160 or 170 jab

[AVOCET]

The fuel smell in the cockpit with Mogas is the fuel seeping through the fuel lines , doesn't mater if there silicon or rubber ,

 

The best fuel line to use with Mogas is the Teflon hose system , they use it in drag racing ect because nothing reacts with it .

 

Or you've got a seeping join or fuel tap , quite common in jabs .

 

Cheers

 

 

[Thirsty]

Yep figured that was the case. Had a good look around at the last 100 hourly and can't find any joins seeping fuel. Doesn't worry me at all just an observation really.

 

 

[AVOCET]

Yep figured that was the case. Had a good look around at the last 100 hourly and can't find any joins seeping fuel. Doesn't worry me at all just an observation really.

Try BP 98 , doesn't seem to make the fuel lines soft , not like caltex vortex 98 ,apparently the caltex has up to 40% toluene , that's what causes the problem

 

 

[Thirsty]

Yes might just try doing that. We use Shell Optimax presently but might try a few different types.

 

 

[dazza 38]

Try BP 98 , doesn't seem to make the fuel lines soft , not like caltex vortex 98 ,apparently the caltex has up to 40% toluene , that's what causes the problem

Interesting, I have used Caltex 98 in my motorbike since new (sometimes vortex 95) my bike is 10 years old now and it still has the original fuel lines. No leaks, no smell. I guess the fuel lines that KTM use must be pretty good stuff.

I don't know what brand it is but it is Black, I assume some type of rubber, and it is sheathed in a black braided material. I would use in a experimental with no worries in the world. The fuel lines runs very close to the cylinder, so heat must not be a real problem.

 

 

[blueline]

Another vote for mogas from me. Nearly 1800 hours of mostly mogas with only scheduled maintenance.

 

Never had fuel leaks

 

 

[Keenaviator]

Another vote for mogas from me. Nearly 1800 hours of mostly mogas with only scheduled maintenance.Never had fuel leaks

What aircraft?

 

Laurie

 

 

[AVOCET]

What brand of Mogas ?

 

Mike

 

 

[blueline]

J160.

 

I had been using 98 Shell but recently changed to 95 octane Caltex after reading of the issues some others have been having with Shell fuel. Personally I have never had any issues with Shell but changing fuels was easy.

 

What is not easy is lumping all those Jerry cans around....

 

 

[motzartmerv]

The 160 is the better aircraft of the two. Hands down. The 170 is a frankenstein amalgamation of bits of the 160 and the 230.

 

The only advanbtage the 170 has over the 160 is its usable load and better lift on warm days.

 

The 160 is faster. It handles much better. The secondary effects of the ailerons and rudder are not as pronounced. Its higher wing loading means it feels much better in turbulence. The controls are much more balanced (as much as Jabiru's can be) and its a better looking aeroplane, with the wings that match its fuse size. The 170 was an after thought IMHO and Jabs reaction to the lift issues at MTOW on warm days that the 160 suffers from. Ive always had the feeling the 160 could do with 15 or 20 extra horse power. The 160 with 100 hourse would be an un beatable training and touring aeroplane. An absolute industry leader.

 

Ps. Just to put it in context, i dont have as many hours in the 170 as the 160. probably around 1500 in the 160 and only 600 in the 170..At a guess.

 

 

[frank marriott]

Merv

 

Does your time in 170s include the D model? Or does your view include the D?

 

(I haven't flown a C)

 

 

[motzartmerv]

Mostly the C Frank. Some time in the D. The D improved things slightly, however they stopped using Frize ailerons (i believe) which did nothing for the handling issues.

 

 

[facthunter]

Frize ailerons appeal to some (not me) generally. They generate drag but that is an individual pilot thing. Less adverse yaw with a drag penalty (although it is not much, it is still a factor when everything counts)..

 

I know of people with the jab 430 who have trouble in warm climates .( Central Australia) with lack of "lifting ability" The case with the two aircraft comparison raises a similar consideration. If you must have hot and/or high performance you need more power or more wing. The excess float on landing is just a pilot thing with coming in too fast and the pilot MUST address that on short strips, at least. Nev

 

 

[Russ]

thanks guys.......this is a good read, keep it coming>>>>>>>>

 

 

[motzartmerv]

Agreed Nev. However, the 170 has the ailerons 3 or 4 feet further away from the longitudinal axis than the 160. The yawing moment induced by the aileron drag is excessive with those things hangin way out there and only a relatively short fuse to couple the forces (and stability in the logitudinal 'plane') together. The result is a very mushy, unbalanced feeling aeroplane at low speeds and very susceptible to 'rubbish' in the flare.

