T04 turbocharger turbine

[turbomarc]

Hi,

New to the forums, and gas turbines for that instance, zero experience, keen for your feedback as to where I can improve.

For the longest time since I first seen a video of some dude that turned an old turbo into a gas turbine engine I've wanted to do one, all that usually came from it was alot of procrastinating, or not having the time to follow it through.

Got a nasty eBay t04 I picked up for cheap collecting dust, so I used that, along with whatever else I could find laying around, powersteering pump, Holden 253 rods, an old fire extinguisher, some gauges I had left over from the last car, some v6 commodore coil packs and a jacobs ladder kit from jaycar.

[turbomarc]

To pump the oil used an old lancer powersteering pump coupled to the best drill $20 could buy from jaycar.





The banjo fitting had the hose pressed on, it was a Sunday I cbf waiting to go to pirtek thought I'd give it a go, what's the worst that could happen, and it all worked out in the end, nothing a heap of thread sealant couldn't fix.

[enginewhisperer]

looks like a tidy setup!

[pitciblackscotland]

Hi Marc,
Welcome to JATO. Hehehe nice heavy duty flame tube Very nice build you have there, that oil vent pointing to the comp inlet is not a good idea as i did that on my first turbojet build and it gum up the comp wheel best to point it away from the comp inlet and vent it out behind the inlet.

Cheers,
Mark.

[pitciblackscotland]

LOL!! i love the con rods that you use to mount the oil tank very clever that's DIY at it's best.

Cheers,
Mark.

[turbomarc]

Cheers enginewhisperer, just curious the name rings a bell are you based up around Hornsby by any chance??

Pitchblackscotland, yes I know the flame tube is "heavy duty" But I try my best to make use of as many parts, materials I have on hand, as you can see with the conrods for the oil tank mounts.

This is the first video I made once it was running, this was the second time it had started, as you can tell by me being pretty edgy when giving it some throttle :lol:

But for some reason this is the only video where it's had flames coming out when more throttle is applied, any thoughts??

youtu.be/_oHeoZ656ao

This was a couple of days later, can see that fuel rail getting eaten up, thus the glorious green copper flame at the start.

youtu.be/BMUSMQLH9vs

Cheers,
Marc.

[enginewhisperer]

haha yep, I'm at Hornsby.

Have we met some time?

[turbomarc]

No we haven't met, I shot you a email or two a couple years back in regards to getting argon for the TIG.

Plus every now and then I would stumble across your blog/Web page.

Cheers,
Marc.

[pitciblackscotland]

Hi Marc,
Hey i make things almost heavy duty that's how i work. And that's the best way of getting parts for your project from your local scrap metal dealer,car wreckers, garage sales, flea markets, hard garbage and of course e bay. I'm sure John W will help you out with getting your engine running properly, as i am still learning and i know i will have some issues getting my big T30 engine up and running. One thing i notice that you are using a copper tube for you main fuel delivery, have you thought about using a steel hex nut? see like i did see pic and will you be planning on running the engine on liquid fuel?

Cheers,
Mark.

[racket]

Hi Marc

Theres a couple of things to mention ..........

Firstly the fuel injector , too many holes and too big of holes for your sized turbo , this will result in a core of LPG going down the centre of the flametube surrounded by your air resulting in poor combustion until the fuel reaches the tertiary zone where the larger wall holes will penetrate far enough to breakup the LPG core , the air through the smaller Primary Zone wall holes will only penetrate a limited distance into the flametube .

Change the fuel injector to one with 6 X 1mm dia radial holes 60 degrees apart around the tube ( end of tube sealed) , the smaller holes and limited number will require a much higher pressure drop across the holes resulting in a high velocity fuel stream that will extend out to, and mix with, the air coming thru the wall holes, position the fuel injection holes opposite the top row of primary zone holes .

Secondly , the outlet of your flametube , does it sit on the domed end of the outer can...............or is there a gap ??

