skypics added a topic in Rotax and other enginesGen 4 Jabiru 2200This new engine has improved and resolved all of the earlier issues with the top end of the engine.
1) Smooth idle down to 600 RPM
2) No added oil between il changes
3) Larger cooling fins keep CHTs low
4) Starts instantly without using the choke.
5) Oil stays cleaner longer.
Finally: Why does clicking on some subjects on this forum take me to a pharmacy advertisement?
- 2 replies
- 251 views
skypics added a topic in Rotax and other enginesStuck lifter
I think I have posted about this before, but it needs repeating.
I have pulled the heads on my Jabiru 2200 several times and each time I have had this problem.
The hydraulic lifters on the pulled head do not relax after reinstalling the head.
This causes the valves, sometime only one, but many times both to be partially opened.
You will be able to see this by comparing the position of the valves on the head you didn't work on. They will not be as far out and near the edge of the rocker box edge as the untouched head.
So when you turn the prop by hand you will find one cylinder with no compression. If the intake valve is held open too, you may see one of the other cylinders with no compression because of lack of vacuum.
If this happens you have a couple choices:
A) remove the head again and pull the lifters and soak them to get all the oil out. You should be able to compress them when they are clean.
B) Start the engine and let it run roughly until the oil temperature builds. This can take 5-10 minutes. You should see the EGT start to build on the soft cylinder and then after the oil is heat soaked the hyd lifters will relax and the engine will smooth out.
Flew it for an hour for check out. All is well now.
- 0 replies
- 95 views
skypics added a topic in For Sale and wanted, you got it, I want itZenith 750A friend is dealing with lung cancer and is selling his Zenith 750 powered with 912 ULS.
Engine and airframe have 259 hours.
Sharp looking paint scheme.
Larger tires for the backcountry strips.
He is asking $69K
- 0 replies
- 119 views
skypics added a topic in Avidfoxflyers General HangarTests of new Gen 4 2200It's been just 21 hours so far after installing my new Jabiru Gen 4 2200.
I have flown behind 2200s for over 3,000 hours and in that time I have had a sucked exhaust valve, a displaced valve seat and relined my valve guides 3 times. Of course, this also happens to "real" aircraft engines. That said, I have always thought that while the bottom section of this engine was very robust, the top section had many design flaws caused by inadequate rocker box lubrication.
This causes early valve guide wear which causes sloppy valve positioning which can result in valve head separation.
In contrast to the earlier generations, the Gen 4 appears to have addressed these flaws with;
A) Larger fins
B) Head and jugs are now cast aluminum instead of CNC. This allows tighter tolerances since the piston and cylinder are of the same material.
C) The rocker boxes are lubricated up through the pushrods where the oil moves into the rockers and to the rocker bushings.
D) The engine starts every morning in two blades without using the choke. When warm the engine starts instantly. I believe it may be hand propped. I will try this soon.
E) The engine can idle smoothly at a mere 600 RPM.
F) After tweaking the air duct to fit under my Avid MK 4 cowl, all CHTs and EGTs are well within specs as recently tested on a long climb out from 533 MSL to 9,000 MSL at full power.
G) After 21 hours the oil still looks clean and still is at the dip stick full mark.
H) There is only a tiny bit of water/oil collection in the breather bottle.
I am swinging a Whirlwind 66"two-blade prop.
So far I am well pleased with this engine.
I did have to buy a new engine mount since the new engine moved the top two engine mounts 15 mm to clear the larger fins.
The new mount cost $895. I sold my old MK 4 mount for $300.
Sold my old 2200 for $2K.
The new engine was $15K plus shipping.
- 1 reply
- 108 views