Jabiru Gen 4

[Kyle Communications]

Well thats it Nev. I wanted more hp and the Jab fitted the bill nicely. The UL would be nice but being able to justify the 35k to get one well I couldnt justify the price. So I put a lot of scrutiny on the Gen 4 version..far more than probably most because I do have a line of info that others dont have. I decided not to take that risk and spend the money on a engine that I know well and fit it with a proven big bore kit which will give me 114hp and hopefully a few more with a better exhaust. So almost at the same power although I would prefer a lower revving engine but that is not to be. I will stick with what I am comfortable with. I also know a hell of a lot more about the rotax and internals AND the problems they have. Those problems have been mitigated by attention to detail and a huge amount of experience by my engine builder with experience with ALL types of aero engines and also normal car and race car engines. This guy knows his stuff.

I hope they get these bugs out of the Gen 4 as it certainly is better than the previous generations Rotax have bugs too and I am certainly aware of most of them but for me...well I am happy with my decision

[facthunter]

Yes the UL does look very professional. Our dollar is in a dismal state so everything from overseas is now too expensive. Good luck with the project. You are stuck with the crank and rods as there's NO room for anything else in there. Nev

[Kyle Communications]

The crank and rods are original as you say. The crank is now welded to take the extra bit of hp just in case it also has been balanced and so has the flywheel to suit. Interesting though is the pistons in the big bore kit are all 504 grams exactly..not one iota of difference. The cyl are beautiful and the liners look fantastic also it is all nikasil in the boreas well. My engine guy when he first looked it all over and was super impressed..he reckons they have done it perfectly correct and should be a ripper. He didnt want to part with the engine after he finished it last week :)

[Jim188]

Oh Boy,

 

I have read this thread from beginning to end and after 3 pages of verbal diarrhoea coming from some of our first Class Members, I am actually a shame, as to how my fellow pilots act on this forum.

 

The topic was "Jabiru Gen 4" and the question, "Has anyone replaced their old Jab with the new Gen 4? Did it just fit right in with the old cooling ducts or are new ones required, is it really a direct swap? Are you happy with the performance, is there a noticeable difference in the operation? Thanks... "

 

Recently we purchased a Jabiru with Gen 4 engine in it. We did own a Cessna for many years and in more recent times have been hiring both a Jabiru 230 and Cessna's 172 as required.

 

 

So let’s put this engine thing in a little perspective, I have a friend who has had a number of sticky values over the years with a bend value in his Cessna. Rotax had issues with crankshaft breaking or ignition coils failing on one model of their engines. So nothing is perfect, but all we can hope as pilots, our aircraft engine manufacturers are always striving to overcome any issues they find with their engines.

 

 

So let's get back to the Jabiru Gen 4, I don't exactly know when the first Gen 4. 3300 hit the flying market, but in my case our Gen 4 was installed by Jabiru in July 2017, it now has 60 hours on it. The previous owner lived on the coastal strip and over the 2 years did not fly as regularly as he liked. So I was told by a LAME, if this was an older Jabiru engine it would have most likely had a pretty good chance of at least one barrel that would have got some corrosion on it and that would have lead to it having cylinder compressions issues.

 

 

But with the Gen 4 engines and new type barrels, it has compression tested as you would expect for a low time new aero engine, so it seems the internal barrel corrosion issue may have been resolved.

 

 

Most of us have been given the drum about doing 80 knot cruise climbs, as Jabiru engines have little tolerance for being overheated as this overheating will cause de-torquing of the through bolts, heads and barrels. Further you can easily shock the barrels and heads if you don't allow the engine temps to normalise after starting and before you taxi and fly the aircraft.

 

So how does my Gen 4 go with its temperatures on climb out, no comparison to the old Gen 2 or 3, the Gen 4 CHT and EGT run well within their limits all the time, even when pushing the climb and when on the ground on those very hot summer days.

 

 

So if all else is equal, I am thinking the Gen 4 with its new heads and barrels being one unit, the barrels being very corrosion resistant and the CHT and EGT temperatures being well with in specs, this should all lead to a Jabiru engine that should be able to maintain it's cylinder compressions year on year without too much drama, here's hoping,

 

I hope this is a help to someone.

 

Regards

JimJab

[jacmiles]

Oh Boy,

 

I have read this thread from beginning to end and after 3 pages of verbal diarrhoea coming from some of our first Class Members, I am actually a shame, as to how my fellow pilots act on this forum.

 

The topic was "Jabiru Gen 4" and the question, "Has anyone replaced their old Jab with the new Gen 4? Did it just fit right in with the old cooling ducts or are new ones required, is it really a direct swap? Are you happy with the performance, is there a noticeable difference in the operation? Thanks... "

 

Recently we purchased a Jabiru with Gen 4 engine in it. We did own a Cessna for many years and in more recent times have been hiring both a Jabiru 230 and Cessna's 172 as required.

