Engine Monitors

Ted

Ted

The pilot formerly known as Twin Engine Ted
Joined
Oct 9, 2007
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iFlyNothing
In the process of replacing the starter on my right engine, we made the observation that the aluminum battery cables that Piper used to save weight back in 1969 are in really, really bad shape. Lucky me, the copper cable is "only" a bit over $500. Better yet, the school is doing an electrical class, and so I'll save a bunch of money on the installation. Next Friday I'm leaving the country for a week and a half, so I was looking for something that could be worked on on the plane while I'm out of the country anyway, and that happens to be a good use of the time.

Here's the catch: it just so happens that the stuff you have to take apart to install an engine monitor. Well, I want to do that at annual, but now is a good opportunity with the cheap labor and they have that part of the plane apart anyway. So, guess what I'm going to be buying ahead of schedule.

I'm figuring on an Insight Gemini 1200. Best bang for the buck, and gives me all the info I need. I'd get a JPI if there was a better deal, but the Gemini is $700 cheaper, and provides the same info as far as I'm concerned. I've flown behind both and while I like the JPI better, I don't like it $700 better. I'm also not going to bother with the fuel flow meters. The plane has the mechnical fuel flow meters installed that, while not the most accurate things in the world, give me enough information.

My question: Does anyone have a recommended source for ordering the Gemini and/or know of some screaming deals that exist on either unit? I'd buy the JPI if I could get some deal that brought its cost down to closer to the Gemini. I'm probably going to try to order this by Monday.
 
Just curious why you don't even mention EI. Their customer service is far superior to JPI or InSight
 
I hadn't considered them, Tim. Do they have a unit for twins? Their 6-cylinder single unit is $2000, and a pair of those would end up costing a lot more than the Gemini or JPI.
 
You know, I don't know if they have a twin unit or not...I thought about that right after my last post.

Great company though. They replaced my UBG-16 when it was three to four years out of warranty.
 
Ted,

I've been all over the three monitor mfr's websites lately. EI does not make a twin-engine analyzer, so you're really down to JPI and Insight.

Do you plan to try to get the engine data off of the unit? The Insight GEM 1200 will need an ancient HP-200LX (infrared port) to retrieve the data. :nonod: JPI has a wired serial port and also offers a USB option to which you can attach a thumb drive to download the data.

Also, it looks like JPI is having a $300 rebate on their EDM-760. (at least I think that's how that reads. The grammar is terrible)
 
Ted: I have the JPI and had that on my previous plane. Downloading is fairly easy; they now have a thumb drive or whatever the current terminology is.
On runup, I put the JPI in normalize mode to test each mag. Also use that feature when LOP to adjust FF. Go to a known lop point; 16 gph on my plane or just a bit less. Let it stabalize; go to normalize mode and adjust FF to best power keeping CHTs under 380. Usually about 16.5 gph at FL180.

There were some lengthy discussions on another board about the other provider not being able to reasonably service some parts. JPI got bad for awhile, but seems to have improved now.

Keep in mind, the Lean Find mode on the JPI is an algorithm; if you lean in the same manner several times, you will get a different result each time. That's why I use the above method.

The newest system out there doesn't have a twin version yet, but it's supposed to be out soon. Might be worth checking.

Best,

Dave
 
I'm not planning on downloading data, and have no interest in using lean find. When I deal with these engines in the test cell environment, we just get straight numbers that we deal with, none of the gadgets. That's what I'm used to and am looking for. I'm also not going to need to mail the data off to anyone since the person I'd be mailing it off to is... me. :)

According to that JPI ad, it looks like it's only $300 off of the single engine units, and that's if you add fuel flow. So it's a $1000 add-on instead of a $1300 add-on for fuel flow, which isn't something I want.

Still, I'll give JPI and Insight a call to see what they say. I do agree the JPI is a better unit, I just don't think it's $700 better.

Thanks for the insight! (no pun intended)
 
I would recommend downloading the data.

Recently I had some odd things happening and being able to go back over historical engine data was very useful.

I have an EDM700, 2002 firmware, which works but if one waits for too long between data downloads and lets old flights get overwritten, only the most recent JPI software is capable of extracting any data from the corrupted downloaded (.dat) files. In turn, this new software is no longer capable of saving in .csv format; only .xcl (Excel) format is available. This may be an issue for some people.

