whee wrote:

Bear_Builder wrote:If having a dead battery is such a fear with an injected engine, then why not install a back-up battery? With the new Lithium batteries ( http://aerovoltz.net/en/aervoltz-4-cell-lithium-battery ) it would add less than a pound. Wire it so it charges when the engine is running, but with a diode inline to prevent it from discharging. Add a bypass switch to run the booster pump if the main battery is dead. Heck, for 3 or 4 pounds you could add one big enough to crank the engine!

Since I'm planning to run dual electronic ignition this is exactly what I plan to do with my ignition circuit. If I end up with a dead battery in the middle of nowhere, I can flip a switch and hand prop it. Or if the alternator craps out a thousand miles from nowhere, I have that much more reserve power to keep the fan turning till I get back to civilization.

Phil
Electrical Engineer.

How bout we leave the magnetos and mechanical fuel ejection and install larger fuel lines that feed the positive displacement engine driven fuel pump so enough head is provided by gravity that no boost pumps are required. No need for a backup battery or any battery for that matter.

Jon
Mechanical Engineer

Sorry, couldn't resist

These sound like a good engine and seems like one would fit my needs nicely.

If gravity will provide enough pressure for a FI engine to start, then I'm all for that. All mechanical systems fail eventually, but gravity never has. I'm keeping an eye on the Rotec mechanical TBI system, that sounds like a great compromise between simplicity and the performance of a MPI system. But I'm sticking with an electronic ignition, at least until I can find a mag. that has variable timing based on RPM and MAP.

Phil

Phil, I was just ribbing you.

gbflyer wrote:Dump Truck Engineer

Probly the best kind of engineer their is...well maybe second to Farmer Engineer.

There is a later, BIG bearing model 'B' in the MN.

At higher altitudes, lower octane fuel will do the job, so, if at sea level, keep one tank of 100, then switch to Mogas at altitude. If live at say, 5,000', then can use Mogas all the time. I don't have any hard numbers on this, just check the auto gas octane on the gas pumps for cars. Less oxygen at altitude, therefore, makes less heat, slower burn.

8GCBC wrote:

Battson wrote:

gbflyer wrote:I don't think arguing that a FI engine isn't as good for back country is valid.

+1 from me,

Provided you can prime the engine (carry a teeny-tiny spare 12V battery) then I can see no disadvantage at all.

Just curious... How many hours do you have behind xxx540 engines?

I have over a 1000 in a injected M6 Maule, 98% in AK. If you are worried about priming an injected engine if your battery is dead and if you do it often enough you can add a hand primer!, Also one of those little bitty wallmart jumper battery's for $29 bucks will save your butt.

8GCBC wrote:

Battson wrote:

gbflyer wrote:I don't think arguing that a FI engine isn't as good for back country is valid.

+1 from me,

Provided you can prime the engine (carry a teeny-tiny spare 12V battery) then I can see no disadvantage at all.

Just curious... How many hours do you have behind xxx540 engines?

Not tonnes, 100 PIC for the one I installed + uncounted more as passenger in GA installs .

Battson wrote:Not tonnes, 100 PIC for the one I installed + uncounted more as passenger in GA installs .

I do not want to imply to much theory in my post (which takes restraint at times). But...

Everybody has a different scenario and a different aircraft. What makes me happy is my good old 0-360 (and hopefully I can afford it). I love many fuel injected and turbo engines. But, only when the mission requires it. For what I do now the Scout is my favorite.

I have about 500+ PIC in Aero Commanders, Aztecs, and Navajos (MEI, ATP, A&P, CFII) I soloed in 1976. And flew model airplanes and gliders from age 12.

Did you ever have any issues keeping the injectors clean in a (T)IO-540? Maybe it's just me but, the nozzles seem to clog about every 300-500 hours. Most engines were high time however. The maintenance manuals usually call out scheduled cleaning of the nozzles.

I love your airplane and obviously you know exactly what you need. I fully admire what you have done!

Most if not all fuel injected engines run an engine driven fuel pump. SOME fuel injected airplanes also are equipped with a primer. The Cessna 185 and 206 had a primer as an option. A very useful option. If your battery is dead in the boondocks, you can prime the engine, and prop it, and off you go.

