JPI 700 Temps? Confused

[Northern Mooniac]

Flying my plane home for the first time.

It has a JPI 700 and with a 450 Fuel Flow.

360-LB with Turbo and Intercooler.

Using the POH we set a recommended cruise but found cylinders 3 and 4 were running at about 412 degrees.

We could not lean out and ran almost full mixture to keep under 400 degrees and a TIT if 1525.

The old analog CHT showed temp of around 340-360 degrees.

Altitude of 11,000 feet and OAT of -2 Celcius.

I'm planning to get a new JPI 830 but just wondering if any others have had an experience like this? Is the 700 starting to show issues?

Looking for some advice.

 

[kortopates]

What was your max FF at takeoff? it may not be high enough causing to run too lean.

Remember your OEM CHT gauge is just one cylinder; probably #2.

Don't hesitate to use cowl flaps if necessary till you get to the bottom of the issue.

[Cruiser]

Engine monitors are wonderful things. You just found out why.

You are now getting data on each cylinder rather than just one. 

Find out which cylinder the original CHT is on, determine how they JPI is also getting temperature from that cylinder. 

I am not familiar with the engine but CHT is controlled by two things, internal engine generated heat and external compartment cooling (cowl flaps, baffles etc.) both are very important.

 

[milotron]

If I recall, the stock CHT sensor on the K is on #5,  right hand side front. It might be sharing the probe well with the JPI sensor and will read low compared to it them.

Did you have cowl flaps open?

 

11,000 and OAT of -2C is not very cold at all. Where were you? I have had cooling issues at 12k and above with my K, even with temps much colder than that, prompting more cowl flap opening than down lower.

 

Just looked up in Flightaware ( because I am Canadian and we have to stick together...)  What was your fuel consumed on that leg from Springbank to Regina?

Edited March 25, 2017 by milotron
Eh?

[Pritch]

I have the JPI 730 on my K, #3 is the stock CHT.  I rarely get over 370 on the CHTs' and keep the TIT below 1570. I do have GAMI's intercooler and Merlin.

Pritch

 

[Northern Mooniac]

we did not open the cowl flaps, we only had them open for take off and closed once we set cruise.

We had almost full mixture and running about 13-14gph.

My friend has the same plane just no intercooler and we don't have these issues, but he does have a new 830 installed.

[Pritch]

Just now, Kevin Pare said:

we did not open the cowl flaps, we only had them open for take off and closed once we set cruise.

We had almost full mixture and running about 13-14gph.

My friend has the same plane just no intercooler and we don't have these issues, but he does have a new 830 installed.

If he is a good friend swap out your 700 with his 830 and do a flight and see what the readings are.

Pritch

[Northern Mooniac]

ha I wish, I'll have mine here in a few weeks I hope! along with some gami injectors

[carusoam]

Look around for a few threads, on Turbo charged operations.  We have a few people that have discussed how they operate including their hardware, cowl flaps used, and LOP... @jlunseth is one of the authors in that group.  Excellent read...

Best regards,

-a-

[wpbarnar]

Since the airplane is new to you, when was the fuel injection system last adjusted?  TCM has a specific procedure for this (SB97-3) and it should be noted in the log book.

Your stated stated full rich fuel burn (13-14 gph) seems low so I suspect your full power fuel flow is low too.

Making sure your fuel injection is set up properly is good starting point on a TSIO 360 before attempting to trouble shoot other issues. 

Bill

 

[jlunseth]

10 hours ago, Kevin Pare said:

we did not open the cowl flaps, we only had them open for take off and closed once we set cruise.

We had almost full mixture and running about 13-14gph.

My friend has the same plane just no intercooler and we don't have these issues, but he does have a new 830 installed.

Well, first of all, if you were running at 13-14 gph you weren't at "nearly full fuel flow," which is 22.5-24 at full power and at cruise settings is somewhere in the 19 neighborhood.  Actually, my standard ROP setting is 13.3 gph with an MP of 29 or 30" and RPMs of 2450, but I rarely fly ROP anymore.  Some of the POH settings are good and some not so good.  The Best Economy settings believe it or not are pretty much a good LOP setting, except I run with a higher MP than what is in the POH when running LOP, which puts you further from peak.  If you want to run ROP and use the 13.3 gph, 29" and 2450 you will be fine.  

