JJ-1400 in Sweden

Bought this jet engine from jet joe in China. It works fine, 160'000 rpm, 2600r/sec!!! 14lb of thrust. I had some problems with the rpm sensor, not working properly, so I turned it upside down, to avoid self destortion by its own cable going past the sensor, as it was from the bigenning. and also shift the side of the glow plug cables.
Many have JJ engines in the US. I think that I'm the only one in Sweden so far with an JJ, but hopefully not for long!

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• JJ1400
• rc
• jet

[happyhouse152]

Hi

Why did you have to use a lighter to ignite the start gas when there is a glowplug that automatically ignites the gas.

Very nice engine by the way

Thanks

[pmk1974]

Hi, thanks,

I used a lighter because the glow plug couldn't ignite the gas every time, no matter how much I turned up the heat. Lately I've learnd that its important to use a gas mixture of butane and propane. The gas I was using was only butane. With the gas mix, it ignites the first time every time.

I also had to get a new ECU, insted of the chiniese one. The engine runs much better and cooler now with the new Xicoy-ECU. I'm running it at 165K at full throttle without any heat problems.

[Quokka57]

@pmk1974 If you can, get yourself some 80/20 Propane/Butane mix. There's a few camping gas 80/20's the fit the JJ gas adaptor. You'll find that the Propane makes it light-off fast, and the Butane gives it some extra grunt to vaporise the Kero quicker so that it goes through your fuel-ramp stage faster - and you shouldn't get those annoying flame-outs either.

Oh, and one thing to remember when things aren't going so good - turn your gas pressure *down*. Too much gas pressure can blow it out...

[pmk1974]

Thanx Quokka57, very helpful info!

I've got the gas pressure working fine. The engine runs great! more flight next weekend!

[claytonrspro]

how long does it take from idle to MAX?(seconds)Thanks

[pmk1974]

@claytonrspro

it takes about 4 sec. The ramp time is programed in the ECU. Shorter ramp time results in hotter running temperature (not good for the engine), and more fire out the exhaust while accelerating. Nowdays it runs with a Wren turbine wheel. The original jj1400 wheel was of scrap quality. It was out of balanced and the hole was not correct diameter (0,2mm bigger than the shaft).

[Kate800]

Ska köpa en sådan ( vill bli nummer 2)

Vare krångligt att beställa / leverans?

och vad för bränsle behövs?

[Kate800]

Vad har du för bränsle och var fick du tag på det? :)

jag ska absolut bli nummer 2 att skaffa en.

vare krångligt att beställa och hur länge tog leveransen ?

[happyhouse152]

Hi

Why did you have to use a lighter to ignite the gas when it has a automatic glowplug that ignites the start gas?

Thanks

[pmk1974]

kanske, har inte riktigt koll på namnen på alla, men om han är jetflygare så känner jag säkert pratat med honom. Det var en kille som sa att han hade en JJ, kan vara han kanske.

[TechnicalFreak]

Du, pmk1974.. Känner du en Magnus möjligtvis? Han hade också en sån där motor...

[lomix903]

vad kostar dom?