Oil temperature

[biggles5128]

I own a J230, have been using Exxon LL100 oil since the change from mineral oil post run in.

 

I have just changed to Shell 15-50 as recommended for all year around running.

 

I have immediatly seen oil temps increase. In the climb it is now 110 deg C, and in the cruise, 100 deg C. I feel this is a bit too hot. Have had discussions with jabiru however would like to see if anyone else has a similar story.

 

biggles 5128

 

 

[quentas]

Have you done the cooling mod with the oil cooler shroud and removing the gull wing baffles? Its in Service letter JSL 004-1. I almost fixate on the oil temp guage when it gets to 100c. In cruise it stays around 90-95c on a normal day.

 

 

[biggles5128]

Thanks quentas, no I have not done the mods as I was very happy with the temps when using the LL100 oil. All that has changed is the oil brand and grade, my way of thinking that does not warrant doing mods... simply go back to previous oil. Just interested if any others had similar......

 

 

[Guest brentc]

I'm wondering what your temps were on the old oil?

 

I would suggest that they are probably still higher than the ultimately desirable and that the mods should be done. Worth a call as I don't think Jabiru actually charge for the modification if you call them and tell them your woes. For the record, temps below 90 in the cruise would be desirable.

 

 

[biggles5128]

Thanks quentas, no I have not done the mods as I was very happy with the temps when using the LL100 oil. All that has changed is the oil brand and grade, my way of thinking that does not warrant doing mods... simply go back to previous oil. Just interested if any others had similar......

 

 

[facthunter]

Revert to previous.

 

All things being equal if the only thing that you have altered is the oil , Go back to where you were. I still use a monograde, (in a lycoming) and the only problem that I have is that I pay more attention to achieving minimum oil temps prior to take-off. Some people that build engines , feel that the old oil keeps engines in better shape . SHELL advertise the the multigrade is superior across the range. If the oil temps have risen then the solution is obvious.. Nev..

 

 

[Thruster87]

Shell oil convinced people [40 yrs ago]that the new synthetic oils where better.Yes they were for engines that are running most of the time.Engines that were run only now and then [weeks between runs to operational temps] started to experience corrosion/wear problems sooner then when using the mineral oils.It seems that the mineral oil stays on the surfaces longer protecting it.Haven't read any data on the latest oils so see how they have progressed. Cheers

 

 

[Captain]

I own a J230, have been using Exxon LL100 oil since the change from mineral oil post run in. I have just changed to Shell 15-50 as recommended for all year around running.

I have immediatly seen oil temps increase. In the climb it is now 110 deg C, and in the cruise, 100 deg C. I feel this is a bit too hot. Have had discussions with jabiru however would like to see if anyone else has a similar story.

 

biggles 5128

My experience has been the opposite in my 230.

 

My temps are a few degrees cooler with the multigrade than with Shell's 100 grade and the oil pressure doesn't fluctuate as mush as it did.

 

On a hot day I don't see above about 92 C at top of climb, but I do that at 90 knts or above, and at cruise I see high 70's C or a tad above 80 C.

 

Do you have the deflectors at rear bottom of your cowl on 5128, as I believe that they really aid airflow. Are your CHT's perhaps on the high side too?

 

Hope this helps. Regards Geoff

 

Sorry Big. Just realised that I have asked some questions same as others ... so ignore those.

 

 

[facthunter]

results.

 

I am very interested in the proper assessment of this. I was going to go to the multigrade, but have stuck to the 100 plus on the advice of a guy who has been doing a lot of aero engine inspections/ builds over the years..

 

NOTE. I am not talking of synthetics here. I am referring to the multigrade oil option and recently recommended by Jabiru.

 

A multigrade contains polimers which prevent (to some extent) the loss of viscosity that oils experience with temp change. Polimers do not last forever and "wearout" over time. they are not a lubricant. They are a viscosity index improver. Nev..

 

 

[Guest brentc]

Hi Biggles, what is your oil temp in the cruise that you are happy with on the old oil and what is the maximum that you have seen it at with the old oil?

 

 

[biggles5128]

Thanks to all. Just to clarify, when the engine was brand new I used the recommended mineral oil for the run in period. I saw very acceptable temps through this period. After 25 hrs I changed to semi synthetic Exxon 100 aviation oil, I still saw very happy temps. Jabiru then stated to use 15-50 for all year round running, not just for winter. Since the change to this oil I see higher than usual temps.

 

I used to see about 90 deg C in the climb at 90 kts, then in the cruise 60 - 70 deg C.

