Vev

Attached below is a a part qoute from from the press realese re Rod Stiff being awarded the August Raspet Momorial Award at Oshkosh last month.

Not sure if anyone in the forum knows the details, but clearly Jabiru are building a range of new props?

If you are considering a new prop, it might be worth your while to contact Jabiru and find out about these new developments?

"The Jabiru product range includes Jabiru factory manufactured aircraft, experimental kits, and aircraft engines. A range of propellers, designed to complement Jabiru engines, is being developed." (Rod Stiff)

Cheers

Jack

Good point Qwerty … you’re correct, but it does depend… hope that clears things up for you J?

Jack

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

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

Hi Yenn,

I agree with you … I really can’t see any of these engine mods doing much to reduce bore glazing. In my old motorcycle days there were inlet or exhaust restrictors fitted to engines to detune them for children to ride them with less power. Be it a 4 stroke or 2 stroke engines they all had deposits problems along a high propensity to suffer with bore glazing. Apart from your suggestions to use full throttle and steep climb out, I think a chat with Rod Stiff a good idea as well.

Regards

Jack

It’s not so much the engine speed (RPM) that causes bore glazing, it's the load …. The engine needs to be loaded up and run at the correct engine temps. Light loads and low temps will cause glazing, high oil consumption and short engine life. Full power at take-off and 75% + at cruise is the way to go.... not sure how you do this as it sounds like you have more grunt than you need.

Regards

Jack

Hi Moroa,

Attached is a link on VGs.

http://www.recreationalflying.com/forum/general-discussion/4403-vortex-generators.html

I tried them on my 160 and was disapointed with the outcome and removed them.... take a look at the link for more details and comments.

Regards

Jack

Hi Modest,

Your pic in your profile is too small … love to see your spats more clearly, can you try and post a larger picture?

One of the things I tried was to fit a small trim tab to the back of my front spat, although, like you, it only really worked at one power setting, which I set up at cruise.

After I took the front spat off and fitted the hub cap the ac became coordinated at all power settings.

Cheers

Jack

Hi Rob,

I have played around with various combinations of spats/wheel covers and found that you may lose 1 or 2 knots if remove the spats.

Interestingly I found my front spat worked in some conditions like a servo on my rudder and wouldn’t allow the ac to bank and remain in coordination as well as it would without the spat … I was working the rudder all the time and once I removed my front spat it made my 160 much nicer to fly as it remained in coordination without me having to tap dance on the pedals.

The other combination I have tried was to buy a set of wheel covers from the UK (Instrument panels) which seemed to give me the same speed as the spats and where fantastic for dirt strips and a little lighter too.

Currently I have settled on a wheel cover on the front and the Jab spats fitted on the mains when on my home strip (Tyabb) …. I fit the wheel covers if I’m doing dirt strips.

Hope this helps?

Cheers

Jack

I saw this other day ... it's a video from the EAA on how to do minor repairs on wooden props.

http://eaa569.org/videos/propeller.html

Cheers

Jack

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

G'day Theo,

Its a 2 blade Revolution ... they are made up in Bundaberg.

It works very well in terms of performance but made the 160 feel like it had a turbine up front.

I also know a couple of guys that have the 3 blade prop on the 6 cylinder Jabs and they say the same.

Cheers

Jack

Hi Bruce,

I would think balancing a prop would be a good thing. Whilst I don’t have any first hand experience with balancing, I have grown to appreciate the positive impact of getting the blades pitch the same in terms of achieving smoothness. I fitted a carbon fibre ground adjustable prop almost 200 hrs ago to my 160…. The adjustability aspect is great for performance set ups but it’s fabulous for reducing vibration with identical blade settings. I can’t imagine that prop balancing wouldn’t be a positive step forward..... I’m also keen to know if these gismos work too?

Cheers

Jack

I was with a mate a few weeks ago and he was pulling through the prop of the aircraft we were about to do some ribbon cutting in prep for a club comp…. A LAME came up and reminded us that if the magneto earths had failed (despite being turned off) for any reason we could be at risk of hand starting the engine with both of us in front of the prop. Ok nothing to do with a poor starting, but a safety reminder when pull over by the prop to make sure you do it safely.

