are worse (i.e. they increase by altitude faster than the TAS you can get at WOT). Thanks for your post, and interest. It is really neat that folks here are interested in facts and data (instead of dogma) regarding their engine operations.

Hi Kris That GAMI spread is really nice. Don't forget the engine is far more efficient if it is unthrottled, e.g. wide open throttle or WOT as it is abbreviated. I see you are running 23" and 2300 RPM. Remember any advice to run "square" or "undersquare" you may have received in your training for the complex airplane endorsement to your license (or any subsequent "advice") is absolute balderdash. Try your run at 6500' WOT and do another GAMI lean test, and share the results if you are so inclined. 23 square at 6500' is 62% power at "best economy" for the IO-360-A3B6D as installed in the M20J (from Benchmark) so ~58-59% or so LOP depending on your fuel flow, at WOT/2300 you are at 68% BE and maybe 63% ish LOP. Also, if you ever have the slightest indication of any spark plug issues, such as a poor runup, see the posts here regarding Tempest spark plugs. By the way, thanks for posting the data. Flight test types just eat that stuff up!