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Post by smithy1 on Mar 21, 2016 3:22:23 GMT -5
Interesting thing,thanks for sharing it! Thanks Stephan, appreciate it..  Cheers, Smithy. |
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Post by racket on Mar 21, 2016 3:39:45 GMT -5
Hi Smithy
Has there been a problem with the check valve I had originally installed ??
Yep , plenty of battery power there :-)
Heh heh , theres always something with our "toys" to keep those brain cells working , even if they complain at times .
Cheers
John
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Post by smithy1 on Mar 21, 2016 16:39:52 GMT -5
Hi Smithy Has there been a problem with the check valve I had originally installed ?? Yep , plenty of battery power there :-) Heh heh , theres always something with our "toys" to keep those brain cells working , even if they complain at times . Cheers John Your original check valve isn't there anymore John...I've changed many things in the fuel system since then....I think I need to have a good think before I do more mods.  Cheers, Smithy. |
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Post by racket on Mar 21, 2016 17:48:29 GMT -5
Hi Smithy
LOL, sounds like me trying to workout this starter wiring , its a birds nest of wires that I really have no idea about :-)
Cheers
John
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Post by smithy1 on Mar 22, 2016 16:52:03 GMT -5
Hi Smithy LOL, sounds like me trying to workout this starter wiring , its a birds nest of wires that I really have no idea about :-) Cheers John LOL....Welcome to my world  Cheers, Smithy |
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Post by smithy1 on Mar 23, 2016 17:16:44 GMT -5
New high pressure stainless braided -4 fuel lines and fittings have been ordered should arrive soon, I'll get onto making them all to the correct lengths/angles etc....fit the injector check valve in the right place and I should hopefully have a nice high pressure fuel system with no more flame-outs..!
New Aluminium oil cooler and high quality "Goleby's" -10 AN fittings and hose are working a treat....not even a solitary drip from three consecutive ~5-6min runs on the weekend...happy that's finally sorted...oil temp never went above 85-90C..!
Cheers,
Smithy.
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Post by racket on Mar 23, 2016 18:12:38 GMT -5
Hi Smithy
That should sort her out :-)
Cheers
John
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Post by smithy1 on Apr 10, 2016 15:42:45 GMT -5
Hi All,
Been doing a few more "mods, updates and testing" etc... All the new high pressure braided fuel lines and fittings have arrived and have been made to "length/size" and fitted to the beast.
John, after a couple of quick engine test runs I've still got the flame-out issue, even after fitting the check valve "upstream" of the accumulator, admittedly it's a lot better than before but still happens on sudden decreasing throttle changes, if I "slowly" reduce the throttle, it appears to be fine...
I might do some more testing with progressively higher idle rpm/P2's to see if it helps alleviate the problem...ATM the P2 at idle is very low, maybe 2psi which may be a bit too low and possibly causing poor fuel atomization and inconsistent flame front...although the engine does sound good at idle, smooth with no fluttering and is able to accelerate cleanly away without any hint of surging etc...I only using the low rpm/P2 to help give a good flame show but I my have to change things I guess.
Since I've been changing things in the fuel delivery system I've needed to do a few engine test runs... I have had the max P2 limited to ~30psi for testing purposes to give me an idea of maximum/minimum fuel requirements etc, however, during the last run I opened her up a bit to see what fuel pressure is required for higher P2's, It seems I may have the 36v fuel pump motor running a little on the slow side, currently I'm using 4cell 16.8v batteries and I'm restricted to ~300-325psi at full noise....a bit low for the fuel flow I'm requiring at the top end and I was only able to see a max of ~33psi P2...so....over the weekend I have fitted a secondary fuel pump relay to allow me to use a higher voltage battery to supply the pump, independent of the Kart's normal power supply system. I'm now using a 6cell Lipo, 25.2v fresh off the charger, 22.2v nominal. This has upped the pump rpm dramatically and I now have access to well over 500psi of fuel pressure...much better, it's amazing what a few extra volts can do..!
I hope to do some more testing during this coming week.
John, I also hope to have it all running well by the time I come up to Port Mac and hopefully we can get together for some much needed "talking of crap"..!
Here's a thought John...If your new engine is running by the weekend of the 7th of May, I'm sure I can organize it so you are able to put it on display at the car show along with all my junk as well, even if it's not running you can at least put it out for people to have a look?? Waddyathink??
Cheers,
Smithy.
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Deleted
Joined: January 1970
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Post by Deleted on Apr 10, 2016 16:10:38 GMT -5
Hi Smithy
I think your idle P2 is very low, i have never set any of mine below 5 psi , at 2 psi things are only just running and i would think very close to hung or stalled condition.