As to contaminated injectors, I flew fuel injected airplanes for over 10,000 hours, and never had a fouled injector, except in one airplane....a new Cessna 1985 185. That airplane fouled injectors regularly between 100 hour inspections for the first 300 hours of its life, after which apparently all the "gunk" installed in that airplane's fuel tanks by Cessna was passed through the system. I flew that airplane an additional 3000 hours, and it never fouled another injector.

Simple solution: Don't put crap in the tanks, use clean fuel, and you'll not foul injectors. And, by the way, I put a lot of five gallon cans of gas in that 185 as well.

MTV

mtv wrote:Most if not all fuel injected engines run an engine driven fuel pump. SOME fuel injected airplanes also are equipped with a primer. The Cessna 185 and 206 had a primer as an option. A very useful option. If your battery is dead in the boondocks, you can prime the engine, and prop it, and off you go.

As to contaminated injectors, I flew fuel injected airplanes for over 10,000 hours, and never had a fouled injector, except in one airplane....a new Cessna 1985 185. That airplane fouled injectors regularly between 100 hour inspections for the first 300 hours of its life, after which apparently all the "gunk" installed in that airplane's fuel tanks by Cessna was passed through the system. I flew that airplane an additional 3000 hours, and it never fouled another injector.

Simple solution: Don't put crap in the tanks, use clean fuel, and you'll not foul injectors. And, by the way, I put a lot of five gallon cans of gas in that 185 as well.

MTV

Seems like you fly ever airplane nearly perfectly. As usual.

Were the injectors cleaned IAW service instructions? There must of been a cleaning schedule, if you had that many hours. You seemed to be rather blessed. My guys were never that lucky.

8GCBC wrote:Did you ever have any issues keeping the injectors clean in a (T)IO-540? Maybe it's just me but, the nozzles seem to clog about every 300-500 hours. Most engines were high time however. The maintenance manuals usually call out scheduled cleaning of the nozzles.

Thanks for the kind words.
The fuel system has 4 strainers at the tanks, gascolator after the selector, filter before the boost pump (/primer), and the fine-gauze 'last chance' filter in the servo. I've never seen anything except lone lint fibres in the last chance filter.
At this rate, I hope to put over 200 hours on the plane this year, most of it just having fun in the back country so if the fuel injection does give any grief, I reserve the right to change my mind!

Right now, burning 8-9 gal/hr & not worrying about carb ice is making me happy, so I say it's a good thing. Clearly YMMV.

Sorry Whee, this is about 100NM off topic.

Battson wrote:

8GCBC wrote:Did you ever have any issues keeping the injectors clean in a (T)IO-540? Maybe it's just me but, the nozzles seem to clog about every 300-500 hours. Most engines were high time however. The maintenance manuals usually call out scheduled cleaning of the nozzles.

Thanks for the kind words.
The fuel system has 4 strainers at the tanks, a b after the selector, filter before the boost pump (/primer), and the fine-gauze 'last chance' filter in the servo. I've never seen anything except lone lint fibres in the last chance filter.
At this rate, I hope to put over 200 hours on the plane this year, most of it just having fun in the back country so if the fuel injection does give any grief, I reserve the right to change my mind!

Right now, burning 8-9 gal/hr & not worrying about carb ice is making me happy, so I say it's a good thing. Clearly YMMV.

Sorry Whee, this is about 100NM off topic.

Whee is really cool and forgives easily!

FI and Turbos are wonderful. They require "a little to much effort" ($) for my personal flying scenario. I miss my Aztec, there will never be a stronger light twin made. And the IO-540 is a major workhorse, I would fly one anywhere any time.

I truly appreciate your airplane more than you can imagine ! Fly strong!

8GCBC wrote:

mtv wrote:Most if not all fuel injected engines run an engine driven fuel pump. SOME fuel injected airplanes also are equipped with a primer. The Cessna 185 and 206 had a primer as an option. A very useful option. If your battery is dead in the boondocks, you can prime the engine, and prop it, and off you go.

