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Post by enginewhisperer on Jun 2, 2015 23:05:00 GMT -5
I don't have a sheet metal roller unfortunately, but I've had decent success with cutting a few Vs in a tube and bending the ends in to make a funnel - then welding the seams.
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turbomarc
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Joined: May 2015
Posts: 56 
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Post by turbomarc on Jun 3, 2015 1:05:41 GMT -5
Yeah, all good, i might be able to out source some rolling, see how things pan out.
Plans fell thru using my mates beaver to cut a thread the full length of the fuel rail, but of improvisation, just drilled the centre out of some threaded bar.
Might be a bit of a stupid question.... What are your thoughts on using air compressor quick release fittings for gas??
Only reason being my current gas line is copper pipe, and doing this will allow movement on the gas line so i can adjust the position of the fuel rail.
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Post by enginewhisperer on Jun 3, 2015 1:09:13 GMT -5
I have done it before and had no problems - but I guess it's not something anyone would be too happy about  My old setup just went from copper line to a rubber pressure hose (which is rated for more pressure than I could ever get in the turbine fuel supply anyway), which then connected to some braided line to the injector. |
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turbomarc
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Joined: May 2015
Posts: 56
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Post by turbomarc on Jun 3, 2015 1:12:42 GMT -5
Yeah, nice, the premade hose i got from the gas shop is the same thread as the air fittings, co-incidence, i think not!!! Should have the new fuel rail done tonight |
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Post by smithy1 on Jun 3, 2015 3:20:58 GMT -5
Marc,
I have a couple of aircraft rated -4 (7/16") JIC stainless braided hoses (pressure tested to 3000psi), both ends have female swivel ends, you're welcome to use them if you wish, I have a couple on the go-kart. They're ~60cm long each. I can also supply some male stainless fittings to suit if you need 'em. All this is available from Pirtek etc....but they charge like wounded bulls.
On my little dragster I use quite a few Festo push seal quick release fittings and valves etc....they work well when not near hot stuff.
Cheers,
Smithy.
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turbomarc
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Joined: May 2015
Posts: 56
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Post by turbomarc on Jun 3, 2015 4:46:27 GMT -5
Appreciate the offer Smithy, but should be sweet, i have made the fuel rail fairly long for the reason being, using compressor quick release fittings, and it should have the fitting about 100-150mm away from the combustion chamber depending on final location of the injector, and i will route the hose far away from heat sources, most likely thru the inside of the frame.
1mm drill bits, made by the devil, snapped two, got one hole drilled.... I guess if it was easy everyone would do it.
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Post by smithy1 on Jun 3, 2015 14:19:00 GMT -5
Appreciate the offer Smithy, but should be sweet, i have made the fuel rail fairly long for the reason being, using compressor quick release fittings, and it should have the fitting about 100-150mm away from the combustion chamber depending on final location of the injector, and i will route the hose far away from heat sources, most likely thru the inside of the frame. 1mm drill bits, made by the devil, snapped two, got one hole drilled.... I guess if it was easy everyone would do it. No probs....the offer is there anyway.. Pffttt...You think 1.00mm drills are small....try using one which is only 0.0125" (0.32mm)..! What I would really like to know though is.....how the hell do they make 'em..!!?? Cheers, Smithy. |
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turbomarc
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Posts: 56
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Post by turbomarc on Jun 4, 2015 7:07:54 GMT -5
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Post by pitciblackscotland on Jun 4, 2015 7:22:02 GMT -5
Hi Marc, That's the way to go Cheers, Mark. |
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Post by smithy1 on Jun 4, 2015 14:36:41 GMT -5
That's near perfect mate.... well done. As Mark says...."that's the way to go".
That along with the adjustable depth, you should be able to get it spot-on. Look forward to seeing some testing.
Cheers,
Smithy.
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turbomarc
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Posts: 56
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Post by turbomarc on Jun 5, 2015 4:47:21 GMT -5
I figure, to make the collar seal on the flame tube properly, i would need to cut the dome section off the extinguisher, weld the collar in, then reattach to the rest of the tube, and after all that, still be stuck with the disrupted flow issues due to the vena contracta effect. So i might as well make a new combustion chamber, i got in touch with a local fab shop to do the rolling up of the steel today, should hopefully pick it up next week some time. It will be a slightly larger diameter, with the reducer to the turbo flange a removable section, and should flow a lot smoother than the current design. But where i have the inlet from the compressor housing, is there an optimum spot where it should enter the combustion chamber?? I noticed my current one blows straight in on not much of an angle, should i be trying to have it come in on an angle to encourage the air to swirl around the flame tube similar to this? Or it doesn't matter as much, as long as the air gets in there?? Cheers Marc. |
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turbomarc
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Posts: 56
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Post by turbomarc on Jun 9, 2015 0:16:10 GMT -5
New pieces arrived today..... Cylinder that will become my new combustion chamber, and the pressed conical section for the transition from flame tube to exhaust housing of the turbo   |
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Post by racket on Jun 10, 2015 0:20:54 GMT -5
Now that looks like a smooth transition :-)
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turbomarc
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Posts: 56
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Post by turbomarc on Jun 10, 2015 2:57:44 GMT -5
what are the comp and turb wheel dimensions , also the turb scroll A/R , there could be a mismatch of sizes that is causing some of those temperature problems. Hi John, I just remembered this earlier post of yours and thought while i have it apart i'll get some measurements for you, hopefully you can see something i can't, and it has a A/R of .63  As i mentioned earlier it's a ebay spec turbo, so the fact that it is still spinning is a bonus from here on out, but after i removed the exhaust housing, i rotated the small cover for the bearings and seals and it felt as if it was full of sand, after much fiddling around i seem to have got it all out thru the 1mm gap between the cover and the core housing. As you can see in the circle, the grit and shit that came out, it can't be a good thing.  Now i know it might be a bit late in the game, but, majority of this build has been from rough guides i found online and some guess work, is there any comprehensive guide/rules to doing builds like this, as i'm really starting to think about perhaps another one, a bit more refined that i can try and make some thrust with, as opposed to just making noise and flames like i am now. Cheers, Marc. |
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Post by racket on Jun 10, 2015 4:45:19 GMT -5
Hi Marc
Turbine wheel is a tad small for the sized compressor inducer ( mass flow) , we generally require a turb exducer with ~20% greater area than the comp inducer if we want to have adequate flow area out of the comp to allow the comp to flow at its best , you really need a turb exducer of ~64 mm to better match your 58.2mm inducer .
Are those bits of "shrapnel" metalic ?
Or are they carbon flakes from an oil leak from the turb seal forming coke behind the heat shield ?
As for "comprehensive guide/rules" we had some "Rules of Thumb " in the Files Section over on the Yahoo DIY Turbines Group
Cheers
John
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