Modest Pilot

Couple of points about 4 way valves. First the both on position is usually 180 deg from the off position. A number of Cessna's have tried a takeoff in the off position, the engine often cuts at around 50 feet. The Andair fuel valves have a pull up pin before you can go to off, not perfect but maybe a help. On low wing aircraft with no header tank, with low fuel and the selector in the both position un-porting can occur, air can enter the system and cause at airlock. Vans aircraft kits no longer have fuel valves with a both position after a company employee had an engine stop on final and right off his brand new pride and joy. Apart from the draining on the ground problem on Jabs in the air unless you keep the aircraft perfectly trimmed for yaw (no rudder trim on Jabs) fuel will always drain from one tank first and you will fight a wing heavy situation which is a pain on long flights.

I can't remember the details but Jabiru increased the size of the float cutoff seat in 3300's as some engines showed problems such as yours. Ring Don at Jabiru for the details.

Moree is a popular stop for those coming from the North. BP card required but the agent usually is there prior and after Natfly and takes cash or Credit cards.. It's around half way if you are coming from YCAB. You will find it a little to the west of the direct track, but this will keep you away from the High terrain and the trees south of Wee Waa.

Check the brass plug below the butterfly valve. The one you use for the manifold pressure gauge.

That's it Jaba. Took me all day, it's hardly worth removing the engine, as the time works out greater. The factory have it down to about 3 hours with two guys on the aircraft. Hint: a stud clamp would be handy, saves having to double lock stop nuts to stop the stud turning when you put( or take off) the first nut. I was probably over cautious and did one nut at a time, which meant that you have to wait 10 minutes or so to let the Locktite set up and not let the first nut turn, so that's 2 hours gone. You might be able to set up a sequence that's faster and not risk distortion of the case. I spent the time cleaning the lead build up off the heads! It's worth doing an oil change as the cowls are off, taking off the oil filter and adapter, gives a better swing for the Torque Wrench on the lower forward nut. Also the new ratchet torque wrench's are hopeless for this job; you need to keep the crows foot adapter at the same angle for the correct torque. I would not do this job with a non certified wrench either. Having said all this I must add that this is one of the nicest and easiest engines I have worked on.

There is also a cheaper Locktite with similar specs available, but beware as the temperature rating is to low. Also the latest 620 containers breathe and have a much longer; if any; use by date.

To replace the barrel nuts the Heads and the pushrods and their tubes have to come off to reach the lower nuts.

All bolts stretch it's just a question of how much, it depends on a lot of things including the tempering. A lot of time and money is spent finding out how much! If you think about it, an aircoooled aircraft engine has a whole bunch of different metals madly expanding and contracting a different rates. The pretensioning and a calibrated turn would be ideal. I guess cost will rule it out for low volume production.

My engineer brother put me on to the new electronic strain gauge activated torque meters. I bought a 3/4" drive certified one (0% to +1/2% error) on the net that does 20ft/lb to 60 ft/lb for $50 bucks. Gives LED warning lights green, orange , red as well as the LCD read out. Stores the last 50 readings. I agree there are better ways to tighten bolts (check a Falcon auto manual on how to tighten the head bolts and you will get the picture) but you may as well start with a decent tool.

Hope I'm wrong but the plenum chamber still looks on the small size. My J230 is updated as follows: 290 needle jet and new needle to match, flow straightner, and the biggee 3/16" equalizer vent and 3mm emulsion tube holes. The latter brought the EGT range down to 650-680 F at 2800 rpm 20" MP and 23lt/hr with a Senesnich 56" pitch prop. at 2000' and 23 deg OAT. T/O really gets up and goes @ 42 lt/hour F/F and even lower temps. Had to reset the idle down from a little over 1000rpm; Seems smoother from 850 rpm-3300rpm than before. Starts going rough below 800rpm. So unless the new plenum offers a huge improvement I think that wraps up my tuning efforts for a while.

Be aware that if you change the factory prop you may have to re jet the carb, it's a bit tricky I'd talk to Don at Jabiru first. You need EGT and CHT's to make sure that you don't go to lean, you will probably need to cruse at higher cruise rpm to keep the EGT's down.

That's exactly what is about to happen. A new rudder is awaiting certification. No more flat sides. A more efficient 12% chord standard NACA airfoil. The J230 will get the same treatment if all goes well. Makes the aircraft feel nicer to fly.

An unexpected increase in manifold pressure turned out to be a minute crack in the tube at the take off point. It's located right under the butterfly valve. Interestingly the EGT spread narrowed to 10-15F, with a minute increase in overall temp's. Jabiru think it maybe turbulance create on the opposite side of the carb from outlet of the atomizer. It gave a constant 3" less reading accross the cruise/climb range. Jab are still working on the new manifold at this stage you will likely need new or modified inlet pipes to fit it.

Easy enough to get to Lax. There are heaps of good value airport hotels if you want to take a break. The flights tend arrive early morning giving plenty of time to wander around to Southwest Airlines. They usually stop once so if you get one through a close stop like Las Vagas you can grab a good seat by the overwing exit (lots of legroom) as deplaning pax get off! They have 4 services a day to Gen Mitchell Field Milwaukee, (costs around $500 return) much quieter than O'Hare and cuts an hour and half off the trip to Oshkosh. Also you just walk across the road to get a rental car avoiding the dreaded shuttle bus! This is worth considering as they do road works in summer and the turnpike from O'Hare can be like the harbour bridge in peak hour. I'd also recommend the EAA hotline and stay with an America family, most houses are airconditioned and it can be stinking hot and humid in summer; might even score a swimming pool if you are lucky. The locals are friendly and will more than likely take you to places that you would never find on your own.

One thing to keep in mind is that if yopu use carb heat, use it for at least a minute as per ops manual. This avoids the posibility of re- freezing. Just how cold the manifold can get was bought home recently on my mates 180HP J250. It has two Bing Carbs and a large x-over balance tube. The temp up here has been in the 30c range but with 90% humidity. The crossover tube gets no Carb Heat and has been freezing to the touch with frost all over it. (and you know how hot a Jab gets under the engine cowl!)