JPI EDM-700-6 with Fuel Scan

[sj]

Howdy Folks,

First let me say that this website and the 170 assocation has made my recent purchase of a 52' 170B a WHOLE HECK OF A LOT more informed than I would have been without it. I sincerely appreciate the patient advice I have recieved to my stupid questions. Another one follows:

First, the admission: I'm scared of the continental engine in my plane. Ok, there. I said it. Now I am prepared for public humiliation, chiding, and general abuse. HOWEVER I have only previously owned Lycomings and only flown a couple conti's in Bonanzas and 180's and 182s, and of course a little cub or two. I would say of my meger total time of 1000 hours, 910 of it is in Lycomings, and 70 of it is in my 170.

What does this have to do with the subject of the message? While, I am gradually getting more comfortable with the engine (it only has 90 hours on it now), all the talk of carb ice, stuck valves (two of mine were stuck already), it just makes a guy jumpy!

So I am considering the amazing JPI EDM-700-6 with Fuel Flow and a carb ice detector and oil temp probe. Yes, it is a pricey beast, but I figger I might have insight into any problem that is developing, which would give me some additional peace of mind as I get comfortable with the new horse, so to speak.

Has anyone used this unit, or any of the JPI fuel flow units? The only reason I thought I might chose JPI was Aviation Consumer rated them a little better than Gem.

Feel free to abuse me for my distrust of this engine with 50% more moving parts than I am accustomed to, I love how smooth it is, and how ecomnomical it is, I just gotta have FAITH I guess!?

sj

[GAHorn]

Firstly, don't think I'm disparaging Lycoming engines. They are pretty good at what they do, all things considered. But the reason many people believe Lycomings are somehow more durable than Continentals is because Lycoming made a huge marketing effort to claim higher TBO's. Lycoming claimed 2,000 hour TBO's in lightplane engines even though they knew most engines would not go that far without some serious repair work. Most people do not own their engines from Overhaul to TBO. They acquire them sometime in between those magic figures and usually also sell them before TBO..... That is what most people do. So they rarely actually have any first hand experience with them getting from new or overhaul all the way to that advertised 2,000 hour mark without major repairs. (In fact, data accidentally released a few years ago pointed to 1100 hours being the average time that "top" overhauls of their O-320/360 series occur.) In particular, Lycomings have suffered valve train and oil pump and lately, of course, crankshaft problems.
One of the serious weaknesses of Lycomings is their valve trains. The Continental engines have always enjoyed a more realistic recommended TBO, and one of the major reasons that Continentals enjoy a high reliability is because of a superior valve train. Read http://www.prime-mover.org/Engines/Marvel/tbo3.html and you can find a disinterested third-party opinion by experts.
The only "problem" engines Continental ever had was the 520/550 series and those have largely been solved. The C-145/O-300 engines are noted in the industry as one of the top performers with regard to longevity, reliability, and economy.
Sticking valves in a C-145/O-300 have been addressed elsewhere in this forum. The most common causes is improper maintenance and infrequent operation. Properly set up cylinders, correctly maintained and flown regularly rarely have problems with sticking valves. Continentals that do experience such valve troubles are easily/inexpensively fixed. Lycomings with such problems usually put a hole in a piston and/or lose the engine.
Re: the JPI- Save your money and use it for fuel and oil changes. The carbureted engine will not allow you to make accurate use of the JPI. It will be like the old adage "Measure it with a micrometer, mark it with a grease pencil, and cut it with a hatchet!"
You don't need any better carb-ice detector than your tachometer. Set your power and note the tach setting. Look at it every so often...about as often as you look at your altimeter or compass. If the rpm has dropped more than 50 rpm, then apply full carb heat for 30 seconds. Notice if the initial drop recovers (indicating that ice was present but melted out with heat)...or if it just stays there (indicating no ice was present.) Push the carb heat back in, and correct your selected power setting. Anytime you operate at a power setting below the green arc in the tachometer, apply carb heat first. That's all there is to that.
Re: fuel flow indicators--Save your money. Your engine operated by the book will burn fuel same as the book says. A fuel flow meter is only accurate enough to be worthwhile in a fuel injected engine or a turbine.

[sj]

Thanks, George!

That is great information. I'm not predjudiced, just ignorant!

I was looking for the JPI to provide me with an early warning system for a bad cylinder, broken ring, bad plug, or valve situation, which I know it can do from using them in Lycs. Not so concerned about leaning, etc.

Fuel flow was for peace of mind. I made all the hourly calcuations as a very inexperienced pilot and ended up in a field once due partially to my inexperience and partially to a problem with the engine. My car has an idiot light that tells me when the gravity challenged female will deliver her last aria.... so to speak, and it would be a handy feature.

But as you say, there are probably better things to throw the money at!

