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Half tank lean
- Thread starter Blazer X
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DOOBEEWHA
HPISF languist expert
- Messages
- 1,332
- Location
- Petaluma,Ca,
Thank you, Crash...
Wow... I forgot about this thread.
After reading it again, I would have liked to have expanded on the pressure factor provided by the pipes return line...
That in it self adds another demension to the the whole half tank lean thing.
My guess would be that the added pressure of the pipes return line reduces the effects of half tank lean in a big way.
The only problem with relying on the return line is the fact that the pressure will vary based on the rpm's of the mill at
any given time, making the pressure source too erradic to for precise and consistant fuel flow.
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Blazer X
Well-Known Member
- Messages
- 973
- Location
- Hoosierland
- Thread starter
- #35
http://www.neweramodels.com/item.cgi?session_id=&part_id=1704 I think this is it jester
rex_hvn
luv RC but my wallet don't
- Messages
- 160
soz i should have added this
i have just gotten the Savage X SS and i have been running it in and the other day i started it up and gave it abit of a flogging and the temp went up but i was thinking could it just be if giving it some gut or is it half tank lean
thanx
i have just gotten the Savage X SS and i have been running it in and the other day i started it up and gave it abit of a flogging and the temp went up but i was thinking could it just be if giving it some gut or is it half tank lean
thanx
ya i have the new era tank conversion on my truck and it looks stock! and i love the idea of it having its own mounting bracket as apposed to it sitting on the chassis plate! less broken tanks I'm sure! and with all of the tank on the outside of the chassis plate lots more room around the engine!!!! better air flow now!!! and all the new era tank conversion is, is the ofna 125cc tank with the mounting bracket!! i like the way the ofna tank is made alot better then the stock tank but as was said a bit shorter run times though!
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DOOBEEWHA
HPISF languist expert
- Messages
- 1,332
- Location
- Petaluma,Ca,
The best way I've found to deal with it is to tune the engine after it's warm and do the tuning at the half way point of the tank...
Now...
You can either just only fill the tank half way and have it run pretty tuned or just fill it all the way and have it run abit rich for the
first half and perfect for the second half.
You might deside to tune inbetween this tuning zone to get a better proformance out of the first half, but you'l be taking away
from the second half...
Really sux. Or should I say, doesn't suck. Either way,... It definately BLOWS.lol
I hate it. But that's how we cope with the problem unless your willing to go to the other extremes like what the past posts have
suggested.
Now...
You can either just only fill the tank half way and have it run pretty tuned or just fill it all the way and have it run abit rich for the
first half and perfect for the second half.
You might deside to tune inbetween this tuning zone to get a better proformance out of the first half, but you'l be taking away
from the second half...
Really sux. Or should I say, doesn't suck. Either way,... It definately BLOWS.lol
I hate it. But that's how we cope with the problem unless your willing to go to the other extremes like what the past posts have
suggested.
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rex_hvn
luv RC but my wallet don't
- Messages
- 160
wot bout if i tried to have a pick up on either side of the tank i have access to things like that so if you have a sender on either side of the tank do yuo think this will help but when you think about it once you pass that shelf you will suck air
ill give it a go at home see if i can get my hands on a cheap tank
thanx doob
ill give it a go at home see if i can get my hands on a cheap tank
thanx doob
DOOBEEWHA
HPISF languist expert
- Messages
- 1,332
- Location
- Petaluma,Ca,
Good luck with any experiments you can conclude on, but the only true way to address this issue is an
actual electric pump that regulates a constant pressure to the carb inlet,.. and batteries.
And then ,.. and only then, you'll sill have to compensate at the needles to restrict the flow of fuel for
a propper regulation.
Piece a cake,, right?.. lol
actual electric pump that regulates a constant pressure to the carb inlet,.. and batteries.
And then ,.. and only then, you'll sill have to compensate at the needles to restrict the flow of fuel for
a propper regulation.
Piece a cake,, right?.. lol
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DOOBEEWHA
HPISF languist expert
- Messages
- 1,332
- Location
- Petaluma,Ca,
I will say this...
Gzus11 and I will likely agree that the best defense against dealling with half tank lean is to understand
what is actually happenning in the process of the physics involved.
It doesn't have to be a compliicated ordeal, just simply understood. That way you'll have a basis for an
approach in dealling with it.
And that means in most cases...simply tolerating it.
Now ,.. If someone came up with a tank that maintained a constant shelf below, or above the fuel inlet
and didn't sacrifice fuel capacity ai the same time while being protected from the rigors of normal use,...
Then,.. you would have something.
Gzus11 and I will likely agree that the best defense against dealling with half tank lean is to understand
what is actually happenning in the process of the physics involved.
It doesn't have to be a compliicated ordeal, just simply understood. That way you'll have a basis for an
approach in dealling with it.
And that means in most cases...simply tolerating it.
Now ,.. If someone came up with a tank that maintained a constant shelf below, or above the fuel inlet
and didn't sacrifice fuel capacity ai the same time while being protected from the rigors of normal use,...
Then,.. you would have something.
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savagebasher
Member
- Messages
- 45
i just bought the new savage x 4.6 and it doesnt suffer from half tank lean knock on wood.
ScooterB
Well-Known Member
- Messages
- 177
- Location
- Layton, Utah
I'm impressed!!
One of the best discusions on mid tank lean I've read and I've tried pumps and regulators and done a ton of research on the subject. Theres a couple guys here that get it and understand what it is and why. Reps given!
The best points I read were that there are no 100% cures but the reasons it happens and how to minimize the effects should be a huge help to many others. Although the midtank setups Ive seen do put most of the fuel above the carb which is why I believe they are effective in minimizing the effects.
