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Posted

Can I ask a stupid question, does 100wt oil need a different filter than one designed for multi-grade oil? I would have thought that the 100wt oil cold wouldn't get through most automotive filters.

 

 

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Posted
Can I ask a stupid question, does 100wt oil need a different filter than one designed for multi-grade oil? I would have thought that the 100wt oil cold wouldn't get through most automotive filters.

Filter can usually be "pressure relief" bypassed until the oil is warm. This also stops a "full dirty" filter from stopping oil flow.

The filter is there to remove foreign material no matter what the oil type or grade. You wouldn't go to a filter with bigger holes, you would go to a filter with bigger surface area for filtering to cater for heavier oils.

 

 

Posted

A filter that is bypassing when cold runs the risk of letting unwanted "grunge" through the engine. You can in some instances get different filter "particle size" related filters. Short oil change operations could justify a coarser mesh. Nev

 

 

Posted

FT

 

There are no stupid questions mate.

 

The product Aeroshell W100Plus is actually a straight SAE 50 weight oil.

 

It is not a SAE 100 weight oil as the name might suggest.

 

So it is ok for automotive oil filters the same as the Aeroshell 15w50 which is a true reflection of the viscosity range of it's oil.

 

If you google Aeroshell W100Plus as I just did you can read all about the product.

 

Safe Flying

 

JabSP6

 

 

Posted

It refers to an older flow spec. It used to be called 100 seconds. (of time to flow a quantity of oil at a specified temp through a calibrated hole). Viscosity is flow resistance. Nev

 

 

  • Informative 1
Posted

My mate the Charlie the engine rebuilder reckons that the vast majority of the time the filter is running with the bypass valve open. The oil filter only really works when the engine is < ~1500 rpm.

 

 

Posted

Never heard that ft. They only bypass on cold mornings when the engine is over-revved or the filter clogged. Newer stuff has low volume filters that would require a bit more looking into. A by passed filter can let a lot of bad stuff through. Not a safe or normal situation. The engine is meant to be Protected from that. A Bypass is a no oil or unfiltered situation. The best of 2 bad situations.

 

An engine with very worn bearings will flow more oil when cold too so that helps it to bypass.

 

Jabiru recommend the multigrade mostly and the "straight" 50 grade where it doesn't get cold... Pretty much what is recommended for all aircooled aero engines . Nev

 

 

Posted
It refers to an older flow spec. It used to be called 100 seconds. (of time to flow a quantity of oil at a specified temp through a calibrated hole). Viscosity is flow resistance. Nev

Correct Nev .... it's called Saybolt Universal Seconds (SUS) ... it was 100 sec @ 210 deg F to flow through a calibrated orifice ... this basically said the viscosity is getting close to the top end of the viscosity range for a SAE 50 grade base oil.

 

Cheers

 

Vev

 

 

  • Informative 2
Posted

Thanks Vev. I should have added the aero oils are formulated for leaded avgas and have storage corrosion inhibitors to stop camshaft corrosion when not in use. ie Aeroshell w-100 plus. (the plus is the additive). originally formulated for Lycomong which have the camshaft in the top of the case.

 

If you guys want comples questions answered regarding oils Vev is in the oil technology game, so ask HIM..Nev

 

 

Posted

Hi Vev, I have a question for you, please keep answer simple then elaborate if you must.

 

Why not use a synthetic lighter viscosity multi-grade oil in jab engines disregarding legal and manufacturers recommendations ?

 

What effect on oil does lead content have on oil and how long does it take to have effect. ?

 

What effect do additives such as "Moly" have on oil other than friction modification ?

 

A high viscosity oil in an engine that should be using a lower viscosity oil, would this cause heat in the engine trying to compress this oil, eg bypass and close tolerences, ?

 

Would excessive wear be likely due to a high viscosity oil unable to freely move into areas of small tolerance to adequately lubricate ?

 

My motive for asking is related to something I am aware of and want scientific facts from an oil man (industrial chemist) to verify or discredit.

 

I'm a motor mechanic, probably won't change much for me, but let it rip.

 

 

Posted
Maybe he is not free. Nev

Vev probably having a graze, I very much respect your opinion Mr Facthunter as I am aware of your background and would like any input you have thoughts on, let it rip, I am all ears ( and eyes ).

 

 

Posted

Hi Camel,

 

Yes was having a graze...

 

There is lots of complexity in your questions but I'll just try and hit the high points if thats ok?

 

Why not use a synthetic lighter viscosity multi-grade oil in jab engines disregarding legal and manufacturers recommendations ?

 

I really don’t see an advantage in a lower viscosity in relation to its lubrication protection in a Jab engine. 15w is the equivalent to a SAE 15 @ 40 deg c (100 degF) and the “w” stands for winter and has a pour point at -32 deg. The 50 is the equivalent of a SAE 50 @ 100 deg c (212 f). All of this gives excellent start up protection with a lower vis and good film strength (this is hydrodynamic film that separates the surfaces) with the higher (SAE 50) during normal operation temps. Btw, Aeroshell is already a semi-synthetic. If you lower the vis you will get less internal resistance (low viscos drag) but could compromise film strength and potentially rupture the oil film and have metal to metal contact. In this senario you are completely reliant on the additive chemistry to protect the surfaces.. much better to use a physical layer of oil to protect the engine. In terms of Syn lubes ... these are good but I prefere the good old minerals with a blend of semi-syn as these have much better clean properties as well as keep the contaminates in suspension to be caught in the filter.

