How to improve the reliability of the 6 Cylinder Jab

[deadstick]

Thought had crossed my mind. lol

 

 

[fly_tornado]

just about mandatory in an air cooled engine

 

 

[jetjr]

Knock sensor......excellent more lights/guages!!!

 

I havent seen these in stand alone setups, only in ECU EFI setups. How do they register?

 

Re separate carb per cylinder, the other option is EFI, individual port injection. Not that dear ~ $2K Id guess, and should solve mixture issues and a few other problems too.

 

Anyone know Mr Milsteed and can pass on his details in a PM?

 

 

[fly_tornado]

yu can buy standalone knock sensors have a look on ebay. all you need to do is drill a hole into your block to mount it...

 

 

[REastwood]

Knock sensor......excellent more lights/guages!!!Anyone know Mr Milsteed and can pass on his details in a PM?

I'll ask him next time he is here and see if it's OK to pass on his number.

 

Or you can call Custom Aircraft Centre (Lyndon Trethewey) who helped/did? the installation with John. The only number I have for Lyndon is: 0417 802 964

 

 

[jetjr]

Thanks

 

 

[darren_p]

Hi all, I have been reading this thread with interest, I have used a hire J230 for remote community work in WA and love the aircraft and have even considered the J430 for the extra weight etc. I have been a bit disappointed to hear of the issues with the Jab3300 and went off the idea. However reading this thread has shed some interesting light on the subject, would you all recommend this aircraft with the mods as descibed as a longterm prospect, I dont like the idea of a forced landing and remote areas, although I do follow the roads.

 

Andrew and John, how has the mods improved your engines.

 

Thanks.

 

Darren

 

 

[JabSP6]

Darren

 

The jabiru is a fantastic plane for the price and i would recomend one to anyone as long as you get it set up right. Good cooling for the heads and not running too lean. I have done several things to get low head temps and with 150 hrs on it i am very happy with the results.

 

Send me a pm with you details and i will discuss further.

 

Andrew

 

 

[bushpilot]

We have 2 J230s in our school - doing circuit work, navs and private hire. One has done 440 hours in 18 months and the other 405 hours in just 9 months. We have had no problems with either - altho one has been slow to start when temps got under 5C. But mechanically - no issues at all. I would like to see Jabiru do something about the brakes; they require constant adjustment. Bottom line: A great a/c for the money - roomy inside, fast, low consumption, good looks.

 

 

[Guest JRMobile]

DarrenThe jabiru is a fantastic plane for the price and i would recomend one to anyone as long as you get it set up right. Good cooling for the heads and not running too lean. I have done several things to get low head temps and with 150 hrs on it i am very happy with the results.

 

Send me a pm with you details and i will discuss further.

 

Andrew

I had the great pleasure of flying to Bundy last weekend to meet with Andrew (JabSP6) and discuss some of the many mod he has carried out on his SP6. What an eye opening experience.

Some but not all the mods include:

 

Balance the bottom end

 

Piston and gudgeon as well

 

Nikasil Bores and better quality (chrome) rings.

 

·Ceramic coating on the top of the piston and Teflon coating on the piston side skirts.

 

Fine Finned Heads fitted

 

·This includes different length rockers and different size rocker covers

 

·Fitted K Liner inserts in the valve guides

 

·Stainless Steel 1 piece valves fitted with matching spring retainers and collets.

 

·Ceramic coating in the exhaust port and on the complete combustion chamber

 

·Ported and polished heads to even out flow between all 6 heads

 

Replaced the engine Through Bolts

 

Extractor exhaust system that eliminates gaskets.

 

·Separate header per cylinder with a bevelled flange.

 

·3 into 1 collector with a 2 inch pipe.

 

·1 ¼ inch balance pipe

 

·1 ½ inch perforated stainless pipe wrapped in exhaust packing inserted up the 2 inch pipe as a muffler.

