FrontEngineDragsters.Org Forum
Technical => Spud Miller's Cave => Topic started by: noslin on July 21, 2019, 11:45:49 AM
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im wondering if we are having fuel draw issues on our rig. yesterday on the stand it started no problem three times. we filled it to the top in the tank and proceeded to start three times using most of the 5 gallons in the tank without issue. at the track we started it on the stands no problem and im pretty sure i filled it up to say 1/2" of full. made a test pass and it started no problems in the staging lanes like it should.
we went up for the second pass and it just would not prime/start. i dont know how full the tank was, im guessing within an 1" of full. the pump was just rebuilt by Enderle, its an 1100. it has six startups on it. the second you take the fuel bottle away it dies. the last time trying to start he just squeezed the bottle to keep running and it should of primed but it didnt. so we are wondering if there is a problem with height of tank and pump elevation.
all feds have the tanks way up front. I just put solid 1.25 alum tubing straight from tank to the pump thinking the braided i had on there was sucking air. we just stuck on the new pump inlet fitting on it, new o-ring etc and made sure it was seated correctly.
its just frustrating to us seeing how it ran fine one time and then next time its a little bitch and wont run. its a simple system but we are wondering if the fuel level and pump elevation might be part of the problem. what perplexes me is how can you start it three times without refilling the tank and it starts perfect each time with varied fuel levels and then when its time to go play it decides not to. he was pouring the fuel in to keep running and long enough to prime and second he pulled the fuel away it dies so we know the pump isnt priming as the feed line up to the BV is dry. I checked the pump drive shaft and its just fine.
Lets talk about fuel level and pump elevation. sitting on the ground the tank is 11" to the top. so full would be about 10.5". the bottom of the pump inlet fitting is 10", the barb is 1", the bottom of the pump is 13.5", the center of the pump is about 14.5 (guess).
Do we need to make a taller tank?
my buddy was doing some research and he noticed a lot of the older feds the motors sat lower in the frame (guessing) so the tanks were tall enough to prime etc no issue. whats the history on evolution to the new modern chassis design to the older ones if there is one? I know each chassis is custom fabricated and no industry standard. is there a target crank shaft height guys shoot for or does that matter.
Thank you
Dean
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I hope someone has a solution as we are having the same issues. We have discussed but not yet tried these idea's - a check valve, primer pump and raising the tank. Look forward to hearing the feedback.
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The pump can draw fuel up some but you do want to make it easy as possible. I think it is always difficult to make a MFI system start nice and clean on alcohol. They are touchy, too much alcohol it floods and does not want to start. Same if there is not enough fuel. Mechanical injection dumps a lot of Fuel at low RPM because it does not have pump shot. And alcohol is harder to start in colder weather. Mine runs better when motor is hot but is harder to start. So you are trying to get the right fuel mixture to get it started and run.
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Dean take the outlet line to barrel valve off at fuel shut off and crank engine to see if pump is working. Have seen a couple good pumps just stop working. Easy check before any changes.
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The pump can draw fuel up some but you do want to make it easy as possible. I think it is always difficult to make a MFI system start nice and clean on alcohol. They are touchy, too much alcohol it floods and does not want to start. Same if there is not enough fuel. Mechanical injection dumps a lot of Fuel at low RPM because it does not have pump shot. And alcohol is harder to start in colder weather. Mine runs better when motor is hot but is harder to start. So you are trying to get the right fuel mixture to get it started and run.
where learning that too. was using gas, then went to meth and a mixture of gas/meth, now back to gas.
Dean take the outlet line to barrel valve off at fuel shut off and crank engine to see if pump is working. Have seen a couple good pumps just stop working. Easy check before any changes.
weve ran the pump couple times with just a drill and tried that. it actually pumped fuel. this pump is basically brand new. enderle just rebuilt it and put new cover plate on it. just counted and we have one pass and seven starts on it. the drive is ok too.
we will get the fed out of trailer and get solid numbers on elevations. i think the differential is about an 1".
