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Post by slittlewing on Oct 25, 2020 14:29:31 GMT -5
Hi All, I thought I best start a new build thread, as I am the lucky owner of the 10/110 (10" wide casing, 110mm comp inducer) engine and kart built by AndyM! Andy got in touch around the start of the year looking to give it a new home, and although it was never in “the plan”, I couldn’t resist owning such a lovely piece of engineering!    The engine is custom designed by Andy, made from custom CNC machined components and John (racket) has done the calculations behind it. It has a 110mm Inducer Compressor and a HX82 Turbine Wheel, Andys build thread covering the engine is here: jetandturbineowners.proboards.com/thread/1025/hx-102-255-money-pitMy plan for the project is to get the afterburner working, and learn about the base temperatures and pressures the engine likes to run. Then re-engineer the control system to fully electronic, via a Mk2 ECU (not yet designed, but based around my Mk1 ECU in my Jetbike). I collected the kart in June, and quickly discovered I would need to make a working platform/storage trolley as space in my garage is so tight now. Using a roller cabinet that was being thrown out and some timber, I ended up with a reasonable solution!    A few months have since gone by without me touching it, mainly due to an attempted house sale/move and also as I have still been working on the jetbike. However with the house move looking unlikely I have recently started on the afterburner tweaks. In Andys latest tests the AB was seen to ignite/pop, but not run. The AB is scaled on Richard Staveleys (jetric) well proven design which many of us have now used successfully, so I think fuelling is all that needs fettling to get it working. That means changing fuel amount and/or spray... The original fuel ring had 15x3.0mm holes, so I plan to switch to 1.0mm holes for better atomisation. Johns previous Kart with similar airflows used 20x1.0mm holes which seems about right based also on my Jetbike (~25% airflow of this engine, has 8 holes running at a low pressure of ~5bar). So I will be trying 20 x1.0mm holes. In terms of the actual fuel “ring”, my Jetbike used a “P” shape ring, with a sealed end welded back to itself. This is relatively easy to make but not great for distribution at high flows, because the pressure drops along it. Therefore the first hole would see full pressure, the last hole much less. A work colleague modelled it and suggested I use a ring which had two entries and was a loop. This would have much better pressure distribution and an 8mmOD/6mmID tube could easily give the 5l/min required, whilst being easier to bend than 10mm dia tubing (and less obstructive to flow in the AB airstream). One additional benefit of this design is that there are no welds to the fuel ring in the hot section. This means alot less risk of cracking due to sudden contraction, which I think has happened to some in the past. After giving it some serious thought on how to actually manufacture this, I ended up making a jig. The tube needs to do two quite hard 90 deg bends from the vertical. I filled it with kiln sand and then got it red hot with a propane torch, at which point I could do sharp bends nicely. Then a lever and an £8 ebay “rope pulley” was used to pull the tube round a 60mm boss:          Lastly, I copied Johns “offset hole” idea, alternating around the ring centreline to give an even distribution.     I need to tig weld the AB back together still. In terms of initial AB fuel control, I plan to use a high side PWM driver. With the jetbike ECU, one of the main problems I encountered was not being able to easily “tweak” the PWM drivers without reprogramming. So for the initial AB testing with the kart, I have designed a new standalone single channel PWM Driver, that has inputs for a Potentiometer and pressure sensor and outputs for a simple 16x2 LCD display. I should therefore be able to just turn a knob and see the corresponding pressure and PWM I am getting. I also added some extra functions (Pins that can be used to record to SD card, a couple of on board Pots for testing and tuning PI control, pins for Servo output). Thus I should end up with a single box that I can use to map or characterise any fuel or oil system before going to full ECU control. It uses an Arduino Uno, and the PCB is only 100x100mm. The highside driver is also a new circuit design (uses both N and P channel Mosfets), the 5v is provided by a switching power supply with EMC filtering to try and avoid some of the problems I had with Mk1 ECU. In other words, this little box is kind of pre-testing most the elements of the MK2 ecu on a smaller scale. I took a bit of risk having it manufactured before testing with breadboard haha, will see if it works or not!! It is also designed to be able to operate pumps with 12-> 24v battery voltage, as the Kart currently has 18.5v system and supply to the AB fuel pump.  Hopefully more to report in the coming weeks! Cheers Scott |
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Sweetenough
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Joined: April 2016
Posts: 121 
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Post by Sweetenough on Oct 28, 2020 4:37:31 GMT -5
Hi Scott,
Congratulations to the new project! Really looking forward to see the cart running.
Innovative design to continue the tube back out again. Should also improve strength of the ring considerably.
As always, love your circuit design.
