Wildguzzi.com
General Category => General Discussion => Topic started by: rodekyll on May 30, 2015, 04:12:53 PM
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In the course of building the trike, I've been re-inventing the Convert. I tossed the gearbox but kept the front hydraulic drive section. Where the clutch basket used to attach to the torque converter output shaft I've attached a forward/reverse gearbox with no gear reduction -- all of that will be done via the torque converter. So there is no clutch or gears -- just a hydraulic coupling between the engine and differential.
So far this part is working. I can start the engine and make the wheels go this way or that way. But the fluid isn't doing its job. Symptoms are weird.
The hydraulic fluid loop starts at the bottom of a radiator that has top and bottom tanks and about 4x the cooling surface of the oem cooler. The radiator is located a bit farther back than the oem unit -- about at the end of the top horizontal frame tubes. So there is more length of hose than oem (~18"). The radiator cap has a 15# popoff like a regular car.
From the radiator the fluid takes the traditional route through the pump and fluid drive assembly and returns to the tank. Again, the hoses are a bit longer than oem. I am using Gates transmission hose in all locations.
Symptoms are:
I am not getting a good t/c lockup -- massive slip.
Tiny bubbles in the sauce
If the cap is off the radiator I idle at about 5-6# atf pressure. Pressure does not want to come up much until the engine revvs, and then it's reluctant and low. The wheel motion is proportionately slow and weak, and I can stop the wheels with no rpm drop. At idle the wheels don't spin (rear axle in the air). I can see circulation in the tank.
If the cap is on the radiator the pressure builds to about 17# idle and the wheels spin weakly as I rev -- but no power -- no lockup. If I rev the engine I get better spin, some lockup, and what appears to be rapid heating of the fluid.
If I pop the cap (engine running) I burp out some fluid.
If I pop the cap (engine stopped) I burp out air.
***system holds pressure with cap on for hours***
If I crack the pump side banjo heading into the fluid drive section I get nice clear red fluid like cherry juice with the occasional little bubble.
If I crack the return side I get sputtering and 'milkshake' of tiny bubble foam.
I've been burping the heck out of it at the tank level. I pump up the pressure, stop the engine and burp the air (rinse and repeat). It always seems to have more air to burp. The only controlling factor to the burping seems to be the amount of headspace in the tank -- less space = less burp.
I've been burping the heck out of it at the banjos. There is always some more foam on the return side.
I've changed the height of the tank +/- 4" from my original location -- no change.
I've added a second intake hose from the bottom of the radiator to a T-barb at the pump (2x5/16) on the theory that the extra hose length is making the pump suck too hard and it's not drawing enough fluid, leading to either a starved condition or cavitation. -- still no improvement. I'm reluctant to run it as a pressurized system simply because it's not the way it's 'supposed' to work.
I don't think it's leaking air into the system because I see no leakage and because the system holds pressure for hours after shutting the engine off.
I'm too far out of the box to see it anymore. I need ideas or I'm going to have to return the fluid loop to oem, and I really don't want to do that. So you hydraulic guys need to pitch me some new thoughts.
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I used to work a lot with fluid couplings-what you are experiencing I'd expect would come from low fluid level in the unit. Can you check that?
Of course the fluid couplings didn't have cooling ciruits or pumps, but besides the extra component in the converter, the principle of the thing is the same.
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RK, possible relief valve in pump letting go too soon, sounds like pressure is the common denominator here,seems to act as internal bypassing. As you say when the pressure builds it starts to work. also what size I.D. are the hoses? :pop
Paul :BEER:
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First, thanks luap for managing to preserve recent topics. I would have really hated to retype all that.
Hose ID are all 5/16 (8mm). This is the natural OEM size of the banjo barbs.
Ah! A fluid coupling guy. Exactly the sort of expertise needed! Thanks for checking in. I might be coloring too far outside of the lines to be able to discuss this in purely guzzi terms. I think the theoretical level might be more productive.
I agree that fluid level could be a factor, although I'm not sure why. I do not have a big reservoir or 'tank' as such. The reserve fluid lives in the radiator. I can see fluid circulating in the top tank of the radiator, and do not see the tops of the tubes. Could 'low fluid level' = 'cant drop atf down the radiator tubes fast enough to feed the pump'?
I did a really mickey-mouse test last night before giving up in disgust and retreating to the comfort of wiring up my dash (comic relief). The test was to put 500mL of fluid into a beaker and stuff all the intake and return hoses into it. Sitting on the ground I wasn't pumping much of anything except air. I could feel weak suction with my finger plugging the intake end. At the return hose I had a steady stream of bubbles -- a couple dirigibles more than the system could possibly hold. I'd occasionally get a fart of sauce at the main return, but not much flow. The 'other' return -- the one for the shaft bearing lubrication -- was returning nothing at all.
Before we point fingers at the atf pump drive piece, let me point out that the system does show circulation when it's all connected, and it generates pressure -- up to 25# -- as long as the radiator is sealed (it might build up more, but I only proofed the radiator to 15# . . .). If the pump shaft was stripped I'd expect a weak flutter of pressure and zero circulation.
Right now I'm thinking one or more of the following:
length of hose exceeds ability of the pump to prime
lift of hose "" ""
radiator can't drop fluid as fast as the pump wants to pick it up
Less popular things I can think of:
pump gears are worn out and can't move fluid
installed t/c mouth seal backwards
Since the system holds pressure quite well and there is no external leaking (bellhousing dry) I'm not putting much stock in a seal problem.