As to contaminated injectors, I flew fuel injected airplanes for over 10,000 hours, and never had a fouled injector, except in one airplane....a new Cessna 1985 185. That airplane fouled injectors regularly between 100 hour inspections for the first 300 hours of its life, after which apparently all the "gunk" installed in that airplane's fuel tanks by Cessna was passed through the system. I flew that airplane an additional 3000 hours, and it never fouled another injector.

Simple solution: Don't put crap in the tanks, use clean fuel, and you'll not foul injectors. And, by the way, I put a lot of five gallon cans of gas in that 185 as well.

MTV

Seems like you fly ever airplane nearly perfectly. As usual.

Were the injectors cleaned IAW service instructions? There must of been a cleaning schedule, if you had that many hours. You seemed to be rather blessed. My guys were never that lucky.

It has nothing to do with how I fly airplanes. It has everything to do with using clean fuel. And, since these. Airplanes were operated commercially, they were subject to 100 hour inspections. Nevertheless, if you've had as many fouled injectors as you suggest, you well know just how rough an engine with a fouled injector actually is.....like you're looking for a place to land, or in a twin, you're shutting the engine down. It's not something that is found at periodic inspections.

What is found at inspections is junk in the screens, as noted by Battson. It is certainly good practice to check and clean those screens periodically, but if you're getting fouled injectors that frequently, someone needs to look at your fuel sources, and maintenance.

Injected engines operate tens of thousands of hours and more every year, and I'd bet that if you ask the pilots who fly those airplanes regularly how often they experience injector fouling, the answer will be "rarely". Sorry, 8GCBC, but injector fouling just isn't as common as you suggest.

And, in case others want to know what a fouled injector does, it causes your airplane to shake like a dog shitting peach pits.....

MTV

What I have seen is a rise in fuel pressure and higher than normal CHT/EGT on the clogged injector. The feel of the airplane was completely the same. Never had a violent reaction. IO-540.

Injectors will not clog if they are maintained. Injectors will clog if they are not maintained. That's all. It is not complex.

TBO - For whatever it is worth, we've got +1850 hours on an IO-360 on the M5 and it is making good compression and making no metal (yet)

Oil Analysis done each oil change and we try to be gentle on power additions and reductions. nice engine… be nice to me…(picture petting a dog). Also try to fly it every 10 days, if possible, to avoid sitting-around-itis.

I'm no engine expert but do operate the engine in question…took me a while to get the hot start thing figured out. Better now.

good luck Whee.

whee wrote:I felt that the 180hp lyc O360 was sufficient for me in a Bearhawk and I don't want the extra weight of a 540.

I struggle with the same question. The 540 is pretty popular on the Bearhawk, but definitely some extra pounds there. The reality though, is, you have 2 kids Your performance is going to dwindle year after year as they grow. The fuel savings isn't much, especially with injected, but the empty weight when solo (and doing fun things) won;t be as favorable.

I fly an O-360 172 right now, 2 of them actually. 1450 lbs vs 1520 lbs. I need more power. I used to fly a Hawk XP occasionally, too. That was a great motor, the IO-360 Continental, at least for the few hours I flew it. Definitely a little snappier, but I think the magic starts to happen around 220hp. The IO-390 is tempting, or rather, the XP-400.

Check this if you are experimental...

http://www.superiorairparts.com/xp-series-engine/engine-models/

The Chinese are standing up to the plate, big time!

8GCBC wrote:What I have seen is a rise in fuel pressure and higher than normal CHT/EGT on the clogged injector. The feel of the airplane was completely the same. Never had a violent reaction. IO-540.

Injectors will not clog if they are maintained. Injectors will clog if they are not maintained. That's all. It is not complex.

If that's all you ever saw, then you never had an injector really fouled. They shake REALLY hard, because one cylinder is not producing any power. You're correct that's what you'll see if you have a wee bit of junk in an injector.

In that 185 that fouled injectors regularly for a while, I carried a kit with me to clean injectors. A number of times I landed quickly due to a fouled injector, and cleaned it, then on my way. That was a VERY rare situation. Turns out someone at cessna left a rag in one wing tank while they were sealing the wet wing, and the fibers from that rag were working their way through the fuel system. We never found the rag, but it eventually worked its way out.

