MOP Adjustments
07-21-2007, 02:43 AM
#77
I wanted to comment on this idea before this thread slides into obscurity:
Besides this bit of trivia:
Think about this:
You should consume anywhere from a 1/2 to a full quart of oil every 3000 miles. If the OMP is working correctly and the oil level is not going down, that would mean you are "blowing-by" 1/2 to a full quart of gasoline into your oil.
Think about the implications of that and how it is completely impossible...
Originally Posted by me
Plus, any blow-by on the compression stroke is going to go out the intake port and any on the power stroke will go out the exhaust port.
Those are uncovered by the side seal as it goes by. One or the other is almost always "open" inside the side seals.
Only at TDC are no ports available to the sides of the rotor.
[only at] the point of maximum dynamic pressure, the exhaust port is exposed to the side of the rotor, inside the side seal.
Those are uncovered by the side seal as it goes by. One or the other is almost always "open" inside the side seals.
Only at TDC are no ports available to the sides of the rotor.
[only at] the point of maximum dynamic pressure, the exhaust port is exposed to the side of the rotor, inside the side seal.
You should consume anywhere from a 1/2 to a full quart of oil every 3000 miles. If the OMP is working correctly and the oil level is not going down, that would mean you are "blowing-by" 1/2 to a full quart of gasoline into your oil.
Think about the implications of that and how it is completely impossible...
07-21-2007, 10:39 PM
#78
the enemy in the mirror
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so does this mean that it doesn't learn against the stop screw or only that the sensor input if difficult to manipulate for any significant change?
it would seem that the sensor is there to make sure the stepper motor continues to function but not to determine the amount of oil injected.
it would seem that the sensor is there to make sure the stepper motor continues to function but not to determine the amount of oil injected.
07-22-2007, 03:48 PM
#81
So just increasing the flow of the OMP would solve all this. It would function the same with an increased volume (GPM) of oil.
Next time I'm over Jeff, lets take that OMP apart. The spring on the needles could be changed. Weaker spring. Less force (PSI) to open and it would hit max flow sooner at lower pressure. I need to see how this thing flows/pumps oil.
I think?
Next time I'm over Jeff, lets take that OMP apart. The spring on the needles could be changed. Weaker spring. Less force (PSI) to open and it would hit max flow sooner at lower pressure. I need to see how this thing flows/pumps oil.
I think?
07-22-2007, 07:49 PM
#82
cant both needles be modified to increase all flow? Thats what I was thinking. I believe RB just choose to do the high flow only. Could be wrong but thats what I was the impression I gathered.
One thought--OK say all this good info leads to a real ability to increase flow. Arent we only lubricating the apex seals with the omp? What about all the others? Pre mix?
I am learning here.
Does pre mix help with seal chatter?
olddragger
One thought--OK say all this good info leads to a real ability to increase flow. Arent we only lubricating the apex seals with the omp? What about all the others? Pre mix?
I am learning here.
Does pre mix help with seal chatter?
olddragger
07-25-2007, 12:13 AM
#84
The only way I know how to increase flow is to increase the pump size or increase its capability to turn more rpm's. Thus increasing it's displacement.
Are these two needles on the OMP intake side (suction) or are they on the output (discharge) side? Do they meter the oil intake of the pump, or meter the oil displacement of the pump.
07-25-2007, 12:20 AM
#85
The needles are on the output side.
They are not moved by pressure, but by the rotation of the cam on the stepper motor.
As the cam rotates, more of the "notch" on the needles is revealed, increasing flow.
The springs just return the needles to the seated position.
They are not moved by pressure, but by the rotation of the cam on the stepper motor.
As the cam rotates, more of the "notch" on the needles is revealed, increasing flow.
The springs just return the needles to the seated position.
07-25-2007, 12:45 AM
#87
I'm missing something. If I recall the spring is on the inside of the needle. So it is holding it outward, and is this not the same direction we saw that the stepper pushed the needles? The needles are already being pushed outward by the springs. Something has to push/hold them inward as to contact the stepper motor. So the stepper could move them outward. I thought the outside of the needle was against the cover. So how could the stepper move them out when they are already out?
