Author Topic: Flame plug, also called a Thermo start. (Read 24644 times)

greasemonkey · « **on:** December 12, 2012, 11:49:52 AM »

Well its working now. Started this morning, it did turn over a few times, but fired with no throttle, and ticked over perfect. Another blast on the plug took away the slight lumpiness of the tickover.

I still think its not getting quite enough fuel, the brake pipe coming out of the plug is to narrow a bore, so I might just put the rubber pipe straight onto the plug. Except I will have to join it now, because its to short.............

The plug pulls 10 amp, the solenoid will handle 30, and the wire is 27 amp. I don't know how I did it, but I got it into my head somewhere that the plug pulled 30 amp, so doubled up the wires. I realised what I had done the instant I finished doing it.............

There was no where under the bonnet to put a fuel tank, no hight, so I had to run a pipe through the cab.

I ran the negative control lead of the solenoid in through the bulk head and in through the back of the cab, to an auto return switch. I've got a few controls mounted on a box in the back of the cab.

Dickjotec · « **Reply #1 on:** December 12, 2012, 11:57:54 AM »

Nice job how well does it work? Thinking it could be good on the lister?
Dick

greasemonkey · « **Reply #2 on:** December 12, 2012, 12:02:59 PM »

It would be ideal for the lister, Dick. All you need is a diesel supply, and a 12 Volt supply.
This was the cheapest plug I could find on the net, although someone has told me since that you can get a plug from an agricultural engineering place for a little less.

The thread on this one was wrong for the hole in the manifold, but I just about got away with it.

Tony · « **Reply #3 on:** December 12, 2012, 12:10:57 PM »

Interesting. So how does it work? Does it dribble diesel down a hot glow plug? What stops the diesel when the power is off?

greasemonkey · « **Reply #4 on:** December 12, 2012, 12:26:59 PM »

Quote from: Tony on December 12, 2012, 12:10:57 PM

Interesting. So how does it work? Does it dribble diesel down a hot glow plug? What stops the diesel when the power is off?

Basically there is a coil in the mouth of the plug, which heats up red hot when you give it power. After about 6 seconds, the heat causes a valve to open, I'm told its a bi metal strip type setup, and lets the diesel through, which the vaporises on the coil, and bursts into flame. When you let go the switch, the coil cools, and the valve closes.

Some tractors have the diesel tank below the level of the inlet manifold, and someone told me the plug will sort of pull the diesel through the pipe. I can't remember the term the used now. same as liquid rising up between two plates of glass??

I still think the brake pipe is stopping the flow though. I can see whats going on by pulling the inlet pipe off the manifold, and triggering the solenoid with a piece of wire off the battery. It seems to burn for a few seconds then loose its intensity.

Tony · « **Reply #5 on:** December 12, 2012, 01:12:06 PM »

Capillary action? If that's the case it must surely only work with very narrow bore pipe.

Brake pipe bore must be greater than that required for capillary action, so perhaps it's the length of the run that's causing a flow issue?

greasemonkey · « **Reply #6 on:** December 12, 2012, 01:21:04 PM »

Capillary action, that's it. He could well have been wrong about that though.
It probably is the length of the run, and the brake pipe going to the plug. I can live with it anyway.

Julian · « **Reply #7 on:** December 12, 2012, 01:27:17 PM »

It would be interesting to set it up on a test rig (outside might be safest) and see what the flame is like with various fuel supply arrangements, positive vs negative head etc.

Tony · « **Reply #8 on:** December 12, 2012, 01:41:30 PM »

And with biodiesel

Sounds like a fun thing to show off at the BBB too.

greasemonkey · « **Reply #9 on:** December 12, 2012, 01:50:54 PM »

There are a few videos on you tube of them working. It would be interesting to try one on bio, to see what happens, because if it worked, you could plumb it into the fuel system. Little point in trying it on veg, I thought. I think it would just smoke and soot up.

Julian · « **Reply #10 on:** December 12, 2012, 02:20:59 PM »

Found this at ... http://www.beru.com/products/diesel-cold-start-technology/glow-plugs/glow-plug-for-flame-starting-systems-gf

1.Electrical connection
2.Insulation
3.Plug housing
4.Fuel connection
5.Fuel feed
6.Metering device
7.Evaporator sieve
8.Evaporator pipe
9.Electtrically heated heater rod
10.Protective tube
11.Flame sleeve

Rotary-Motion · « **Reply #11 on:** December 12, 2012, 06:41:25 PM »

is this plug in the air intake somewhere?

looks really good though and a good idea, so you say this takes away hunting and the van ticksover?

are you 100% veg oil and whats the ambient temp when you tested?

well done chap

greasemonkey · « **Reply #12 on:** December 12, 2012, 07:30:58 PM »

The plug is in the inlet manifold. I'm on around 50/50 veg/dino. This morning it was -3.5C, yesterday was similar temperature.
I would have expected it to start anyway, but not as quickly as it did. What I have been finding is that it is slow to fire, on full throttle, and when it does fire, it takes a few moments to rev up.
Non of that with the flame plug, it fired up in a few turns of the engine, no throttle needed, and revs straight away.
To be honest, it started better than it was last year, and that was on straight diesel with no plug.

william crosby · « **Reply #13 on:** December 12, 2012, 07:35:06 PM »

these are fitted as a standard part on the renault master 2.8 di which is a iveco engine they work quite well but they are controlled my temp switch only to operate below a set temp

Rotary-Motion · « **Reply #14 on:** December 12, 2012, 07:43:19 PM »

wouldnt mind seeing this in action on a test rig...

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Flame plug, also called a Thermo start.