• Check and make sure the mags are off
   
   
  
• Apply the brakes
   
   
  
• Stand to the side
   
   
  
• Keep a good clearance between you and the prop
   
   
  

Cheers

Jack

Hi Phil,

You know, I think there is something in your LAME’s observation, although I think it could be related to the brand of filter used.

When I replaced my original filter with the Ryco A360 I noticed the seal around the rim of the filter was slightly thicker than the original, which was a RAF17, I didn’t know it at the time but RAF17 is Repco filter (See previous post from JR) … I noticed that the new Ryco prevented me from tightening the cover home as I was causing distorting to the cover … this distortion would most certainly allow unfiltered air into the engine. In the end I settled to just tighten it down to the point I was happy I had a consistent seal. I’ve since checked it again and all seems to be ok.

Never the less, I’m tempted to go down to the local Repco and measure the seal thickness on the RAF17 and see if it is in fact narrower in new condition and replace the Ryco filter at my next 50hrs maintenance schedule if it looks a better fit…. I’m not too keen on the idea of things not being completely secured, as in this instance it could also effect the carbie heat function if cool air can sneak in around the filter seal.

While I’m mentioning the carbie heat … I was also wondering if this could be a source of concern for the supporters of oiled foam filters and why there have been reports of oil pooling in the air box? I wonder if the hot air from the carbie heat function is causing the oil to reduce its viscosity and fallout? I also wonder what effect the heat has on the foam too? I don’t know the answers to these questions but I thought I would mention and see if someone does?

Regards

Jack

Hi Nev,

I wonder if the Bing is more of a problem regarding fuel mixture sensitivity than the engine … could the Bing be restricting potential performance and durability of a very nice engine.

No not really interested in being anyone’s test pilot, hence the question to see if others knows the answers.

Cheers

Jack

There seems to be a number of Throttle Body Injectors available on the market... they all make a lot of claims about performace improvements. I did speak to a chap on the weekend who has a Aerocarb fitted to is Sonex, which has 4 cylinder Jab power plant, and said it provided better performance over the Bing.

Keen to hear any opinions or exposure to these TBI's?

AeroConversions Products -- Power to the Sport Pilot!

Ellison Fluid Systems: Home Page

TBI

Regards

Jack

My flter has been in service for the past 275 hrs and has been been cleaning each 50hrs.

I spoke with the Jabiru engine guys and they did say that dirty filters has been the cause of some poor engine power issues and recommend replacing if the filter becomes dirty.

I guess personal choice in terms of filter manufacture is up to the owner .... Ive bought a Ryco A360 as the replacement from Super Cheap for $16.50 and think for the peace of mind this cost is not worth trying to avoid to maintain performance and durability and above all safety.

Regards

Jack

Hi Nev,

Thanks for the input. Just not clear on the reason you don't trust paper filters... can you please give me a little more detail behind your concerns?

Regards

Jack

How do you clean a K&N filter? Does it have a long service life or do you have to replace it after a couple pof cleans?

Regards

Jack

Hi Nelson,

Recently I flew my 160 Jab from Melbourne to Lake Eyre and other iconic inland locations … by the way, I had a ball and the Jab didn’t miss a beat.

On my return to Melbourne I found a fine layer of red dust on the filter. I’m not sure if I picked this up from the dirt strips I used along the way or if this was dust in the atmosphere??

Never the less, I thought a replacement filter a cheaper option to maintain durability and performance than attempt to clean it.

Best regards

Jack

Many thanks JR ... this is great.

Regards

Jack

Thanks Guys

I'm mindful some brands are better than others as I dont want to get caught out with a cheap poor quality copy... any ideas?

Regards

Jack

Does anyone know what the (quality) replacement air fliter is for a 160 from the local auto parts shop? Part number will be useful too.

Regards

Jack

I’m keen to know if anyone out there in Jabiru land has fitted an Throttle Body Injector to replace the Bing on either a 4 or 6 cylinder engine and what was the result... good or bad?

Regards

Jack