I have quite a bit of variance among the CHT's, and after doing some lean testing concluded that it is not the result of differential fuel flow.  With one exception (my cylinder 2) my cylinders are fairly close together in terms of mixture.  The difference is cooling.  In my case, it is partly an issue of the baffling getting a little old, and I am not too worried about it right now because I am nearing TBO anyway.  But that is the first place I would look.  The cooling in the LB is not ideal.  

The Best Power settings in the POH are not the best.  Lots of people run at 12.5 gph or so.  That is about the worst place to be in terms of engine health.  Sure you get lots of power of out of the engine.  You are also running it somewhere between peak and 50 ROP, dead in the "red box."

I have my mechanic set the cowl flaps to trail slightly for summer.  I might lost a knot or two, but it helps the CHTs quite a bit.

[kortopates]

As I stated above , it really looks like your max fuel flow is too low. if full rich was 13-14 GPH in cruise that pretty much confirms it. On takeoff you should have your JPI on TIT & FF to be monitoring for an insufficient FF situation. The high max FF number for the earlier GB & LB engines is 24.7 GPH and we at Savvy like to see that plus 0.5 to 1.0 GPH higher for a bit of improved cooling or 25.2 to 25.7 GPH. (These numbers are identical with the Turbo Plus intercooler too.) So I suspect, based on your commenst, your take off max FF is considerably below that and if so needs to be adjusted back up to spec ASAP. 

[Northern Mooniac]

On take off, it was in that 24-5 gph for flow during take off, in level cruise at 2500 rpm we ran about 27-28in with almost full rich and got 13-14 gph.

[jlunseth]

Well, I don't completely agree with Paul here, and he is a pretty smart guy on these issues, but not getting 22.5 at a cruise setting is not abnormal.  The fuel flow does "taper off" as you pull the power back (reduce MP).  Its good that you are getting what you should on takeoff, yes you probably should have the mixture setting looked at.  I have seen the high 16's at a full flow setting at a ROP cruise MP like 28", but don't ever recall seeing as low as 13-14 unless I lean it out to that setting myself.  It would depend on what MP you pull it back to, because the MP and fuel flow are interconnected so the fuel flow will come down with the MP.  That is normal.  You won't be able to make 22.5 at 27-28", even with proper fuel flow settings and no matter you hard you push the knob in.  Its possible that with the fuel flows set correctly you would see a fuel flow that low (13-14) at 27.  I would expect a little higher.  But if you were truly at 27 and 13 gph, and at that altitude, you should not still not see temps that high.  I would expect the vicinity of 380 and possibly as high as 400 on a "bad" (read hot) day.   It is possible you have a wide variance in fuel flows to the different cylinders, but if so you would see some running at your 416 and some running cool.  

I am sorry, my plane is in the shop for the annual or I would go out and fly it to see what I get for max fuel flow at 27".  Its definitely not 22.5-24 gph.

When I first got my plane I had the same problem you are describing.  We had to both rebuild the spider to get the fuel flows working right, and put in new baffling.  But my problems were worse than what you are describing, I could only make 18-19 at full power on takeoff.  In your case I am still leaning towards a baffling/cooling issue.  

When you get the fuel settings checked, be sure to pull out the STC and fuel flow setting instructions from Turboplus, or if you don't have them, get them from Turboplus ( I have a copy, PM me if you need it).  Most mechanics set the fuel flows according to the standard SID (I don't remember the number off the top of my head).  But that assumes your engine makes full power at 40", which is the max MP of the factory engine.  Yours makes full power at 36-37 because of the intercooler.  So the fuel flow set up needs to be adjusted to provide that full flow of 22.5-24 at the lower MP.  The STC instructions say how to do it properly.  That may be your fuel flow issue here, because it would result in a fuel flow of just a couple inches less than what you should be seeing at cruise (that is, you are seeing 13-14 and maybe should see 16 to have full fuel flow).

That said, 27" and 13 gph should not produce the temps you are seeing.  Its not just a fuel flow issue.