 

 

So let’s put this engine thing in a little perspective, I have a friend who has had a number of sticky values over the years with a bend value in his Cessna. Rotax had issues with crankshaft breaking or ignition coils failing on one model of their engines. So nothing is perfect, but all we can hope as pilots, our aircraft engine manufacturers are always striving to overcome any issues they find with their engines.

 

 

So let's get back to the Jabiru Gen 4, I don't exactly know when the first Gen 4. 3300 hit the flying market, but in my case our Gen 4 was installed by Jabiru in July 2017, it now has 60 hours on it. The previous owner lived on the coastal strip and over the 2 years did not fly as regularly as he liked. So I was told by a LAME, if this was an older Jabiru engine it would have most likely had a pretty good chance of at least one barrel that would have got some corrosion on it and that would have lead to it having cylinder compressions issues.

 

 

But with the Gen 4 engines and new type barrels, it has compression tested as you would expect for a low time new aero engine, so it seems the internal barrel corrosion issue may have been resolved.

 

 

Most of us have been given the drum about doing 80 knot cruise climbs, as Jabiru engines have little tolerance for being overheated as this overheating will cause de-torquing of the through bolts, heads and barrels. Further you can easily shock the barrels and heads if you don't allow the engine temps to normalise after starting and before you taxi and fly the aircraft.

 

So how does my Gen 4 go with its temperatures on climb out, no comparison to the old Gen 2 or 3, the Gen 4 CHT and EGT run well within their limits all the time, even when pushing the climb and when on the ground on those very hot summer days.

 

 

So if all else is equal, I am thinking the Gen 4 with its new heads and barrels being one unit, the barrels being very corrosion resistant and the CHT and EGT temperatures being well with in specs, this should all lead to a Jabiru engine that should be able to maintain it's cylinder compressions year on year without too much drama, here's hoping,

 

I hope this is a help to someone.

 

Regards

JimJab

Hi Jim, my jab has been running cool even when pushing a 65kn climb on a hot day it wont get up too high in temp. If Kyle knows something about cylinder issues with the new engines and says he cant say too much about it id like to know who he is protecting. Maybe the boys from the ATSB need to have a talk to him before someone gets killed.

[Paul davenport]

When people ask specific questions on subjects there tends to be a drift away from the subject by well meaning and experienced members who are very knowledgeable but who do not have actually experience in the question asked, and then it turns into a them and us discussion (in this case Rotax v Jabiru) . I would respectfully suggest that when asked a question on ANY forum subject that if you have first hand experience please give us the advantage of that experience, if not don’t enter the discussion

[kgwilson]

I have a Gen3 3300A and have never experienced cooling issues. Why? Well I spent a lot of time discussing cooling with others & Garry Morgan who supplied the materials for my build. I also downloaded & read a paper produced by NASA back in 1982 entitled "An experimental investigation into the aerodynamics and cooling of a Horizontally Opposed Air-cooled aircraft engine installation". It is 150 pages in length and discusses just about everything you didn't think you needed to know. I spent a great deal of time planning my cooling and created a 1 metre wide suction lip at the bottom of the cowl, installed a large 7 row Positech oil cooler with its own NACA duct sealed from the rest of the engine & used the old style low profile plenums with the plug leads on the exterior, deflector vanes of varying sizes glassed in between cylinders and well sealed intake nacelles. I never reach maximums of CHT, EGT & oil temperature even on 40 deg days & in the winter I cover the bottom half of the oil cooler and the air intake for the sump which normally blows cool air onto the finned front sump area.

 

The early Jabirus were awful and a lip kit was eventually designed to be retrofitted to suck more air through. The later models were improved significantly.

[facthunter]

It's reasonable to ask how the new motors are going and I guess the only people who know, are the ones who run them. Better compression (tighter piston fit )and less corrosion (none) of the cylinders MUST be a help. We don't get much response from owners of the new ones.. I've always been optimistic that it would be an improvement but time in service is the final real test.. We NEED this type of engine to work. It's cheaper lighter and simpler. The concept is right for many applications. . Nev

[Jim188]

Thanks KG Wilson for telling us that it can be done to design an efficient aircraft cowl and ducting system that can keep a Jabiru cool for your Morgan. I do know of another home builder owner who has a Jabiru 2200 in his aircraft and he can also keep his engine so cool, that he has to reduce his cooling efficiency for the winter months.

 

Facthunter, I am sure you can see why you would not get much response from Jabiru Aircraft owners or Gen 4 engines owners after reading this thread prior to the last 4 post. I agree with Jacmiles, Kyle if you really think you know something that is not bias bullsh...., then you should be able to point people in the right direction.

