To MOGAS or not to MOGAS

[BigPete]

Anyone out there in Jabiru land regularly using MOGAS instead of AVGAS?

 

Does your motor run cleaner? Have you had any issues (like vapor lock etc)?

 

regards

 

 

[Guest watto]

Yes Pete, I am using Vortex or shell Vpower 98 and have had no problems or performance issues.

 

 

[BigPete]

Thats great Watto, how many hours?

 

regards

 

 

[Guest watto]

Just had a 100hr service done last week, have used mogas for about 50 hours mate and you would not know the difference.

 

The Shell Vpower @ 98 seems particularly good and I would say closer to avgas than vortex.

 

 

[Guest Qwerty]

Peter

 

I bought a Jab recently. The CFI at the airfield told me to run it on premium and Flashlube (at 1000:1).

 

I am cautious about how I operate so I questioned him and others about the Flashlube. The mogas I have no problems with as it is approved (dont know about recommended) by Jabiru).

 

Experience, I have been told has proven the case for Flashlube. It is working fine for me but I only have about 30 hrs since the change from avgas.

 

I'd be interested in any comment (together with thorough background) on the use of Flashlube.

 

And while we are at it what about Flashlube in a 912, should I put it in my 912 as well??

 

Qwerty

 

 

[Vev]

I have been running my engine on BP Ultimate 98, which is nearly always blended with some Avgas top up…. I have been doing this now for 250 hrs and my engine runs as sweet as a nut.

 

No vapour lock, no detonation, plugs look spot on, all temps in range, oil analysis normal and no discernable power change…. No problems.

 

 

Cheers

 

Jack

 

 

[Harthy]

Mogas

 

I also have been running BP 98 for some time now with no problems. I made a conscious decision not to use mogas under 98 octane even though 95 octane is permitted. I also use Flashlube at 1 ml per litre of fuel. Flashlube is a valve seat lubricant.

 

One of the functions of lead in the old leaded fuel was to to lubricate the valve seats. Unleaded fuel does not have this ability, that is why engines are now fitted with hardened valve seat inserts and better quality valves. I believe avgas still contains lead. Engines running on unleaded and in good running condition and tuned properly will have less combustion chamber deposits.

 

Flashlube adds a bit of peace of mind to it. Mainly for if there is a chance of the engine running lean I know that there is some extra lubrication occuring which may protect the engine from damage.

 

A small amount of two stroke oil of about the same quantity 1 ml per litre can also aid in lubricating the combuston chamber with no effect on performance.(Because that is what it is designed for)

 

I have noticed since running my engine on unleaded that the spark plugs are defiantly cleaner.

 

Harthy

 

 

[Guest watto]

The Shell Vpower 98 already has an upper cylinder/valve lubricant in it apparently.

 

 

[Ultralights]

our LSA was run on BP ultimate, as recommended by Jabiru, after 3 hrs, on shutting down, as the prop stopped, and it spriung back on the compression stroke, the engine then fired up again, and ran backwards, with ignition already off, it took a few seconds after shutting off the fuel before it stopped. hence doing untold damage to vacuum pump and other components.

 

as far as im concerned, a Jabiru 2.2 shouldl never see mogas.

 

 

[Guest Maj Millard]

Watto, Found out that Vortex is not 98 but only 95. I was liking it till then. Then went to Shell V power, had a couple of episodes with it like it had E10 in it. Now exclusivly on BP Ultimate which is 98 and doing great so far. Have burnt a lot of mogas this year so far, so lots of time to compare..............................................................

 

Ultralights, When your engine ran backwards, did the plane want to go backwards too ?? :patch: :lol 8:

 

 

[GraemeK]

When your engine ran backwards, did the plane want to go backwards too ??

Nope, but the pilot did .....

 

 

[Vev]

G’day Ultralights

 

 

In my view it would be almost certain that your source of pre-ignition has been caused from a carbon or lead deposit.

 

If anything, BP Ultimate has a very effective additive pack which cleans up deposits, which may have triggered the pre-ignition, albeit I think this is remote.

 

The residual deposit would have been in all likelihood from poor combustion processes, which may have come from the current or previous fuels used … I wouldn’t expect the 98 to be the problem.

 

 

BP Ultimate is actually and typically 99+ RON, as the minimum standard is 98 RON … the oil companies always try to over shoot the marketing specification to ensure they don’t fall below the minimum performance claim and leave themselves open to challenge.

 

 

The other interesting fact about blends of Avgas and ULP - MOGAS is the synergistic effect that the lead in Avgas has on the over all Octane rating. Paradoxically, blending is not linear in terms of octane ratios but synergic +ive in boosting the octane of ULP. Therefore you will always find both the MON and RON north of the linear ratio equation when blended… this could be a useful fact if you have to mix the two products.

 

 

Having said this, always follow the engine builder’s recommendations as they have spent the R&D time around these issues.

