Jabiru 2200 oil pressure problems!

[rick-p]

My aircraft is powered by a Jab 2200 with mechanical tappets.

 

My engine reporting instrument is a Flydat:- oil pressure and temperature, etc.

 

Problem:- oil presure reading on reduced power constantly reading low or the same after a long climb out.

 

Temperature is fine, well within the correct range so not a viscosity problem.

 

Using Aeroshell 100 plus.

 

Pressure at reduced power fluctuates between .9 bar and 1.8 and whilst on full power increases to 2.2 bar to 2.8 bar.

 

The other day it dropped to .4 on finals and .2 on touch down.

 

I placed one s/s washer under the pressure relief valve spring which initially improved the situation then went back to previous readings or worse.

 

No dirt was found under the seat on the relief valve.

 

All other readings on Flydat seem to be ok.

 

I was told by Jabiru that i should have an oil cooler fitted but I don't believe that this is the problem as temp's are perfect and the plane is factory built overseas and the Jab engine installed there.

 

It has the deep sump and the airflow over the sump and engine is optimum.

 

It's an extremley well designed and engineered installation and the designers were no slouches.

 

Apart from instrument or pressure probe problems have any of you guys out there got any suggestions.

 

Your knowledge or experiences will be greatly appreciated.

 

My real concern is that if it is a genuine low pressure problem then the rear bearings will suffer.

 

Does anyone know the correct operating pressure for the Jab 2200 as the book says one thing and the factory tells me something else.

 

I will be this weekend fitting a VDO oil pressure guage to confirm whether or not it is the Flydat that is the problem, the oil pressure switch seems to be operating correctly.

 

Please your suggestions guys.:;)5:

 

Thanks,

 

rick-p

 

 

[Wilfred]

I am no engineer but this is something that i really think you need to liaise with the factory about.

 

I would find it very unusual not to have an oil cooler fitted especially in the area you are operating.

 

The pressures you give seem consistent with a lower pressure at idle the book says as low as 11 psi or about .8 Bar, and it would be expected for your oil temperature to be way up after a climb and your pressure to drop especially without an oil cooler.

 

The Flydat is also probably very sensitive and will register any fluctuations immediately where the VDO seems to have a delay and they are not noticed as much.

 

once again it really needs a bit of liaison with the factory and common sense says fit an oil cooler in our hot conditions.

 

 

[Guest brentc]

The oil pressure will vary signficantly based on temperature and RPM. If you are worried that it is too low all the time, you can simply pull out the pressure relief valve (located under filter) and insert 1 or 2 AN washers (up to four) and it will increase. We did this last week on a 3300 Jab engine with success. It is also in the manual.

 

My 3300 oil pressure varies from 1 to 4.1 or thereabouts. It can be very low on final and very low at high temperatures. It varies significantly with RPM changes.

 

 

[rick-p]

Hi turtle,

 

It's defintely not a temperature or lack of oil cooler problem as at the worst the temperature on a long climb out on a hot day nearly never exceeds 85deg. Normal cruising temp's about 80deg's and only once did it get close to 90deg's but pressure was about 2.1bar.

 

I know the history of the oil coolers on Jab motors and I do believe that in this case it would just be an unecessary addition which would probably create another problem through the adding of extra weight to the aircrafts already maximum empty weight.

 

The air flow over the motor even in long idle situations is so very efficient because of the cowl design etc.

 

The large sump is completely exposed to the slip stream of air off the prop along with the ram air ducting to the top half of the motor.

 

Yes I think your spot on about the Flydat it is sensitive and would register fluctuations in pressure very quickly.

 

Of course I know that I need to discuss the perceived problem with the factory but I may add that I think you and brentc have answered a wealth of questions of mine.

 

At times it us the operators of these motors that do in the long run tend to know them best.

 

In the area of recreational aviation it is the smart guys out there building and flying these planes that are the ones in the know.

 

Without them the manufacturers would never make it.

 

We are the ones that ultimately test the motors for them and you don't have to be an engineer to do that so never sell yourself short.

 

Thanks so very much for your advice.

 

kind regards

 

rick-p

 

 

[rick-p]

Thanks brentc for your advice.

 

I knew that you can add washers as I said in my post that I had added 1 already but I didn't know that you could add up to 4.

 

The thing I have gleaned from your post and turtle's is that my oil pressures are probably ok and I had been misguided in my belief that it should be running around 2.8bar 3.2bar once the motor has reached operating temperature.