 

Here is hoping for all who that want cheaper flying, we will see an Australian made aero engine that can rival other aero engine manufacturers around the world with their time in service. This engine is really a nice simple engine compared to the other modern designs of today.

 

Cheers

Jim188

[facthunter]

Faster types of planes have consistently had less trouble than others over the years. Morgan/Corby. IF your engine tends to run a bit hot don't wait till it gets to a limit . Increase the speed if it's rising at a rate above normal BEFORE it gets to the limit. Nev

[dan3111]

Oh Boy,

 

I have read this thread from beginning to end and after 3 pages of verbal diarrhoea coming from some of our first Class Members, I am actually a shame, as to how my fellow pilots act on this forum.

 

The topic was "Jabiru Gen 4" and the question, "Has anyone replaced their old Jab with the new Gen 4? Did it just fit right in with the old cooling ducts or are new ones required, is it really a direct swap? Are you happy with the performance, is there a noticeable difference in the operation? Thanks... "

 

Recently we purchased a Jabiru with Gen 4 engine in it. We did own a Cessna for many years and in more recent times have been hiring both a Jabiru 230 and Cessna's 172 as required.

 

 

So let’s put this engine thing in a little perspective, I have a friend who has had a number of sticky values over the years with a bend value in his Cessna. Rotax had issues with crankshaft breaking or ignition coils failing on one model of their engines. So nothing is perfect, but all we can hope as pilots, our aircraft engine manufacturers are always striving to overcome any issues they find with their engines.

 

 

So let's get back to the Jabiru Gen 4, I don't exactly know when the first Gen 4. 3300 hit the flying market, but in my case our Gen 4 was installed by Jabiru in July 2017, it now has 60 hours on it. The previous owner lived on the coastal strip and over the 2 years did not fly as regularly as he liked. So I was told by a LAME, if this was an older Jabiru engine it would have most likely had a pretty good chance of at least one barrel that would have got some corrosion on it and that would have lead to it having cylinder compressions issues.

 

 

But with the Gen 4 engines and new type barrels, it has compression tested as you would expect for a low time new aero engine, so it seems the internal barrel corrosion issue may have been resolved.

 

 

Most of us have been given the drum about doing 80 knot cruise climbs, as Jabiru engines have little tolerance for being overheated as this overheating will cause de-torquing of the through bolts, heads and barrels. Further you can easily shock the barrels and heads if you don't allow the engine temps to normalise after starting and before you taxi and fly the aircraft.

 

So how does my Gen 4 go with its temperatures on climb out, no comparison to the old Gen 2 or 3, the Gen 4 CHT and EGT run well within their limits all the time, even when pushing the climb and when on the ground on those very hot summer days.

 

 

So if all else is equal, I am thinking the Gen 4 with its new heads and barrels being one unit, the barrels being very corrosion resistant and the CHT and EGT temperatures being well with in specs, this should all lead to a Jabiru engine that should be able to maintain it's cylinder compressions year on year without too much drama, here's hoping,

 

I hope this is a help to someone.

 

Regards

JimJab

 

 

 

This will put a cat among the pigeons I know you are trying to gain info of a gen 4 engine and performance / cooling . If your engine has only 60 hours tt you are in the safe zone the ones I have heard throw reliable sources 200 to 400 hours is when you start replace heads and cylinders on gen 4. Normally engine noise get louder as exhaust gas flows out between heads and cylinders gets a small crack there .They may have fixed this problem by now time will tell weather fixed or not . You watch all the jab owns attack me on the this site but not care as they have a lot more then I have to lose as they get reliving the dream first hand of this problem . But people on site take personal offence on any faults reported or warning to any thing they fly . For warned makes you for armed to check and keep a eye on aircraft faults. You can take this on board or not, I'm always happy to heard any thing safety related on my aircraft . What is troubling of a lot of aircraft engine used in a private aircraft never seem to make stated TBO with out a rebuild in some way

Edited February 24, 2020 by dan3111

[Yenn]

Do we have any numbers on gen 4 engines? How many are out there and how many have failed and at what hours?

From Nevs statement and my own experience it is clear that running the older Jab engines at higher speeds solved heating problems.

My Corby runs at anything from 50 to 100 plus knots with no overheating problems. That says to me that the jab engine problem must be due to the installation in the aircraft. I am using a modified Jab cowl and the original ducting, so I assume it would be very similar to the Jab installation.

[turboplanner]

Do we have any numbers on gen 4 engines? How many are out there and how many have failed and at what hours?

From Nevs statement and my own experience it is clear that running the older Jab engines at higher speeds solved heating problems.