One point I do want to disagree with is tank shape. Width and length make no difference nor does the overall shape but the height does create a greater difference in head pressure between full and empty.
I wonder if anyone has tried mounting a couple small tanks on the sides below the carb level? Just a thought.
Lower center of gravity, minimal mods, and puts all the fuel below the carb pickup. (no siphon flooding) Anyone? Maybe like a baja? Hmmm? Anyone? LOL
:10:
Thanks guys!
One of the best discusions on mid tank lean I've read and I've tried pumps and regulators and done a ton of research on the subject. Theres a couple guys here that get it and understand what it is and why. Reps given!
The best points I read were that there are no 100% cures but the reasons it happens and how to minimize the effects should be a huge help to many others. Although the midtank setups Ive seen do put most of the fuel above the carb which is why I believe they are effective in minimizing the effects.
One point I do want to disagree with is tank shape. Width and length make no difference nor does the overall shape but the height does create a greater difference in head pressure between full and empty.
I wonder if anyone has tried mounting a couple small tanks on the sides below the carb level? Just a thought.
Lower center of gravity, minimal mods, and puts all the fuel below the carb pickup. (no siphon flooding) Anyone? Maybe like a baja? Hmmm? Anyone? LOL:10:
Thanks guys!
battyone
Member
- Messages
- 32
am going to make a mini "coolcan" just coil up some fuel tubing inside a camera film cannister and try mounting to the rear of shock tower just above carby inlet level. A rather inexpensive experiment too try and cheat the "fluid dynamics of 1/2 tank leaning issue" maybe a check valve but if mounted horizontally may not loose its prime in between runs
so the best mod then for this would be to drop the tank though the chassis so it sit level with the carb inlet so you run on exhaust pressure going into tank than half of it with drop feed and pressure and once your half way just pressure so I'm going as from in the morning i will mod what I'm saying and post it and then try to run and let you guys know how it works
maximusraylius
Well-Known Member
- Messages
- 2,123
not sure if that will take care of it ..I'm thinking its more a air to fuel ratio inside the odd shaped tank itself that causes it... cause even with the tank sitting way above the carb ... its not feeding into the carb with out the exhaust pressure forcing it into the carb ... i think its the wide top half of the tank running different than when it gets to the narrow part do to how much the change of air pressure in the top of the tank changes once the fuels down to the small part of the tank ...
maximusraylius
Well-Known Member
- Messages
- 2,123
also you can drill out the nipple on the exhaust so it has a bigger hole and lets more air through to the tank n drill the tank inlet out same size as the exhaust outlet ... and run a longer fuel line n loop it around the tower a couple times to help ....
i hear what your saying however i think the shape has nothing to do with as in a earlyer post someone said about a fuel pump to keep the pressures the same from start to finish. Now if the tank is above the carb like i said you not only get the exhaust pressure you get drop feed until it get to the point were the fuel is level with carb and your only getting exhaust pressure, witch we all know she runs lean at this point.
also someone said that buggy/truggy and other monster truck as my mate got a traxxas t maxx and the tank is a lot lower than the carb and not one of this rc have the problem the savage has with fuel, a nother guy on her said have a longer fuel pipe witch is a good idea as this gives you a header tank but like he said it helps but not a 100% and that is because you still to some extend you still get a drop feed and the pressure till it get to the half way point or till it equals out
so by doing this mod and the tank sitting below the carb it will keep the pressure right and not getting the drop feed and pressure at one point and only pressure at half way point
also someone said that buggy/truggy and other monster truck as my mate got a traxxas t maxx and the tank is a lot lower than the carb and not one of this rc have the problem the savage has with fuel, a nother guy on her said have a longer fuel pipe witch is a good idea as this gives you a header tank but like he said it helps but not a 100% and that is because you still to some extend you still get a drop feed and the pressure till it get to the half way point or till it equals out
so by doing this mod and the tank sitting below the carb it will keep the pressure right and not getting the drop feed and pressure at one point and only pressure at half way point
ok guys an update to this problem everyone is having as you see from my last post i moved the tank down thats ok but once you get past the half way point of the tank it did not get the right amount of fuel so i went back to the drewing board and went to my local hobby shop and got myself a new tank
part no. MV3031 from xtm racing its only 125cc tank but it fits sweet it sit just below the carb inlet and finish just past the the shelf sits on the savage, not yet tryed it but if it works i will post everything to try and help you guys out that are having this trouble oh i just to add i had to move one of the fuel tanks post other than that it is sweet
i will keep you posted
part no. MV3031 from xtm racing its only 125cc tank but it fits sweet it sit just below the carb inlet and finish just past the the shelf sits on the savage, not yet tryed it but if it works i will post everything to try and help you guys out that are having this trouble oh i just to add i had to move one of the fuel tanks post other than that it is sweet
i will keep you posted
update- on sunday took the truck out and had the xtm fuel tank fitted on filled it up with fuel then started her up let it warm up and did some runs up and down till it got warm then started to tune her and she is running sweet i mean the best i have every seen her run popping wheelies on the button and having a sweet top speed so what I'm saying is this tank cost me £8 from my local hobby shop and what a buy it was and not going to look back
so if you have this problem and want a cheap fix that works link it should then this is the tank and all i had to do is drill one 3mm hole to move the tank bracket over and down
when I'm next out i will try and see if i can get a video of it running from cold to the point she is on fire so you can see for yourself how well it works
so if you have this problem and want a cheap fix that works link it should then this is the tank and all i had to do is drill one 3mm hole to move the tank bracket over and down
when I'm next out i will try and see if i can get a video of it running from cold to the point she is on fire so you can see for yourself how well it works
