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[hurdman]

Hello JATO!

I've been lurking your site for over a year. Great info and great discussions.  I have over 100 pages of notes and rules-of-thumb from just lurking.

Last December I completed my first GT by applying the info available on your forum's threads.  I used a Schwitzer s-300 from a Mack truck.  It did take three constructions of the afterburner to get the AB to ignite and sustain.  Lots of "Art" to a successful AB.  I didn't take any pictures during construction but will take some overall pictures tomorrow for your comments and critique.

I've read closely all of Racket's and Ander's posts on their TV94 builds with great interest.  That being said a question for Racket and Anders:  what are the Garrett part numbers for the turbine/shaft and compressor?  I've found multiple part numbers for the turbine/shaft and compressor spread across at least seven different basic variants (TV9401-TV9407).  Wheel trims, diameters and part numbers vary...

What are the best suited TV94 turbine and compressor for a future GT free-shaft build?  They don't have to be from the same variant.  I'll find your suggested parts.

Thanks in advance

Hurdman

[racket]

Hi Hurdman

Welcome to the Forum, looking forward to checking out your pics :-)

Comp #441813-0007 gives the largest flow and is the one we use , Turb #442208-0001 but make sure the turbine wheel is cast in Inco 713C rather than the inferior GMR235 thats used for cooler exhausting diesels.

Cheers
John

[hurdman]

Racket,
Thanks for the quick reply. The closest Garrett Distributor is about five hours away, and he has the compressor and turbine (Inconel) in stock. I'll go and get this week.

JATO Members,
As promised in my first post attached are seven pictures of my GT I built last winter.

Schwitzer S300, comp ind 63mm, comp exd 87mm, tur ind 80mm, tur exd 71 mm. Split turbine scroll...but the turbo was free. Mass flow 1.03, lbs/sec, 9gal/hr fuel

Diesel fueled, no gas preheat.

Used jet specs for FT, 5" od, 15" long. 33 pri holes@ 6mm, 8 sec holes @ 10mm, 8 ter holes@ 16mm. Ring welded to OD of FT at Tur end that just slides in casing ID. Bell mouthed all FT holes. Combustor casing 6" od. FT and casing both mild steel...I wanted a cheap, easy to mod combustor.

I installed one .5 gph furnace nozzle in center of endcap for starting, but found by 3rd run it wasn't needed. Three 3gph 30deg hollow cone furnace nozzels in endcap as main fuel. Two 255 lph Wahlbro fuel pumps, main and AB. Two P2 referenced FP regulators with static pressure set to 100PSI. One Holley 110 gph fuel pump as lift pump. Three ball valves for prime, main and AB fuel with needle valve on main. Pressure regulators have dump back to tank.

I copied racket's Subaru/500watt motor arrangement as oil system. No "clean" way to seal oil pump shaft so oil pump to motor coupler includes a slinger and a small pulse pump to scavenge void. Automatic transmission oil cooler with motor and thermostat. Two gallon oil tank (filled with five qts for expansion).

Two relay and capacitor buzz boxes for main and AB ignition.

GT core started first attempt, with no further problems. But a sustainable, AB to three different cans/fuel inputs/flame holder. AB main OD is 8"...had to slow down flow. Used one cup SS soup ladle with handle cut off as flame holder. Used 3/8 SS tubing ring with three .060 hole pointing to turbine for AB fuel injection.

P2 runs 32PSI, TOT 610 deg C, rpm 95K.

I have 23 hours on it so far with no problems except for the AB growing pains. I run 5 gallons per run to entertain the neighbors.

Comments and critiques are welcome.

Hurdman

[madpatty]

Hi Herdman,

Nice numbers on TOT and pressure....

Isn't that afterburner a bit too long as it appears in the photo....But still it is always cool if you get the things working according to you....

Cheers,
Patty

[hurdman]

Madpatty,
Thanks for your reply.

I couldn't find any rules-of-thumb for afterburner dimensions as it relates to compressor or turbine size. After my first two failed AB attempts I was convinced that the flow thru the them was way too fast, due to the too small (4" then 5") AB body diameter, to start and maintain ignition. I would get a pop-pop-pop and lots of white smoke when trying to ignite.

