canadamaxxer
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posted September 25, 2005 06:00 PM
Oil pressure improvements
So........we know that the oiling system on the 12R is a little weak for strokers, turbo's, etc. What is possible to improve the 12's oil pump? I have just recently had my oil pump in my hot little hands, and have discovered the physical limitations of the system.
I know that the pump is a gerotor pump, and the only way to improve the pressure and volume of the pump is to install a pump gear that is longer and/or larger in diameter. The problem is that this is not an easy fix, and to my knowledge no one makes anything like this. I will take a look at the system as soon as I get a chance and see if it's possible to bore the pump housing to allow longer pump gears.....then the next step is to source out a shop that can cut new gears.
I am not convinced shimming the relief valve is a good idea. The name of the component signifies its' purpose: as a relief valve. It is NOT a pressure regulator valve and only unseats when the oil pressure exceeds the calibrated spring pressure. If the pressure that it unseats at is too low, then that is one thing, but to shim the valve for the pusposes of increasing oil pressure...is just a bandaid. This is especially true if the volume flowing (or trying to flow) through the relief valve is sufficient to allow oil pressure to creep or ramp up to the point where the oil pump drive shaft shears off (this is exactly what happened to me on the dyno in August). If anything I think the volume that can flow through the relief valve should be higher......
Any ideas???
  
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238mph
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posted September 25, 2005 06:02 PM
 Edited By: 238mph on 25 Sep 2005 19:04
I'm an M.E. Can you post pics??? I don' t have one in my hand to see what can be done...
I have a good friend in Florida that can do a sand casting if there is roon to make a
larger pump body... then he'd machine it smooth and cut the gears...
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trenace
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posted September 25, 2005 06:21 PM
Edited By: trenace on 25 Sep 2005 19:22
I just got some transmission gears in from Bill Robinson of Robinson Industries... I would think for sure he could do this. While a gear for an oil pump probably isn't as demanding for durability as a transmission gear, certainly the material and heat-treat used for the transmission gear would be top-notch for the oil pump.
Interesting coincidence (or perhaps no coincidence, perhaps driven by the same inspiration of something said here recently) because just yesterday I was thinking maybe it would be desirable for the oil pump to be geared to spin just a bit faster, like 10 or 20% faster.
I haven't had the pump in my hand myself though. From the manual I can see only the gear that drives it but not the driven gear. I would suppose both probably would need to be replaced... put a bigger driving gear only and it may not fit; put a smaller driven gear and there may be a gap.
Another possibility is that the problem really (at least in some instances, where there is a problem) may not be nominal quantity of oil flow, but intermittently falling below this (air bubble for example.)
If that is the case then an accumulator would be a good solution. There are huge accumulators available; a pity there is not a small one that will fit on a sportbike, though there's an iterm sold by Redline oils (intended as a pre-lube accumulator) that just might be adaptable to serving as a during-operation accumulator as well, "filling the gap" at any moments when oil flow/pressure stumbles for a moment or few seconds.
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gunner
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posted September 25, 2005 07:08 PM
Actually a small electric Booster pump mounted external might work? Have it switched by a pressure switch at a set pressure and switched back off at another. Feed it from the pan sump and have it discharge into the oil filter adpt. Place a check valve in the return line so it don't backfeed. Just an idea......
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trenace
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posted September 25, 2005 07:12 PM
Good idea to me if any work out the details...
In my own case I've never seen the light come on or flicker at all, and that's despite running a "wrongly" low idle (about 750 rpm or 800 rpm.)
I have been assuming that if I build the engine at the tighter end of spec for bearings, this should continue regardless of the bore increase (which the oil pump should not care about whatsoever.)
However better safe than sorry always in this matter.
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gunner
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posted September 25, 2005 07:31 PM
I know that there are some pumps out there that fit this job. I can't recall them right now though. But for a turbo bike it would lay on it's side right next to the sump where the header pipe once run. The weight shouldn't be too bad and the plumbing simple enough. For all other bikes I'm sure it can be fit down there somewhere. It would simply be used as a booster when the system called for it. The motor would still supply itself at all other times.