[jlunseth]

PS - a thought.  Did you do a runup and did the mags check out ok?  One way to get the temps you are reporting, at the fuel flow and power setting you are reporting, is to run on only one mag, or have one mag operating but badly, or to have plugs that are going bad even if the mags are working decently.  There are people on this site who can tell you how to run an "in air" mag check, that would tell you.  Maybe one of them will come on.  

[Northern Mooniac]

Mags checked out ok. I do have Gami's on their way and going to put in new tempest plugs. We'll see how that helps.

I wouldn't think that the emd700 would be that much out to lunch just because it's old. I think there is a real problem.

[Jim F]

Hi Kevin,

I am with Paul that the fuel flows need to be adjusted. You and I have the same engine but I don't have the intercooler. Our fuel system is very simple with fuel moving through brass plates that must be adjusted correctly or our engine won't run right. 

Start with getting the fuel flows set correctly.  Once the fuel flows are right you can try other possibilities but always start from a "known good"

jim

[Guest]

Here are the fuel values for the TSIO360LB per SID97-3G

TSIO-360-LB  700 2700  RPM, 40.0 IN HG,  Unmetered fuel pressure 6.25 - 6.75, 34.0 - 38.0 PSI,

metered nozzle pressure, 14.7 - 16.7 PSI, fuel flow 135 - 145 LBS/hour, 23.0 - 24.7 GPH

Clarence

 

[jlunseth]

Those are the standard SID numbers that I was talking about, and as I said, don't let your mechanic use that SID.  I am convinced that is the problem 90% of the time 231 pilots who have the intercoolert report bad fuel flow numbers-their mechanic went on autopilot and just used the standard SID.

There is an STC with specific instructions for setting up the fuel flows for engines with the aftermarket Turboplus intercooler.

 

[kortopates]

11 hours ago, Kevin Pare said:

On take off, it was in that 24-5 gph for flow during take off, in level cruise at 2500 rpm we ran about 27-28in with almost full rich and got 13-14 gph.

If you're getting that on takeoff at 100% HP you're only 1 GPH below the target spec and if you were being a little conservative as many 231 pilots are and using a bit less than 37" full power then you could be right at target. But something is not right if the max rich FF you can get at those cruise is only 13-14 GPH. Furthermore, if these indicated values are from the OEM gauges then all bets are off till this is checked with calibrated gauges. I'd trust the JPI for RPM and MAP and 450 for FF if you know the K factor is accurate. (Incidentally, I'd highly recommend eliminating the 450 and wiring the fuel flow sensor to your JPI 700 so FF get's included with your downloadable data).

John is correct that their is a fuel set up procedure for the TurboPlus Intercooler. But the max FF numbers are no different, in fact TurboPlus quotes the outdated Continental documentation for what numbers to set max metered fuel flow, which are as both I and Clarence quoted above. But John correctly identifies the one difference that the TurboPlus procedure specifies, which is that is that full power is at 37.4" at ISA versus 40". The set up document provide a temperature adjustment chart for what 100% power MAP is relative to +/- ISA conditions at redline rpm. Where I am in sunny Calif summertime  temps can get to ISA+15C that amounts to just one more inch or 38.4". Up in the artic north at ISA perhaps with ISA-15C, you would lower one inch to 36.3". Thus it doesn't make a big difference. But the important thing is that target max FF is being set at about 2 1/2" MAP less than the non-intercooled GB/LB engines at 40" and I have to agree with John that some mechanics seem to miss this which leads to insufficient max FF and high TIT's in climb.

Incidentally, the proper reference for TCM fuel set up for FF used to be SID 97-3, but a year ago many of the SID's where incorporated into Continental a new CMI Maintenance M-0. I am pointing this out because all of you with Continental Engines can get all of Continentals documentation applicable to your engine for free online. You simply have to register your engine with serial number on their site at http://continentalmotors.aero/login/ Even if you don't care about maintenance I highly recommend reading and digesting the Continental Operators manual for your engine. You'll learn a lot more details about your engine that isn't in your Mooney POH.