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we had the fuel shut off right after the pump to keep the lines full , belt driven pump, had to raise the frt end for cold starts after warmed started well, we always used gas in the squirt bottles don't know if it's the right but worked for us- 406 na, 406 blown, and 500 blown(had a cam driven pump)
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First thing to check is the pump, I don't care if you say its fresh. Pull the pump, and spin the hex drive, if it spins freely like a top with just your fingers , somehow you killed it by not having enough "free-play" and you drove the impeller into the front cover and opened up the clearance and its not making enough low pressure to pull fuel or even push fuel for idle, the pump is just windmilling. If you are running A/F with a 6.5 gal pump makes matters even worse due to the small pump. I had the same issue and never thought about the pump because it just came back from enderle, the motor was a fresh build and did not check the freeplay. If it takes a wrench to spin the pump, then the problem is elsewhere , but you know its not the pump
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dreracecar good answer seen it done with all kinds of pumps never thought of that.
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First thing to check is the pump, I don't care if you say its fresh. Pull the pump, and spin the hex drive, if it spins freely like a top with just your fingers , somehow you killed it by not having enough "free-play" and you drove the impeller into the front cover and opened up the clearance and its not making enough low pressure to pull fuel or even push fuel for idle, the pump is just windmilling. If you are running A/F with a 6.5 gal pump makes matters even worse due to the small pump. I had the same issue and never thought about the pump because it just came back from enderle, the motor was a fresh build and did not check the freeplay. If it takes a wrench to spin the pump, then the problem is elsewhere , but you know its not the pump
Thank you for your input. when i disconnected the pump and moved it to check the rod then went to put it back on i had to rotate the pump shaft which i did with my fingers with ease.. so thats it then. amazing it would go that quick. we set the free play up and thought we had it dialed but must be off.
we think the pump needs to be lower or taller tank or combination of both. right now with full tank, the fuel level is at 11" above ground, the pump is 16" to the center.i could build another tank and probably get another 1.75-2" out of it putting fuel level at 13" +/- but the fuel should be at the pump from what i understand.
From what i have heard, its not a good idea to run the pump dry for very long or it will go bad in a heart beat. Do guys drop oil down in the pump between starts?
what would be minimum acceptable differential between fuel level and pump center line, bottom or ? getting kind of spendy and frustrating dealing with this.
what are options to lower the pump? I see there is a mag/pump offset drive. could use this, rotate 90 deg and drop pump down a few inches. could use belt drive (guess). would a spur gear pump be better and take more abuse?
I never paid much attention to tanks and pump elevations etc while checking out other feds.
thank you
dean
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At this point, tank level and pump hight is not a player, the pump will draw the fuel. I tend to have the front/bottom of the tank a little higher than the rear so that gravity helps feed the outlet. Fill the tank full with water and the outlet capped, then pull the cap to see the fuel stream exit. should be a nice solid stream, surges and dribbles means that there is a problem with the vent. Try routing the fuel from shut-off back into the inlet side of the pump as when you shut it off the fuel just circulates and the pump doesn't run dry but no fuel goes to the BV
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Unless you changed tank heights between runs, that height is consistent so i would rule that out.
I would fill the tank and disconnect the line to pump and see if it flows, it almost sounds like something is blocking the tank output.
Also, I agree about tank level and pump height not being an issue, but only to a point.
If you do build a new tank, make sure the outlet is at the lowest point.
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At this point, tank level and pump hight is not a player, the pump will draw the fuel. I tend to have the front/bottom of the tank a little higher than the rear so that gravity helps feed the outlet. Fill the tank full with water and the outlet capped, then pull the cap to see the fuel stream exit. should be a nice solid stream, surges and dribbles means that there is a problem with the vent. Try routing the fuel from shut-off back into the inlet side of the pump as when you shut it off the fuel just circulates and the pump doesn't run dry but no fuel goes to the BV
Just took the tank out, plugged off exit/feed. filled it up, put cap back on, pulled plug on feed and it flowed without issue. i did it twice, once without the cap, once with the cap on and the flow was comparative both times. it just pours out.
on the pump, we have it with the loop line from fuel shut off to bottom inlet. Both bypasses go to the tank. i didnt think it was a good idea to return to the main fuel line like i have seen on other cars for concerns of aeration.
For general knowledge on the Enderle pumps like this 110, what makes them go bad? I took this one apart and to inexperienced it looks ok. the brass is new but shows wear. the gear shows no wear, there is no wear in the cover but the vane does show wear on the face. i dont know how the gear teeth and vanes match up though. so, just curious what kills them as they seem pretty fragile.
