janek
New Member
Joined: December 2016
Posts: 2 
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Post by janek on Dec 3, 2016 7:10:35 GMT -5
IMO I think it would need to be a metal with a higher melting point- stainless would be best.
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fidel
Member
Joined: April 2016
Posts: 28
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Post by fidel on Dec 3, 2016 7:38:38 GMT -5
Copper has a meltingpoint at 1084 degrees. It should be enough since the flame is after the injector ring.
I'm fidelling with it on weekends now, flame holder and ignition is done.
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BFTO
Veteran Member
Joined: February 2016
Posts: 128
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Post by BFTO on Dec 3, 2016 7:56:28 GMT -5
Point the holes towards the turbine and I would use stainless.
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mitch
Senior Member
Joined: August 2014
Posts: 285
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Post by mitch on Dec 3, 2016 12:54:47 GMT -5
Hi fidel,
Kind of an off topic question, but I was wondering where you are located. I looked up the oil pump you are using, and found that it is a good pump and fairly inexpensive ($100 USD). I was considering ordering one but I am not sure if they ship to the US. I was also wondering what the max pressure on that pump is, as the page for the specs is in a foreign language, and I cannot read it haha.
Any info would be appreciated. Thanks!
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Post by racket on Dec 3, 2016 16:40:34 GMT -5
You'll note that I drilled my holes a little to the side of fuel spray ring in the Link , if the holes squirt directly at the turbine wheel the spray gets turned back on itself and ends up wetting the spray ring with larger droplets coming off it which take more time to evaporate/burn , whereas if the spray is a tad off axial the axial flowing high speed gases break up the spray better and don't force it back on itself.
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fidel
Member
Joined: April 2016
Posts: 28
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Post by fidel on Dec 4, 2016 7:36:10 GMT -5
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fidel
Member
Joined: April 2016
Posts: 28
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Post by fidel on Dec 12, 2016 10:20:02 GMT -5
I´m about to get everything together but wonder about the amount of holes. I made 1 mm holes but they seem to be too big, there´s a LOT of fuel coming out of the 3 holes i made. I´m thinking of starting out with just 1 hole and see if there really is need for more fuel than that.
What is your input on the matter?
/Fredrik
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Post by smithy1 on Dec 12, 2016 14:02:27 GMT -5
I´m about to get everything together but wonder about the amount of holes. I made 1 mm holes but they seem to be too big, there´s a LOT of fuel coming out of the 3 holes i made. I´m thinking of starting out with just 1 hole and see if there really is need for more fuel than that. What is your input on the matter? /Fredrik Hi Fredrik, You'll need a lot more than 3 holes, possibly up to 16 or so, and with holes much less than 0.5mm. The one I have has 16 x 0.5mm holes... but the turbo you are using only has a comp inducer of ~38mm with ~16lb/min mass air flow, the turbo I am using has a comp inducer of 106mm which has a mass air flow ~165lb/min, this is ~10 times more than yours and the main section of my tailpipe is ~200mm in diameter. Smaller holes will help atomize the fuel better but you will require higher afterburner fuel pressure to do so. As John has mentioned, your spray holes should be "off axis" and directed towards the turbine wheel, this will help greatly with fuel distribution and hence burn efficiency. You'll also need a decent and correctly designed flame holder otherwise the flame will spend most of it's time wasted outside the pipe. There are a few different ways to make a good flame holder, I use the "traditional" type and Andy M has a nice "Step" type in his go kart which also works very well indeed. Cheers, Smithy. |
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