Hello everyone,

I recently purchased a RAM 500 turbine with zero hours of runtime. I have not had any luck getting the engine to run repeatedly. Here is the history of startup attempts:

Day 1

1. Fuel solenoid not opening to release fuel to the turbine. (Removed the fuel solenoid).
2. Successful start. Ran well.
3. Propane ignited, fuel ramp up, turbine did not start, fuel came out of the rear.
4. Propane ignited, fuel ramp up, turbine did not start, fuel came out of the rear.
5. Propane ignited, fuel ramp up, turbine did not start, fuel came out of the rear.
5. Propane ignited, fuel ramp up, turbine did not start, fuel came out of the rear, plug burned out.

Day 2

1. Propaned ignited, not start.
2. Manually fed propane, successful start.
3. Propane ignited, fuel ramp up, turbine did not start, fuel came out of the rear, plug burned out.
4. Propane ignited, fuel ramp up, turbine did not start, fuel came out of the rear, plug burned out.
5. Propane ignited, fuel ramp up, turbine did not start, fuel came out of the rear, plug burned out.

Day 3

1. Propane ignited, fuel ramp up, turbine did not start, fuel came out of the rear, plug burned out.
2. Propane ignited, fuel ramp up, turbine did not start, fuel came out of the rear, plug burned out.
3. Propane ignited, fuel ramp up, turbine did not start, fuel came out of the rear, plug burned out.

My ECU is version 3.0. The settings are:

Low RPM - 50K
Hi RPM - 150K
GlowPlug - 035
PrimePW - 150
StartPW - 78]
Gas - 60

Any ideas?

Thanks,

Chris Wilson

FUEL RAMP IS COMING IN TO SOON.,TOO MUCH.. FUEL STICKS HAVE TO COME UP TO TEMP TO VAPORIZE FUEL.IF NOT ,IT WONT IGNITE..

one possbile thing I learned from my rams is that you cannot run the rpm report wires near any others they must be kept as far apart as possible. Good luck I was a ram dealer and never had any success with our 8 RAM 500s other than one.

Carlos at RTI is the man when it comes to the RAM engines.

786-303-3243

sent you an email.

Hi Chris,
I ran a 500 for many years with good results, but it does take a little tuning to get a good start.

From your settings I would recommend that you raise the glow up to about 45 (that is less heat), which might help the plug burn out.

The start PW is possibly to high, try dropping down to about 55.

60 on the gas sound reasonable but it kind of sounds like your getting to much gas, so raising that might help (that does reduce the flow).

First thing I would try is to take the plug setting up. If you still get ignition then watch the EGT, it should come up smoothly and the fuel ramp begin after several seconds. If the EGT jumps up and the fuel ramp starts in a second or two you have too much gas, go to a higher setting. If it does not reach fuel ramp in about 5 seconds you do not have enough gas, go to a lower setting.

Once the fuel ramp starts keep watching the EGT and the RPM, they should both rise smoothly. If the EGT peaks before idle and then decreases the Start PW is to high, if the RPM hangs for several seconds during ramp the Start PW is a little low. If the EGT rises very rapidly at the beginning of ramp but does not over shoot as it approaches idle then you have too much gas.

When you get it to the point that you are tweaking the settings try bumping the plug setting to find out how far you can take it and still get a reliable ignition.

Also make sure that you are using a cold plug like a Rossi 8.

Hope this helps,
Steven

Chris,

Follow up to our phone conversation.

1. Raise glow plug parameter to somewhere in the 55 -60 range when using the Mc Coy MC 9 type plug. Just remember the larger the parameter number the LOWER the voltage to the plug.

2. Substitute a Jetcat or wren type propane cylinder versus the original co2 type that came with the engine. Once you get this engine set to start reliably you can probably go back to the c02 type and have sucess if you want to. I know some guys that still use the co2 type with good results.

3. With a fully charged battery push the "air " button and make sure it spins up to atleast 8000 RPM. You will probably get more like 10-12,000 on a hot fully charged pack.

4. I would lower the gas paramter slightly to around 55.

5. You may also need to raise the start pw to about 85.

6. Make sure the EGT probe is just barely inserted into the tailcone, between 1/16" amd 3/32". never more than 3/ 32".

7. Make certain that the propane canister is in an upright position and not laying down or upside down.


A normal start sequnece should go something like this:

1. Upon pushing the start button you will hear a short purge or flow of propane and the starter will spin to approx 4000 rpm.

2. the starter will denergize and the rpm will decay to approx 2000.

3. after approx 3-4 seconds you should get the lightoff and hear a noticeable RPM increase immediatly upon light off.

4 When EGT shows approx 90-100c you shoud get the :ramping message and hear and see a fairly rapid RPM rise or increase.

5. From here it should accelerate fairly smoothly unill it reaches the "running" condition as seen on the data terminal, and the idle RPM will stabilize at 50,000 more or less.

From the sound of things for some reason it sounds like you get to the ramping phase and are for some reason hanging up (stalling out) which could be caused by not enough kero or not enough propane or you are quickly losing the lightoff.

Hope this helps. Good luck.

Chris,

Steven Elzey is way smarter than me when it comes to this type stuff but I dont completly agree with everything he said. He is suggesting raising the gas parameter higher than 60 and in my experiance I have not had much luck getting a lightoff at a number much above 55-60. If I am not mistaken he suggests you lower the start pw which will increase the amount of kero during ramping. I have never set my start pw anywhere near this low, if I did I would have a 5 foot flame out the tailpipe. Perhaps this is becasue I have too much propane where I have mine set at. I"m not sure. I need to pay more attention to his suggestions regarding EGT and RPM during the start to know what to do with my parameters. I am quite certain he knows what he is talking about regarding this and suggest you follow his lead in this regard.