All air should go through wall holes for accurate distribution in the correct ratio of ~30% to Primary , 20% to Secondary and 50% to Tertiary main dilution holes .

Thirdly , we need a "funnel" between flametube end cross sectional area and entry duct into the turb scroll , if you are only using the domed end of the "fire extinguisher" as your "funnel" there could be a vena contracta ( en.wikipedia.org/wiki/Vena_contracta ) developing , this will put extra backpressure on the compressor resulting in a reduction in mass flow and possibly surge along with increased turbine temperatures .

Fourthly , your temperatures are too high , so run the engine without any restriction downstream of the turbine wheel , so no jet nozzle at this early stage until you get those temps under control.

Fifthly , 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.

Currently the engine is running , so the hard part is over , just a bit of minor tuning required

Cheers
John

[turbomarc]

Jun 1, 2015 1:09:11 GMT -5 racket said:

Hi Marc

Theres a couple of things to mention ..........

Firstly the fuel injector , too many holes and too big of holes for your sized turbo , this will result in a core of LPG going down the centre of the flametube surrounded by your air resulting in poor combustion until the fuel reaches the tertiary zone where the larger wall holes will penetrate far enough to breakup the LPG core , the air through the smaller Primary Zone wall holes will only penetrate a limited distance into the flametube .

Change the fuel injector to one with 6 X 1mm dia radial holes 60 degrees apart around the tube ( end of tube sealed) , the smaller holes and limited number will require a much higher pressure drop across the holes resulting in a high velocity fuel stream that will extend out to, and mix with, the air coming thru the wall holes, position the fuel injection holes opposite the top row of primary zone holes .

Secondly , the outlet of your flametube , does it sit on the domed end of the outer can...............or is there a gap ??

All air should go through wall holes for accurate distribution in the correct ratio of ~30% to Primary , 20% to Secondary and 50% to Tertiary main dilution holes .

Thirdly , we need a "funnel" between flametube end cross sectional area and entry duct into the turb scroll , if you are only using the domed end of the "fire extinguisher" as your "funnel" there could be a vena contracta ( en.wikipedia.org/wiki/Vena_contracta ) developing , this will put extra backpressure on the compressor resulting in a reduction in mass flow and possibly surge along with increased turbine temperatures .

Fourthly , your temperatures are too high , so run the engine without any restriction downstream of the turbine wheel , so no jet nozzle at this early stage until you get those temps under control.

Fifthly , 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.

Currently the engine is running , so the hard part is over , just a bit of minor tuning required

Cheers
John

Firstly, Fuel rail: Yes i was made aware of that when i had a chat with Brett "Smithy" yesterday, not only the hole sizing and the amount of them, but the fact they are before the primary, he mentioned the hex nut with 6x1mm holes would be a improvement, but to also have the holes located between the primary and the secondary.

Secondly, Flame Tube: Yeah, you caught me out, i didn't even check it sealed till it was too late, I think there is about 2-3mm gap in one or two spots, but I thought i would press on and see if it would fire, have been thinking, maybe get the MIG out build up the end of it, and do the old back and forth, test fit, grind, test fit, weld, until i have it sorted as best as possible, or worst case, just build a new combustion chamber and use my current flame tube with it.

Could the extra air bypassing the flame tube be a reason for it running lean thus creating higher temperatures?

As for the hole sizing, i used JetSpecs, Flame Tube / Combustor Calculator.

Thirdly, Combustion chamber: Yes, I am using the dome as my funnel, that was one of the main reasons i used it, thought it would be an ideal solution, but after reading about Vena Contracta, i can see now, how it wouldn't be a best option for smooth air flow.

Fourth, Nozzle: Makes total sense, will lop it off with the grinder and see how it goes.

Fifth, Sizing, i can't recall the rear wheel size off the top of my head, but my compressor wheel is 60mm and the exhaust housing a/r is .63

Hopefully this should give you a fair idea of where i am at, please keep in mind there was very minimal research done, the only real references i went off where some info a bloke by the name of Colin Furze posted on youtube after he built one with the purpose of using the afterburner to cook snags!?!?, and JetSpecs.