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canadamaxxer
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posted September 25, 2005 07:41 PM
Here are some pics. The outer section of the gear assy rides in the engine case. I took some pics of that area of the cases, but they turned out too blurry. I will try again when it's daylight. If the gears could be made longer and the removable support housing (#16142A in the parts pic) bored to accept the added section of the gears, it would work. Gearing the pup up would also work, but I think it would be difficult to pull off. In addition, it is possible to run that pump so fast that it could lose it's efficiency. The parts pic shows quite well how these parts go together. The drive gear is driven off the back side of the clutch basket(or immediately behind the basket) if I remember correctly.
As you can see with my pump driveshaft, the lugs have snapped off. The only logical thing I can think of was that the pump hydraulic'd due to a pressure spike as a result of the engine flashing up too fast on the dyno and spinning the tire.
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trenace
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posted September 25, 2005 07:55 PM
Edited By: trenace on 25 Sep 2005 21:24
It would be an expensive project to have Mr Robinson make differently-geared versions of 13216 and 16085. I paid about $250 a gear for the transmission gears, though other than
the shaft on the driven gear, these are less complex.
To reduce risk of the particular failure your pump had, a tougher 13107 drive shaft would also be needed -- on the other hand, if there was true hydraulic lock (which I don't understand
why should happen) then strength wouldn't matter, it would simply transfer the breakage elsewhere.
BTW another thought is having the oil galleys Extrude-honed. Also not a cheap process though. However, it's also could be possible that Extrude-honing both them and the coolant passages could free up a pony or two from reduced backpressure, so possibly there might be benefit besides better oil delivery. However, it's also quite possible that the stock passages do not have flaws/restrictions leaving room from improvement (other than overall hogging out which would want to be very limited anyway) from this method: I don't know.
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238mph
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posted September 25, 2005 09:42 PM
Edited By: 238mph on 25 Sep 2005 22:44
Yes you could overdrive the pump with different gear ratios...
As far as your shaft breakage, I'd say the pressure relief valve was either stuck closed
or you shimmed it to hold more pressure...
My suggestion, and what I do, is to run straight 30w (in winter, 40w in summer) oil so it doesn't thin out so much once hot... I also add sticky additive...
Also 13107 is a weak point!!! can't believe Kawasaki would do that!!!
That pin should be welded in from the backside....
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your car is slow
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posted September 25, 2005 10:10 PM
Isnt karl registering some 100+ PSI readings with his datalogger on his big motor 12R?
This would lead me to believe the pump is "pumping" fine...but perhaps its a supply problem on accelleration/decelleration clearing the pickup perhaps?
Far cheaper and easier to implement an accumulator system than to go through all that!
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entropy
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posted September 26, 2005 12:36 AM
Edited By: entropy on 26 Sep 2005 01:48
GREAT thread; I have a big interest in this topic.
I am now logging oil pressure and will take the heap to memphis on Fri to see how the oil pressure varies w/duty.
The data logging recently went on because i have seen the oil light briefly come on when letting off the gas at the big end. I wanna know what my oil pressure is throughout the pass.
My worry is more about starvation than pump rate.
I have also had a pump shaft shear off, going thru the traps. Instant and complete bearing failure. I was un knowingly running warped cases at the time, and figured that was a contributor (pump binding in the cases). CM, yr pump looks really worn.
I have lost several motors to oiling problems...
After talking with lots o' people, 12 n' Busa folk:
1. Coby pan: 5.5qt capacity, anti-sloshing construction; should help w/starvation issues.
2. shimmed the relief valve: stock valve starts dumping oil at about 80-85psi, 10K or so. Shimmed valve lets oil pressure get to a bit over 100psi. NO impact at lower RPM.
CAUTION; IF YOU DO THIS MAKE DOUBLE DAMN SURE THE CIRCLIP IS SECURE!!!!!!!!!!!
3. Mobil 1 15w50: BIG difference from the Dino oil i was running before; increased psi at all rpm. Running this weight oil causes a noticeable hp loss but the increase in psi may save my motor.
4. install a new pump every build, cheap insurance
5. make triple sure the oil pickup screen is 100% clean; there is a scum which seems to get deposited on it (clutch fibers and some snot looking stuff???). Yank the pan and check it regularly.
6. oil pressure logging
Spinning the pump faster would surely help at low rpm, but we'd need to look at the pump curve to see impact at the higher rpm. Shimming the relief is a cheap way to increase high rpm psi, but does nothing at the low end.
Keep this thread going, great stuff.