I ordered a waterman spur gear pump today. we will get the system flowed again.
Dean
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Just took the tank out, plugged off exit/feed. filled it up, put cap back on, pulled plug on feed and it flowed without issue. i did it twice, once without the cap, once with the cap on and the flow was comparative both times. it just pours out.
In my opinion, you should do all your testing with the tank in the car with the car sitting on the ground so you are duplicating actual conditions.
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Its a process of elimination, You have fuel flow out the tank-so its not that. Again it should take a wrench to turn the hex and not your fingers, Running the pump dry and/or slamming the shut-off without fuel circulation, slams the impeller into the cover.When I killed my pump, it would fire but lose fire at the end of the burnout Looping fuel back into the inlet does not cause airation (imo) because as Waterman explained, its a closed loop hydrolic system and no way for air to enter. Most every car built now runs around a 10" crank hight, so all fuel pumps are at the same level and all fuel tanks run the outlet off the bottom, and no issues for many--- whats your problem then??? Have you tried turning the motor over with the feed line to the BV disconnected?? Did somebody mess with the fuel shutoff and its off when you think its in the on position?, Did something happen to the HEX drive off the cam and its not turning?. Fuel systems deteriorate and need to be gone thru over time, But working one time and the next it doesn't, Something changed
Another thing I just thought of, was the pump cover removed and by accident rotated 180*??? that will change the direction of the pump flow
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Running the pump dry and/or slamming the shut-off without fuel circulation, slams the impeller into the cover.
Most every car built now runs around a 10" crank hight, so all fuel pumps are at the same level and all fuel tanks run the outlet off the bottom, and no issues for many--- whats your problem then???
Have you tried turning the motor over with the feed line to the BV disconnected?? Did somebody mess with the fuel shutoff and its off when you think its in the on position?, Did something happen to the HEX drive off the cam and its not turning?. Fuel systems deteriorate and need to be gone thru over time, But working one time and the next it doesn't, Something changed
Another thing I just thought of, was the pump cover removed and by accident rotated 180*??? that will change the direction of the pump flow
Thank you for the reply, the night we went out and ran we were trying to start on the stand and the dummy driver (me) did not have the fuel on. :( I think those four or five dry starts killed it i bet. then when we went to run that first time he heard this noise like two metals rubbing which i think was the pump.
we didnt take anything apart at the track between runs so id rule out all the other concerns. i think i just screwed it up with the dry start the first of the night thinking about it.
with the fuel system, we have the loop line, bypass off the shutoff to tank, and idle bypass off bv to tank. Ill make a braided line setup for the loop line this time as others have mentioned they have had issues with those sucking air too. You would think there would be no problems with brand new stuff but stuff happens.
im hoping we get the pump fairly early next week as we would like to join the nor cal nostalgia eliminator group's race in redding ca
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We had one of our Nostalgia meets today and trialed a check valve fitted to the output side of the shutoff going to the BV.
It worked a treat as is was much easier to start. :)
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We had one of our Nostalgia meets today and trialed a check valve fitted to the output side of the shutoff going to the BV.
It worked a treat as is was much easier to start. :)
what will this do? did you pre-fill the hose above the check valve. how many psi did you set it for. is it a high speed valve if that matters? after installing it did you notice any difference in your fuel psi?
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here some pics of our BV. We'll still use this shutoff on the new pump.
(https://i.imgur.com/NiBpDvC.jpg)
(https://i.imgur.com/qeCymrs.jpg)
(https://i.imgur.com/dZRBEuE.jpg)
(https://i.imgur.com/ZbQkPUy.jpg)
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We have not yet had a chance to check the pressure but I believe the one way has a 2 psi spring. Once fitted and the first start up completed it needed very little squirt bottle to fire up.
We have the shut off directly into the pump, then fitted the one way onto the end of the shut off. The one way has an o ring seal so it both holds fuel in the feed line to the BV and seal the pump from draining back. So far so good. Will be checking pressures in the coming weeks and will post when I have some numbers.