 

As I mentioned I saw no need to do the mods prior to this. I spoke with Jabiru and they are happy for me to go back to the semi synthetic Exxon 100, as all was happy then.

 

I fly out of the north coast NSW which does not get too cold so personally I don't feel the need to use a cold climate oil.

 

Appreciate everyones input, feel free to comment further.

 

 

[Vev]

Hi Biggles,

 

 

I feel somewhat surprised to hear that you are experiencing higher temps with a multigrade lubricant, as generally speaking it should have a better thermo exchange than a mono grade SAE50 viscosity. The multigrade should absorb more heat from the engine and dissipate it better through the cooler…. I can’t really see why this viscosity change would have a negative impact, if anything I would expect to see an improvement.

 

 

For what it’s worth, I Personally I think that a multi grade is always more superior to mono grades in terms of lubrication characteristics…. I won’t go in to details about why but there is a great deal of proven science to support my view.

 

Whilst polymers are used to improve the VI (viscosity index) in multigrade, which allows the lube to change its viscosity to better suit to temperatures in the engine, they are “shear stable” and don’t break down like they did 30 years ago. What’s more, as you top up the oil you give it a fresh dose of IV improver as well as a bunch of new additives which helps maintain the health of the lubricant as well as dilute suspended particulates that are too small to be caught in the filter…. These particulates (soot) cause a lot of problems, therefore top up is good.

 

In terms of synthetics, this is a term that is a little over used … in the context of the majority of piston aviation lubes we are talking about these are a blend of ordinary mineral oils (group 1 base stocks) and hydrocrack mineral oils (group 2 base stocks)… they are not quite a synthetic and really more a term developed by marketers and not the petro-chemist.

 

 

Lastly, anti corrosion, antifoaming, wear resistance, detergency and dispersancy etc etc are overwhelmingly influenced by the additive system blended into the lubricant, oil base stock do play a part but in the scheme of things this is small beer.

 

 

Not sure if this helps, but I suggest you look a little deeper into your problem as I somehow think the lubricant isn’t the problem.

 

Regards

 

Jack

 

 

[Modest Pilot]

The polimers that do the good stuff for viscosity also alter the struture of the oil molicules and it doesn't cool quite as well as mono grade oil. I shot for nominal oil temps of 87deg C at 15deg C OAT. You will have to check your oil temperature indicating system first, and the oil may still be hotter away from the sump walls.

 

If you have the old ribbed oil sump it's easy to construct an aluminum shroud over the slanted section (kick it under the bottom an inch or so) using the tapped sump holes to attach. (should stand off ribs 1/8") Rivet a Jab heater flange on the shroud and attach a stiff steering rack rubber cover to the flange and make a 32mm hole in the cowl. Results: CHT 10-15deg F lower. Oil temp 10deg C lower and no extra bits to undo for cowl removal. I have found this setup good 10-38deg C OAT for takeoff, colder and you have to tape the extra cooling hole with speedtape.

 

 

[Modest Pilot]

Forgot to mention I blocked off the slot on the oil cooler inlet shroud. That's what lowered the CHTs.

 

 

[jeffcb52]

I just replaced the Shell W100 plus I have been using in my J200 3300 (solid lifters, coarse heads) with Exxon Elite 20W-50, and my judgement is that oil temp is unchanged.

 

It's expensive too.

 

Jeff

 

 

[biggles5128]

Thanks Jeff, I have changed back to Exxon and using Elite also, I have noted a considerable drop in oil temperature, back to very acceptable levels...... I can't explain why this has happened. My fuel/oil supplier told me that as Jabiru engines have such close tolerances different oils can make the difference.

 

I am more than happy with the results and am happy to pay the extra for this product.

 

Cheers

 

Danny.

 

 

 

[BigPete]

How much are you guys paying for the Exxon Elite? (per quart)

 

regards

 

 

[biggles5128]

I think around $130 for a dozen 1qt bottles.

 

 

[BigPete]

That's fantastic - no, not the price - the price is OK. BUT,

 

the speed of the answer to my question - FANTASTIC. :thumb_up:

 

(thanks, Danny)

 

regards

 

:big_grin:

 

 

[jeffcb52]

Danny,

 

It's possible the difference is due to your engine having hydraulic lifters. I would happily wear the expense if it worked.

 

Good to meet you last Sunday.

 

Regards

 

Jeff

 

 

[biggles5128]

You too mate, I thought it may have been you replying. It was a good day, hope to see you when we fly into Ballina next.

 

Regards

 

Danny