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canadamaxxer
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posted September 26, 2005 05:12 AM
quote:
I have also had a pump shaft shear off, going thru the traps. Instant and complete bearing failure. I was un knowingly running warped cases at the time, and figured that was a contributor (pump binding in the cases). CM, yr pump looks really worn.
I figured that pump was worn. I intended on replacing all of the related components, and will post some pics of a new vs worn gerotor system. I was talking with my brother-in-law (licensed machinist and millwright) and he suggested that the male/female drive lug system is inherintly weak and that he could possibly build me a spline setup to eliminate the OEM #13107, and modify #13216. When I get my motor pulled apart, I will see what he can do. I understand that there needs to be a weak spot (shear pins, etc), but a poor design like that hurt motors. I suppose that it isn't normally a problem, but when you up the HP output, things get stressed harder...although I still haven't figured out 100% why that part is the problem. Is it a weak spot that is ready to break at any time, or did it happen all at once?
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entropy
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posted September 26, 2005 05:39 AM
your & my shaft shearing are the only 2 examples i have heard of. The builder I had at the time felt stongly that warped cases caused binding then shearing, but who knows, eh??
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dougmeyer
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posted September 26, 2005 11:33 AM
Entropy,
Follow your datalogging very carefully. I will be pleased to hear you report the results as I am sure they will bear out my opinion that there is no deficiency in the pump's design and the flow / pressure output. Would it surprise any of you to know that the pump might actually and successfully be made smaller to provide less hp loss with no negative results?
As has almost universally been the case with most engines, oil pressure drops are caused by flow interruption at the pickup or aeration of the oil, not pumps that do not pump enough.
D.
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canadamaxxer
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posted September 26, 2005 05:00 PM
I have no problem with improving the sump volume.....in fact I would be happy to end up with 4.5 to 5 litres if it's possible. I also have no problem with the idea of manufacturing a new pickup system that is bolted to the lower case 1/2, not held in with friction.......if that is what's neccesary to get this baby to survive. I am very seriously thinking of turbo'ing this bike this winter, and want all of my ducks in a row with regards to any mods I need to make to the motor. I want to build this thing once...and properly. I know I have to go into the motor for sure....but the big decision is whether to turn the mill back into a 1200cc with low compression turbo pistons, or put in a stroker crank. Either way I have to solve any oiling system issues.
I am wondering what would be the cause of any aeration or cavitation of the pump.....would better baffling in the sump create a better source for the oil? Is the stock pickup the source of the problem? Would a swinging pickup help our cause?
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aughtsix
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posted September 26, 2005 05:04 PM
This might be an overly simple question from the peanut gallery, but has anyone considered the problem of modifying the pump to be TOO efficient?
In other words, to pump at a greater rate than the rate at which the oil can return?
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canadamaxxer
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posted September 26, 2005 06:04 PM
quote:
This might be an overly simple question from the peanut gallery, but has anyone considered the problem of modifying the pump to be TOO efficient?
In other words, to pump at a greater rate than the rate at which the oil can return?
Most of the oil in the pressurized system will be floating around the crankshaft area and oozing from all of the bearing clearances. Some oil does go up to the top end, but for the most part the oil stays in the crankcase.
In addition, increasing the sump volume would reduce the likelyhood of this phenomenon happening (in other words starvation of the oil pump)...unless there was an excess of oil getting trapped in the valve cover area....and if this ever did happen, an oriface could be installed to once again restrict the flow to the top.
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entropy
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posted September 26, 2005 10:51 PM
quote:
.....I would be happy to end up with 4.5 to 5 litres if it's possible.
.....would better baffling in the sump create a better source for the oil?
The Coby pan mentioned above has about 5liter capacity and baffling; many say it cures accel/decel intake starvation. Added benefit is you get to bolt on a VERY cool sounding Brock sidewinder (baffles in). 
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entropy
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posted September 26, 2005 11:06 PM
quote:
Entropy,
Follow your datalogging very carefully...D.
Doug, I certainly intend to look for (and report on) any dips in pressure, especially on launch and initial decel at the big end.
Q: the seemingly mojo increase in overall psi (cold & hot) I am seeing with Mobil 1 15/50 vs Castrol 5/30 has me wondering:
1. is the increased pressure at the galley/pressure sensor due to lower flow outa the galley (higher viscosity)???? Is that incr galley psi really good for the motor? I'm guessing it is cause OEM oil specs incl 20/50.