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Personally, I prefer the Enderle BV, with the main jet in the BV, that way the pump compresses the fuel into the BV and then bled off. Right now (as I am looking at the pics) you are bleeding off fuel before it gets up to the BV, almost like having a vairiable pump gpm depending on the jet size and a possible source for air bubbles. To me having the main jet there is like trying to pump up a tire with a hole in it. I guess anything can be made to work if flogged enough, but the enderle style is the most popular for a reason, and those few that run a hilborn hat/injector, usually convert to an enderle BV.
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Personally, I prefer the Enderle BV, with the main jet in the BV, that way the pump compresses the fuel into the BV and then bled off. Right now (as I am looking at the pics) you are bleeding off fuel before it gets up to the BV, almost like having a vairiable pump gpm depending on the jet size and a possible source for air bubbles. I guess anything can be made to work if flogged enough, but the enderle style is the most popular for a reason, and those few that run a hilborn hat/injector, usually convert to an enderle BV.
oh, thank you for the info. this is stuff we dont know and appreciate your input. Enderle checked out the 110 and said there isnt a problem with it. SO.. its interesting what you noted there about air. searching for things, i wondered if maybe that high speed might be open after a run or something like that. we were wondering about the loop line maybe creating an air pocket too with only a pound or two (if that) for fuel pressure at startup.
i got the waterman today, will get some flow numbers on it next week and ill tie the loop into the return to the tank. Ill tell my buddy about it. He has an old K-valve that he picked up with another hat he purchased.
ty
dean
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Most enderle systems rum the hy-speed after the BV going into the distribution block and bleeding pressure there, again I like the pump just pushing fuel up to the BV and not bleeding anything away before it gets there.
Top right is the main fuel inlet, top left is the main jet port plug, bottom left is the secondary idle bypass for when the BV is closed and when the BV is opened the idle port is closed and the main jet fuel return travels thru it, and the right lower is the hy-speed can which is just a spring/shim loaded poppet and it screws into a jet holder and then continues to the fuel distribution block. In any case, the BV always sees full pump pressure/volume, and the regulation is done after that
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Maybe hard to see, but here is both secondary and hy-speed lines going back to the return side of the fuel shutoff and from there into the inlet side of the pump. Its what has worked very well for me.
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Thanks Bruce for posting up the pictures, your help and knowledge is very much appreciated. One great thing about this forum is being able to get answers to things. Being novices both of us want to know the 'why' and 'how' things happen or moreover to be educated about everything even though its frustrating along the way. You go in being naive and not knowing and you take what is given to you as being 'correct' and its not, or is it.. then you start to look at everything else thinking its the problem.... or is it.
We made it back around to trying to get things sorted out. We think the issue is with fuel psi during startup at the Hilborn BV which leads to lack of fuel psi at the hat distribution block and thus not staying started. The motor has always fired instantly, its just getting it to stay started is the whole issue still. I put a fuel pressure sensor before the BV and i have one at the distribution block in the back. We tried to start it Saturday and still have issues but its getting narrowed down to couple things. One is spring pressure on the main and second might be the poppet psi settings for main and maybe idle?
Backing up a bit and again to the intro of this post, we thought there was an issue with the rebuilt 110. Enderle checked it out and said it was fine. Nevertheless, I got a new Waterman with equivalent pump PSI to the 110 and thats what is on there now. Two things that were changed are first, the loop is deleted and now returned to the tank and second, the main return was moved from the pump up to before the BV so there is fuel in the line to that point at least.
Nevertheless, one question we have is as main jet size increases how much change/increase does the spring pressure need to be increased by? The main is set at 5psi and never has been changed. The 110 was worn out when first setup at i think 11.2lbs psi. when rebuilt, it was i think 13.2lbs so the main jet needs to be increased. it was a 140 i think at 11.2lb pump and it was set at 165 to be safe with the rebuilt 13.2lb pump. When we made the pass in July with the 165, the EGT's were right in the ball park with the 165 main.
Reason for asking about spring psi increase on main with jet increase is with the 140 jet and old 11.2 gpm pump setup we really didnt have any issue with the motor starting and stay running. when we put the rebuilt 13.2gpm 110 on, the spring wasnt increased in the main so there was no fuel pressure for fuel to pass through the BV is our thinking. What clued us into thinking about this is, with the Hilborn BV the leak is a lot lower then for Enderle BV and the butterfly's are closed a lot more. ie; 38% and like 5k on the hat. only way we could get it to run was to increase (about 65% and 8k @ hat) the BV leak a TON allowing more fuel to 'dribble' by and that is not correct as the EGT's were WAY fat. So back to the question about main jet spring pressure increase versus jet size increase. Premise is to increase fuel line psi to force fuel passed the BV at idle.