Lastly, the the only ignition issue that would drive CHT up is advanced timing (it lowers EGT and raises CHT). if you were running on only 1 plug in a cyl that would increase EGT but drop CHT, not raise it,  as would retarded timing. But if you want to do a LOP mag test, or a GAMI test, I suggest reading our detailed procedure that we use at Savvy, I just updated the entire procedure a couple months ago adding lot of details for both NA and turbos. http://content.savvyanalysis.com/static/pdf/SavvyAnalysisFlightTestProfiles.pdf  (incidentally, all the simpler pneumatic and fixed gate turbo's like the 231 add the additional pilot workload to maintain a fixed constant MAP while collecting gami spread data, i.e. you'll be manipulating both the black and red knobs while leaning and enriching so that only fuel flow is changing as you go from ROP to LOP and LOP to ROP; otherwise you'll see MAP changes of 3-5" which can really invalidate your results.)  

If you're a new 231 owner and missing any of the TurboPlus documentation (ICA, install instructions, fuel setup, POH AFMS) you can get it by contacting turboplus at http://turboplus.com/contact_form.asp Interestingly, they use to be located a few minutes away from me here in CA but were recently re-acquired back by an original founding partner and have moved up to Washington. 

Good luck and let us know what you find out.

 

[Northern Mooniac]

Happy to report that the installation of gami injectors and tempest fine wire injectors has solved my heating issues. We are also able to use lean of peak as well.

During Climb im using 37" MP, this is giving me about 1000ft/min with 2 souls and full fuel. However only using 20gph for fuel.

It seem slow but the plane is performing well.

During cruise we were using the Merlyn power chart with the Turbo Plus chart to determine how much MP based on the differential.

at 8000ft we were able to get 165kts on ROP using 1550 TIT and 13-14gph, on the lean side we hit about 150-155kts with 1550 tit and 10gph.

Now that the engine is running well we need to do some tweaking but i'm waiting to get my jpi 830 to do that.

[kortopates]

Happy to report that the installation of gami injectors and tempest fine wire injectors has solved my heating issues. We are also able to use lean of peak as well.
During Climb im using 37" MP, this is giving me about 1000ft/min with 2 souls and full fuel. However only using 20gph for fuel.
....
Now that the engine is running well we need to do some tweaking but i'm waiting to get my jpi 830 to do that.

Personally, I would abort any takeoff where my max FF was showing 5 GPH below max spec. This is one of the easiest and fastest ways to burn up an engine; especially a turbo.

Please read the following article on Detonation, on page 5 of 6, Mike is speaking directly to you!
https://www.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2010-09_destructive-detonation.pdf


Sent from my iPhone using Tapatalk

[Northern Mooniac]

I read through that, going to get my fuel flow, timing and a borescope looked at this Week. The plane is new to me with 200 hours on the engine but the previous owner didn't obey any of this., cyl 6 constantly ran over temp and he ignored that. Gamis fixed it, but hopefully there aren't any issues he created that I get to fix.

[LANCECASPER]

On 3/24/2017 at 10:56 PM, Northern Mooniac said:

we did not open the cowl flaps,

I would trust your JPI - this is a hot running engine. Look for the simplest solution first - the cowl flaps. I flew a 231 for three years and in warmer months I always had to keep them partially open. Of course I'm in Texas. Cowl flaps were the last thing I did when setting up for cruise. If temps looked goos once my power and mixture were adjusted I'd see what it looked like with cowl flaps closed. I remember my mechanic later setting the "fully closed position" so that it would trail open and this worked out well. But I can't imagine in most cases keeping cowl flaps completely closed on the TSIO360-GB or -LB engine unless it was dead of winter up North. There is a lot packed under the small cowl on the K - cowl flaps are your friend.

Later I had an Encore that had the -MB engine and most of the time in cruise I could keep the cowl flaps closed.  It had the electric cowl flap motor which allowed for infinite adjustment, so if temps outside were higher I would open it a little and the temps would come down where I liked them.

[Northern Mooniac]

Once I installed the gami's and the tempest firewires all my heat issues went away. My issue now is that I don't hit 24gph on take off so i'm trying to get my fuel flow adjusted this week.

That would be slick to be able to adjust it slightly like that!