We have been using propane and MAP gas to start our turbines without any problems. The MAP gas seems to be our gas of choice - it is hotter than the propane and we get faster and better starts.

In the same turbines we are trying Coleman Powermax and so far not much success. It appears that instead of gas going into the engine it is liquid - at least partially liquid. Watching the propane line you can see a lot of bubbles and the liquid. Starts have resulted in a lot of fire at the output end of the turbine - way too much for comfort. When you shake the can it appears the content is liquid. Also sounds like a clunk inside. The line between the Powermax canister and is the engine is very short. Could this prevent the liquid from gasifying?

We are holding the can vertically - not tilted. The weather was cool when we tried it. Also it was in the shade.

Can anyone shed some light on what we are doing wrong and coach us on using the Powermax ??

Jack Mathias W9FMW
AMA 7654

Oops - Looks like my turbine buddy also posted this problem (c/f).

What brand of turbine are you starting? Most full autostart turbines start very well on Powermax.

We are running 3 AMT Mercury's. 1 AMT Pegasus, and 2 SWB Mamba's. The AMT's are air start and the Mamba's are electric start (propane is not onboard).

The Pegasus in particular does not start well on the Powermax fuel

I believe all the air start turbines use propane. Not sure what SWB recommends on the mamba.

Hello Jack,
My Mercs start very well on the green Coleman propane cylinders used for camping lanterns/stoves. Have never tried the PowerMax except for my P-70.

Skeet

You answered your own question without realizing it. The Powermax cans have a clunk tube in them. If they are held upright you will be releasing liquid fuel. You did not say if you are connecting the powermax directly to the engine or filling an onboard tank. If you are starting the engine directly from the powermax bottle in an upright position you are introducing liquid propane/butane into the engine which will give you the way rich hot starts you are describing(as you are getting liquid,not vapor,gas directly into the combustion chamber.) Scott

Scott,

We are starting the turbines with the Powermax connected directly to the engine. We are not filling onboard containers.

We concur with all that the Powermax is in a liquid state and there is a clunk inside the canister. With these condition verified we are inducing liquid Powermax into the engine.

I guess what we need to know is "Can the Powermax be used in a gaseous state directly connected to the engine or not". If it cannot then we will forget about it. If it can then we would like to know how to use it so gas only (not liquid) enters the engine. As we were using it we were getting HOT and FIREY starts which we do not want.

The propane and MAPP gas canisters sound as if they also contain contents in a liquid state but since there is no clunk line all we get is gas unless the canister is tipped on end.

We appreciate your comments along with the others who have responded. But we still do not have an answer to our question.

Jack Mathias
AMA 7654

Right side up you get liquid with the Powermax. Turn the can over (Top down) and you will get "Gas".

Terry is right-just hold the can upside down when you are starting and all your problems will be solved. This way you are getting gaseous fuel into the engine and not liquid. It is really almost impossible to get a good start when you introduce liquid fuel for the warm up. Scott

These latter guys are dead right, NEVER EVER feed Colemans Powermax direct to the engine or you WILL get liquid propane, it is dangerous. I found out the hard way and it cost me a stab. on my BVM F4. My recommendation, for what its worth, is NEVER connect a Powermax cylinder direct to the engine in case you forget to invert it.

Having said that Powermax is used to start all of my engines, without any problem, but from onboard containers.

Regards,

David Gladwin.

Hi Guys
Here is a very simple cure to your problems with getting liquid to the turbing. If you are using PowerMax all you have to do is put one of the Robert brass ristrictor in the gas line about a few inches from the turbine.
This allowes the liquid gas to turn completly to gas. Problem Cured. I use this methiod on both my air start and full auto start Trubines. Hope this helps. It is cheep and it works.
Paul Hopkins JPOFL[8D]

Geez Paul, like a fixed orifice in an auto a/c system?

Brilliant!

The Powermax cans are primarily for filling on-board tanks with liquid gas. Most modern Auto-start engines now have a pulsed metering facility for introducing gas in a controlled way that allows only gas to enter the engine, and hence no flames (normally) out the back.

As said previously, if you are connecting the Powermax directly to the engine it has to be inverted.

If you are using the Trigger Valve, (Usher Enterprises) then pushing the trigger forward instead of squeezing it, allows constant gasflow without having to handle the can at all during the start-up.