One other thing, i have a boost/pressure gauge connected to the outlet of the compressor housing, and i am curious what should i be seeing at idle, and where is a safe pressure to stop adding fuel?

Well, so far it looks like i've got some tasks to knock over once i get some more free time, John, thank you for the tips, will report back in the next couple weeks when i get a chance to get these done

Cheers,
Marc.

[turbomarc]

Here's a bit better pic of it all together (prior to painting the oil tank and combustion chamber)



As for the extreme temps, this was after about 3 minutes of running the other night, yeah, there is a weird hot spot about the size of a ten cent piece on the collector and even the exhaust housing was starting to get a slight cherry glow.

[smithy1]

Hi Marc,
Was good to meet you on Sunday to share some common interest in turbines..... also good to see you have found our little forum, keep up the good work on your turbine, there's lots of help and expertise available here....many knowledgeable guys to pick their brains, I've learned heaps from the guys here and appreciate everything I learn..... and be sure to listen to John, (Racket), and use his advice, I know him well, he's a very good friend of mine, known him for yonks, (probably too long), he's the one who is responsible for the Garrett 6041 powered Gokart you witnessed on Sunday, I've just had it all apart and made some "modifications" to it ;-)....and he also owes me a cuppa..!!

john....had the 6041 running on Sunday at "Penrith Truck Show" where I met Marc....she was running as sweet as ever with the cool-ish temps we had on Sunday, was only ~15-16c ambient. The A/B is nearly spot-on too, great burner "pops" happening... mid-high 400's EGT @ an idle of ~23,000rpm using my "cheap arse" tacho, ~680c @ 35psi P2 and full A/B.. :-))...and making plenty of thrust too....was close to jumping wheel chocks and pushing 20L drum of fuel along the ground..!! I still haven't upped the P2 to ~40+psi as yet....but I think it's now time..!

Cheers,
Smithy.

[racket]

Hi Mark

Yep , change the fuel injector first , its probably causing most of the problems , combined with the removal of the jet nozzle the temperatures should come down to a point where the turbine wheel doesn't glow , once you have have those low temperatures as a base to work from we can then start to build temperatures knowing the basics are working as they should .

Bloody Colin Furze , a smart guy who acts dumb to make money from his YouTube videos , unfortunately his "jet engines" are only very dangerous noise producers , its takes a little bit more sophistication with the design work and construction to start producing real usable thrust and horsepower from a homemade turbine engine .

Most problems with smallish turbos are caused by having an oversized compressor wheel , the inducer (inlet) diameter of the compressor wheel needs to be several millimeters smaller than the exducer ( exit) of the turbine wheel for there to be a reasonable balance between the two ..............the difference in size gets greater as the turbo gets bigger , the GT6041 on Smith's kart has a 106mm inducer on the comp matched to a 119mm turb exducer .

A "safe" idle pressure ( P2) is generally ~6-7 psi for a "new" engine , once its been sorted the P2 can be lowered to ~5 psi, but lower P2s will generally see TOT exhaust temperatures rising, a safe max P2, without knowing the rpm/tip speeds, will be ~20 psi due to the fact that different compressor wheel designs produce different max P2s , theres no point having a high pressure comp in a turbo OE fitted to a petrol engine running 7 psi of boost, but for a diesel truck running 30 psi boost it'd be whats required .

Also depending on where you are flowing on the comp map its possible to overspeed the comp at modest boost ( P2) levels .

I'll be looking forward to updates :-)

Cheers
John

[racket]

Hi Smithy

Heh heh , 23,000 rpm , you've certainly got her tuned nicely :-)

680C at 35 psi and full noise ............nice.

Yep , time to "explore" 40 plus ;-)

Video please .

Yes, your cuppa is waiting .

Cheers
John