2. in my pointy-headed logic, higher psi = hp loss, i wonder how much
The higher psi w/15/50 makes me feel good, but everytime i start feeling good my motor blows up.
Yr thoughts (and others) would be welcomed.
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Ra12r
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posted September 27, 2005 04:12 AM
I honestly believe the only problem with the oil system is not running 5 quarts. If you watch the site glass on startup, it IMMEDIATELY goes empty. I agree with the peanut gallery that efficiency good enough to pump the pan dry on INSTANT 11,000 rpms (ie: drag racing conditions).
Entropy, the only issue I have running thicker oils is clearances. The clearances designed also take into account certain oil specifications. Too thin vs Too thick cause the same issue.......bearing failure, but for different reasons.
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aughtsix
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posted September 27, 2005 04:22 PM
quote:
I honestly believe the only problem with the oil system is not running 5 quarts. If you watch the site glass on startup, it IMMEDIATELY goes empty. I agree with the peanut gallery that efficiency good enough to pump the pan dry on INSTANT 11,000 rpms (ie: drag racing conditions).
Yup, that's what I'm wondering. All the oil is in play, so to speak, not enough in the pan, instant cavitation.
quote:
Entropy, the only issue I have running thicker oils is clearances. The clearances designed also take into account certain oil specifications. Too thin vs Too thick cause the same issue.......bearing failure, but for different reasons.
Right. If I may make another comment from the peanut gallery, too thick an oil and the flow rate between bearing and journal drops, insufficient oil flow to remove heat, clearances decrease, bearing and journal become kissin cousins.
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canadamaxxer
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posted September 27, 2005 05:03 PM
I have heard it said that a small block chevy engine revving at 6000 rpm holds 5 litres of oil in a vortex surrounding the crankshaft. That premise is the reason for crankshaft scrapers, and to a large extent, dry sump systems. I can understand how the oil level window goes immediately clear upon startup, but I don't think it's because the oil pump is so efficient that it is actually sucking the oil level down that dramatically; I think that the crankshaft may be splashing oil around...and the many gears in the transmission are churning up the oil big time.....and taking up a fair amount of the volume just due to the adhesion of the oil on the gears and shafts. This had to have been taken into consideration when the engine was first designed....and I suspect would still happen REGARDLESS of the volume in the sump......BUT (the good thing is) that with a greater sump volume, the volume not showing in the window would be greater and would theoretically be safer......and that is, of course, a good thing.
The ability of the oiling system to return oil to the sump is absolutely essential....in fact many hot rodders will polish or coat the inside of the block surfaces to make the surfaces more slippery...and return the oil faster. I don't think in our case that the pump is so amazingly efficient that the oil level drops below a safe level.....other than in exceptional circumstances. It is probably very fair to say that the motion of the oil in the sump (sloshing) could very likely be a factor...but in my case was not a consideration....as the bike was completely stationary during the pump failure.
This is not to say that everything is perfect......we know this is not true. I do think the sump is too small. I also really dislike the pickup system. The bottom line to me is one of two things: either the pump is insufficient to the task, or the pump is losing suction somehow. It is possible that the pump is losing suction/aerating the oil due to a partially (or completely) plugged pickup screen or that the pickup is actually too low in the pan and is sucking too much goop off the bottom and temporarily losing suction.
I don't disagree about the viscosity creating a potential for oil starvation despite pressure, but I don't think this is happening, Once Entropy gets his data logged and posted, I suspect (if he still has a problem) we could see his oil pressure having short periods of time whereby the oil pressure is spiking low. If this is the case, it is not a viscosity problem, but either a pump issue, or a supply issue.
The only way I can see that my pump failure had to do with a supply problem would be if the the sump momentarily sucked air and then oil and the shock of trying to compress the non-compressible oil after the very compressible air sheared the drive lugs. The most logical way I can see this happening was if the oil level went too low momentarily. The other (far less likely) option is if the pickup tube somehow momentarily sucked air....either past the seal, or through an imprefection or crack. Adding sump volume and replacing that pickup tube would most likely fix these scenerios.....but destite the fact that I think these are both great ideas, I still don't think this is what happened to my pump.
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