You're right that injectors require a LITTLE bit of maintenance. It takes about fifteen minutes to clean a set of injectors on a six cylinder engine. Clean fuel and preventing contaminants from getting into your fuel system, and cleaning the fuel screens regularly are all key to preventing injector fouling.

Zzz wrote:

whee wrote:I felt that the 180hp lyc O360 was sufficient for me in a Bearhawk and I don't want the extra weight of a 540.

I struggle with the same question. The 540 is pretty popular on the Bearhawk, but definitely some extra pounds there. The reality though, is, you have 2 kids Your performance is going to dwindle year after year as they grow. The fuel savings isn't much, especially with injected, but the empty weight when solo (and doing fun things) won;t be as favorable.

I fly an O-360 172 right now, 2 of them actually. 1450 lbs vs 1520 lbs. I need more power. I used to fly a Hawk XP occasionally, too. That was a great motor, the IO-360 Continental, at least for the few hours I flew it. Definitely a little snappier, but I think the magic starts to happen around 220hp. The IO-390 is tempting, or rather, the XP-400.

There are several BIG advantages to the 540s:

1) Bomb proof engines. Solid bottom end. The 235, 250 and 260 versions are just loafing even at max power.

2) Every mechanic in the country has worked on them. And, lots of parts for them.

3) As engines go, they are relatively cheap. When you consider power, they are about the cheapest engines out there per horsepower.

4) There are LOTS of them out there, used and in good condition.

The four cylinder Lycomings are nice engines, but bring a fat checkbook. There's a reason so many of the go fast homebuilts use the 540s....lots of power, lots of engines, and relatively cheap.

I haven't flown a Bearhawk, but judging from the all up weight, you're going to want some horsepower. Again, you can get some power out of an IO 390 at 210 hp or so, but at that hp, a 540 will cost half as much or less and be loafing along.

MTV

mtv wrote:

8GCBC wrote:What I have seen is a rise in fuel pressure and higher than normal CHT/EGT on the clogged injector. The feel of the airplane was completely the same. Never had a violent reaction. IO-540.

Injectors will not clog if they are maintained. Injectors will clog if they are not maintained. That's all. It is not complex.

If that's all you ever saw, then you never had an injector really fouled. They shake REALLY hard, because one cylinder is not producing any power. You're correct that's what you'll see if you have a wee bit of junk in an injector.

In that 185 that fouled injectors regularly for a while, I carried a kit with me to clean injectors. A number of times I landed quickly due to a fouled injector, and cleaned it, then on my way. That was a VERY rare situation. Turns out someone at cessna left a rag in one wing tank while they were sealing the wet wing, and the fibers from that rag were working their way through the fuel system. We never found the rag, but it eventually worked its way out.

You're right that injectors require a LITTLE bit of maintenance. It takes about fifteen minutes to clean a set of injectors on a six cylinder engine. Clean fuel and preventing contaminants from getting into your fuel system, and cleaning the fuel screens regularly are all key to preventing injector fouling.

I fully believe what you say. If we have clean fuel, and scheduled maintenance an injector will never clog. But, those variable may change and it is important to have the knowledge to detect and mitigate a clogged fuel injector in the backcountry. If properly maintained injectors should perform reasonably well. It is easy to f up and injector by cross threading too. Never done it but, aluminum heads are soft. Mechanics have mentioned it does happen. Thanks.

There are decommissioned XXO-540 all over Honolulu. Everybody went to Caravans etc.

You need a old IO-540? ... come to Dauphin Aero, 100 Kaulele Drive. Deals are to be made for sure!

just a word about mo gas since it gets discussed here for the IO 360.... not approved for the IO 360..if it was I would have gotten the stc long ago... and if you go to the back country. make sure you have a fairly new battery... I don't go to the back country without a fairly new battery...no problems... starts every time....hot starts have never been a problem anywhere at any altitude...I also have a lightweight starter that spins it over quite well, better in fact than the original... so make your own decisions on the IO 360 but I love mine....one other suggestion for an upgrade might be Gami Injectors... but then that's another discussion....