My next test will be to get a 1-gal gas tank with a petcock in the bottom (hard to set down!) hung from an IV stand at a level above the pump so it's all gravity primed. I think that will tell me something, although I'm not sure what.
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RK, after looking at a parts breakdown of the t/c drive assembly it could be leakage between the trans input shaft bushing,or the seal ring inside the flange assembly. looks like stock pressures should be 30psi so its definitely going somewhere internally. If the converter isn't staying full that would raise the temps and aerate the fluid. Standing By...
Paul :BEER:
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So on thinking about this..the converter in principle doesn't need pressure to work, it would function with a fill of fluid until it overheated-the whole pump thing is primarily to get heat out of the fluid.
So it needs flow, and pressure readings are an indirect way to measure flow. And as you've shown you can have pressure without getting torque.
I think you are on the right track, there's a restriction somewhere, and the hose length is one.
Too bad you're so far away, this sounds like fun.
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RK, are you using a traditional coolant type radiator for the hydraulic system ???? If so I believe that is you problem. To cool hydraulic fluid I would use a single pass cooler such as used on an auto trans.
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Good thoughts, all!
The oem cooler is a small version of a side-tanked radiator. If you've seen a new-fangled guzzi engine oil cooler you have a good idea of what it looks like. The radiator I'm using is the same design except it's vertical and has a filler cap. I had tried to find a more traditional, single-tube oil cooler but couldn't find one with any tanks -- they all simply snake a tube through fins. Part of my design idea was combining the cooler and tank into one unit, and then hiding the unit back by the rear axle with an aux cooling fan, just in case.
Yes, the flow seems more important than pressure -- gotta keep the fluid cool. Fotoguzzi put a gauge on his 'vert and saw much lower numbers than I do -- 2 - 12#. I see 17 - 28#. Both of our rigs ran well. My other 'vert has broken its atf pump drive shaft. It went about 2 miles before the lack of flow overheated the atf and broke it down past usefulness.
So we have three ways to go -- literally a trivial problem: restricted flow through the radiator, line restrictions, and a bad t/c flange seal.
I dread taking the transmission back out, and like I've said before I'm lazy, so I'm going to start by eliminating the easier stuff -- flow restrictions. Earlier I said I was going to IV-stand a tank and gravity feed from the tank to the pump and return to whatever's handy. That should confirm or deny the pump's ability to acquire fluid from the radiator. I got lazier than usual yesterday and spent my trike time researching electric fluid pumps. So I'll get with the program today before the boss fires me . . .
I've got a loosely-wrapped theory that perhaps I need to add a reservoir to the loop, more like the oem system. I'm thinking that maybe luigi started out down the same path I've taken and found this same dragon.
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ok.
The good news is that it's not a supply side problem.
The bad news is that it's not a supply side problem
I rigged the gravity feed tank for supply and gave it about 12" drop. I put the return hoses into big vodka bottles. I get no difference in behavior at all. I have gaseous pee from the t/c return and virtually nothing at the tube/bearing return. Anyone got rum bottles? Maybe I'll find a flavor it likes. . .
So with the upstream end apparently working, I'm left with the pump and the fluid drive housing. I did not mess with the timing cover/pump during this project. I did mess with the fluid drive assembly to a fair degree. Did I mention that the bike ran to the shop for disassembly? I wonder what it could be . . . . . :clock: :clock: :clock: hmmmm. . . . . . sucking air . . . . :huh:
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I need all the help I can find. Got any? :boozing:
. . . and it's purple in my harness. Goes to the rear view picture tube relay. I'll see if I plumbed it into the pressure relief by accident.
Seriously though -- I've got all the components to the transmission on a bench out back. It looks like the big seal that the mouth of the t/c spins in is the only thing that seals it. There is an array of other seals and O-rings in the t/c output shaft tunnel, but they are all downstream of my problem and work to keep oil flowing to the bearing and shaft. It looks conceivable that if I didn't get that t/c seal completely seated it could be blocking the bearing oil galley, which would explain the lack of return fluid via that route. The part that I can't get my head around is how it's sucking copious air yet there is no fluid leaking -- bell housing and drain are dry.
On the other hand, I can't see how the pump could suck air either -- but one of the two is and as much as I dread checking either one out, I REALLY dread checking the wrong one first.
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I feel your pain BRO.I am hoping youll figure it out soon because I am experiencing nearly the same symptoms.I will drink six Coors original in your honor,hope it eases the PAIN somewhat!!!
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Morning RK!
I know that I'm in danger of trying to teach my grandmother to suck eggs, but have you had a look at Gregory Benders site?
There's a big chunk on the Convert transmission (under I-Convert)
If nothing else a read might release the hidden power of your mind to identify the problem :grin:
Tris
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Unless the converter is very weird, I suspect (still) low fluid, or possibly something wrong with the stator clutch-as in it's spinning when it shouldn't.
I think I'll peruse Mr.Bender's site.
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It has to be a fluid restriction somewhere for the TC turbine to cause cavitation.
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Further to it, the fluid level is below the minimum required, or possibly the stator clutch has failed-the pressure and feed should have no bearing on torque transmission if the fluid is at the critical level.
It won't work properly if the converter is completely full, either.
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Without actually knowing anything about what I'm saying, it sounds to me like your "sucking air w/o fluid leaking out" situation could be due to cavitation somewhere in the system. More likely to be a supply path blocked somewhere, because it seems that a return path blocked would lead to excessive pressure, possibly accompanied by unauthorized fluid egress. Maybe step around to the other side of the machine and try looking at it from that direction to think of what could have been blocked during the disassembly & reincarnation process. That's all I've got.
