So as some of you may already know, I own an Arion Lightning with a Jabiru 3300 engine. The engine had 700 hours on it when purchased a year ago. About 3 months ago I became aware through some new facebook and other online forums that user groups had sprung up for the gen 1-3 engines because the factory had suspended parts support for the majority of engines in the field after launching their "Gen 4" engines which share virtually no common parts with its predecessors. Jabiru engines have earned a reputation for being unreliable and being unable to generally make their claimed 1000hr to top overhaul. In fact many engines start with top overhauls with as little as 300 hours and few seem to make it beyond 700 hours without needing significant work.
As airplane owners know, the value of your airplane is strongly connected to the value of the engine sitting on its nose and the amount of life left in that engine before it needs significant /expensive work. Given that my engine is pretty much pooped and could really do with that top overhaul sooner than later, that means that its current value is not much more than about $2k, especially in a market where you cant go to Jabiru and buy spares. No cylinders, no heads and no pistons (at least not unless you are willing to bore out all 6 of those irreplaceable cylinders and throw away any chance of doing a second rebuild later) Yes the engine was planned as a 2 cycle engine. After 1 top overhaul and then a major overhaul involving the bottom end too, then after that its just for the junkheap or yard art... So, one can basically deduct about $20k from the price of the airplane and then probably throw in another $3-5k for the labor of installing an exact replacement.
OK, there is no way in hell I am giving Jabiru another $20k of my hard earned money, because they may play this exact same game a few years in the future when they introduce their gen 5 engine. So I will find another way. That way is: Rebuilding a 160 hour core engine that I obtained for $2k + shipping. It was used in developing a supercharger installation for this engine and was retired when 1 cylinder came up low on compression. Just like what happened to my engine at my recent conditional inspection, except in my case it was at 700 hours, not 160. However I think that it is probably worth putting time and money into the 160 hour engine, while leaving the original engine in the airplane and it continuing to be useful in my wifes PPL training program.
So here is the plan: Given this is an officially orphaned engine, with virtually no factory support, I am going to have to find pistons, rings, potentially cylinder heads from aftermarket/automotive sources. It is rumored that Shadowlite in ZA have had cylinder heads made by a 3rd party due to the factory stopping production. While I am at it, I will give the engine multi point fuel injection and variable timing electronic ignition. The factory PM alternator was already removed previously so now I can remove everything associated with the weird aluminum multi piece flywheel and replace with a single piece CrMo flywheel with trigger wheel incorporated for clock timing for the engine controller. Im going to remove both distributors and the mechanical fuel pump. The carb will be replaced with a throttle body and a manifold pressure transducer. One of the distributors will be replaced by a backup alternator which is capable of running all of the engine systems. The primary alternator will be the Rotec Denso alternator driven by a V belt. The backup alternator will be unloaded (freewheeling) until it is called to action due to some sort of problem.
Im going to have to see what the options are as far as cylinder heads. The gen 2 heads have to be re-torqued every 25 hours (current oil change interval). One of the reasons for the short oil change interval is that the oil runs very hot and the piston and heads also run very hot and these parts tend to coke oil. Rings jammed in their grooves through coked oil are the main reason why cylinders develop low compression. The other is that if the head gets too hot the clamping force of the fasteners will plastically deform the head with the result that valve clearance diminishes and has to be constantly adjusted (every 25hrs with solid lifters in some cases). Rotec offers liquid cooled heads, and they definitely seem to resolve the cooling problem both for the heads and the cylinders (through conduction) but Rotec does not seem to have a stellar reputation for quality control. Another factor besides heat is lead. Jabiru engines run hotter than Lycomings and thus the lead fouling combines with the carbon in helping immobilize the rings. I'm fortunate that I have 94UL fuel within 15 min flight time of where the airplane is hangared, so while it may not help on a long cross country flight, from a training flight point of view it can all be done on UL fuel which I am sure will make a significant difference to the health of the engine.
Timeline: I should receive the engine in the next month, it is being shipped from near Tucson AZ. Then complete tear down. Then reverse engineering. I am probably going to have to upgrade the case bolts from 3/8 to 7/16". The condition of the unobtanium parts (cylinder heads and cylinders) will be carefully examined. The crankcase halves will be examined for fretting. If that is the case it has to go to Shelbyville for machining followed by line boring to get everything flat and the crankcase bore circular again. Will have to be quoted first... Will obtain the forged Mahle pistons which then have to be machined for circlips since the piston pin is floating in the Jabiru design where it was a press fit in its original Buick application. Rings to match the pistons. Hopefully all the cylinders are OK, they will be honed so that the new rings will bed in properly.
I have corresponded with a local pilot who owned a brand new Lightning LS-1 SLSA and who had to put it down in a freshly plowed field when the engine quite while descending due to carb ice. It just seems that in this day and age we have better and safer options. Its not as if these old carbs are cheap, they certainly are not. The original Bing on this aircraft could only adjust the mixture to 5000ft, after that is was basically going to be too rich. Now add in a "hackman" mixture adjustment system and you still need an anti carb ice system and it all failed this guy, it was too far gone by the time he realized what was going on. So the EFI system will resolve that and also allow a proper uniform mixture to each cylinder with automatic correction of the mixture based on the manifold vacuum and a manual mixture override for leaning in cruise. No cables, no hoses, no pressure loss in the intake system and definitely no carb ice.