Looking at one of the first logs with 11.2gpm psi pump setup, we had about .8x psi at idle at the hat distribution block. I didnt have a sensor setup before the BV so i dont know what that was. Yesterday i added a sensor before the BV, we had an average of about 9psi and only about .2x psi at the hat distribution block. As mentioned, with 11.2 psi pump setup we had .8x psi roughly. that leads back to spring psi vs jet increase in main jet???
Everyone runs the Enderle setups, with this hat we cant without major mods (i think). Looking at the front of the hat, this hat has provisions on the left side only for a BV. Looking at the hat, All Enderle stuff is on the right side of the hat. Really dont want (and wont) mod the hat so stuck with the Hilborn BV and this hat for now. Its a bitch'n hat and would really like to use it.
So, I have a few questions.
- is there a ratio or percentage to increase main poppet spring psi as main jet increases/decreases?
- should the idle poppet psi be less then the main psi on a Hilborn BV setup. Main is BEFORE the BV, not after. Main is at 5psi, Idle is at 12psi. To me the main should be higher then the idle, otherwise why have an idle bypass.
- for those with the Hilborn BV setup and main before the BV, what is the main spring psi set at. are you blown or injected?
- For those that run hat and port nozzles, at what PSI do you have your port nozzles flowing fuel? 1psi, 50psi, or and why
- for those that have logged fuel psi at the distribution block, what idle fuel psi are you getting.
- for those that log fuel psi at the BV, what PSI are you showing before the BV at idle & RPM? is the fuel psi sensor before the main or after the main poppet. eg; is your main at the BV or off the pump. if main is at the BV then is fuel sensor before or after the main but before the BV.
To me, I think there isnt enough psi at the BV to force fuel past the BV at start/idle. Further, with the main before the BV and the idle off the BV why have a low main psi (lower then idle psi). that doesn't make sense. I would think hypothetically if idle was 5psi and main was say 7 or greater would make more sense. to me, the main is in play and dumping fuel before it even gets to the BV, or at least reducing the psi at BV to get fuel back to the distribution block. if im understanding things correctly, the idle poppet is out of play after about 30-40 degrees of BV rotation. Idle should be main fuel bypass i would think .... at idle, not the main.
Thank you
Dean
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so today we took another stab at it. Jeff talked to a person at Hilborn a bit and we think were headed in correct direction. he said main spring between 2-5lbs, the idle (i guess secondary) at maybe 6 or so. set bv at 50-60 and butterflys at 6k. The guy also said the same thing that Spud told him on the phone before and that is before starting, open the hat and turn it over till fuel dribbles out the nozzle in the hat. then go ahead and start.
long story short, were about 58% guessing (need to test as was getting late) on the bv and 8k on the butterflies which got us in the ball park of idle about 2100. the egts are higher then we would like so we messed with the secondary and it wants to be guessing about 4-5lbs.
we need to get a better guage or something to test the lower psi numbers as we really dont know where its at becuase of the leak down tester i have. the low numbers i think start at 4 lol so its a guess.
we will mess with it maybe Wednesday or Thursday again and try to fatten it up a bit.
interesting deal, i would of thought that the main would need to be bigger then the idle. the way it sounds though, there is so much fuel flowing in the system it needs to be open soon to bypass it all. the secondary gets us in the ballpark with the idle egts. I wonder with it at 12lbs maybe it was too much fuel then at start guessing.... were bypassing more fuel now and its starting easier. The other thing too were finding is needing to leave the bottle on it a little longer till it takes hold.
looking at the fuel psi, the bv psi is about 7-8lbs and the hat distribution is actually showing a little vaccum, about -.25lbs psi fuel.
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Unfortunatly, you are asking questions that no racer (except pro level) looks at, so its hard to get answers, and since you have a Hilborn which regulates on a different princible then Enderle, I suggest again that you stop guessing and send the system in to get it set up and flowed, once this is done, the only jetting will be for altitude by swaping out the main for every 1000' change from baseline, just bolt it on and leave the rest alone