Good luck!
Howard
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I've studied on the parts that make up the fluid drive assembly. Assuming I got the intake and return holes in the output shaft tube properly aligned, the big seal at the mouth of the t/c looks like the only thing that could interfere with fluid flow. Since fluid does get into the t/c and return to the tank, I think the tube is correct. The seal could have been flopped during assembly, could be mis-seated, or could have torn.
So I'm tearing back into it today. I've designed the trike so the bellhousing and fluid drive stuff comes out without crabbing the frame -- just the drive shaft, alternator belt, exhaust crossover and a dozen nuts and bolts need to be removed and the fluid drive section slides straight back on a rail. I didn't want to prove it so soon. I hope to have a stare at the seal this PM.
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I've troubleshot more hydraulic and lube systems than I would care to admit. In my experience, bubbles in the system is indicative of air getting drawn in past the pump shaft seal into the suction side of the pump. I've cured a number of these by going larger on the suction line.
Your idea of eliminating the reservoir and putting it in the heat exchanger is sound.......in theory.
The flow velocity of the oil in the suction line should be below 2 feet per second. For 2 gallons per minute (SWAG)you would need to use 3/4" line.
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Hey RK,
I have seen where the internal lining of a hose is compromised/delaminates and collapses when under suction giving the effect you are seeing. If it can, air will suck past a seal but normally they just cavitatie like crazy and expel froth. I have seen this in hydraulic and fuel lines and also vacuum systems I work on in my present line of work and as we know, it is all about flow :thumb:
Food for thought
Adam
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I have all new Weatherhead and Gates transmission hose installed -- 200# and 250ºf in 5/16. It's stiff to the point of annoying and even when I try to pinch one closed with the hose clamp pliars I can't collapse it.
I'm nervous that I'm going to go through the grief of pulling the fluid drive and then discover that problem is the pump.
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I've troubleshot more hydraulic and lube systems than I would care to admit. In my experience, bubbles in the system is indicative of air getting drawn in past the pump shaft seal into the suction side of the pump. I've cured a number of these by going larger on the suction line.
Your idea of eliminating the reservoir and putting it in the heat exchanger is sound.......in theory.
The flow velocity of the oil in the suction line should be below 2 feet per second. For 2 gallons per minute (SWAG)you would need to use 3/4" line.
Any opinion on what a reasonable flow rate would be for a Convert? I've never measured that. I tried the other day by returning fluid to a gradient but with the bubbles and all I don't think it was a valid measurement.
Flangeman - the banjos have 8mm (5/16) barbs for all connection points. In the past I've successfully run 1/4" return lines by boiling the ends and stretching them over the barbs. (I only did it because ther ewas no 5/16 hose in town -- but it worked until the next time I changed hoses)
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Here is the formula. You want to size your flows based on the max normal speed of the motor. I realize the ports at the pump are small but is is easier to draw through a short restriction than a long one.
http://www.hydraulicsupermarket.com/upload/db_documents_doc_16.pdf
One other thing. You say the oil cooler is mounted in back. What is its vertical relationship relative to the pump? If it is above you could consider the pump to be flooded suction. If not, then the pump has to draw the fluid. The OEM was mounted high for that reason.
Is the OEM tank vented or sealed?
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The oem tank has a vent. I have never tested to see if pressure is still possible in the oem tank.
The cooler is mounted in the back, at about the rear axle if this was still an EV. The tank is tall. The top nk is a couple inches above the oem tank level and the bottom is lower. I have the pump feed at the bottom tank and the return feeds to the top tank.
With the cap off the radiator I idle at about 5# and have intermittent pressure increase as the engine revs. I can coax it up to about 17#. At about 12# the rear wheels begin spinning, but I can stop them easily with my hands and they don't accelerate at the same rate the engine does. I'm 1:1 back to the differential, so I would expect some sort of proportionate increase in wheel speed with an increase in engine speed.
With the cap on the radiator the pressure comes up to about 8# at idle (initial start). If I burp air/quickly restart I can coax the idle pressure to about 17#. Rear wheels start spinning at about 10#. Although there is a better correspondence of wheel speed to engine speed, it is still a 'limp' coupling -- wheels slow down and speed up at constant engine speed and I can still stop the wheels with my hands. Returning fluid is foamy and heat builds up quickly.
cavitation. I know cavitation happens when we spin a propeller (impeller) faster than it can move the fluid. This cause a void on the low pressure side of the vanes and the resulting 'cavity' produces some sort of bubble. What is the bubble made of, and can cavitation continue to generate bubbles indefinitely?
Again -- system does not leak fluid externally. All fittings and the bellhousing are dry.
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Another troubleshooting thought --
I've been looking at 'lectric oil pumps. It looks like I can get a continuous duty pump that operates 12vdc, handles boiling temps, lifts to 4 meters (~6.5#) and pumps a couple gallons/minute. Does anyone see an advantage to an alternate pump source? @~$65 it could be cheap . . .
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Part of a reason for a tank in a hydraulic system is to allow the fluid to deaireate (sp) those little bubbles need to go somewhere and not back into the flow of fluid. Just a thought.....
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So you're suggesting that the tank might be for more than just storage -- it's also for settling out the bubbles. I was hoping that the drop down the radiator tubes from top tank to bottom would act as the burping agent . . .
