deadstick

DeadstickQuestion: If the float level was the problem, would not the problem also occur with the electric pump???

Also if an obstruction such as the finger filters was the cause would it not also occur with the electric pump??

 

I'm certainly open to suggestions - just checking if my logic is right.

 

Given the problem did not exist before the new installation my thoughts are something other then fuel blockage/restriction?

 

The float level certainly fits this thought process, but what are your thoughts about it being ok on the electric pump?

Hi frank, I understand what your saying, if it's starving at full power there's not enough volume of fuel being supplied, the gravity feed is effected by the finger filters being partially blocked, there is a minimum requirement for the mechanical pump to work( it's in one of the manuals) have you done the gravity flow test? The float seat is a long shot and it does behave slightly different under pulse flow( mechanical pump) and constant ( facet boost pump) if it's set just a touch lower than standard it has the effect of leaning the mixture slightly, if it gets lower and the flow isn't enough to keep the head of fuel available you get a lean cut. Just about every jabiru that has minimal fuel in the tanks ( no head pressure)will flash the fuel PX light on mechanical pump alone. Can you blow through the fuel tank vents in the fuel caps as a blockage can cause poor gravity flow? Check all the basics first ( vents fuel tap fully open etc) then check for flow as per the manual. Check the fuel level in the header tank. Where are you located? I'd've happy to assist if your nearby.

 

 

Have you performed the gravity feed check? cant remember what the figure is but with the hose disconnected at the firwall it should flow so many litres an hour. This will and has caused the symptoms that you describe, in the wing fittings there are finger filters, also check the fuel float seat for correct height.

 

 

Was there any mention of price on the 3300?

 

 

For Anyone that was at Natfly and attended the Camit stand: - what's the cable system bolted to this 3300 crank case?

 

 

 

What about 2-3 psi from a small turbo? would that help normalise the uneven mixture distribution?

 

 

Im heading down, departing Tamworth 0700 Friday returning that afternoon, weather looks to be great on Friday

 

 

Yes none of the tweaks really worked very well, even higher cost like new plenums etc did little in sorting it out. Anything BUT repeatable!I did ask Ian a while ago but dont think he had achieved much either.

I do know lots of hours has gone into sorting this problem out with little result. By design, having plenum end fed by basic carb isnt a good position to start with in getting even flows.

 

Isnt a new issue auto makers struggled for years getting carb plenums and runners working right, if their R&D budget couldn't sort it out what hope does Jabiru or Camit have?

 

Auto makers love multipoint EFI as many of these issues including average design, poor grade fuel, cold starts, altitude and hot weather problems just disappear.

 

I still believe much of Jabiru failures can be linked to detonation and overtemp running. EFI solves much of it.

Jetjr, I have developed a theory over the years dealing with split EGT's and unrepeatable results, it really only twigged when I heard from an operator of the solid lifter engine that his EGT's some split are always the same. It occurred to me that not all Hyd lifters are the same! one lifter to another may have slightly different characteristic's, some pump up fast others slower, tolerances are just that a limit for uneven duplication, so I theorised that each valve is seeing a different amount of lift or slight delay, I noticed on inspection that lifter preload is different across the lifters. just a theory!

 

 

Hell! were you on board? was it Mittagong? memory is foggy... Hmmm yes, there are L2's and there are L2's, its like any industry.

 

 

Seriously thinking of attending Natfly, 2.1 nil wind from my place, but that's got a bit of tiger country in it, so I may well fly an arc, paddock hopping all the way. Is your project an ex engine, hard landing by chance? ( pm )

 

 

Lol, I didn't expect to have any of the failures I've had. Good luck with your project mate .

 

 

Just looked at the original pic, lot clearer. No chewed up teeth or tips missing. There are lots of hypothetical causes but given the statistics of failure previously probability dictates the cause is the same. It will happen again and again and again until the engineering is robust enough to cancel out the cause when it presents. Interestingly the engineer said the dowels were still ok and straight, so I would think torsion ( detonation, power pulse, prop stile etc) wasn't the cause. Some sort of harmonic and bolt stretch due hammering would be my stab, and it's just that... A guess, it's certainly above my pay grade!!!

 

 

Don't understand what you mean by the "perhaps it's just buried somewhere" do you mean in the design?

 

 

I have had no end of trouble with the wooden jab props, same issue as you and delamination, went to the sense inch on the 230 and what a massive difference. The 160 has the jab wood laminate prop, a few minor issues but still tracking ok, spent a lot of time getting the track and spinner true first of all, but have noticed over the years that they like half the weight required spread either side of the light point, giving two nodes. I'm intending on putting the transducer near the flywheel soon to see what the difference is front to back.

 

 

Here's what I achieved on my 2200, to do it I had to balance with two weights separated either side of the low spot.

 

 

 

Oscar, The stud broke because of incorrect nuts, they have admitted that and warranted that part of the overhaul.

 

 

Oscar, if jabiru didn't change this bolts during overhaul then they certainly have violated their own manual. Install of that engine was as per the manual as all ways, inclusive of the propellor. The environment at Nowra is very corrosion friendly and that level of corrosion is not uncommon.

 

 

Oscar, I seriously doubt jabiru would reuse old bolts. Surely their quarantine is a lot better than that. The info from the contrails site is an interesting read. I change flywheel bolts at every 500 and any chance I get really, equally important though is continual inspection of the prop bolts and balance up front. Any vibe at the prop flange is very large by the time is gets to the rear of the crank.

 

 

Looks like it flew for a while with a few broken! Given that all are rusted except one freshly sheared bolt. Some are bent to by the looks, wonder if that happened before or after.

 

 

Here are some images of a friends 2200 fitted in her 24 rego J170, she found this on her pre flight after pulling the prop through and it feeling strange. This engine has as far as Jabiru engines go been fairly good, with only major work a broken through bolt repair, new cam and 'Top end' 278 Hrs ago at 839 TTIS. Looks like the latest configuration of the dowels too...

 

 

 

 

 

 

 

 

Comp,

 

I have seen this on multiple Jabiru engines and to some extent every Jab engine that I have stripped, the culprit historically has been the barrels being out of round from overheating and unequal cooling, the only fix is a full top-end. One engine had only done 100 hours!

 

On a side note, whoever does your topend, ask them to finish hone the cylinders with a dummy head torqued down, another common issue is cylinder distortion at the top of the stroke due to the head bolt torque, I see it on every jab cylinder.

 

 

I have dealt with cammit and have no problems recommending them to anyone, fast efficient service and no bullshit.

 

 

Kyle, I would pay money for a seafury that size, how do I go about getting one?

 

 

Fatal Gyro crash this morning.

 

http://www.southcoastregister.com.au/story/2153065/man-killed-in-gyrocopter-crash/?cs=203

 

 

Puddles, I asked the same question to the powers that be! For a C model factory built you can fit the exact same cammit engine parts and remain 24 rego'd. The D models are different due to the factory being the engineering authority. For a 19 rego'd aircraft you can fit whatever you like.