 

 

Cheers

 

Jack

 

 

[Guest Qwerty]

Watto, Found out that Vortex is not 98 but only 95. I was liking it till then. Then went to Shell V power, had a couple of episodes with it like it had E10 in it. Now exclusivly on BP Ultimate which is 98 and doing great so far. Have burnt a lot of mogas this year so far, so lots of time to compare..............................................................Ultralights, When your engine ran backwards, did the plane want to go backwards too ?? :patch: :lol 8:

Major,

 

What is E10???

 

 

[jetjr]

E10 = basic ULP with 10% ethanol

 

 

[Jabiru Phil]

Interesting discussion.

 

I recently had to have a stipdown due to through bolt oil leakage (out of warranty).

 

I rang Rod Stiff and after asking me the way I ran the motor including what fuel I used (Avgas) he supplied all parts, labour and the latest pistons and cam, bearings etc. free of charge to bring up to the the latest specs.

 

I wonder after reading this post whether he would have done so if I was running Mogas!

 

Just a thought.

 

 

[Harthy]

Running Backwards

 

It would be interesting to know the circumstances surrounding your backward running engine. As previous posts asked was it run on Avgas prior.

 

The question I ask is, did it have adequate time to idle before it was shut down. And what revs was the engine doing when it was shut down, was it higher then idle speed? Both of these situations allow a retention of heat in the cylinder which can cause engine run on.

 

Vortex fuel does come in 98 and 95 just have to get it from the servo that sells 98.

 

Harthy

 

 

[Ultralights]

the engine was getting old, it was the third engine in that airframe,(now over 6000hrs on the airframe) and had run Avgas all its life at Hoxton park, since moving to Bankstown, we tried BP Ultimate, as the cost was significantly cheaper per ltr compared to the tanker avgas price.

 

the engine ran fine on the BP, no loss in performance, temps all normal. no dramas, until after a few hrs with the running backwards pre-ignition. i think the pre ignition was caused by caron buld up, as that engine had always used a lot of oil.

 

 

[RetiredRacer]

The wife recently bought a Kawasaki GPX 250, which has to run on min of 95. The dealer told us to use either Vortex or Ultimate, do not use V-Power as they have had trouble with bikes that have been run on it.

 

 

[Guest watto]

No Maj, not vortex its called Vpower it is a different product to the vortex and is not available at all sites.

 

 

[Guest watto]

Retired Racer, I have a Kawasaki KLR650 and was also told to run premium but as I do a lot of km's I decided to try normal ULP and there has been no noted issues and not detectable loss of performance and I have since done 25,000km and it is all good.

 

I have been riding mororcycles for 30 years and unless it is a high performance machine then there is no real advantage, the KLR engine as with many of the simple machine Kawa make has an engine that they have used for many years and is very robust.

 

 

[Guest Maj Millard]

I may be wrong but I suspect the Shell V power may be pumped up with Ethenol or something similiar, which my 912uls don't like. Wouldn't we all be running Avgas if it was cheaper ???..... ran some today (50/50 mix) and my engine loves it, and runs smoother. To have to pull the plugs a little more often for cleaning or replacement is a minor thing.......otherwise I'm on BP Ultimate for now..........................................................

 

 

[Lowflyer]

Recently bought a P92 Echo with a Jabiru 2200a engine, not being used to the plane was surprised after landing that the tickover seemed fast, went to do the shutdown and as I hit the mags she flicked back and ran the other way, only for a few rotations.

 

After my initial shock I realised that the choke was still on and yes I had done the whole flight with choke on full, very difficult to see as the lever is hidden under the panel when applied.

 

Now written a good check list.

 

Have been running on 95 Ron Mogas since taking delivery and she seems to run fine, guess the richness did not help on the shutdown.

 

Always a learning curve.

 

Roly (pom flyer)

 

 

[robinsm]

I use caltex premium 98. Tested it, no ethanol, no additives show up at the water/fuel interface in the test jar. 2 Years now and no problems.

 

Maynard

 

 

[Vev]

I’ve read the published Technical Data Sheets for Shell, Caltex and BP … whilst both Shell (V power 98) and Caltex (Vortex 95 & 98) make no statement, that I can see about ethanol, it looks as though neither of these fuels has any ethanol, albeit implied and interpreted by reviewing the various specs/formulation published. On the other hand, BP Ultimate 98 clearly states it doesn’t contain any ethanol, which in my opinion, is supported by its Technical Data Sheet and published formulation.

 

 

If you want to test for ethanol, simply fill a glass jar with 50ml of tap water and make a line on the jar with a marking pen or a bit of tape… then fill the jar (taller the jar the better) with an additional 200ml of fuel and the shake it up vigorously, and then some more … if the water looks like it has increased, (as water and ethanol have almost the same specific gravity) you have found ethanol…. Don’t use it!

 

 

At the end of the day, don’t take my word for it, do your own research and check with the engine and fuel manufactures.

 

 

Cheers

 

Jack

 

 

[Guest Qwerty]

Veverjg, Are you saying that at any other time of day, I CAN take your word for it?

 

I take "the end of the day" to mean at midnight although I am aware that some people refer to the time of finishing work as the end of the day. Please clarify.

 

Qwerty