. . . I can add a tank if I need to. I mapped out some space for one when I placed stuff. I was hoping for success with the more elegant radiator-as-tank solution. I'm about halfway in to the disassembly for seal inspection right now. I'll ruminate on this development as I bust knuckles. :undecided:
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I'd try and rig a tank at approx. the same elevation as an OEM one and plumb it without a cooler of any kind. See if it works. Would be pretty easy if you have an extra OE tank laying around.
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I do have an oe tank on-hand. I'd have already done that test, but with the IV tank not helping at any level +/- (with and without the cooler in the loop) I couldn't see replumbing it back to complete oem without taking a look at that seal. I guess part of it is that reverting to oem is a tacit admission of defeat -- that my design is bad. I'd much rather find a brain fart in the assembly or a bad pump. I scratched my head raw thinking this concept out and if it's possible for it to work, than yb dog ist's gonna! problem ---> :violent1:<----me
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Yes, I can go back to oem if I have to. There's nothing about the trike that prevents it except me.
I got the bellhousing off and took a peek -- everything looks pristine and normal. Nothing visibly installed wrong. No leaks and no signs of abnormal rubbing or stress. When I separated the units I lost a couple ounces of fluid -- nothing to suggest the t/c is filling completely. However fluid is dripping from the mouth of it (as it ought to with it hanging open), and it looks fresh and clean. Where's that pounding my head on a nail smarm when I need it?
Well, unless anyone has anything for me to check while I've got it open, I think I can eliminate the fluid drive section as my problem. I'm waiting for input before buttoning it back up.
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Ok a dumb question..I don't know how the convert system is configured but I have some experience with auto type fluid converters and theory of operation from school.
So the question is this. Are you running allot more fluid thru the system, (more than the convert specifies) and did you bypass the cooler you installed (non oem?) and try operation?
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Yes, I bypassed the cooler. I hung a tank and gravity fed to the pump. I put the return lines into bottles. So it was a 'total loss' oiling path. When a bottle filled I'd change it and dump the fluid through a paint filter back into the IV tank. I ran about a gallon through this way and still saw bubbles in the return bottles. I'm not talking little whimpy beer bubbles. I'm talking Mike Nelson doing SEA HUNT in my torque converter -- big, gulpy, SCUBA-sized bubbles in an urgent and steady stream.
I'm not sure what you mean by 'running a lot more fluid through the system'. Do you mean total system capacity? I think my system holds about what the oem did. I'll be able to tell the volume better when I repair the other bike. I'll be draining the system to get at the pump.
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I think he means is the converter overfilled. It won't work if it is too full. I'd gues any more than 1/3 full will start to cause trouble, maybe a bit more.
Stator sprag clutch working OK?
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Yes that is what I mean. Normally fluid torque systems are designed for a certain amount of fluid and if you over fill it can cause big problems.
I guess I'm at a lose. It seem to be a flow thru the converter problem/ cavitation of the stators? The air injected into the system may have been caused by that. If everything is right with the converter it should lock up (with a small bit of slippage) pretty solid until it stalls the engine unless the clutch slips to prevent that.,but you say you can stop the wheels (both?) buy holding them with your hands. Curious! If assembled correctly and sealed with no leaks then the stators HAVE to hook pretty solid (if under stall rpm) if they have the proper amount of fluid.
Maybe it is the clutch.
Wish I had more but I would be shooting in the dark.
Hope its something overlooked and simple.
mike
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Silly me, I just reread your original post and can see that you have removed the oem clutch and gearbox!
So what you have is a one to one connection from the torque converter to the rear end thru a high gear and a reverse gear. That converter was designed to work thru a primary reduction (low gear) to the rear drive and what you have has maybe overwhelmed its ability to produce enough torque from the engine to get the thing moving.
What I mean is that the driven stator and the driving stator have to come up to approximately the same rpm for the thing to hook up properly and maybe you are operating in a stalled condition without the mechanical advantage of the transmission. It was sized that way for fitting in a small place. You might need a larger converter! or the oem gearbox?
Dominos!
OTOH,
Maybe its the wine I had for dinner!!
mike
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RK,please post information about the electric oil pump you mentioned earlier,Ive installed a cheap universal fuel pump and intend to keep it onboard I just need a heavy duty type. I also am experimenting with HEAVY oil (LUCAS) so far with good results. PS I got a mild hang over from all the beer WE drank the other nite!!!
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If I recall correctly, the Vert transmission is a 1:1 reduction for high and a 1.6:1 reduction for low.
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Even with no reduction, there's a serious torque coming out of that-I'd guess at stall you have at least 2x input torque.
If you could get the COOLING pump out of the equation, fill the converter with about 1/3 full and block the pump lines, you could at least eliminate internal converter problems (which I'm sure aren't the issue but a bad sprag clutch on the stator might cause low torque).
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Right. No clutch.
The rear axle is in the air. There should be no stalling with no load, should there?
The ratio is 1:1 to the differential. The differential is 5:11. The final ratio is about 10% lower than what we worked out for the final difference on the oem tall gear.
Fubar -- this is an example of the pumps I'm looking at.
http://www.ebay.com/itm/12V-DC-CPU-Cooling-CAR-Brushless-Water-Pump-Speed-Adjustable-2000L-H-Brand-NEW-/381250988937?pt=LH_DefaultDomain_0&hash=item58c4546b89
It does continuous duty ~8gal/minute @6# and says it's good for 200ºc. Foroguzzi has made a real good argument for the suitability of low pressure/high flow with a project he did a few years back. He had a pressure gauge screwed directly onto one of the transmission fluid joints and (iirc) reported 2 - 12#. I felt that more pressure was better and boosted one of my bikes to idle ~ 14-17# and run ~20 - 26#. Both answers were correct.