Kind Regards
Thomas
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Post by slittlewing on Nov 14, 2020 14:37:11 GMT -5
Cheers Thomas! The custom PCBs arrived and I ordered the components to make one. Today, after some soldering and basic Arduino programming it appears all is good with the new design  Just need to 3D print a case and hook up a pressure sensor ahead of any AB running!     Cheers Scott |
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Deleted
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Post by Deleted on Nov 15, 2020 19:26:27 GMT -5
scot , nice post on group, but get things right, the afterburner did not light becuase of bad fuel mix.... the engines ideal was to high... the fuel had no chance to got to the afterburner, thats only reason it did not work. Its design is like richards, but scale is to my own calculations,
you have added a new stress area to the afterburner, with cuting and I guess welding back the area you have, you will get heat stress cracking
You mention about the fuel ring not giving even pressure to the holes, but if you look at my afterburner video below, do you see any uneven flame shape or colour
As for you hole size, that afterburner had bigger hole area then , than you are planning now ?
Pluss your new fuel ring will now have bigger total front area, taking up more free space, there is because of uneven heating caused by the way its been contructed, the thing will twist. if you put suports in you will again be taking up more of the free area... in affect making the area in the dump pipe less....
"One additional benefit of this design is that there are no welds to the fuel ring in the hot section. This means alot less risk of cracking due to sudden contraction, which I think has happened to some in the past". nope...
only issue has been were the pipe went in to the afterburner, welded to the outer skin , which was sorted, now you have two pipe, with out the solution in place
Yes OK its yours... OK, but we spoke at lenght, and from what was said, was that to start it was going to be run as is? you mentioned about the afterburner, and as i have said, there would be no issue. When we did the deal, one of the things that was talked about, was i was willing to let it go to you, because i felt you would respect my hard work, and hope you would still let me be a part going forward ?
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Sweetenough
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Joined: April 2016
Posts: 121
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Post by Sweetenough on Nov 17, 2020 4:55:37 GMT -5
Hi Scott,
Nice board as always! Jealous of your electronic skills!
Is it a bosch 044 copy that you are planing to use?
Will follow this closely since I have pump capasity problem for my AB.
Used first an 044 copy and then uppgraded to a AEM400 pump with a full flow check valve to increase flow but still it is not enough.
Increase the voltage is an option that I have not really thought of.
Do you have any feeling for how much "over voltage" a 12V pump could take?
Kind Regards
Thomas
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Post by racket on Nov 17, 2020 15:11:45 GMT -5
Hi Thomas
They'll take considerable over voltage .
Some time ago I was having fuel supply problems with my 12/118 engine and Smithy did a range of testing on a 044 clone pump using his aero standard calibrated flow testing equipment at his works using a range of voltages and delivery pressures.
Heres a few of his readings..........
At 100 psi and 18 V it flowed 300 lbs/hr , at 25 psi and 18V it flowed 465 lbs/hr , at 60 psi it flowed 386 lbs/hr at 18V.
By comparison , at 13.8V , at 100 psi 162 lbs/hr , at 25 psi 362 lbs/hr and at 60 psi 272 lbs/hr
Smithy used Mil Spec calibration fluid, specific gravity 0.770 @ 60 deg F , so that 465 lbs/hr at 25 psi on 18V = 7.75 lbs/min = 3.52 kgs/min / 0.77 = 4.57 lpm
I ended up using 24V and a PWM to get my flow/pressure , but eventually went to larger injectors and lower pressures
Cheers
John
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Post by slittlewing on Nov 28, 2020 15:14:23 GMT -5
A small update... I welded the new “loop” fuel ring into the AB and then put the outer cone/skin patch back on. After welding this, there was some distortion to the cone (inevitable with stainless, particularly with 1mm gap from the cutting disc)
I don’t think the end result was “good enough” quality for the kart, so I will be rolling a brand new entry cone and placing the fuel ring in front of it, simplifying things as it only then has to go through one skin 🙂 on my Jetbike, this design has had no ill effects or cracking.
In response to Andy’s comments - I referred to my “closed P” shape Jetbike ring in terms of fuel distribution, not any previous AB of Andy’s. Without doubt, the new fuel ring has less cross sectional area to gas flow than the old 10mm one (including stays that will prevent any twist), it also has a higher feed flow area thanks to the twin tube feed. My personal view of why the AB has not worked so far is due to poor atomisation, hence trying the new ring, of course could be incorrect but it’s the first thing I wish to try!
If this modification is the reason Andy has left the forum I find it very odd, we discussed a new fuel ring and getting the AB going to be the first job on “the list” for the kart before I change it to ECU control. I bought this as a “project” and will be working on it/modifying and improving it as so.