After rereading I am now confused about one thing. I am of the impression that raising the start pw parameter to a higher number DECREASES the amout of kero duiring ramp/start. After reading Stevens post again I am not 100% sure I am correct about this. ?????????????? Its been awhile since I adjusted this.

Thanks for all the help guys! I am going to try the changes mentioned tomorrow and I will report back with the results!!

-Chris

I have two RAM 500, both of them ran fine, but there are some things that needed to be concerned:

on ECU version number CO3 -
higher gas values means less gas at rampup, both my rams have a value op approx 35.
lower glowplug value means higher voltage - for OS F or OS 8 glow plug that uses a standard voltage, the value should be between 120 to 90 (when 120 is low power for the plug)
if you are using the original fuel pump, a start PW of approx 80 sounds right, you should have an indication for the amount of fuel when starting up, PW too high will result a shutdowm due to high temperature.

as turnnburn wrote, the sequence is quite simple and easy to follow, things to look at:
the ECU will ramp the turbine on the gas up to approx 22K-24K, if you cant reach these RPM numbers, you dont have enough gas.
if the RPM drops from 24K to below 20K, your start PW is too low.
if the RPM rise but the turbine shuts down due to high temperature, your start PW is too high.
if you continuously burning glowplugs, your glowplug value is too high (low number) and need to be lowered (increasing the glowplug value)

other things need to be consider as well -
the RAM500 fuel needles are very thin and gets blocked easily, DO NOT run the engine without a proper filter at the fuel input of the turbine.
I use two filters, one at the input of the pump (between the UAT and the pump) and one at the output of the pump.
this insures a clean fuel line running to the turbine and keeping the needles clean.

if you have any other questions, i would gladly help.

yea, the settings can be confusing. For the CO3 the glow plug and gas settings are controlling the pulse off time, thus the higher the number the less power. But Start PW and Prime PW control the on time, so bigger numbers are more power. For the CO3 the way I remember it is that if you need to make an adjustment to correct for large changes in air temp, the settings for glow and gas follow the temp. On hotter days you need less gas and glow so you can take the values up to extend plug life. On cold days you need more gas and more plug to light off so you move the values down. Actually the reason that the gas needs adjustment is that its pressure, and thus flow rate, changes with temp. Which brings up another subject; if you have just filled the gas bottle it is probably cold, thus the gas will not flow as well. Warm the bottle up with your hand before you try to start.

The final settings will vary a lot depending on how long all the tubing is and how constricting the fuel tanks are. So unfortunataly there is no one setting that always gets it done.

The newest version of the Bob Price ECU has all the values as voltage now; much easier to follow. It also has some other nice improvements.

Steven

(1)Did the engine ran up to full rpm 150K ?.
(2) If not check if your fuel line is not in your propane line & make sure your starting motor is disengaging during startup.
(3) Burning plugs, The lower the plug # the higher the voltage. Take the plug out and raise the plug # to about 85 then try a test start with the plug connected. If the plug still blow out then there is a short with your MOSFET.

Ram500 starts are problematic. Once you get all the parameter settings dialed in it may start fine for a while, then all of a sudden it won't start. The settings are sensitive to the weather, how much pressure is in your gas canister and the ECU battery voltage. The gas pressure changes based on outside temperature, how recently you filled it and how low your Powermax can is getting. The other issue is that Ram's quality control was poor and any two engines don't necessarily act the same.

From your first post it appears that yours is lighting off fine, then you're getting too much kero too soon during the fuel ramp phase. It is difficult to get the gas just right. It seems that when you have it set for consistent light-offs you don't have enough to heat up the combustion chamber prior to ramping in the kero. If you increase the gas to get it through the ramp phase then it has too much gas for light-off.

After playing with mine way too much I found that the best way to start it is to keep the Powermax can connected during starts. Let it light off, when the kero starts ramping you will notice the rpm will sag a bit. At that point give it a shot of Powermax. One shot is usually enough to heat things up enough to get it through fuel ramp and start.

Always start with a fully charged ECU battery, leave the Powermax can connected, connect the data terminal so that you can watch rpm and EGT throughout the start. That will help you determine how much extra Powermax to give it.

Good luck,
Joe

I used to have a RAM 500, it was my first Turbine
It taught me many things about Turbine operations and how to repair them

My recommendation would be to ditch the on board "co2" tank and directly connect, see
http://www.rcuniverse.com/forum/m_63...mpage_2/tm.htm

You then can regulate the gas flow manually, if the pressure drops off on the propane bottle, just shake it and it will rise back up

As others have mentioned you have to get the parameters just right, once you do she will start every time...until the weather changes[X(]

Hey guys,

Just an FYI - today we test ran one of Ravivos' RAM 500 turbines on an A123 pack (2S1P = 6.6V 2300mAh) with a CO3 ECU, and after adjusting the glow plug value (lowring from 100 to about 85 if i recall correctly) and allowing a higher max PW for the pump (due to lower voltage) of 650 instead of 600 - the engine runs perfect up to 155K with no problems. it is worth mentioning it got to the stock 150K settings without the max PW change, but since he's running 155K it needed a little extra.

The big advantage to this is that we found the glow ignition to be very voltage sensitive and even with a 20C lipo - after a few starts it would have a hard time igniting gas due to the small battery voltage decrease. the A123 packs have a constant 6.6V rating up until they empty almost completely, and since their voltage is more stable - gas starts are much more stable as well, so we are going to fly it on A123's from now on. of course you also need to change the "ECU battery limit" to about 6.2-6.3V to match these cells, but its quite easy overall, and works great.

there is also another advantage and that is that the A123 cells are much safer than lipo, and could be charged inside the model in most cases.