 

What effect on oil does lead content have on oil and how long does it take to have effect. ?

 

Automotive Lubricants are supposed to have backward compatibility and there are some obscure GM engine test that use to measure lead contamination performance. However these days any lead in the fuel will quickly damage many engine sensors and its not really a consideration. In terms of aero engines and Aeroshell as an example, it will tolerate lead contamination but it will plate out around the engine over time and turn into sludge if left too long. All combustion contaminates (including lead) will cause oxidation, causing the lube to chemically break down. Changing the oil often (ie 25hrs) is a good way to keep things under control. Just as a side issue.. synthetics are less capable (owing to lower solvency or aromatics content) than mineral or, to a lesser extent, semi-syn lubes in terms of managing lead.

 

What effect do additives such as "Moly" have on oil other than friction modification ?

 

Most moly particulates are quite big (1 – 100 um) and will just get caught in the filter. Personally, I’m no fan of MoS2 in engine lubes, I know others will argue differently.

 

A high viscosity oil in an engine that should be using a lower viscosity oil, would this cause heat in the engine trying to compress this oil, eg bypass and close tolerences, ?

 

Using to higher viscosity will potentially cause an increase in temp owing to high shear … it is sort of like the oil having its own internal resistance to flow where stationary molecules and high speed molecules interface at a shear point and generate heat. What’s more, a higher viscosity lubes doesn't transfer heat as well and not as effective as a lower vis.

 

Would excessive wear be likely due to a high viscosity oil unable to freely move into areas of small tolerance to adequately lubricate ?

 

Yes particularly at start up when the oil is thick and slow to get around the engine. However, more often this is seen when viscosity get too high in gear boxes you get “channeling” when the oil is too thick to recover onto the surfaces and runs dry.

 

My motive for asking is related to something I am aware of and want scientific facts from an oil man (industrial chemist) to verify or discredit.

 

I'm a motor mechanic, probably won't change much for me,

 

Hope this helps? Cheers Vev

 

 

  • Informative 2
Posted

Thanks Vev, questions well answered and happy, you are the man.

 

My first Question as to advantage to lower viscosity was related to the fact that Jab engines do have closer tolerances than most aero

 

engines and therefore poor circulation and possible extra heat generation. Seen bottom end of Jab engines with copper showing on big ends

 

and mains at 200 hours and bores oval at 400 hours. Rocker gear and valve guides also have excessive wear under 200 hours. A well known problem with

 

Jab engines is the rings getting gummed up and sticking causing loss of compression.

 

 

Here's another one for you and am keen to know where the major difference lies in determining what design characteristics are to deem it designed to

 

use Ashless Dispersant aviation piston engine oils such as AeroShell W Oils, Used in air cooled Teledyne Continental Motors,Textron Lycoming

 

and Jabiru engines.?

 

 

Posted
Here's another one for you and am keen to know where the major difference lies in determining what design characteristics are to deem it designed to

use Ashless Dispersant aviation piston engine oils such as AeroShell W Oils, Used in air cooled Teledyne Continental Motors,Textron Lycoming

 

and Jabiru engines.?

Ashless really mean non-metallic detergent ... detergents plate out on surfaces and stop particulates sticking to them... it doesn't really clean like you would think of dish washing liquid does. The metallic additives use to leave residues that could cause pre-ignition, I've really got no practical experience with this as they are simply not used these days in aero engines you mentioned and therefore not seen. Dispersants, in simple terms, envelopes particulates to stop them sicking together and holds them in suspension to get caught in the filter.

 

Cheers

 

Vev

 

 

  • Haha 1
Posted
A little dicky bird has told me that testing has/is being carried out by Shell, both in Europe and Australia testing Jabs with another commonly used oil for 912s. The performance difference and reliability has increased dramically over the currently oil recommended by Jab. Unfortunatly I am in the loop, but sworn to secrecy also, until Shell is happy. Thats all I know ATM.................................................................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

This was discussed last Sept @ AUSFLY, no news yet but I did see the Manuals have changed and particular types/brands of oil are now not mentioned just SAE and Mil spec

 

If its the Aeroshell used for 4 stroke LSA theres only one option isnt there?

 

I do know a guys whos been using similar for some time - no idea why hes doing it but apparently its very similar to a current Motorcycle oil which is way cheaper...........so he says and he does have close links to Shell.

 

 

  • 2 weeks later...
Posted

Goodaye all

 

There is something that has not been mentioned, the oil companys have removing the zinc in oils for many years.

 

This reduces the shear properties of the oil and wears cams and valve stem quicker to the point wear they can fail after a few hours.

 

Zinc in autmotive oil had to be reduced due to the catalytic convertor getting gummed up, l should see that aero oils have not been reduced either.

 

PS a tip for car owners Penrite mineral oils still have a high Zinc content.