I'm interested in what you have to say about heavy oil. I've tried about every kind of hydraulic fluid I can get my hands on -- the aviation 5606A as well as all of the modern ATF formulas, power steering fluids, hydraulic jack fluid, fork lift hydraulic oil, etc. I've tried them with and without additive. I have not experimented outside of these viscosities. So far the 5606A is the best replacement for Dexron II that I have found.
On the overfill -- As said in a previous post, I caught a couple ounces +/- when I separated the bellhousing from the engine. About what I expect. I can see fluid in the t/c. T/c looks fresh -- no discoloration from heat and so far no stink from scorched fluid.
Kirby -- we see air and we talk about "yup, it's in there!" but so far I'm not getting any satisfactory sense of where the air is coming from. Cavitation doesn't invent air. And unless Lloyd Bridges (who puts two LL's at the beginning of a word?) really IS filming SEA HUNT in the t/c, there's just no physical way that much air could be trapped inside it.
Normally I get a perverted glee out of winning a game of "stump the experts". This time not so much.
Aaron -- I'm not ruling out a problem with the t/c itself, although it's low on the list. Remember the donor bike 'ran when parked' :evil: . That means I drove it to all three ends of the road just for old time's sake before pulling it through the bay doors and taking it apart. I was both sad that I was stripping down a good runner, and excited to get it running again in this incarnation.
I'm not sure this t/c has a sprag clutch. I *think* it's just a pair of simple turbine vanes, one drive and one driven. How could I tell (I have a spare on the bench I can run the tell on)?
As a side note to that -- last year someone was saying they had a dead t/c they were thinking about sending me so I could cut it apart and see what is inside. I don't remember who you are, but now would be the time! I used to have a cut open one lying around, but it must have fallen victim to spring cleaning.
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I've been asking that question with my sea hunt monolog. So far Mr. Nelson isn't talking. :sad:
If I could find the source of the air I think I'll have found my problem. I opened up the bellhousing first because that's where I had my fingers last. The only other place I can see that the system intersects air is the pump.
I guess it's possible that this problem pre-existed the trike project, but if it did, I can't explain why the bike ran so well.
I've been thinking on Aaron's idea of prefilling the t/c and sealing the exits. The system would only function for a few minutes -- until the fluid got too hot and scorched -- but that might be enough time to confidently eliminate the t/c as an issue. I've got another one, untested. I'm quite reluctant to change it on speculation because it's a PITA to center it in a vertical position and I'm sure as hell not pulling the engine again to tip it on its nose.
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The cooler (radiator) is the tank, so it is both upstream and downstream of the pump. Flow looks like this:
tank/cooler bottom -> pump -> fluid drive --> tank/cooler top -> drop through radiator tubes to bottom tank.
Yes, I proofed the radiator to 15#, which I thought would exceed any internal pressure by a bunch. To do it I plugged all the spigots, added a Schrader valve and pumped in metered air while immersed in a tank of water. When I got the spigot plugs all tight there were no bubbles and it held at 15# for quite a while ~(1 hour) before I released the pressure and called it good.
The big question remains -- who's got air and why are they sharing it?
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Yes, I have a permanent pressure gauge in the pressure line from the pump to the t/c. That's where I'm getting my numbers for this conversation. Fully assembled, cap off, it tells me what the high pressure part of the system is doing. If I cap the radiator, right now it tells me total system pressure since the entire system is pressurizing. Ideally it should still be telling me what the high pressure segment looks like, since the rest of the system should not be pressurized.
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Quick review of torque converter vs fluid coupling.
A fluid coupling has 2 sets of vanes-the input side is called impeller, the output is the turbine.
Torque in = torque out, no reduction.
A converter is similar but adds a stator, which redirects the fluid from the turbine, and is on a sprag clutch-which allows for the torque multiplication feature of the converter.
It only goes one way-if it doesn't, no multiplication, and fluid from the turbine will be able to hit the impeller (also called a pump in converter-speak) so may cause problems.
In either case, if the unit has oil and all parts inside are even sort of working, you will have output torque at least as high as input torque. Too much or too little oil will also cause problems.
The external pump on the convert is only for cooling. Maybe it is over or underfilling, and if the stator clutch is working there isn't much to go wrong, at least in the way you are describing.
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The t/c output side spins freely in both directions -- no difference in resistance either way. But you're saying the sprag clutch sits between the impeller and the turbine. Is there a way to bench test it?
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:popcorn:
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Glad I'm not boring you. :boozing:
Headed out to button it up and maybe run over my head with the LR wheel. I think the next test will be to block the exits and holler "FIRE!" at the fluid trapped in the t/c just to see what it does.
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I have two candidates for 'lectric pumps. Here are examples:
http://www.ebay.com/itm/NEW-Heavy-Duty-Rear-Mount-Turbo-Oil-Gear-Pump-12v-12-volt-Scavenge-Replace-STS-/191194745050?hash=item2c841848da&vxp=mtr\
http://www.ebay.com/itm/12V-DC-CPU-Cooling-CAR-Brushless-Water-Pump-Speed-Adjustable-2000L-H-Brand-NEW-/381250988937?pt=LH_DefaultDomain_0&hash=item58c4546b89
Any thoughts on which is the better gamble? The plan is to get one in, use it to get the other bike going and see how it performs on a known good ( :rolleyes: ) 'vert. If it works there, try it on this problem child.
