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Post by racket on Jan 19, 2016 20:08:43 GMT -5
Hi Smithy
The slightly "longer" burning period is to be expected with droplets rather than "evaporated" and gaseous fuel which starts burning pretty close to the lid as it was delivered "upwards" rather than the conventional spray method "down" the flametube , all sounds good , a necessary development completed :-)
Cheers
John
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Post by smithy1 on Jan 26, 2016 16:50:54 GMT -5
Morning Chasps,
John & Andrew,
Some surprising results...I've had a short amount of time to play with the "clone" 044 fuel pumps at my work. I'm using AN-6 inlet and outlet fittings. Initially I just connected one pump to my test rig and supplied it with 40psi inlet pressure, I then gave it 13.8v and even at 100psi outlet pressure it was showing a whopping 520lb/hr (327L/H) flow...!!! That's a huge amount of flow, I was quite surprised with that. I also tried just 10psi inlet pressure and 100psi outlet pressure... the flow only lost ~40lb/hr...480lb/hr...still a huge flow.
Seems there's a very big difference between having to draw fuel up opposed to being supplied with inlet pressure. I'm a bit pressed for time at work atm...but I'll do a couple of different pressure/flow comparisons hopefully tomorrow. Seems these pumps like a bit of inlet pressure, they're much quieter too!
BTW...I gave the outer combustion case a coat of "Matt Black" paint....will take a couple of pics when I get it all back together, should look OK. No Anders, your suggestion of Pink with "Hello Kitty" stickers didn't get a look in..!
Cheers,
Smithy.
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Post by enginewhisperer on Jan 26, 2016 17:33:44 GMT -5
interesting results! I guess once you have the same type of pump supplying the inlet pressure, it will be sucking fuel in and its flow will be more limited. Sounds like in standard form the pumps are choking the inducer  |
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Post by racket on Jan 26, 2016 17:49:22 GMT -5
Hi Smithy
Very interesting :-)
Cheers
John
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Post by smithy1 on Jan 26, 2016 17:57:32 GMT -5
interesting results! I guess once you have the same type of pump supplying the inlet pressure, it will be sucking fuel in and its flow will be more limited. Sounds like in standard form the pumps are choking the inducer I suspect you're right Andrew....even so, with half that flow it will still be more than enough. I've "doctored" a couple of C20B fuel nozzles which have different flows depending on the supply pressures. Will be interesting to see what I finally come up with. Cheers, Smithy. |
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Post by smithy1 on Jan 26, 2016 18:59:44 GMT -5
Hi Smithy Very interesting :-) Cheers John Yes John, very interesting indeed, seems these pump are capable of more than we first thought when hooked up in series...I hope to do some "higher" outlet pressure testing, up to possibly 200psi, this may be of interest to yourself as well. We must also be mindful of the increased current draw associated with the increased pressures/loads, must remember to put a multimeter across the pump during the higher pressure testing. Cheers, Smithy. |
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Post by racket on Jan 27, 2016 0:03:35 GMT -5
Hi Smithy
LOL.............you're coming up with some rather promising developments :-)
Got my outer can wall back to the sheet metal guys to reweld after I removed a tad of the circumference to produce a tighter fit over the front cover O'ring seal .
Cheers
John
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Post by smithy1 on Jan 27, 2016 14:49:18 GMT -5
John,
I did a couple of quick tests this morning and the pump seems good to only ~175psi with 40psi inlet pressure, showing ~250lb/hr, at higher outlet pressures the flow drops of quickly. Current draw at the 175psi point was just shy of 19amps @13.8v !! The pump does indeed go to 200psi, but the flow is near zero, obviously the internal relief is doing it's job at it's design delta pressure. As we thought, the outlet pressure rises and falls basically with the inlet pressure...the pump does indeed run to it's designed delta pressures.
I then ran the pump with just 2psi inlet pressure and the flows are still good, outlet pressures of 160psi and under are possible and produce usable flows. I suspect a decent flowing "pre-pump" will be the way to go for those of us requiring heavy fuel pressures. It appears these pumps run much better with a positive pressure supply.
So...I guess the ~90psi you'll need for your new engine is indeed easily doable, even with a pump drawing fuel from a tank. I just did a quick test at "negative 2in-hg" inlet "vacuum" and 90psi outlet pressure....result = 455lb-hr..! Plenty for your application, (and mine), with heaps to spare using just the one pump. I'd suggest that a small head of fuel above the pump level would be the way to go. Happy days.
Cheers,
Smithy.
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Post by smithy1 on Jan 27, 2016 14:50:54 GMT -5
Hi Smithy Got my outer can wall back to the sheet metal guys to reweld after I removed a tad of the circumference to produce a tighter fit over the front cover O'ring seal . Cheers John Bugga....would a thicker section "O"ring help maybe?? Cheers, Smithy. |
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Post by racket on Jan 27, 2016 16:21:22 GMT -5
Hi Smithy
It was just a bit too much clearance , ~1mm diametric , I've reduced it to less tha half that which should be OK as the front cover will expand into the outer can for a tighter fit once running, that 1 mm diametric clearance would never have tightened up unfortunately , and it would have created problems once the screws were tightened as there would have been even more clearance in spots as the outer can "buckled" between screws that tightened down some parts of the can tight against the outer cover rim forcing other bits further away , just one of those things that had to be fixed.