 

Maybe I have been overly concerned for no reason and everything is really ok.

 

I would hate to stuff the rear bearings because of low oil pressure and hence lack of lubrication to those bearings.

 

Anyway thankyou kindly for your advice it is much appreciated as I said to turtle it's you guys that really in a lot of case are the experts because you are empowered with the experiance of use.

 

Kind regards,

 

rick-p

 

 

[Guest micgrace]

Hi

 

I would be fitting an oil cooler. All oil pressure fed 4 strokes use the oil to cool the engine as well as the air flow. A 6 pass cooler ie 6 tubes with some AN fittings would be in order.

 

Why you would drop pressure at idle after a hot run is due to less volume circulating/sec and therefore oil being in contact a lot longer with the hot parts especially after a full power run. ie heat soak Air flow over sump is insufficent to cool oil in all but the lightest load applications.

 

Micgrace

 

 

[rick-p]

Micgrace thanks for the advice, i will be discussing problem further with the factory tomorrow, Monday.

 

I will post the outcome of those discussions and findings.

 

regards,

 

rick-p

 

 

[Captain]

Rick-p

 

The manual for my 3300 specifies the min oil pressure in descent as 80 kPa and min in level flight or climb as 220 kPa.

 

The oil pressure yellow arc is 80 - 220 kPa, Green arc is 220 - 525 kPa with the red line at 80 kPa.

 

It further specs the oil temp green arc at 50C - 118 C with the red line at 118 C.

 

I hope that helps somewhat and I say again that the above are for a 3300 and I assume they are similar but can someone confirm what the manual says for a 2200??

 

Now I know we are mixing units in this post so maybe we should spec these figure in both.

 

Regards

 

 

[rick-p]

Thanks Captain, I was previously advised similar figures by the factory for the 2200.

 

My temperatures are excellent at all times it's the pressure that has thrown me but i'm starting to think the pressure is in fact ok and it's just the quick reporting of the Flydat that is throwing me.

 

As i have previously stated in this thread fitting an oil cooler creates not insubstantial problems for me because of the aircraft the Jab 2200 is in.

 

Such as new cowl, over max takeoff weight and few other issues to boot.

 

Incidently the s/s washers under the pressure relief valve I think made the oil pressure less, figure that one out!

 

Regards.

 

 

[jetboy]

I run a 2200 and had the following conditions (aeroshell 15/50)

 

rpm psi temp F

 

2400 20 220

 

2700 20 230

 

2900 22 240

 

Then I did the oil pump SB which made absolutely no difference.

 

Then, in preparation for an oil cooler, I fitted the adaptor with AN hardware ans 6' of AE601 hose, in the form of a large loop.

 

startup 50 psi

 

warmup 65 psi

 

idle @ 120 deg F 50 psi

 

2800 rpm cruise,

 

50 psi 180 deg

 

47 200

 

40 220

 

35 230

 

I went on later to fit the cooler, which did not change the pressures, just the temps.

 

The point is that adding 6' of braided hose just might help smooth out those pesky high pressure fluctuations that Jabiru allude to on their SBs, which may prevent the relief valve being forced open and dumping oil pressure. i dont care which theory is correct the results are what matters.

 

At the time I reluctantly fitted the cooler more 2200s were being trashed because of the cooler than without. I used a proper automotive engine pressure type cooler which I think is what they switched to later anyway. You are right to leave it out if you dont need it.

 

Now done 180 hrs runs OK

 

Ralph in NZ, serial 1680 or therabouts

 

 

[Guest micgrace]

Hi

 

Ever measured the oil temp and pressure at high angle of attack in the 701? Airspeed gets pretty low, but engine power is high. Just interested.

 

Micgrace

 

 

[jetboy]

At high angles, oil pressure is normal but temp will climb steadily. Well lets say i've seen 245 on a bad day. The 2200 in 701 is not ideal and i avoid 30 Kt climbouts unless necessary. Flap down 50 Kts can do full throttle climb satisfactorily. This gives better cooling than the "cruise-climb" GA technique. The engine power is not that high, 2900 rpm = maybe 65 hp? I think the prop 60 x 38 too coarse for 701 climbing. WOT level flight on a good day = 3050. So I never get to see 80 HP.

 

Even after 180 hrs "development' I'm still fine tuninig the little things. Plan to add inter-cylinder baffles next service to get a little more cooling to the rear. 701s go nowhere fast and I have a friend up North doing one with a 3300. I hope he can get enough cooling. I have the larger ram air ducts, and CHTs are well in limits, mostly below 300 F, except steep climb work.

