|
|
Post by sweattechjet on Sept 13, 2016 21:46:34 GMT -5
I had been an Enthusiast of the DIY jet Community for about 16 years now. It's now time to start the dream. I have three European turbos (KKK 4LGZ). They are all in good condition and it's time to build my triple turbo build. There are some things that are up in the air and might need to be tweaked but I think I have a pretty good idea. Originally I was going to build three separate combustion Chambers for each turbo and combine all the exhaust together for a giant afterburner. Now after talking to Chris Krug he is suggesting I do one large combustion chamber. Either version will combine all three into one giant afterburner. I am a machinist and truck driver by trade and have access the great materials and junkyard components. And I'm not going to build a smaller one or single engine because I like noise and annoying The Neighbors. Chris told me to build the engine like it had a 4-inch inducer. Each turbo has 2.34 inch inducer. Thanks Tyler |
|
|
|
Post by racket on Sept 14, 2016 0:21:52 GMT -5
Hi Tyler This will be "interesting" ;-) May I suggest you don't use the Jetspecs flametube hole sizes for such a large engine , the diameter of the flametube will require larger holes for sufficient depth penetration of the air jets . Another consideration is your turbo wheel sizes , the turbine wheel exducer is rather large compared to the compressor inducer , what size is the turb scroll A/R ?? If the turb scroll A/R is a "small" one then you might be OK , but if its big , then your comp flow will be way over in the choke region . Checkout the GT6041 build thread for some ideas for combustor sizing jetandturbineowners.proboards.com/thread/78/garrett-gt6041-powered-kart , if you intend using a single spray nozzle in the flametube then your Primary Zone holes need to be a single row of at least 0.5" dia holes Cheers John |
|
|
|
Post by sweattechjet on Sept 14, 2016 16:03:14 GMT -5
Hi Tyler This will be "interesting" ;-) May I suggest you don't use the Jetspecs flametube hole sizes for such a large engine , the diameter of the flametube will require larger holes for sufficient depth penetration of the air jets . Another consideration is your turbo wheel sizes , the turbine wheel exducer is rather large compared to the compressor inducer , what size is the turb scroll A/R ?? If the turb scroll A/R is a "small" one then you might be OK , but if its big , then your comp flow will be way over in the choke region . Checkout the GT6041 build thread for some ideas for combustor sizing jetandturbineowners.proboards.com/thread/78/garrett-gt6041-powered-kart , if you intend using a single spray nozzle in the flametube then your Primary Zone holes need to be a single row of at least 0.5" dia holes Cheers John Here is two of my exhaust housings. I have to like the one on the right and one that is a slightly bigger one. Imagine this might make for a slight imbalance with 1 turbo running a little bit harder than the other two. I might consider going out and buying new turbos but I have to get a deal. From what I was thinking I would have to run 1 50 gallon per hour nozzle or three smaller ones. I also would like to run an idle now sold it just does preheating and low-speed idling. The only pipe that I can find in the sizes affordable are propane tank and Air tanks which I have plenty of. John with the information available what do you think my tube sizes should be? Tyler Attachments:
|
|
|
|
Post by racket on Sept 14, 2016 16:47:46 GMT -5
Hi Tyler
You've got to run matched turbos , those two scroll housings are miles apart in flow capacity , probably the biggest and smallest available , nothing but problems if you run them .
A "4 inch" engine can use a flametube of 7" diameter , so 9" OD outer can would be plenty big enough , as long as theres at least 3/4" gap between them for the air to get to the flametube holes.
Cheers
John
|
|
|
|
Post by sweattechjet on Sept 14, 2016 17:25:26 GMT -5
Hi Tyler You've got to run matched turbos , those two scroll housings are miles apart in flow capacity , probably the biggest and smallest available , nothing but problems if you run them . A "4 inch" engine can use a flametube of 7" diameter , so 9" OD outer can would be plenty big enough , as long as theres at least 3/4" gap between them for the air to get to the flametube holes. Cheers John Well I guess I can always run a double.  also while thinking about it I think the one turbo has too much damage so this might work out better anyway. How does the math change if you were doing a double vs. A single or a triple or or theoctagonal engine of Doom.? Thank you very much for all of your help so far |
|
|
|
Post by racket on Sept 14, 2016 19:53:56 GMT -5
Hi Tyler
A double would require a flametube with a ~5.75" ID , a section of 6" stainless pipe will do ................the flametube needs to have a cross sectional area of 3 times the inducer/s area .
Each of your turbos have inducer areas of 4.3 sq inches , so 8.6 sq ins for 2 , requiring 8.6 X 3 = 25.8 square inches which equates to 5.73 inch diameter, outer can at say 7.5"
Cheers
John
|
|
|
|
Post by sweattechjet on Sept 14, 2016 23:19:13 GMT -5
Hi Tyler A double would require a flametube with a ~5.75" ID , a section of 6" stainless pipe will do ................the flametube needs to have a cross sectional area of 3 times the inducer/s area . Each of your turbos have inducer areas of 4.3 sq inches , so 8.6 sq ins for 2 , requiring 8.6 X 3 = 25.8 square inches which equates to 5.73 inch diameter, outer can at say 7.5" Cheers John Ok thats amazing. 6" is easy to get. Easier build and still fun. Any other tips? Tyler |
|
|
|
Post by racket on Sept 15, 2016 0:14:30 GMT -5
Hi Tyler
Which turb scrolls are you going to be using , the fat ones or the skinny one ??
The different scrolls will allow different flows from the compressor wheel which will influence how the engine is to be configured.
Cheers
John
|
|
|
|
Post by sweattechjet on Sept 17, 2016 4:08:39 GMT -5
Hi Tyler Which turb scrolls are you going to be using , the fat ones or the skinny one ?? The different scrolls will allow different flows from the compressor wheel which will influence how the engine is to be configured. Cheers John I have two of the skinny ones. I think that will work really well. Is there a specific way to guess how much fuel you're going to need on any engine? Like for piston engines where we use brake specific fuel consumption. Tyler |
|
|
|
Post by racket on Sept 17, 2016 4:46:36 GMT -5
Hi Tyler
Yep , the skinny scrolls are best .
Fuel burn rate is at ~60 :1 A/F ratio , you have 8.5 sq ins of inlet area and you can work on 12 lbs of air per minute per sq inch so ~100 lbs/min , so ~100 lbs of fuel /hour .
Cheers
John
|
|
|
|
Post by sweattechjet on Oct 30, 2016 17:34:31 GMT -5
The project will continue here in a little bit but I've been building a bunch of stuff for cider and alcohol making at the farm.
|
|
also while thinking about it I think the one turbo has too much damage so this might work out better anyway.