Need advice on oil system

[racket]

You need to get propane ignition before applying the starter airflow .

[willisdaye]

Hmm I've never heard of that. So start the ignitor and slowly add propane until it ignites, and then spool it up with air?

I tried starting it this way, and I didn't have much luck. I got one kind of pop noise, and the smell of burned propane, but it didn't last. I feel like my spark plug isn't enough  even though I gapped the plug out more than stock. Would it be safe and effective to use a torch at the jetpipe and ignite it there?

[racket]

Standard procedure for starting.

Oil pump on , check pressure

Ignition on

Supply a small amount of propane and hear it ignite

Apply starter air whilst increasing propane quantity and/or start feeding in kero/diesel

Once up to idle switch off ignition and propane if liquid fueled

[willisdaye]

Okay, I tried that a bunch of times, but all I get is a sudden whoosh noise from the combustion chamber, and a slight rotation of the shaft. I know that this is propane igniting, but does this mean the engine is ready to be spooled up, or is it just a small, unsustainable combustion of propane?

[racket]

Hi

Yep , sounds like you've got ignition , maybe cut back a bit on the propane , you want ignition and some flame but not to suddenlyburn all the oxygen until you start providing more with the blower

Immediately you hear ignition and the "whoosh" , apply the blower and start getting more fuel into the engine to keep the flame alive .

You'll soon get the hang of how much fuel to add , enough to maybe get a tad of flame from the turbine wheel for several seconds until the rpm increase and the flame will retreat inside.

Keep the blower attached until the engine is starting to make some P2 pressure , basically until the engine is sucking more air than the blower can provide , you want to feel some resistance to removing the blower as the engine tries to keep it sucked onto the comp inlet .

We've all had the same difficulties getting our first spoolup , but once you have that first one, it gets much easier :-)

Cheers
John

[willisdaye]

Alright still no start. When I try to supply only a little propane, the pop never comes, and when I add just a little more, it's too fast to sustain.

[racket]

May I suggest you hold the operating blower a little away from the comp housing inlet , far enough that theres only a gentle breeze exiting the turbine wheel , then supply your normal "pop" amount .

Hopefully you'll be able to maintain the initial combustion giving you time to force the blower hard against the comp housing inlet whilst simultaneously increasing fuel supply .

Every engine needs a slightly different approach , so you'll just have to find it .

Cheers
John

[willisdaye]

Thanks for the advice, I got the thing to fire! It spools up, and there's some flame blowing out the turbine. However, it won't stay running without the air supply. Do you think it needs to be spooled more (I have a more powerful blower) or should I just add fuel and try to get it to run by itself?

There's also some steam coming from the turbine, should I be concerned about that? It might be from oil but I have no idea.

[racket]

Hi

Do you have a pressure gauge to measure the compressed air pressure coming out of the compressor ??

It sounds like you need to keep spooling up, a common problem with first timers is that they feel a turbine engine should start like an IC engine from low rpm , you need to have an idle rpm of ~30% of maximum, we need strong starters which keep on supplying power as the engine accelerates.

Is your blower to compressor housing inlet sealing well , we need every bit of air energy coming from the blower , so no leaks .

You're getting there , just need more rpm to get "over the hump" to self sustain :-)

Don't worry about the "steam" , probably just some oil thats leaked into places it shouldn't be , it should clear itself once the engines running .

Cheers
John

[willisdaye]

Thanks for the info. Another thing that keeps coming up is that there seems to be some kind of shutoff valve in my propane cylinder that stops the flow if I open the needle valve too much. It's really sensitive, and really frustrating.

[racket]

Hi

You'll have to get rid of that propane tank and use one without the safety device , you'll never get your engine running with the tank you have .

Check with a large propane distributor about whats available , you may need an "industrial" tank without the domestic safety device , tanks for forklifts might be what you'll need .

Cheers
John

[willisdaye]

Crap. Okay, i'll find a place open on Sundays and ask them what they have. Where do you get yours?

[racket]

Hi

LOL..............we don't have those safety devices here in Oz , any old 20 pound BBQ bottle will work for us :-)

Cheers
John

[smithy1]

Yeah.....or we "modify" them to suit our purposes....I use a small 3kg BBQ bottle to start mine...works every time and I get a good 30+ starts out of it.

Smithy

[ripcrow]

I had the same problem with mine the first start. It self sustained but had the turbine glowing red and no throttle response at all. Got rid of the pressure regulator valve and she went well until I melted it down after modifying it. On the oil subject in heavy truck motors the oil temp is kept to 110 - 118 degrees Celsius for efficiency. The turbos produce up to 40 psi pressure with oil this hot at about 230 Kpa. Any hotter and the oil losses its ability to protect components and any lower creates excessive lead on components due to viscosity.