Sean

Have you gotten any feedback as to the two "FLAMEOUTS" at Waco? You said the engine data had been sent to jet Central and I was just curious as to facts which may have been discovered. Were the two related in any way?

Still working on it. The data supported the position that the throttle position never changed, the RPM's dropped, and the fuel pump voltage increased. Thus causing the tailpipe fires.

However, there appears a chance that I caused the problems over time feeding too much propane into my engines over time. Something I had no idea could cause a problem.

When all of the data comes back, and the engines have been inspected and wheels placed in a micrometer and checked out, I will start a new thread in the jets section describing what happened, and how others can gain from my experiences.

For years I have been stupidly telling other modelers to follow my lead on propane starts. So far my advice has been sounds except for one detail. The object of a good safe start is to use as little propane as possible to get the engine going.

Again, this will all be explained in great detail in about two to three weeks in the jets section.

I sent all four of my engines down to Mexico to be reviewed, and have had multiple conversations with Felipe about them.

We have both agreed that whatever the causes we will get down to it and come up with a plan for this not to happen again.

Also, keep in mind that the weather conditions at Waco were extrememly HOT. When Artes sets an engine ramp up speed, they do so at 6000 MSL and try to set for the whole world. I'm certain that on that particular day, my engine ramp up speed was too agressive for that day. That also played a lot into the issues I had.

So stand by, I'll share it all once I know for sure.

Sean

Sean: Any chance of Water contamination, From Condensation?

Thanks for the update. I'm sure you guys will figure it out and learn something in the process!

Not a chance. The fact is, when I go to a jet rally, I usually haul 6 jets, 60 gallons of fuel, spare engines, asseccories, etc. All four of my Artes Engines failed at the Waco Jet rally in one form or another. For now, I am taking the blame for this at least until my engines are placed in a micrometer. Two of my engine failures were on startup, and two were in the air. The failures in the air were almost certainly due to a too agressive pump setting for that particularly HOT day!

The other two failures were almost certainly due to too much propane during startup.

At first there was a suggestion that there was a fuel problem.

This can not be, the same fuel was flown 15 gallons through a P-200 same weekend, and about 5 gallons through a P-70 same weekend, and about a gallon through a P-120. Before my Rhino quit in flight, I had 10-15 gallons through it the first few days of the Rally (Tuesday through Friday).

A friend of mine loaned me a P-70 for my F-86 and I flew that no problems.

These Artes engines are good engines, no doubt about it, I have 500 flights on them easy. The tolerances on them are tighter than other manufacturers which gives you more thrust for the same size engine than say jetcat. However, you run into potentially more problems over time than jetcat.

It's like the difference between a Ford Taurus and a 67 corvette. Which is faster, but which is more reliable does not require working on maint, or taking care of issues on the weekend.

I'm sure Artes is working on getting to worry free engine performance over time. I'm not worried about any of this at all.

When four engines go out for one reason or another, that's something, when it is all under the operation of ONE GUY? I become the suspect, and I don't blame anyone for feeling this way.

We will know here in a couple of weeks for sure.

What is the hypothesized failure mode caused by too much propane? I am baffled by this?

Hope your brother is doing well. Thanks bro.

Sean, I hope this issues are not concern with the by passing the prop selonid. Some of us when start having problems at the start up just diconect the prop line and jut insert the propane without using the selenoid. If by any reason we have to do this, wich is NOT recomended by the manuf. we still need to use the filter and restrictor, even if we use the regulator cap valve in the coleman bottle. Also important is that we need a one way valve to not causing any pressure difference between the air and propane while starting. This difference in pressures can cause a backdraft causing a reverse flame that can burn the festo conectors and lines inside the cowling. I'm no expert but this is what Juan Ramon told me at the phone last time I was having issues with the gas lines in my eagle. With the new bigger restrictor most of the problems at the starts had been solved. It's a shame that you are having problems with all 4 engines at the same time. [:@] I'm sure that Felipe and gang will take care of you. These engines are more delicate than the other brand we are using. There is not doubt that they are solid, reliable and fast. But care have to be taken with them. I'm very very happy with my engine and the support and service of the factory. Let us know what Juan find in your engines so we can continue taking care of ours. The artes family is growing very fast. Wow, now we have two big good familes. The other one don't have to be mention here. You guys know her very well. Sorry if I still mispeling, you know my english is not the best.

Rgs
Alejandro

Turns out there is laminar air flow in the combustion chamber and the propane line goes and "T's" into one of the fuel injectors on the opposite side of the temperature probe.

IE, when you pump gobs of propane into the engine during startup, one side of the engine is getting hotter than the other during startup and you are not reading the correct temperature.

This can distort the EGV such that the turbine wheel will rub.

Some engine manufacturers pipe the propane line into an even number of fuel tubes so you get uniform heat during startup.

In fact, I found out recently that you can pipe propane to your fuel line and run the engine on propane through all the injectors, obviously this would not be manufacturer recommended.

I have not been using a solenoid on the propane lines for years. All my jetcat engines were started up this same way, and never not even one time did I ever see a rub or a problem with jetcat. This seems to me to be a problem of uneven heating in artes engines.

I did not ask specifically, but I believe jetcat is using an even number of propane lines T'd into the fuel lines, or separate lines completely into the comb. chamber.

Too much propane with too little RPM can give you a "hot start". It's a turbine engine phenomena that happens to full scale engines as well as ours.

I believe that is why they have restrictors and solenoids it to regulate the EGT at start up. Without these items...you have lost your overtemp protection, which usually sooner than later leads to premature failure of the engine.

B

I don't think I was in Texas that week Sean, but I may have overflown it...thats close enough to feel the effects of the Black Cloud.
Sorry buddy, its all my fault[]

I'll have to bring extra beer to Lake Wales just in case I have the same influence.

Freakin Jet blue, you probably dumped the crapper as well, cause pieces were falling everywhere as evidenced in this clip (I'm the F-86, and I nearly hit the debris field).

http://youtube.com/watch?v=DWHCzoaDz_U

That reminds me of IsoBurst at Superman many years ago.

I tried but the heat there melted it all by the time it got to the ground. Besides you like blue and brown tie dyed shirts anyway don't you?