Jabiru 2200 engine temps

[barryk]

I've been asked to re-post my experience with Jabiru engine temps and runing at low RPM here (originally posted on krnet.org).

 

In my experience the Jabiru will not last long if run at 2700 rpm as the barrels will glaze and then oil consumption will go through the roof. I have 2 Jabiru 2200 4 cylinder engines, one in my KR2 and one in a Jabiru J160. The KR2 I have only ever flown hard, 2950 rpm plus, the CHT's are around 310 Fahrenheit, and have had no problems with the engine. On the other hand the J160 was flown more conservative, 2750 to 2800 rpm because it constantly had CHT's around 360 Fahrenheit. The J160 has had the heads done up 3 times, 2 new sets of barrels in 500 hours. I modified the cowling and the RAMAIR ducts and bought the temperature down to 320 Fahrenheit and now run it at 2950 rpm and have no problems (and get there faster).

 

The same applies to the 3300 engine as I regularly fly with friends who have the 6 cylinder engines have and also had problems. One of them would throttle back for hours and fly at my cruise speed and that stuffed his engine (we think).

 

Jabiru specify:

 

- Max. CHT (Climb) 200°C (392°F)

 

- Max Continuous CHT (Cruise) 180°C (356°F)

 

In reality we have found max of 180°C (356°F) and cruise 160°C (320°F) gives us best results.

 

I have my Grand Rapids EMS alarm come on at 175°C and rarely have that come on. Another trick to play with is to try flying with the ball off centre and see what that does to your temps. On climb in the J160 I fly with the ball off centre to the left by about 1/16 inch and that drops the temp on the hottest cylinder by 5°C........WOW.

 

Regards

 

Barry Kruyssen

 

[email protected]

 

http://athertonairport.com.au/kr2/

 

 

[Guest rocketdriver]

Thanks Barry!

 

Cheers

 

RD

 

 

[Guernsey]

Thanks for your post Barry.

 

We are running the Jabiru 3300 in our Morgan Sierra and know that we should be running the engine 'Hard' however this increases the fuel consumption dramatically.

 

We realise that extra fuel costs are better than major engine repairs but is there some sort of compromise. e.g. when travelling cross country is it o.k. to run hard for some of the time and throttle back for some of the time or do you recommend high revs at all times except in the approach. Our engine has just completed 50 hrs and had it's 50 hrs service.

 

We do not have engine cooling problems due to the design of the Morgan Sierra.

 

Alan.

 

 

[barryk]

Hi Alan

 

I can only reiterate what the factory recommends, run it hard, our experience has been reduced engine life when run at low cruise settings for extended periods. Fuel is cheap compared to $800 per pot last time I replaced barrels.

 

Also you will probably find on cross country trips your fuel consumption is not any higher as the extra speed results in less engine hours. On a recent trip where a J160 and J230 did a trip of 38 hours plus, the fuel consumption is very simular between the aircraft with the J230 departing after the J160 and arriving before it on each leg of approximately 3 hours.

 

Regards

 

Barry

 

 

[Guernsey]

Thanks Barry we shall take your advice on board.

 

Once we have done more hours on the engine we are also considering fitting the Rotec fuel injection carby, it seems to have some very happy Jab Engine users.

 

Alan Marriette.

 

 

[Guernsey]

Wow! it looks like I have mentioned a banned advertiser here, however I'm sure you know the one I mean.

 

Sorry Ian.

 

Alan.

 

 

[barryk]

Hey Alan

 

Please email me the name of that fuel injection carby [email protected]

 

thanks

 

barry

 

 

[Guernsey]

Hi Barry, email sent as requested, let me know if you received it ok

 

My email is [email protected]

 

Regards,

 

Alan Marriette.

 

 

[jetjr]

The carb looks good but it isnt "fuel injection" or anything like it. Its an Ellison type copy and some report excellent results but the root problem is fuel mix distribution (have you got EGT on each cylinder?) No carb can sort this out.

 

There are some guys at Murray Bridge who do EFI conversions which seem a better way to spend your money ...... just more of it required.

 

 

[Guernsey]

The carb looks good but it isnt "fuel injection" or anything like it. Its an Ellison type copy and some report excellent results but the root problem is fuel mix distribution (have you got EGT on each cylinder?) No carb can sort this out.There are some guys at Murray Bridge who do EFI conversions which seem a better way to spend your money ...... just more of it required.

I understand what you are saying with regard to fuel mix distribution however with better fuel atomisation, would not the fuel distribution be better than the currently used single Bing Carb.

Alan.

 

 

[jetjr]

yep better for sure, but doesnt solve the core problem.

 

Evidence from others shows the distribution issues still exist after this sort of carb is used

 

Vanes in air cleaner outlet and cobra head also help, as does the new plenum Jabiru have now on offer but NONE of these solve the issue 100%

 

Problem is some engines show great distribution, some fairly poor......majority of owners dont know. Without EGT on each cylinder theres no other indication its happening.

 

As they have no float, gaskets etc they would act superbly as a throttle body for an EFI setup providing non electric backup if ever needed but too expensive just for this.

 

When an 3300 engines fairly new its best to vary revs but after then run at 2850-2900 - just my opinion. Shoot for even EGT's around 700 deg C, CHT cooler the better.

 

I have a factory reco engine done ~ 25hrs and have EGT spread from 610 to 720 at any one time in cruise which is pretty bad for the engine and needs to be fixed but everyone is out of ideas.

 

Cool cylinders have too much fuel, rinsing oil off bore resulting in excessive wear, hot ones are danger for valve burn and then major problems if they get damaged enough.