 

Next on the list would be a larger, but finer pitch prop, around 62 x 32 or 64 x 30. I'm not keen to go experimenting right now till the Flywheel issues are more settled.

 

Ralph

 

 

[John M]

My aircraft is powered by a Jab 2200 with mechanical tappets.My engine reporting instrument is a Flydat:- oil pressure and temperature, etc.

Problem:- oil presure reading on reduced power constantly reading low or the same after a long climb out.

 

Temperature is fine, well within the correct range so not a viscosity problem.

 

Using Aeroshell 100 plus.

 

Pressure at reduced power fluctuates between .9 bar and 1.8 and whilst on full power increases to 2.2 bar to 2.8 bar.

 

The other day it dropped to .4 on finals and .2 on touch down.

 

I placed one s/s washer under the pressure relief valve spring which initially improved the situation then went back to previous readings or worse.

 

No dirt was found under the seat on the relief valve.

 

All other readings on Flydat seem to be ok.

 

I was told by Jabiru that i should have an oil cooler fitted but I don't believe that this is the problem as temp's are perfect and the plane is factory built overseas and the Jab engine installed there.

 

It has the deep sump and the airflow over the sump and engine is optimum.

 

It's an extremley well designed and engineered installation and the designers were no slouches.

 

Apart from instrument or pressure probe problems have any of you guys out there got any suggestions.

 

Your knowledge or experiences will be greatly appreciated.

 

My real concern is that if it is a genuine low pressure problem then the rear bearings will suffer.

 

Does anyone know the correct operating pressure for the Jab 2200 as the book says one thing and the factory tells me something else.

 

I will be this weekend fitting a VDO oil pressure guage to confirm whether or not it is the Flydat that is the problem, the oil pressure switch seems to be operating correctly.

 

Please your suggestions guys.:;)5:

 

Thanks,

 

rick-p

Rick:

 

In regards to needing and engine oil cooler as related to oil pressure.

 

Having a cooler and associated hosing will increase oil pressure due to the the resistance of the afore mentioned.

 

Having low blood pressure is a good thing...right. But, having vessels occluded with plaque raises the blood pressure. The resistance of the cooler and hoses will increase back pressure that can be seen by the oil pressure sensor.

 

This begs the question: Is it better to have more oil flow at less pressure or less flow at more pressure.

 

I think you will find that and oil cooler system WILL indeed RAISE the oil pressure.

 

By the way...

 

I have my oil pressure sensor moved from the normal mounted position to the gallery hole just below that placement. This both eliminates much of the pulsation from the oil pump and let me know the oil pressure in the engine galleries.

 

Here in Southern California where temps get into the tripple Farenheit levels an oil cooler is manditory.

 

John M

 

 

[facthunter]

It's an old thread John and might be rectified by now, though it didn't appear to be then. Nev

 

 

[geoffreywh]

do yourself a favour and dump the VDO sender and gauge. They are notorious for inaccurate readings....Use a real one (mechanical) Then you know what the oil pressure actually is....youi may be chasing your tail....

 

 

[XAIRVTW]

Had a similar problem with my 2200. Replaced the pressure sender fixed the problem. Being a mechanical sender there is a little diaphragm inside this can foul up. I replaced mine with a solid state sender.

 

cheers

 

 

[rick-p]

Fixed it all a long time ago by installing oil cooler and second instrument gauge (mechanical), all is good now, both pressure and temps.

 

Also as advised by someone very knowledgeable, on this site and an engineering friend I have been adding 50mls of top shelf outboard motor 2 stroke oil to 20 litres of avgas, it has made one hell of a difference to all readings in respect of the engine operating specifications. For example all cylinder compression readings are now equal at 155lb. Turning it over by hand first before starting now has the correct feel.

 

All is good.

 

Thanks.

 

 

[geoffreywh]

One shot of Redex or two Sir? Upper cylinder lubricant may well be relevant. Always stopped my Dad's M21 outfit from seizing even whilst lighting his fag on the glowing exhaust pipe. (oo er! that doesn't sound politically correct )

 

 

[freeman28139]

Hello all,

 

I have a 2200A ser#1932 that has started running below the minimum oil pressure. I have about 430 hours on it, at cruise 2600 rpm it is fluctuating from 26 to 31 psi, minimum is 31. Checked pressure relief valve assembly, no visible issues. The motor had 3 washers under spring from factory. Anyone got any ideas? I have talked to Jabiru and they have suggested checking clearance in oil pump, then bottom end if no clearance issues. Needless to say I am concerned about that step at just over 400 hours. I am running a oil cooler and have read about braided line and even a retro fit for the 3300 pump. Looking for experience, ideas and suggestions. Thanks in advance.