Thanks again!

sj

[Bill Venohr]

I have a carburetor temperature guage, which has been pretty reliable at letting me know when carb ice is likely. I had never flown with one before, but it has been pretty much on the mark so I think I'll keep it. Like George said, the rpm drop has always been my best indicator.

[sj]

Actually, I have a carb temp gauge now. But it always hovers around 4 degrees until I pull on the carb heat, then it runs up to 50 or so. Not sure I could detect it from that.

sj

[N1478D]

Have your exhaust valve guides reamed. Get a clock with count down mode and set it to 3 hours when you fill your tanks and turn it on anytime you are flying. When it gets down to 0 minutes or before, be on the ground getting fuel.

[sj]

Reamed all six exhuast valves recently, maybe I will get a 3-hour hour glass...

[GAHorn]

I keep a small 30-cent spiral notebook in my glovebox. When I top off with fuel I write down the tach reading. At 8 gph I know that within 4 hours I need to buy more fuel. 4 X 8 = 32, leaving 5 gallons usefuel (pun intended) which is about 30 minutes reserve. I keep a flight log on that notebook, so every engine start, I enter the date and tach reading and Airport Identifier. At the end of the tax year, or annual inspection, or any other purpose,....I have a log of dates, destinations, flight times, fuel/oil purchases. It doubles as my oil-change record.
When I buy fuel, I enter the amount, price, location, tach, and date. At any time I can divide hours by fuel and know if anything has changed with regard to my engine. (My oil is logged in the same notebook. My oil consumption is 0.09 qts/hour. When I first bought my plane, before I fixed it's oil leak, it used 0.2 qts/hr.)
This record keeping only takes a moment while I wait for the oil pressure to come up and cyl heads to warm up for takeoff. It has become a pleasureable habit performed as part of my pre-takeoff runup. A photo-copy of them has also made the IRS auditor quit looking at my taxes very quickly, bless my refund, and move on to less documented taxpayers to harrass.
(Find a JPI or GEM that will keep records better than that for less money AND help get me a $8,200 tax credit like my little notebook did for 30-cents, ...and I'll buy it.)

[sj]

Sounds like I need to expand my documentation. I do something similar, in that I keep a tach log, date, fuel, and oil, but no where near your level of reporting!

sj

[N3243A]

If you have a digital EGT you can detect carb ice even before a tach drop. After leaning out and stablizing your EGT temp, make a mental note what it is indicating. If after a while the EGT seems to spontaneously drop 30 or more degrees with no other configuration changes pull the carb heat. After 30 seconds or so push it back in and watch the EGT climb back to your intial setting.

Bruce

[N1277D]

My 170A has the JPI-450 fuel flow meter installed and it works very well. The 170A is used almost totally flying the rocky mountains regions of the USA/Canada. These flying conditions make it difficult to properly assess the amount of fuel used/remaining. There have been a few times where I had to land in terrible conditions to obtain fuel when I did not have to, just cause the fuel gauges were bouncing from empty to 1/2; due to the turbulent air conditons, climbing out of decending into valleys etc. Normal methods of time and gph just dont work to well. So the JPI-450 went in. It is very accurate usually within 0.1 gallon of the total fuel used. With the JPI one has a much better idea if one needs to land and get fuel or go on to the next place with better surface conditions.

[sj]

Cool! That's what I'm talking about. A little technology to make the day go better. I tire a little of the "ain't never had it before, shor' nuff don't need it now either" attitude a lot of folks take towards aviation.

Yes, you can throw good money at stuff that does not do that much, but take for example GPS. I STILL find crotchety old instructors trying to find reasons not to learn this technology. Some of them are not so crotchety either. These are the same guys that think the ADF was delivered from on high just a few minutes after the 10 commandments. There are even folks out there in the kansas city area still encouraging students NOT to wear headsets!!! The world changes, and while we don't have to ride the first wave, adopting new things that makes life safer is a good choice.

Now I know I am here (at least until to you throw me out) in the realm of "the beautiful airplane that cessna created should not be altered", but we are not talking about fender flares and a rolls royce grill here, we are talking about small safety improvements.

As several have pointed out, maybe and engine monitor is worthless. If so, why are so many sold... ? Does it not provide a hint of peace of mind?

sj

[zero.one.victor]

I'd rather spend my carefully hoarded money on (mo)gas & oil & hangar rent than on an engine monitor,it's all in what blows your skirt up...... Speaking of which,George,tell me how I can get this $8200 tax credit you're bragging about!

Eric

[sj]

Yes, that would by several engine monitors with some left over for gas...


sj

[N1478D]

Cool! That's what I'm talking about. A little technology to make the day go better. I tire a little of the "ain't never had it before, shor' nuff don't need it now either" attitude a lot of folks take towards aviation.

sj

I don't get tired of hearing other people's opinions! Believe there is a place for those that enjoy keeping it simple, and a place for those that enjoy exploring the latest, newest technology.