I then read in a reference that AB gas speed should be below 400m/sec. I tried some numbers and came up with the 8" dia AB main body, then doubled that for the 16" straight section, then added an 8" inlet and 8" outlet transition. No science, just a SWAG and it worked.

Thanks for your interest
Hurdman

[Johansson]

Hi Hurdman! Very clean build you´ve got there, thanks for sharing!

[Richard OConnell]

Hi Hurdman, sweet build! Would you happen to have a picture of your flame holder setup?

[racket]

Hi Hurdman

Nice clean unit :-) ............very professional "plumbing" .

Yep , we need to get A/B gas speeds <400 ft/sec at the flameholder for easy combustion , my GT6041 kart's A/B was right on that limit with its 6" A/B body and was difficult to light.

Did you check the "Garrett" price on those TV94 bits ??

The comp and turb can generally be purchased cheaper from other turbo repairers.................check the prices for the comp/turb here www.powertechnologies-turbo.com

Cheers
John

[hurdman]

Johansson,
Thanks for your interest and praise.

Richard,
Thanks for your kind comment.
I just removed the AB and tried to take some pictures of the flameholder in the AB for you, but since the flameholder is "buried" in the AB, I can't get a clean picture...Here's a verbal description, let me know if it suffices.

I bought the ladle at Wal-mart for about $6. Its SS and the width is 2 1/2", .060" thick. The rounded end faces the turbine of course and the open front face is in plane with the joint from the inlet transition cone to the main body. Four legs of 1/2" wide x .060 SS with an "s" bend in the middle of each leg are welded between the ladle body and the inlet transition cone ID.

Racket,
Thanks for your comments and approval.
Thanks too for the parts link. I compared prices: turbine $637@ powertechnologies, $456@ the Garrett dist; compressor $116@ powertechnologies, $124@ the Garrett dist. I will still go to this distributer me thinks... He's in Atlanta, Ga and I'm located in Jay, Fl. When I spoke with them today, after receiving the correct Garrett part numbers from you, they said when I come to buy rummage thru their turbocharger scrap bin. No telling what I will find.

Thanks to all for your kind words, interest and advice.
Hurdman

[racket]

Hi Hurdman

Thats a good price on the turbine wheel from the Garrett distributor, just make sure its the Inconel wheel so you can run decent temperatures to maximise your output.

Yep , rummage through the scrap bin for goodies while you have the opportunity :-)

Cheers
John

[hurdman]

Hello Earthlings,
I went to the Garrett distributor and picked up a TV94 compressor and turbine wheel. The craftsmanship is impressive. The distributor was most helpful with documentation, alternate part numbers etc.

We spoke for a few minutes about off-shore copies of Garrett turbochargers. All end in woe. He spoke of several instances of copies being bought into the shop for "warranty" work, after they had shucked blades or the wheels crashed into the diffuser.

I don't know exactly what this build is going into. I have several months of part and material sourcing, and I still have to install my current thrust GT into the go-cart frame.

If any of you come across a 4th stage c20 turbine wheel, please post or PM me.

Have a great weekend

Hurdman

[nersut]

Hi Hurdman

There is a 4th stage turbine wheel & NGV from a Allison 250 gas turbine on eBay, turbine wheel (buy for $299.99) and the NGV (bid) or NGV (buy for $450).


Cheers
Erik

[hurdman]

Erik,
Thanks!!

Hurdman

[racket]

Hi Hurdman

Those 4th stage bits on Ebay are a bit overpriced for what is essentially "scrap" ................the NGV flow area is too great for our use , some of the passageways would need to be blocked off .

I'd be offering only a fraction of what they're asking ,

Cheers
John

[hurdman]

John,
Thanks for the heads-up. After reading yours, Anders and AshPowers TV94 build threads, I assumed that the c20 4th stage wheel was the closest commercially available (even as scrap) to "fit" the TV94 gas generation characteristics. Is there a more suitable turbine wheel that you are aware of? As I mentioned above, I'm in the parts sourcing business for the next several months. I have time to find the right wheel.

After reading Eric's EBay suggestion and looking at the offering, its hard to tell if the wheel has simply timed out and is good-enough for me, or if it has structural problems...

I've got time. Plan, design and build the gas generator, get the numbers, then attack the free-power problem.

Suggestions?

Thanks in advance
Hurdman