 

 

[facthunter]

Yes Merv, I realise from the training viewpoint the ailerons you prefer are a better proposition, and I am glad you brought the matter up as it gives a better overall assessment for people to consider. Storing them in a hangar is valid too but I am being a purist with planes flying physics. It is the one thing I didn't like about my Citabria. It complicated spin entry/recovery and doesn't work upside down when slow. Not relevant in your situation. (I hope). Nev

 

 

[Russ]

Just to add a bit more to the mix here.........."water cooled" heads............pro's and con's...

 

 

[jetjr]

Pro - constant head temps in all conditions, supposed less head/engine problems, better materials.

 

Cons - cost, weight, complexity.

 

If you can get air cooled temps sorted out there shouldn't be an issue using fine finned heads. This does take some fiddling to achieve but 100-120 deg C is possible. Jabiru USA have a good worksheet on balancing and getting head temps down.

 

Below 100 deg C (advertised for LCH) is maybe too low for lead scavanging and could bring issues of its own.

 

On older engines with thick finned heads, LCH would be a serious option @ overhaul.

 

Nice design and implementation and great to see aftermarket work being done with Jabiru engines.

 

 

[facthunter]

The LCH's are an option, but you have added complexity of radiator and piping. IF you can get the temps OK with aircooling, it's simpler. Be helpful/essential in a pusher installation. Nev

 

 

[fly_tornado]

Note the EGT and CHT values at the end of a 30+ day in SLC.

 

This is a jab 6 running the standard pusher scoops in a Tornado S.

 

 

 

[AVOCET]

When I made the the Avocet I had originally had intended to have an aircooled tractor on the turret, but it would have ment having the prop arc over the top of my head ,

 

I resolved myself to a pusher and was concerned about the cooling of the 3300 jab

 

I couldn't believe my luck when I heard about LCH and was the third person to install a test set of heads , ( first pusher ) any way , long story short was they worked straight out of the box with quite a small radiator , I had had made , every thing including hoses and pumps fit snugly into the turret ,( see my photo album on my site , just press avitar. ) so on a tractor instalstion jabby there's plenty of room under the cowls .

 

I know of at least 4 installations in j 230 's that work great and turn the jab engines into a 6 cyl type rotax , the weight penalty isn't that much , and the jabs have plenty of power and capacity .although , I had to put a 30 amp alt , the one that goes on the vac outlet, and leave the jab alt for a back up ,

 

It adds more cost , but you end up with a reliable engine and duel every thing .

 

Like any thing , time will tell , but at the moment I carnt speek highly enough of LCH

 

Like most things , LCH , fuel injection ,electric ignition ,is the way of the future , way of the future , way of the future ......... The way of the future.....

 

Cheers Mike

 

Ps quote last line of post : The Aviator . ( the film of Howard Hugh's )

 

 

[AVOCET]

Note the EGT and CHT values at the end of a 30+ day in SLC.This is a jab 6 running the standard pusher scoops in a Tornado S.

 

Carnt read the numbers , can you write them for folk on I phones , please cht +egt

Thanks mike

 

 

[fly_tornado]

EGT are in the 1250 range and the CHT are around the 260-290 range with one around 210

 

 

[facthunter]

Are you talking Fahrenheit ? Nev

 

 

[Russ]

160 it is then...........getting the Ok to fly me gyro about phillipines was becoming a right head *****, so i looked into permission for a factory built/certified craft.....hence a jab.....this they've Ok'd.

 

With lot's of homework this last mth or 2, and info via here as well, i'm more than comfortable now re jab 160 and the "engine".....even looked into a 912 installation, which was to be a definate possibility. ( absolutely doable, and "certified " )

 

Have been convinced the 4 cyl jab, reworked a tad, and run on mogas with upper cyl lube at all times is a reliable/honest engine.......CFI this way is getting big hrs on his jab, has caused no grief whatsoever.....it just keeps humming.

 

Now.............any info re island hopping to phillipines ( customs requirements, etc etc )...........ANY info at all i would be grateful.