Thats it for now, next post when we get the donor engine.
As airplane owners know, the value of your airplane is strongly connected to the value of the engine sitting on its nose and the amount of life left in that engine before it needs significant /expensive work. Given that my engine is pretty much pooped and could really do with that top overhaul sooner than later, that means that its current value is not much more than about $2k, especially in a market where you cant go to Jabiru and buy spares. No cylinders, no heads and no pistons (at least not unless you are willing to bore out all 6 of those irreplaceable cylinders and throw away any chance of doing a second rebuild later) Yes the engine was planned as a 2 cycle engine. After 1 top overhaul and then a major overhaul involving the bottom end too, then after that its just for the junkheap or yard art... So, one can basically deduct about $20k from the price of the airplane and then probably throw in another $3-5k for the labor of installing an exact replacement.
OK, there is no way in hell I am giving Jabiru another $20k of my hard earned money, because they may play this exact same game a few years in the future when they introduce their gen 5 engine. So I will find another way. That way is: Rebuilding a 160 hour core engine that I obtained for $2k + shipping. It was used in developing a supercharger installation for this engine and was retired when 1 cylinder came up low on compression. Just like what happened to my engine at my recent conditional inspection, except in my case it was at 700 hours, not 160. However I think that it is probably worth putting time and money into the 160 hour engine, while leaving the original engine in the airplane and it continuing to be useful in my wifes PPL training program.
So here is the plan: Given this is an officially orphaned engine, with virtually no factory support, I am going to have to find pistons, rings, potentially cylinder heads from aftermarket/automotive sources. It is rumored that Shadowlite in ZA have had cylinder heads made by a 3rd party due to the factory stopping production. While I am at it, I will give the engine multi point fuel injection and variable timing electronic ignition. The factory PM alternator was already removed previously so now I can remove everything associated with the weird aluminum multi piece flywheel and replace with a single piece CrMo flywheel with trigger wheel incorporated for clock timing for the engine controller. Im going to remove both distributors and the mechanical fuel pump. The carb will be replaced with a throttle body and a manifold pressure transducer. One of the distributors will be replaced by a backup alternator which is capable of running all of the engine systems. The primary alternator will be the Rotec Denso alternator driven by a V belt. The backup alternator will be unloaded (freewheeling) until it is called to action due to some sort of problem.
Im going to have to see what the options are as far as cylinder heads. The gen 2 heads have to be re-torqued every 25 hours (current oil change interval). One of the reasons for the short oil change interval is that the oil runs very hot and the piston and heads also run very hot and these parts tend to coke oil. Rings jammed in their grooves through coked oil are the main reason why cylinders develop low compression. The other is that if the head gets too hot the clamping force of the fasteners will plastically deform the head with the result that valve clearance diminishes and has to be constantly adjusted (every 25hrs with solid lifters in some cases). Rotec offers liquid cooled heads, and they definitely seem to resolve the cooling problem both for the heads and the cylinders (through conduction) but Rotec does not seem to have a stellar reputation for quality control. Another factor besides heat is lead. Jabiru engines run hotter than Lycomings and thus the lead fouling combines with the carbon in helping immobilize the rings. I'm fortunate that I have 94UL fuel within 15 min flight time of where the airplane is hangared, so while it may not help on a long cross country flight, from a training flight point of view it can all be done on UL fuel which I am sure will make a significant difference to the health of the engine.
Timeline: I should receive the engine in the next month, it is being shipped from near Tucson AZ. Then complete tear down. Then reverse engineering. I am probably going to have to upgrade the case bolts from 3/8 to 7/16". The condition of the unobtanium parts (cylinder heads and cylinders) will be carefully examined. The crankcase halves will be examined for fretting. If that is the case it has to go to Shelbyville for machining followed by line boring to get everything flat and the crankcase bore circular again. Will have to be quoted first... Will obtain the forged Mahle pistons which then have to be machined for circlips since the piston pin is floating in the Jabiru design where it was a press fit in its original Buick application. Rings to match the pistons. Hopefully all the cylinders are OK, they will be honed so that the new rings will bed in properly.
I have corresponded with a local pilot who owned a brand new Lightning LS-1 SLSA and who had to put it down in a freshly plowed field when the engine quite while descending due to carb ice. It just seems that in this day and age we have better and safer options. Its not as if these old carbs are cheap, they certainly are not. The original Bing on this aircraft could only adjust the mixture to 5000ft, after that is was basically going to be too rich. Now add in a "hackman" mixture adjustment system and you still need an anti carb ice system and it all failed this guy, it was too far gone by the time he realized what was going on. So the EFI system will resolve that and also allow a proper uniform mixture to each cylinder with automatic correction of the mixture based on the manifold vacuum and a manual mixture override for leaning in cruise. No cables, no hoses, no pressure loss in the intake system and definitely no carb ice.
Thats it for now, next post when we get the donor engine.