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If you can get the coverter out, you can reach inside and feel for a splined area-this will be the stator, and it should turn in one direction only. If it is free in both directions, the converter won't transmit much torque.
So try to fill the converter about 1/4 to 1/3, it should produce strong output. If not, I would suspect staor clutch failure.
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I can access it in situ and spin it with a spare output shaft. Stand by . . .
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I have two t/c's on hand. I put an output shaft into each and engaged the splines. Both turn freely in either direction, so they might both be bad? So I can't confirm or deny the operation. Does anyone have a known good t/c they could do the spin test with?
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There is air in that system at atmospheric pressure or close. You really can't get it out! It won't take much to make bubbles, lots of bubbles. (also gas in the fluid)
The question is not how much torque is being produced by the engine, it how much is transferred from out put(engine) to in put. It just can't even overcome the wheels off the ground unloaded condition.
There is too much resistance on the output side to quickly do this. If you were to maybe set the engine to 1200 rpm and let it slowly spin the wheel(s) faster (help it by hand) and would likely, after some time finally lock up and turn the output shaft to near the same rpm. That's why they made a two speed with a low gear to lessen the torque required to get to lock up.
Your a 'vert guy so tell me how long would it take to start in high gear and accelerate to cruise speed? Its like me trying to take off in my old pickup in high gear. Sure I can do it but I will have to slip the shit out of the clutch and it will take some time.
Even though you have the wheels off the ground there is still allot of mass to accelerate and little mechanical advantage in a 1 to 1. Torque increase should be linear as the stators come up to the same or near same speed and lock up.
The real implications are that the small t/c from a 'vert is going to give you fits on any incline. Its just not big enough to overcome the high breakaway forces in 1 to 1. (from a stop).
That's why they had to use a low gear, to get it locked up and away you go.
I think the t/c is too small for what your expecting on a 1 to 1, yes even with a very low axel ratio.
FWIW
mike
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Kirby , 'Verts aren't truly an auto trans , one either selects low or high range and motors away .
Dusty
Thanks!
But we are talking about torque converters here not transmissions.
:-)
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Oh -- we're past the 'standby'. I did the test and the t/c spins both ways. I just got off the phone with MPH. Mike walked through the t/c construction with me and says that since I do not have concentric output shafts (one spins inside the other) I do not have a locking torque converter. I have a simple fluid coupling which does not have a lockup capability. This was my original understanding of the function. His reaction is that it's a pump problem.
So I'm really going to button up the back. Really. Right now.
Kirby -- I understand that you're not talking auto-transmission, but let me entertain you with a monolog anyway . . .
The legend has it that the original prototype 'vert had no gear reduction either. MG was marketing it to LEOs, and they complained that it was unnatural to not shift a bike, and also that the stop-go urban traffic would cause the battery to discharge during the workday because the engine wasn't going fast enough to work the alternator. MG responded with the 2-range gearbox and coupled it with a moped/scooter clutch pack. The clutch pack was designed to run wet, but it was used dry. With 11 or so drive/driven 'wet' plates running unlubed, it never cleanly disengaged and gear changes on-the-fly were discouraged.
the gear change is made manually, before starting to roll the bike -- low range for town so the alternator charges, and high range for everything else. In normal operation you choose your range and use it from 0 - XXX. The time difference between hole shots in low and high isn't significant. The only real difference is the amount of slip getting to speed and the possible top speed/range. I have another 'vert that I locked in high gear, threw away the shifter and clutch control, and pinned the clutch pack so it is impossible to slip the clutch or change gears. I've been all over the continent in high range without shifting. The whiz kids at WG helped me calculate my final drive ratio. Given the Ford rear gear choices, I could go either slightly higher than oem final ratio or about 10% lower. I installed the 5:11 Ford gears for the 10% lower. I figured with the extra weight of the trike frame/body my curb weight is probably close to my loaded weight in 2-wheel configuration.
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Thanks for that RK, I have only seen one convert, FUBAR's and watched as he tried to pull a heavy picnic table across a park on it. It would not even spin the rear wheel but did finally put the table to its new position!
I think it did managed to spin the rear once on the grass .
Anyway I tried to get some data on the workings and there isn't much out there I could work with. It does seem to me that the converter is stall/caveating which is releasing some gas bubbles. It also seemed to me that if your using a ford (read auto) rear it has to be much heavier than the 'vert components which could have a detrimental effect on its (t/c ) performance.
I will let it be now and hope you find an answer to your problems. As a fellow experimenter it would be sad to see the considerable effort you have put in wasted.
cheers
m
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As in "Caveat Emptor"? Sorry Mike , couldn't help it , I am :evil:
Dusty
SPELL CHECKER!!!!! That's my story adn I'm sticking with it!!!
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Wait. There is a difference between a fluid coupling, a torque converter, and a locking torque converter.
The Convert is a plain old torque converter. No lockup, no concentric shaft. Unless Guzzi decided to misname the bike, in which case it might be a fluid coupling-like old Mercedes and older GM automatics, but I really doubt it.
The stator in the converter does not lock, it causes the torque multiplication. If the stator is spinning freely in both directions, it will act like a bad fluid coupling. Real bad.
The stator is not connected to the output shaft. It is mounted on a splined hub, splined to the impeller side. You may not be able to see or feel it from outside, putting a shaft in will definitely not work.
Anyway, I suspect the fluid levell is low, how do you check it in a Convert? Is there a spec for total fill? Is the new tank locaation radically higher or lower, or the lines so long that the fluid in the system isn't high enough?
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I reinstalled the stuff (less drive shaft), with the t/c gravity loaded to the lower lip of its mouth.