On the HX80 which I am not 100% sure but i dont think your comp is not that much bigger, I am getting 34 psi with the afterburner back pressure drop, with Bosch efi pump and 16 volts.... i can understand some of the benefits to a high pressure
system, but think its a little complex for a diy engine. The extra kit involved and complexity and more weight :-(. But i admire you pursuit of excellence and look forward to seeing you getting some speed runs in
Did you tie the new power supply for the fuel pump into the oil pressure switch
All Best
Andy
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Post by smithy1 on Apr 10, 2016 18:04:13 GMT -5
Hi Smithy I think your idle P2 is very low, i have never set any of mine below 5 psi , at 2 psi things are only just running and i would think very close to hung or stalled condition. On the HX80 which I am not 100% sure but i dont think your comp is not that much bigger, I am getting 34 psi with the afterburner back pressure drop, with Bosch efi pump and 16 volts.... i can understand some of the benefits to a high pressure system, but think its a little complex for a diy engine. The extra kit involved and complexity and more weight :-(. But i admire you pursuit of excellence and look forward to seeing you getting some speed runs in Did you tie the new power supply for the fuel pump into the oil pressure switch All Best Andy Hi Andy, I'm tending to agree with you regards the low P2 pressures....I'm going to raise it to see if it helps. Actually the engine will run smoothly with pretty much nothing registering on the P2 gauge....obviously there must be some pressure happening but I suspect it's a bit low for the gauge to register. I normally have the idle at ~22-23,000rpm, again, probably a fair bit lower than optimal...but it will happily run at rpms as low as ~17,000....any lower and the egt starts to rise...which is to be expected. I'll take your advice and see what 4-5psi P2 does for me. Yes the new fuel pump power supply is tied into the original oil pressure "Hobbs" switch, it actually uses the original relay as a "pass-through" to the new relay...simple really. The only reason I'm using the higher fuel pressures is due to me using a "proper" turbine fuel nozzle...which requires fairly high pressures to operate/atomize correctly, the original vaporizer system John had fitted has been burnt/damaged... so, I fitted some real turbine engine parts in there....not a problem really as I have access to most of the gear to do it. The new pump and motor does weigh a bit more than the "twin" 044 pumps I was using...but not a great deal. I'm not really worried about the weight of the kart, I just want it to run reliably and nicely. Doing speed runs these days in Aus is very difficult....too much in the way of "safety concerns" and public liability etc...my local drag strip won't even let me run up the track slowly, let alone at any speed. According to them, I must have a roll cage, 5 point harness and a parachute to even be considered....LOL...the last place I want to be if the kart goes over...is in it..! Finding a decent "local" pace to run the kart at speed is proving rather elusive. Cheers, Smithy. |
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Post by racket on Apr 10, 2016 19:49:20 GMT -5
Hi Smithy
LOL, I might be able to get the 12/118 to the kart track , don't know about having it mounted on the test stand though ,the last time it was in the trailer I had to reweld a lot of its joints , but I could make up a bit of a mount for the engine so that it can sit on a table , that way I could just sit it on the car floor to get it to the show .
Those rpm of yours are very low , sub 20K rpms makes it a very flexible engine , its only ~22% N1 at 17K , something closer to 30 K would be my normal idle .
Heh heh , a suitable track for test runs...............its just opposite the Port kart track ;-)
Cheers
John
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Post by smithy1 on Apr 10, 2016 20:45:41 GMT -5
Hi Smithy LOL, I might be able to get the 12/118 to the kart track , don't know about having it mounted on the test stand though ,the last time it was in the trailer I had to reweld a lot of its joints , but I could make up a bit of a mount for the engine so that it can sit on a table , that way I could just sit it on the car floor to get it to the show . Those rpm of yours are very low , sub 20K rpms makes it a very flexible engine , its only ~22% N1 at 17K , something closer to 30 K would be my normal idle . Heh heh , a suitable track for test runs...............its just opposite the Port kart track ;-) Cheers John No need to bust your buns and put the 12/118 in a trailer John, I can easily plonk it in the back of my Transit van..! I have ramps, internal winch, tie-down points and plenty of ratchet tie-downs... I think your place is only ~10-15mins away from the kart track so I could easily unload all my gear and be back at your place in no time...then we can be back at the track with plenty of time to finish setup etc...Christine will be with us so she can look after the stuff at the track while I'm off picking you up..! Easy peasy.. We're staying in Port Mac so only ~10mins away from the kart track. We're driving up on Friday so I might even be able to drop in and say G'day late on Friday afternoon if it's convenient with yourself and SWMBO. Christine has helped me start the "Beast" a few times already....she's an old hand at it now..! Yes I know, you and others told me many times already that my P2/idle is too low I just like the big soft fluffy flames out the back..  Really looking forward to seeing you and making some noise & corruption together again...has been way too long Cheers, Smithy. |
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Post by racket on Apr 11, 2016 2:44:32 GMT -5
Hi Smithy
Might just take you up on that kind offer, it really takes two people to man handle the test stand , thank you :-)
Yep , by all means pop in on the Friday night on your way through , we'd both love to see you.
The kart track is about half way between here and Port , just off the highway .
Just about ready for another spoolup attempt , got the tach and TOT gauges mounted right in front of me whilst twiddling the fuel and starter controls , a much better setup than I had for the first attempt , ............hopefully I've learnt from those mistakes.
Cheers
John
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Post by smithy1 on Apr 11, 2016 14:31:03 GMT -5
It'll be a pleasure John....consider it done..!
Cheers,
Smithy.
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Post by racket on Apr 11, 2016 17:17:28 GMT -5
Excellent , I'll look forward to that :-)
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