 

Phillip

 

 

[facthunter]

As a general rule, jacking up the relief spring pressure is not a cure for hot or slow RPM oil pressure problems. You may even overload the oil pump drive if it can't bypass enough oil at low temps, due to the relief valve not being able to lift off it's seat enough, before the spring coil binds.. The oil pump may lose efficiency if it has harmonics in the drive, if it is a bit worn as well. Nev

 

 

[jetjr]

First is to check with second sender or mechanical gauge, they are common failure.

 

 

[Dafydd Llewellyn]

Couple of observation from the 2200 running so far in test cell (basically running-in a freshly overhauled motor). Oil was "straight" aeroshell 100.

 

Firstly, the modification to the oil filter/cooler adapter and the oil pressure relief valve as supplied by CAMit were on this engine; the mod. provides a machined seat for the pressure relief valve, which eliminates variable oil pressure due to "floating" of the loose washer normally used; secondly, the seat also prevents the oil filter/cooler adapter from turning on its central spigot, and partly shutting off the communicating hole.

 

Secondly, the standard location for the oil pressure sender measures the pressure upstream of the oil filter and the oil cooler (if fitted). Just below the standard pressure sender location, there is a plug, which closes the front end of the main oil gallery - see photo. If you have the "long" propeller flange, it's possible to re-locate the sender to this position, by swapping the sender and the plug. (This may possibly reduce the sender life - no data on that as yet). The oil pressure reads lower, but it's the actual pressure reaching the bearings; and there was a reduction in the pressure fluctuations when the sender was in the lower position. (I verified the sender and gauge calibration by a dead-weight tester, to eliminate that unknown).

 

Thirdly, the standard Jabiru oil temperature probe reads the oil temperature close to the wall of the sump; it may not be the real oil temperature going into the main gallery; In the test cell, the engine was uncowled, so the sump was exposed to the full propeller blast (an early finned sump). I had a second temperature probe looking at the temperature of the oil returning from the oil cooler - which is going straight into the main gallery. I could not get the oil temperature into the normal flight range until I enclosed the sump with stick-on insulating foam - whereupon I was able to get it into the normal range, and control it by controlling the airflow through the oil cooler.

 

So the airflow over the sump does have a significant effect, but it's likely to vary considerably from one installation to another. With the oil going into the main gallery at 69C at 900 RPM, that engine was showing a bit over 60 psi (about 410 kPa) - which seems high, but is evidently not unusual with a "new" engine. It came back to around 45 psi at 900 RPM at 85C. (I think this engine needs to go to Aeroshell W 80 once it's run in). The oil cooler was reducing the oil temp by about 12 C compared with the standard sump sender.

 

Lycoming and Continental generally use a thermostatically-controlled oil cooler bypass, and it's set to hold the oil temp at 85 C or thereabouts. That's so the acids from partial combustion products and so on, that accumulate in the oil, get a chance to boil off; the oil can definitely be too cool.

 

 

 

[freeman28139]

Appreciate the responses...

 

Going to check clearance on the oil pump gears this weekend and will take a good look at the relief valve for wear or insufficient seating. I am puzzled by the Jabiru at 420 hours on a 2000 hour TBO. I am curious about the machined seat on the CAMit mod. My engine casing has a snap ring groove which secures the outer washer and the pressure relief assembly. How do they do the machined seat? The other thing that puzzles me about Jabiru is 3 washers under the spring(max according to manual) from the Factory.....Has anyone ran across that?

 

 

[AVOCET]

Ive had a bit of success with reversing the washer so the beveled edge faces in

 

And the plunger sits on the sharpish edge , seems to seal itself better ,

 

Or try a new washer ?

 

Old trick from Don at Jab

 

Mike

 

 

[jetjr]

There is a thermo unit for the Jabiru from UK

 

Thought Ian was looking at something similar?

 

Oil pressure is critical in hydraulic lifter engines, too high or low can have big problems. I have suspected this might be linked with some seen problems. The standard oil pump and regulator setup onst that good

 

Ok for solid lifters. Above info is good, some have been using that port for some time. It was raised some ime ago when there was oil pump cavitation problem and some pretty restrictive auto oil collers being used. Gauge reading plenty but being held up in cooler.