RE: Starting gas and set up
 

dbateman

I have just transferred my 44 to another model so I thought I would try a start to see if I could find the cause of your problem.

Start procedure (45oF air temp.)

I have a manual start 44 (wand) which , apart from the fact your starter is pre-mounted everything else should be the same as you have full control over the starter rpm's.

1. Propane / butane mix (powermax) with Wren supplied valve (I have used another simple screw down valve and it has worked just the same)

2. Shake gas can well before attempting start.

3. Spin turbine and let revs decay before opening gas valve.

4. When gas pops give gentle blip on starter, temp should very quickly reach 100 degrees if it does not open gas valve further.

5. Watch ramp temp closely and do not reapply starter until about 200o has been reached (this should happen very quickly).

6. Keep starter applied until rpms reach around 30k )My turbine will self -sustain from about 30k)

I had two perfect starts gas light to idle in no more than 15 seconds, no flames, absolutely straightforward and my 54 is exactly the same.

I think your primary problem is the gas being propane and holding the starter on. With the fitted restrictor in the gas line it should not be the valve. Again check your fuel system for air leaks. Keep trying!

John Agnew

RE: Starting gas and set up
 

dbateman

As an aside I used to have a Ram500 (autostart) which came with an on board small gas tank. I had loads of problems trying to start it.
Eventually I threw away the on board tank and connected the gas can directly to the gas line with a non return festo.

This immediately cured the problem and I had very few poor starts after that. I did burn out the starter motor though.

If I had kept the Ram I would have put a fadec ECU on it and removed the starter motor and started it manually. As you can probably gather I am a fan of manual start. Autostarts were, I believe, introduced to get rid of the need for scuba tanks as turbines were started with compressed air a few years ago.The Wren starter wand is the answer to the scuba tank and is so simple I can't understand why no one thought of it sooner.

I actually think that a lot of people who are new to turbines are slightly frightened of the start procedure and think that an autostart is going to be the answer to their problems. To be fair I have a Jetcat P70 which starts perfectly but that's because you don't have the option with Jetcat.

Autostarts were sold on the premise that the whole start operation could be remotely controlled from outside the model and would look most impressive. I for one NEVER would start a turbine with the hatches closed in an enclosed turbine fuselage. I like to see what is happening around the turbine and, if you are unlucky enough to have a fire you can get the extinguisher as the source of the fire much more easily than trying to fire it up the intakes .

Just some food for thought.

John Agnew

RE: Starting gas and set up
 

I think #5 in your startup is the key. Even if the starter does start to cool the engine down, it will ramp long before reaching the 100deg mark. On the other hand you could get too much fuel on the way up to 200deg and get flames if not on the starter.
Another alternative is to get up to 200deg on low trim with no fuel ramp, hit the high trim and starter at that point.

RE: Starting gas and set up
 

My first problem is the straight propane. The higher BTU rating of powermax [because of butane] will cure that problem. Second problem is my starter battery doesn't have the capacity for a prolonged and repeated start. Harry, even though the starter did get me to 35,000 the heat buildup during that time was enough to give me an overtemp before idle stabilized. Any fuel that is pumped to engine before self sustaining point or even idle without a coresponding jump in RPM does nothing but cause an inferno in the combustion chamber. Anyway I found a nice 9.6 volt battery pack in an old shop tool with charger. Rated 2600mah and cells check out ok. I've been getting some nice E-mails during all this from Wren. They are outstanding with product support!!. Stay Tuned, Doug

RE: Starting gas and set up
 

Update...... have 5 consecutive starts without a hitch. Once you get a procedure down it's very consistant. I don't go full on starter until kerosene ignites, this takes a few seconds after fuel ramp starts.Earplugs are a must!!!!! Doug

RE: Starting gas and set up
 

dbateman

Glad you have persevered and everthing is ok now. Enjoy!

John