 

regards Bruce

 

 

  • Informative 1
Posted
Goodaye allThere is something that has not been mentioned, the oil companys have removing the zinc in oils for many years.

 

This reduces the shear properties of the oil and wears cams and valve stem quicker to the point wear they can fail after a few hours.

 

Zinc in autmotive oil had to be reduced due to the catalytic convertor getting gummed up, l should see that aero oils have not been reduced either.

 

PS a tip for car owners Penrite mineral oils still have a high Zinc content.

 

regards Bruce

Hi Bruce,

 

Just a couple of points if I may:

 

Zinc has been replaced with a new Zinc technology .. Mostly known as HyperZDP, which maintaines cat life and provides all the boundary lubrication protection needed to protect cams, followers and more.

 

There is no Matalic Additives, including Zinc (ZDDP) in aero engine oils ... They use a different technology.

 

Cheers

 

Vev

 

 

Posted

Thanks Vev

 

That's it the ZDDP was what l was thinking of.

 

I am afraid the newer replacement doesnt work that well with older engines very well, kills cam lobes quick smart if the cam isnt run in.

 

There's a story from the 80's l could tell, but that doesnt relate to aircraft.

 

regards Bruce

 

 

Posted

Hang about, doesnt Jabs use Automotive valves and lifters??

 

You could agure the incoreect oil is used.

 

From a 5 litre Holden for instance???

 

regards Bruce

 

 

Posted
Hang about, doesnt Jabs use Automotive valves and lifters??You could agure the incoreect oil is used.

From a 5 litre Holden for instance???

 

regards Bruce

Hi Bruce,

 

Are Jabiru experiencing cam and lifter wear?

 

I think there's good protection in the currently recommended aero oils.

 

I know trials have been conducted over the past 3 or so years to test an automotive formulation in Jabs by a major oil Co... there is still a lot to be considered as this is not without risk in terms of combustion chamber deposits. I think there is already enough evidence that detonation can be fatal to these engines ... adding a potential new detonation trigger will be a major concern for those conducting the trials.

 

I'm sure Nev can answer this better ... aero air cooled engines burn engine oil owing to their larger piston clearances, that is, larger clearances than water cooled automotive engines. Automotive lubes have additives that can leave deposits on the piston crown that can cause pre-ignition and detonation.

 

Time will tell if automotive lubes will work in Jab engines .... however for now, let the guys with the big cheque books take the risks ... I think sticking with the recommended products is the safest bet for you and me.

 

Cheers

 

Vev

 

 

  • Like 1
  • 4 months later...
Posted
I have read so much in recent times about the Jabiru 2200 engine's problems and I think that I can safely say that it is very hard to seperate fact from fiction.On this point I don't think that I'm on my own.

Anyway just an idea but how about we seperate the fact from the fiction and use this thread to report on the factual problems the end users of this power plant have experienced.

 

That is anything ranging from a minor problem to a major problem resulting in a complete engine failure.

 

The reporting should be brief at first just enough to establish a trend and then a more in depth examination of the issue could be embarked upon.

 

For example state the problem and the resultant effect and only if 100% known the cause of the problem, no guessing please.

 

We don't at this point need engine hours, place of incident or the time of the year.

 

These matters to start with are irrelevant to the initial categorisation of the various problems.

 

It is my view that by approaching the issue this way with the reporting of absolute fact not theory or guess work the end result will benefit all end users of these motors.

 

Also there should not be self denial, everyone who has had a genuine mechanical problem with these motors please report it here in this thread.

 

No Jabiru knockers please as this type of activity achieves nothing for anyone.

 

It is my view that by doing this if there are genuine major problems with the subject motor then they need to be identified and rectified, not just be the Saturday night topic of bellyachers and whingers.

 

It does work look what Tony Hayes has achieved with the Thruster Group.

 

Regards to all,

 

Rick-p;)

RicK;

 

808 hours on s/n 3237 Jabiru 2200 with no complaints. See my detailed responses to other on this engine.

 

John M

 

 

  • 7 months later...
Posted
A bit of patience gentlemen. There are pending revelations from that little ole WA country boy that will ring around the aviation world. Thou shalt be in absolute awe, I promise.

Has there been any revelations from that little ole WA country boy?

 

 

Posted
Has there been any revelations from that little ole WA country boy?

Yup. It eventuates that, what was deduced and worked out by a rec flying small business owner (motor engineering) in a little WA country town (viz the piston orientation), had already been identified and attended to by the South African importing agents some 8 or so years previously. It's said by the S. Africans at the time that the Bundaberg organization didn't acknowledge their findings or issue any SBs regarding reversal of the pistons. As you probably are aware RS & Co recently went public with a first time ever acknowledgement of this 'urban myth' (???) and went to great lengths to assure the paying public that their engineering studies proved that piston orientation played no part in the number of maladies being experienced by their low time engines. It is believed that Camit now have a very comprehensive upgrade of the 4 & 6 cyl engines (previously being manufactured strictly to certification code under licence) ready for marketing. Big light at the end of the tunnel and interesting times ahead with the possibility that a great little Australian aircraft will achieve the recognition that has been denied it thus far. cheers Riley

 

 

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