Those pump flows sorta mean I could probably get away with just adding some supply pressure to the existing pump , thanks for the info :-)
Cheers
John
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Post by smithy1 on Jan 27, 2016 17:19:10 GMT -5
Hi Smithy It was just a bit too much clearance , ~1mm diametric , I've reduced it to less tha half that which should be OK as the front cover will expand into the outer can for a tighter fit once running, that 1 mm diametric clearance would never have tightened up unfortunately , and it would have created problems once the screws were tightened as there would have been even more clearance in spots as the outer can "buckled" between screws that tightened down some parts of the can tight against the outer cover rim forcing other bits further away , just one of those things that had to be fixed. Those pump flows sorta mean I could probably get away with just adding some supply pressure to the existing pump , thanks for the info :-) Cheers John Fairynuff on the outer can...Some of the early Jet-Joe engines had the same issue...poorly fitting outer casings etc...when it was running you could see/feel the air coming out. I believe you could even run an 044 pump without any inlet pressure....as long as there is a head of fuel to it...you should be ok. I think a lot depends on the inlet and outlet fittings too, I had differing results with -4 fittings opposed to the -6 fittings I used this morning...there's lots of variables. Cheers, Smithy. |
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Post by smithy1 on Jan 28, 2016 13:36:18 GMT -5
Hi All, Been doing a little fiddling over the last few days, I find it quite "therapeutic" just doing small mods etc...: A little hi-temp "Matt Black" on the outer case.  Single clone 044 pump for the engine...will possibly be "twins" in series soon to help with pressure requirements,  Accumulator to hopefully help with flame-out prevention during quick decelerations. John, the original accumulator had started to crack/leak around it's lower joint, so I thought it prudent to rectify before I spayed 100psi+ fuel everywhere.   Cheers, Smithy. |
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Post by racket on Jan 28, 2016 18:13:53 GMT -5
Hi Smithy
She's looking sharp :-)
LOL...........One of these days you'll add the roll bar and safety harness during a "therapy session "
Those high frequency screams/vibrations from the A/B were probably the undoing of the "sore thumb" accumulator.
Could you provide some info/specs on the new accumulator please ??
Cheers
John
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Post by smithy1 on Jan 28, 2016 19:33:35 GMT -5
Hi Smithy She's looking sharp :-) LOL...........One of these days you'll add the roll bar and safety harness during a "therapy session " Those high frequency screams/vibrations from the A/B were probably the undoing of the "sore thumb" accumulator. Could you provide some info/specs on the new accumulator please ?? Cheers John Hi John, A roll bar maybe, to protect the rather prominent combustion case, but a harness may be a moot point....there's no way I'd want to still be in the kart if it went over..  Your old accumulator started leaking around the joint at the bottom where it connected to the flow control tap fitting, I suspect the braze/solder joint was suffering, no matter, was easily repaired. The new "accumulator" is actually an old C20B PC air filter housing, I'm guessing it's ~2.5-3 cu-in capacity. I just blocked one end and it uses the internal ambient "air" as the pressure medium, similar principal to your original I suspect. Time will tell whether it works or not, it should, yours certainly did, so no reason for the new one not to. Cheers, Smithy. |
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Post by smithy1 on Jan 31, 2016 15:42:27 GMT -5
Hi All,
John, as mentioned previously I have four C20B fuel nozzles of varying flows vs pressures, ranging from a stock C20B fuel nozzle which runs as little as 20lb-hr @ 50psi up to ~300lb-hr @ 400psi. Obviously I don't have 400psi available so I have doctored a couple of nozzles to reflect this. I have adjusted one nozzle to flow ~190lb-hr @ 160psi which should be very close to what the 6041 requires at a P2 of 35-40psi...ish. I also have a nozzle which flows a similar amount at 120psi to take the P2 delta into consideration so we should be close-ish. I'll just have to test them to see what the actual "real life" results are.
I did a couple of test runs on Saturday, still with the single pump, I found after my fist test run with a higher flow fuel nozzle fitted, I could get the beast to run but throttle control in the lower P2 regions was a bit sketchy, obviously when I fitted a lower flow nozzle I required a higher pressure to achieve the same rpm/P2, but the pump would struggle at the higher pressures required. Will be interesting to see how things work out with the twin setup.
Late yesterday afternoon I fitted and plumbed up the "twin" pump setup in series to the "Beast" just to see what would happen pressure wise, interesting results too. I'm using -6 AN fittings in and out of both pumps except the final outlet which has an 8mm (5/16") ID hose to the fuel control. With a single pump drawing fuel from the tank I can only get ~90psi before the flow drops off to unusable limits. With the twin "series" setup I can easily achieve 160psi and still have a goodly amount of flow, so it looks promising.
I've also replaced all the flexible fuel lines with either braided SS lines....and from the pump to fuel control I've fitted new high pressure 300psi rated EFI reinforced hose...don't want our fuel hoses popping now do we!!? In the future I'll set about getting the required fittings etc for a full SS braided setup for all the high pressure lines, but for now these will suffice.
I have a car show this coming weekend, so hopefully I'll be able to give the Beast a bit of a test run to see if all is good.
Ideally we want a nice high pressure, fine spray pattern with these types of nozzles and as you're well aware, lower pressures tend to give larger fuel droplets and a poor flame front. All part of the trials and tribulations of DIY turbines I guess..!
Cheers,
Smithy
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