My Corby runs at anything from 50 to 100 plus knots with no overheating problems. That says to me that the jab engine problem must be due to the installation in the aircraft. I am using a modified Jab cowl and the original ducting, so I assume it would be very similar to the Jab installation.

I just checked RAA reports for the last six months and didn’t find any Gen 4 failures.

 

The older engine failures were intermittent so you can’t say installation is the solution; yours might just be 1 of the many destined for 1,000 hours +.

[kgwilson]

Why is it that the Gen 4 engine has problems that no-one is prepared to verify and none have been reported to Ra-Aus?

[Kyle Communications]

Turbo thats because its all been done without reporting...being hidden from view..its a numbers game so they need to keep the recorded numbers down

 

I doubt that there are many reports on Rotax failures either...so long as a Mayday or PanPan hasnt been called and someone heard it then its pull the covers over to make sure nothing is recorded

[turboplanner]

Turbo thats because its all been done without reporting...being hidden from view..its a numbers game so they need to keep the recorded numbers down

 

I doubt that there are many reports on Rotax failures either...so long as a Mayday or PanPan hasnt been called and someone heard it then its pull the covers over to make sure nothing is recorded

There are two types of failures; one where there is no safety issue with the aircraft, and the other which causes a fire or a forced landing.

With a forced landing there's the possibility of it producing injuries or fatalities.

 

In the first category there isn't any real need for us all to know because the end problem is really a financial one between the customer and the manufacturer.

 

In the second one, it would be worth the people who don't report trawling through the CASA material to find the penalty for not self reporting the cause of a forced landing.

 

They think no one knows but reports go in from several sources including ATSB as you mentioned, the manufacturer, members of the public, and RAA.

 

In the same period that zero Gen 4 showed, there were 13 failures on older units, designated 2200, 2000B, 3300, 3300A, and unless any of those were GEN4, I'd thinkit was doubtful that people would be reporting the older ones but not GEN4. If any GEN4 issues were occurring which fell into the first category I mentioned, I wouldn't see that as an issue.

[Jim188]

Honestly, I would prefer to hear about problems with an unbiased truthfulness. I am happy to hear if barrels are cracking as that's much better than the old days of pistons blowing apart with values coming apart.

 

I would image somewhere along the way Gen 4 engines could have some teething problems. But I think the fundamental design of the Gen 4 is really good start. Barrels cracking are not a new thing to GA aero engines as shock cooling with glider tug work and or some types of flight training have all caused barrel problems in the past.

 

What is a big problem, why aren't these Barrel failure being reported if they are happening. Turboplanner has made some inquiry to RAAus and it seems there is no incident reports about any of them. So if there is truth in all this, who is not putting the reports into RAAus on the Gen 4's, the owners or the L2's?

 

I also made a phone call today, to someone involved with RAAus and they have not heard of any problems either.

[turboplanner]

Turboplanner has made some inquiry to RAAus and it seems there is no incident reports about any of them.

Just a slight correction there; I haven't made any inquiry to RAAus, I just look at the data published by RAAus and it has been quite reliable since I first started looking at it in 2007.

[facthunter]

Unless there's a secret way of getting new barrels( if they are cracking) it would be easy to check with the gen 4 . Failure of barrels at the shrink band was sometimes" expected" with high time radials( even the trusty DC3 P&W 1830) .That was a fatigue based matter. .Where a through stud is part of a design that effect doesn't apply to the cylinder assembly. Most head cracks don't cause engine failure with Lyc or Cont. motors. They get picked up on inspections unless an insert dislodges

. Head to barrel join is best to not have one. (always a potential problem). Smaller sized components are less affected by heat cycles... expansion is a % of something. Bigger gives more. Nev

[Yenn]

When someone posts that there are failures, but will not say where and when, but rather that "they" want to keep it quiet, I wonder about the veracity of their statements.

Telling me Gen 4 engines are rubbish is just not good enough to make me believe it. I need instances to be detailed. So far we do not have any info about how many or what failed.

One question. Is there a cylinder to head joint in the gen 4?

[facthunter]

There was in the first version as well as a long section extending into the head which I thought would make disassembly difficult OR make heat transfer compromised if it was a looser fit.. Nev

[Thruster88]

 

One question. Is there a cylinder to head joint in the gen 4?

 

The cylinder is permanently screwed into the head just like a Lycoming or Continental.

[Corky]

Well, my Jab has never had a water leak, gearbox problems or unbalanced carbies....

What about al the other problems???

[turboplanner]

What about al the other problems???

Why even engage with him, unless he has changed engines he doesn’t have a Gen 4

[kgwilson]

What about al the other problems???

Here we go again. Putting a cork in it would seem quite apt.