I plugged the intake and outgo of the transmission and the pump.
I started it. The drive shaft flange didn't move, so I looked closer and revved it. (NOTE TO SELF: Don't do that with the drive shaft missing.) It spun up so fast that it flung the EP moly grease out of the CV flange all over every damn thing -- like the trike, the carport, and of course, the first thing it encountered -- my face. :coffee: I'll clean up the mess and continue this test. Good thing I wear safety glasses. But the test looks promising . . . .
Kirby -- I appreciate your input. All the comments are pieces of the puzzle. I just need to figure out the fit. :thumb:
Dusty -- have I spoken with fubar on the phone before?
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Have a long bar? Do a dyno! Just kidding.
Do you have a way to see if you are getting decent torque? Should be double (or close) the crank torque at stall. Or just see if the wheels are turning with authority.
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Heuristics, Dusty, Heuristics.
I got the drive shaft back on (takes longer than the rest of the R&R) and torqued down. Plugged the intake and outgo right at the tranny right at the spigots. (do NOT mistake this for any current events in the news). Started it up. I gave it about 30sec to settle in and rolled on the throttle. It was herky-jerky for another 30sec and then the rear started spinning with what you're calling 'authority' -- I call 'vigor.' It resisted the brake. That hasn't happened before. [NOTE TO SELF: Those silicone plugs I use for powdercoating have a variety of uses and come in a mind-boggling variety of sizes and shapes]
I didn't do any stall tests because I'm concerned about frying fluid, but if I hold one wheel stopped the other spins right up. More wheel speed than I've seen thus far X5 or more. This needs a toke and screwdriver (the yellow kind) to ruminate with, but once I get my head around it I think we'll finally tree the possum. (hey luap -- where's the possum smarm?)
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Excellent news!
Now, I have no direct Convert experience but the cooliong system is likely low pressure? Has the reservoir been moved up or down quite a bit? Either way could be part of the problem, either over-or under-filling the converter.
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The reservoir has been made taller by substituting a radiator, and combines the cooler and tank. The return is higher and the intake is lower. It is also served by longer hoses than oem.I'm not sure of the significance of any of that.
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I'm guessing the tank on a Convert is fairly close to the same height as the converter? I'm thinking the level of the system is changed by moving the level of the reservoir and cooler higher. That would raise the oil level inside the converter.
An overfilled converter won't work. The oil has to be "flung" from the impeller to transmit torque. I would not expect hose length to be a big issue.
Try getting the header/reservoir at some level below center of the converter and see if it works better. Unless there is some sophisticated scavenging system in there (I don't believe it) that should give you lots of torque.
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The tank top level is +/- 2" from the top of the old tank location, however the fluid level might be different in order to make the volume -- top tank, with stuff in it is necessary to give me a total of a couple liters in the system. Less than that and I'm concerned for volume. Maybe I need to splice in the oem reservoir tank to give it the needed volume at a lower level, fill to the reservoir's proper level and let the radiator act as a huge cooler . . . . ?
Did I mention before that before this last test, a few seconds after shutting the engine down there was always a massive burp of fluid out the main return hose? I mean 100cc or so. I don't know if that means anything.
Keep in mind that my main motivation is laziness and I really dislike pulling my timing cover to screw around with the pump. Case in point -- my running bike sits for want of a new atf pump drivepiece during the nicest season I can remember here, only because I hate removing the timing cover. So if there are reasonable steps to take on the way to that inevitability, I'm almost all ears.
My next step was going to be enlarging the holes at the banjo fittings to be sure I'm flowing as freely through the pump as is reasonable. I can drill those holes for free, but I'll be chopping up $40 worth of hose to splice in the tank. . . . I think I'll use the drill press first, just to scratch that itch. :whip2:
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Ive used KENDALL 6505(?)military grade its blue in color. In reguard to pumps I will use the first one you suggested(turbo gear brass oil pump) thank you much. :bow:
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I just bought the other one. Reasons are
more flow
less power draw
higher pressure
probably quieter (based on design)
has a speed controller (not sure if that's a useful feature or not)
The one you got has the advantages of
easier barb customization
more convenient shape
more easily serviced
I'm getting mine because I have two bikes with probable pump problems and I'm getting real tired of replacing that hex shaft. At this point it's worth the $100 to install an electric pump and see what happens. If it doesn't suck enough (which would really suck) I can still use it to transfer fuel on the boat -- I sometimes run with a couple 50gal barrels on deck to get the range I need, and hand pumping to the main tank also sucks.
As with all Converts, electrical power is critical -- can't push start them. So the 'lectsessories need to fall into an energy budget that leaves room for starting the bike. The pump I chose draws 3.8a to deliver 30L/min@6#. the other one needs 5a to push 9L/min@0#.
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I have decided to take a break from this madness for a day and ponder the shifter and dashboard instead. I'm going to have to replumb everything to wedge the oem reservoir between the pump and radiator, measure it all out to oem relative levels, and then spill the stinky atf everywhere. I don't want to face it today. I'll pick it up again on Sunday or Monday.
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Any check valves in that cooling circuit?
I like the electric pump idea, that hex drive thing sounds awful.
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No one-way valves as such, but there is a pressure relief valve -- simple ball on a spring.
The hex drive is awful. Even if they'd made it 8mm instead of 6 it would be an improvement. The hex was a redesign from the original flat-blade-in-slot which was worse. So they upgraded from worse to awful.