However, I am sure (and hope) Andy will be back on the forum in future 🙂
Cheers
Scott
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Post by andym on Nov 29, 2020 6:24:45 GMT -5
A small update... I welded the new “loop” fuel ring into the AB and then put the outer cone/skin patch back on. After welding this, there was some distortion to the cone (inevitable with stainless, particularly with 1mm gap from the cutting disc) I don’t think the end result was “good enough” quality for the kart, so I will be rolling a brand new entry cone and placing the fuel ring in front of it, simplifying things as it only then has to go through one skin 🙂 on my Jetbike, this design has had no ill effects or cracking. In response to Andy’s comments - I referred to my “closed P” shape Jetbike ring in terms of fuel distribution, not any previous AB of Andy’s. Without doubt, the new fuel ring has less cross sectional area to gas flow than the old 10mm one (including stays that will prevent any twist), it also has a higher feed flow area thanks to the twin tube feed. My personal view of why the AB has not worked so far is due to poor atomisation, hence trying the new ring, of course could be incorrect but it’s the first thing I wish to try! If this modification is the reason Andy has left the forum I find it very odd, we discussed a new fuel ring and getting the AB going to be the first job on “the list” for the kart before I change it to ECU control. I bought this as a “project” and will be working on it/modifying and improving it as so. However, I am sure (and hope) Andy will be back on the forum in future 🙂 Cheers Scott Yes Scott we talked about the afterburner, and as i said at the time, the only reason it did not work in the one video I tested it, was I had know time in that video to let fuel make it way throgh.... the ideal was to high to get it to lite wth ease. I had already put system inplace to sort the high ideal when lighting the afterburnerthe design of the fuel ring and afterburner follows that of the 5 or 6 other afterburners i have made. Again like we talked about.... the plan was to run things as is, the only reason I had not done a second test... was issue with a few that live near me... there was no reason why it would of not worked..... and nothing at all to do with " poor atonisation " as shown in many of the videos of my afterburners, you all so mention the wavey end of the dump pipe being the reason the afterburner not working...... and again as i said at the time.... it had been done in others, even the one that set the world record on the Quarter and the Mile.... so no reason why it would not work . What was talked about was i was waiting for a new fuel ring, that was being CNC made from stainless... and at first run as is, and once the new one was done swap it out.... So now you going to change thing again, change the relationship of the fuel ring to the dump tube, the cone.... oh and who saw the distortion coming, before you have even run it.... but just what would of happen when you ran it. as for replacing the cone, it needs to be the same stainless, any guess whats going to happen when you replace the cone... well at laest if you dont use the same grade, as that used to build the afterburner. they will have differing heat expantion rates ? I have done the math, and you whole area is not bigger than the holes already there and that they are smaller, means you will have a bigger pressure drop arcoss the holes, you ring is bigger, sits in defferent place to the one i had, again the position of this was learned from the other afterburners made... but yours being bigger and having to add supports, more area, but the tube will twist dispite the supports, the tube sitting in front will see more heat, and the one sitting behind will be cooler as it sheilded by the one in front.... it may only be a few degrees, but will cause twist But, what would i know.... not like i been doing this for 10 years pluss.... I said in my last what I disliked about what you had put... I guess yes my pride was hurt... spent years getting to the stage i could build something like that engine... I had hoped that you respected that when we talked, you respected what i had done... the help i had given you before.... |
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Post by slittlewing on Nov 29, 2020 12:23:29 GMT -5
Hi Andy, I am glad you have returned to the forum You are correct, I have chosen to go for less hole area with the new fuel ring (15mm2 vs 106mm2). The tube delivery area is larger in cross section thanks to the twin feed (56mm2 vs 50mms2) The cross sectional area (blockage) to the gas flow of the new is approx 1005mm2 vs 1272mm2 for old. We all do this hobby for one main reason - enjoyment. I therefore have no interest in arguing over any small detail, modification or difference of opinion - in this case, something as minor as wanting to trial a fuel ring. Of course you have been doing it 10 years, experimenting with new ideas and learning along the way - exactly what I am doing right now. As I have said, I think the engine is a piece of beautiful engineering. To me, respecting the engine means making the kart as quick as possible and realising its full potential - which is what we discussed and what I am doing. If you want to chat further about it, then feel free to message me in private - I would prefer to keep this as a "build thread". Cheers Scott |
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Sweetenough
Veteran Member
Joined: April 2016
Posts: 121
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Post by Sweetenough on Nov 30, 2020 8:50:54 GMT -5