For a future install, I would consider a different product.

EI claim to have thicker EGT probes and that is definitely a good thing because the JPI EGT probes do fail eventually. I have got through 3 of them. Usually they fail open-circuit, with the failure being preceeded by an excessively high EGT indication - this presumably being caused by the "open thermocouple" detection circuit inside the instrument (normally a pullup resistor) causing the apparent output voltage to go high due to erosion of the TC tip just before it fails completely.

That said, I think most owners find the bigger chunk of the installation cost is the wiring, not the instrument. Recently I was watching an installation on a twin and it took ages, pulling the very long wires laboriously through tight orifices in the wing roots etc.

Also, puchase the oil temperature option. This provides a backup oil temp reading for a minimal cost.
 
We've got a JPI in our Aztec. We download the data every couple of months. By looking at the graphs of when we were in "normalize" mode, we've found both weak exhaust valves and dirty injectors long before we would have noticed them otherwise.

Call Marc Polizzotto, Vice President of Operations, 18003454574. He gave me the best price at OSH on the internal fuel flow upgrade that they now offer for the EDM760.
 
peter-h said:
EI claim to have thicker EGT probes and that is definitely a good thing because the JPI EGT probes do fail eventually. I have got through 3 of them. Usually they fail open-circuit, with the failure being preceeded by an excessively high EGT indication - this presumably being caused by the "open thermocouple" detection circuit inside the instrument (normally a pullup resistor) causing the apparent output voltage to go high due to erosion of the TC tip just before it fails completely.
Click to expand...

I have an EI TIT gauge and a JPI 700 monitor. Various other EI stuff in the plane (fuel flow, ammeter, etc).

I will echo the above comment. I get 200-500 hours out of a JPI EGT probe (same proble used for JPI monitoring of TIT). The EI TIT probe has not been a problem - it's pushing 800 hours. The EI probes have slower response. JPI is faster. I've probably spent as much in replacement probe costs as the JPI unit cost to start with, installed.
 
Ted DuPuis said:
I'm not planning on downloading data, and have no interest in using lean find. When I deal with these engines in the test cell environment, we just get straight numbers that we deal with, none of the gadgets. That's what I'm used to and am looking for. I'm also not going to need to mail the data off to anyone since the person I'd be mailing it off to is... me. :)

According to that JPI ad, it looks like it's only $300 off of the single engine units, and that's if you add fuel flow. So it's a $1000 add-on instead of a $1300 add-on for fuel flow, which isn't something I want.

Still, I'll give JPI and Insight a call to see what they say. I do agree the JPI is a better unit, I just don't think it's $700 better.

Thanks for the insight! (no pun intended)
Click to expand...

I have the "cheap" Classic Scanner from JPI in my Hiperbipe. It as the same fast response probes as all JPI products do. The Classic Scanner cycles thru all 4 (or 6) CHT then goes thru the 4 (or 6) EGT during auto scan. It also has a manual scan that lets you go thru the clyinders with the press of a button. The readout is 1/2" tall red LED. It has pre-set alarms for high CHT and EGT. It also will thll you the Buss voltage when you hold in the "advance" button.
It costs $650.00 USD

It is STC'ed for most aircraft (it's been out for 20+ years).
I myself only needed the engine moniter to moniter my engine and diaignose problems real time. This unit does that!

On the JPI website you have to look for this unit...they are trying to sell the "Ubergeek Upscale" stuff on the front page after all...!


Chris
 
Well, I just made the purchase - Insight Gemini 1200. It and the new battery cables will get installed while I'm out of town, and I should come back to a new toy and faster spinning starters. :)

Of course the engine monitor will probably uncover another couple hundred dollars worth of repairs (at least)...
 
Pretty soon you'll have a new plane.. ;)
 
You mean I don't already? ;)

I like doing the upgrades that at least make me feel like I'm getting something out of it. In a few years time I'll really have the thing the way I want it.
 
I have a JPI EDM 700 in my Tiger. Its held up well the eight years and 650 or so hours I've logged with it. The probes have never failed on mine Bill. (knock on wood!)
 
AFAIK one can use the thicker-skinned EI probes with the EDM (JPI) products.

They are standard thermocouples - type J or K (can't remember which).
 
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