The tradeoff for electric is that it's electric. I mistrust electricity. Shocking, I know. But my biggest objection to my first Guzzi was lack of a kickstarter. They have such small charging systems.
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Plumbed it back to oem tank in the oem position and am still having the same symptoms. I've been as systematic about checking things as I can be. Things inside the timing cover are about all that are left to check. If I had to make an assumption at this point I'd have to say the pump failed coincidently with the trike project.
Given the choice of putting weekend energy into this wild card or into a known quantity, I tore into the rodekyll, which I know has a bad pump driveshaft. At least when I'm done with it I can go for a ride. I ran out of back before the job was done so I'll finish up tomorrow. When I verify that my fix is good I'm going to pencil in the electric oil pump I bought and see if it will drive the wheels. If that is successful I'll strap the pump onto the 3VL TWIN and see what happens.
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I got the electric pump in today. It's smaller than an efi external fuel pump and has an attached control box to adjust the flow rate. The plan is to try it on the rodekyll first, and if it works there, then try it on the 3VL Twin.
The procedure is to first finish fixing the rodekyll. I stripped the 6mm hex shaft for the atf pump a few weeks back and just got around to replacing it over the weekend. I had also decided to change out the fuel hoses, all the fluids, and do the valve adjustment (this is a solid lifter 1100). I should be through all that today. Assuming it all tests out, I should be evaluating the electric pump tomorrow.
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I have no idea on the intricacies of what you are trying to achieve RK, but I am absorbed in your approach to find the solution. :bow:
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I'm curious too-did you confirm that the old pump wasn't pumping? It isn't a hydraulic system after all.
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Aaron, I don't know what you mean by "it isn't a hydraulic system after all."
No, I have not proven that the pump isn't pumping yet, although I'm working it down to that. I want to get the other bike running properly. Then as I purge the burnt fluid I'll do flow testing to see what sort of volume I ought to have at idle and compare to the trike.
I got stopped again. The pump I bought has 1/2" straight pipe threads. My hoses are 5/16 (8mm). I can't get barbs in town that have a 1/2" female thread and a 5/16 barb. The stores that stock them have empty bins, and the others sell 1/4" and 3/8" but no 5/16". I can use a series of adapters to get there but it will cost about $35 in brass bits and make the rigid part of the assembly about 8" long -- very messy. So I lost yesterday's project time running around town looking for unobtainium stuff instead of adjusting valves and etc. Now I'm going to check Graingers and some other places for the $4 barbs. That should kill another week or so while they ship.
It's always something.
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RK, hang in there man. Even Dr. Frankenstein (Steen dammint, Steen) had to wait until the perfect storm came along before his project came to life. Humm, for some reason I keep seeing Dusty in the Igor role. :wink: :laugh: :grin:
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but no 5/16".
Some time back I warned you about the line(s) size on the suction. :rolleyes:
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Some time back I warned you about the line(s) size on the suction. :rolleyes:
Yes, you did. :)
But the working bike has 8mm hose (5/16) and the oem banjos are too small for 3/8 -- can't get a clamp tight on them with 3/8 hose. So the oem intent was 8mm. If everyone's Converts are running well with this size hose (including this one, which logged about 30k before the project), how can it also be wrong?
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It's been 20 years since I've even looked at a Convert plumbing system but something in the back of my mind tells me that line was bigger. Definitely won't be the first time I was wrong. :shocked:
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is it uphill from your tank to the pump (the suction hose)?
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is it uphill from your tank to the pump (the suction hose)?
Kind of. The line from the 'reservoir' runs uphill but the top of the reservoir is a couple inches above the pump.
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It's been 20 years since I've even looked at a Convert plumbing system but something in the back of my mind tells me that line was bigger. Definitely won't be the first time I was wrong. :shocked:
I did in fact attempt to plumb in 3/8 after your first comment about it -- I've had a niggling feeling that it's a supply side/available volume/flow issue on the upstream side of the t/c. 3/8 fit like a used condom on a new pencil. I looked through the stash to see if I'd somehow grabbed the wrong banjos -- I have nothing else with a combination of those banjo rings and snouts (pump side snouts have VERY unique wiggles in them). I am not resistant to trying a larger diameter hose. I just can't see how to fit them.
I too get this deja-vu thing about a bigger supply side hose. I think it's because the oem was a super-reinforced tube (wire braid in the plys even) with braid on the outside and huge swedged cap clamps at the banjos. I think it might have looked bigger than it is. I've been looking for an oem to compare ID to, but it seems they've been lost to time.
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I got the rodekyll running today after changing out the hex shaft in the atf pump. I found some interesting things:
Volume of the oem system (tank/cooler/hoses/t/c) and my system in development (radiator/hoses/t/c) are within a few ml of each other. Tank and radiator are almost dead equal.
Properly running the system pumps about 4L/min (slightly less) with the rear wheel stopped, at idle.
Idle pressure is about
there are no bubbles in the return fluid stream, either foam or scuba.
I also noticed that it is possible to bottom out the banjo fittings before completely sealing the joints. I got bubbles in the oem system when I first put it back together. I was using the same crush washers. I replaced them with three washers between the timing cover casting and the banjo to be sure it was the washers and not the bottom of the casting stopping the bolts. Pressure came up immediately and there were no bubbles. T/c pushes the bike like a big dog and temperatures are normal (gauge starts at 100f and doesn't move in 5 miles).
The bad news is that my starter gave up during testing. I have to order in a replacement to continue.
The pissy news is that the front brakes are spongy every moring and I have to do a one-pump bleed at the m/c to firm them up. It's always something.