 

Increased air flow to the heads

 

·Increased the inlet size of the top engine cover

 

·Have a larger air duct over the cylinders and heads so that only 4 fins are not covered

 

Ignition System

 

·Iridium spark plugs fitted to give improved spark which has improved cold start

 

Carby

 

·Polished the throat of the carby

 

Inlet Manifold

 

·Removed the aerofoil shaped deflector and replaced with 12mm round bar ( only minor improvement).

 

·Fitted fibreglass cross in the air box outlet with slight improvement

 

3 blade Patroney Prop and Cummins Spinner

 

·Adjusted to 15 degrees to give 2800 rpm on ground run up and 3300 straight and level flat out

 

The best part was we went for a test flight to enable me to compare my jabs performance, on start up the smooth running is most evident (a sewing machine comes to mind), after warm up we taxied out and took off. Rolling and climb at 2800rpm with a climb rate of 1200 to 1300 fpm, 80/90 kts all the way to 4500 ft. Andrews CHT were in the range of 130 degs. C. all the way to top of climb and reduce 5/10 degs again in cruise. Now that's impressive to someone who does staggered climbs, for the past 5 years, to keep CHT in check.

 

Andrews mechanical knowledge with regards to his aircraft is truly impressive and his workmanship the same.

 

As he said in an email -

 

"hope we can get the motor to the point where we are completely confident to jump in it and know it will perform the way it should for 1000 hours or more."

 

Thanks for your time and sharing your knowledge Andrew, invaluable stuff.

 

 

[JabSP6]

John

 

It was a pleasure to spend time with you last weekend and i hope that i can share some of the things i have found to help improve our motor. I am only too happy to talk about anything that we can do to improve these potentially great motors which is why i started this thread. I am home most weekends and would love to hear if anyone else has had some good results from improving something with this motor no mater what they have done.

 

Safe and Happy Flying.

 

Andrew

 

PS.

 

John. I haven't forgotten the discs. Still waiting on them. Will send them as soon as i receive them.

 

 

[bushpilot]

I had the great pleasure of flying to Bundy last weekend to meet with Andrew (JabSP6) and discuss some of the many mod he has carried out on his SP6. What an eye opening experience.Some but not all the mods include:

Balance the bottom end

 

Piston and gudgeon as well

 

Nikasil Bores and better quality (chrome) rings.

 

·Ceramic coating on the top of the piston and Teflon coating on the piston side skirts.

 

Fine Finned Heads fitted

 

·This includes different length rockers and different size rocker covers

 

·Fitted K Liner inserts in the valve guides

 

·Stainless Steel 1 piece valves fitted with matching spring retainers and collets.

 

·Ceramic coating in the exhaust port and on the complete combustion chamber

 

·Ported and polished heads to even out flow between all 6 heads

 

Replaced the engine Through Bolts

 

Extractor exhaust system that eliminates gaskets.

 

·Separate header per cylinder with a bevelled flange.

 

·3 into 1 collector with a 2 inch pipe.

 

·1 ¼ inch balance pipe

 

·1 ½ inch perforated stainless pipe wrapped in exhaust packing inserted up the 2 inch pipe as a muffler.

 

Increased air flow to the heads

 

·Increased the inlet size of the top engine cover

 

·Have a larger air duct over the cylinders and heads so that only 4 fins are not covered

 

Ignition System

 

·Iridium spark plugs fitted to give improved spark which has improved cold start

 

Carby

 

·Polished the throat of the carby

 

Inlet Manifold

 

·Removed the aerofoil shaped deflector and replaced with 12mm round bar ( only minor improvement).

 

·Fitted fibreglass cross in the air box outlet with slight improvement

 

3 blade Patroney Prop and Cummins Spinner

 

·Adjusted to 15 degrees to give 2800 rpm on ground run up and 3300 straight and level flat out

 

The best part was we went for a test flight to enable me to compare my jabs performance, on start up the smooth running is most evident (a sewing machine comes to mind), after warm up we taxied out and took off. Rolling and climb at 2800rpm with a climb rate of 1200 to 1300 fpm, 80/90 kts all the way to 4500 ft. Andrews CHT were in the range of 130 degs. C. all the way to top of climb and reduce 5/10 degs again in cruise. Now that's impressive to someone who does staggered climbs, for the past 5 years, to keep CHT in check.