Hi Thomas They'll take considerable over voltage . Some time ago I was having fuel supply problems with my 12/118 engine and Smithy did a range of testing on a 044 clone pump using his aero standard calibrated flow testing equipment at his works using a range of voltages and delivery pressures. Heres a few of his readings.......... At 100 psi and 18 V it flowed 300 lbs/hr , at 25 psi and 18V it flowed 465 lbs/hr , at 60 psi it flowed 386 lbs/hr at 18V. By comparison , at 13.8V , at 100 psi 162 lbs/hr , at 25 psi 362 lbs/hr and at 60 psi 272 lbs/hr Smithy used Mil Spec calibration fluid, specific gravity 0.770 @ 60 deg F , so that 465 lbs/hr at 25 psi on 18V = 7.75 lbs/min = 3.52 kgs/min / 0.77 = 4.57 lpm I ended up using 24V and a PWM to get my flow/pressure , but eventually went to larger injectors and lower pressures Cheers John Hi John, Thought I responded when I read your post but apperently not. Many thanks for your valuable information! Time to crank up the voltage Kind Regards Thomas |
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Post by andym on Dec 5, 2020 4:05:14 GMT -5
Hi Andy, I am glad you have returned to the forum You are correct, I have chosen to go for less hole area with the new fuel ring (15mm2 vs 106mm2). The tube delivery area is larger in cross section thanks to the twin feed (56mm2 vs 50mms2) The cross sectional area (blockage) to the gas flow of the new is approx 1005mm2 vs 1272mm2 for old. We all do this hobby for one main reason - enjoyment. I therefore have no interest in arguing over any small detail, modification or difference of opinion - in this case, something as minor as wanting to trial a fuel ring. Of course you have been doing it 10 years, experimenting with new ideas and learning along the way - exactly what I am doing right now. As I have said, I think the engine is a piece of beautiful engineering. To me, respecting the engine means making the kart as quick as possible and realising its full potential - which is what we discussed and what I am doing. If you want to chat further about it, then feel free to message me in private - I would prefer to keep this as a "build thread". Cheers Scott Scott we spoke We spoke before you picked the kart up We spoke when you picked the kart up We spoke before about fitting ecu.... it was best to run as is, make sure all works well, with out introducing new issues etc We spoke about why the afterburner did not work in the one test that was done, how it was not because the wavey edge to the dump tube, or " poor atonisation " the desgin have been proven to work Your comment " My personal view of why the AB has not worked so far is due to poor atomisation " is just not true.... so ok, you want to make it faster... you dont know how fast it was... you dont know how well the afterburner would of worked, given the mods i hade already put in place. Why would i want to chat further, the faith i had before in what you said has gone.... you dont respect what was said, or even what I made... because you have just brushed it aside. Oh you held up, how well your afterburner worked before.... not so well on the track.... |
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Post by slittlewing on Feb 6, 2021 18:00:20 GMT -5
Hi All, A little update.. finally managed to get round to tacking up the new afterburner injection end. I rolled a new cone (laser cut) and a formed a new fuel ring again. Today I welded the fuel ring in and tacked up the tubing with a new V band flange. The old AB didn’t have a proper flange and had sealing issues which should hopefully now be sorted. I will attempt to fully purge the AB before welding together, as this prevents slag build up on the inside which can crack at higher temp. The rest of the AB (hot end) doesn’t look to have been purged but hopefully it’ll be fine! I had a bit of an annoyance with the tig, the pedal wasn’t working throughout so I had no current control which made it difficult. Found after that one of the wires in the pedal plug had not been soldered properly and come off, common isssue according to mig welding forum (cheap Chinese pedal haha). Will fix it before finishing the AB off!          Cheers Scott |
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Post by andym on Feb 7, 2021 1:54:18 GMT -5
There was a reason the afterburner mounted the way it did, and there had been know issue with it "The old AB didn’t have a proper flange" Yes the afterburner was gass backed when welded together, and as the five or six other afterburner I have made have not broke ?, dont see why this one should. None of these did www.youtube.com/playlist?list=PLO-dgzVeQXyka9ZZRBDxywiF4nN7y6ipfBut it is now going to , expantion and contraction of metals, heat, and differing grades of metal ? |
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Post by slittlewing on Feb 7, 2021 16:25:01 GMT -5
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Post by racket on Feb 7, 2021 18:26:03 GMT -5
Hi Scott Do you have any sort of rebate on your mounting flange to provide concentricity with the engine exhaust , I normally have some sort of projection jetandturbineowners.proboards.com/attachment/download/222 . Andys original A/B had that length of slipjoint that provided concentricity as well as sealing of the gases , a flat Vband flange isn't the best to provide/maintain concentricity especially at the heats the A/B attains , the Vband clamp will possibly "loosen" during use and the flanges get out of alignment. Cheers John |
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