 

Andrews mechanical knowledge with regards to his aircraft is truly impressive and his workmanship the same.

 

As he said in an email -

 

"hope we can get the motor to the point where we are completely confident to jump in it and know it will perform the way it should for 1000 hours or more."

 

Thanks for your time and sharing your knowledge Andrew, invaluable stuff.

Truly impressive stuff indeed... Any other comparisons on before and after - like IAS (at what RPM) and fuel burn??

 

 

[JabSP6]

Chris

 

After the rebuild i did have to ajust the pitch of the prop to reduce the RPM back to the recommended range. I was seeing 3550 RPM straight and level flat out. I now see just under 3300 RPM straight and level. When in cruise at around 2850 RPM i now see just under 20 lt/hr.

 

I'm happy to have a chat if you PM me with your details

 

Andrew

 

 

[Guest clamar floats]

ChrisAfter the rebuild i did have to ajust the pitch of the prop to reduce the RPM back to the recommended range. I was seeing 3550 RPM straight and level flat out. I now see just under 3300 RPM straight and level. When in cruise at around 2850 RPM i now see just under 20 lt/hr.

I'm happy to have a chat if you PM me with your details

 

Andrew

Hi Andrew, can you PM with contacts please?

Regards

 

Clamar

 

 

[Old Koreelah]

ChrisAfter the rebuild i did have to ajust the pitch of the prop to reduce the RPM back to the recommended range. I was seeing 3550 RPM straight and level flat out. I now see just under 3300 RPM straight and level. When in cruise at around 2850 RPM i now see just under 20 lt/hr.

I'm happy to have a chat if you PM me with your details

 

Andrew

Andrew while searching for posts on platinum or iridium plugs I happened on this thread. I'm trying to improve reliability in my J2.2 and some of your mods are exactly what I'd like to do. After five years, how is it going?

 

 

[quentas]

Change your flywheel bolts ASAP if you have done 500 or more hours. I learnt the hard way. Luckily I was on the ground idling when it happened. It's a big messy job to change them when some of the bolts have already snapped above the lock tite. Sticking your finger in the rear or checking they are loose with a torque wrench is pointless.

 

 

[jetjr]

Theres an SB on it

 

 

[facthunter]

If the bolts have been near loctite and snapped later getting them out won't be easy. With a used engine there's a lot of oil about in that area, which you would be better off without. Nev

 

 

[quentas]

Sb released october 2015. Im guessing after a spate of failures?

 

 

[jetjr]

No there have been failures going back years and several SB attempting to fix with dowels, bolts, different attachments

 

I still havent heard a solid believable answer from Jabiru on why these bolts break

 

Mostly blamed on others props so now they have to replace bolts every 100hrs. Its not a nice job even if they arent broken.

 

Possible causes are harmonics between prop and flywheel or starting torque as starter has to get to high speeds and it drives off flywheel

 

Replacing bolts does nothing to fix either.

 

Belt drive altenators and CAE mounting could go a long way to fix but Jab wont look at it.

 

 

[facthunter]

Won't be cured until the starter gear is moved to the front of the engine like the Lycoming. Nev

 

 

[quentas]

Won't be cured until the starter gear is moved to the front of the engine like the Lycoming. Nev

I agree. Jabiru suggested I had a prop strike. You think you'd know if that happened? I think they have nasty harmonics running all along the crank? If you own a Jab, next time you are doing run ups, try and get some light glinting of the back of the prop and rev slowly from 900 to around 1500 rpm. Look at the 11 o'clock position on the prop 'disk'. Tell me what you see

 

 

[jetjr]

Prop balancer tells an interesting tale too, even smooth running ones are way out

 

 

[facthunter]

CAMit have a motor with the drive at the front behind the prop. The starter itself is still rearwards to make the cowl better shaped than would be the case otherwise.. Nev

 

 

[jetjr]

Seen it, reckon that might pop up on a future version

 

They have changed flywheel mounting and method on tension plus belt drive alt has apparantly made big improvement