07-25-2007, 06:53 AM
#88
Registered
I know I've suggested something like this before but now we have more information from two rotors which is:
After every 12 ignition cycles, or after the battery is reconnected, the MOP goes through a type of reset cycle. This cycle entails establishing a zero, and then turning the motor 60 steps. At the 52nd step, it looks for the sensor switch to change state. It thus establishes its zero, and satisfies itself that the span is OK. It then just runs blind, assuming a given step moves the needles a given amount.
I suggested earlier that it got its zero by banging up against the mechanical stop. If you look at the step traces, the motor appears to be at the zero for a few step attempts, which might be interpreted as the motor repeatedly running up agaist this stop (electrically) to assure itself that it can move no further and that this is true zero.
Therefore, to fool this thing into delivering more oil:
-Crank down the mechanical stop so the motor starts counting from a higher delivery position
-Move the sensor switch an equal amount away from the stop to ensure the span is unchanged.
The motor should now be happy but unknowingly be delivering oil at a higher rate. But the devil is in the details, and we will want to know:
- How much can this stop and the sensor switch be moved?
- How can we move the sensor switch the same amount as the stop?
- Will it hit something at the other end, that is, will it still have the 60 step span?
With regard to the first question, from the pictures provided by MM it looks like the mechanical stop can be moved quite a bit (can always be replaced by another screw if not enough) and Jax_RX8 says the sensor can be moved about 30 degrees towards the direction of increased flow.
With regard to the second question, again from Jax_RX8, it looks like there is quite a bit of tolerance before a CEL will be thrown. It may be that it will accept some tolerance in the span to account for sensor wear, movement over the years etc. but continues to operate with primary reliance being on the mechanical stop.
With regard to the third question, MM said earlier that it had plenty of room to move in the upward direction.
If one has a working spare MOP, a good experiment would be to:
-Unplug the MOP from the vehicle and make the connections to the spare. Apply a multimeter (on the voltage scale) to the sensor connections.
-Disconnect and reconnect the battery (or turn the ignition switch on and off until a reset is initiated).
-Observe how many revolutions, or how far the sector gear turns for the 60 steps, and observe when the multimeter voltage changes (It should be about 86.7% of the span). Mark the positions adjacent to the sector gear. Start the engine and watch the sector gear movement as the motor decides the oil flow it needs for varying engine states (RPM?). It may move back and forth a little even at a steady engine state.
-Stop the engine, move the stop screw and the sensor an equal amount (by eye). Go through another cycle, make any adjustments required, and see if the sector gear settles out at a higher flow position.
After every 12 ignition cycles, or after the battery is reconnected, the MOP goes through a type of reset cycle. This cycle entails establishing a zero, and then turning the motor 60 steps. At the 52nd step, it looks for the sensor switch to change state. It thus establishes its zero, and satisfies itself that the span is OK. It then just runs blind, assuming a given step moves the needles a given amount.
I suggested earlier that it got its zero by banging up against the mechanical stop. If you look at the step traces, the motor appears to be at the zero for a few step attempts, which might be interpreted as the motor repeatedly running up agaist this stop (electrically) to assure itself that it can move no further and that this is true zero.
Therefore, to fool this thing into delivering more oil:
-Crank down the mechanical stop so the motor starts counting from a higher delivery position
-Move the sensor switch an equal amount away from the stop to ensure the span is unchanged.
The motor should now be happy but unknowingly be delivering oil at a higher rate. But the devil is in the details, and we will want to know:
- How much can this stop and the sensor switch be moved?
- How can we move the sensor switch the same amount as the stop?
- Will it hit something at the other end, that is, will it still have the 60 step span?
With regard to the first question, from the pictures provided by MM it looks like the mechanical stop can be moved quite a bit (can always be replaced by another screw if not enough) and Jax_RX8 says the sensor can be moved about 30 degrees towards the direction of increased flow.
With regard to the second question, again from Jax_RX8, it looks like there is quite a bit of tolerance before a CEL will be thrown. It may be that it will accept some tolerance in the span to account for sensor wear, movement over the years etc. but continues to operate with primary reliance being on the mechanical stop.
With regard to the third question, MM said earlier that it had plenty of room to move in the upward direction.
If one has a working spare MOP, a good experiment would be to:
-Unplug the MOP from the vehicle and make the connections to the spare. Apply a multimeter (on the voltage scale) to the sensor connections.
-Disconnect and reconnect the battery (or turn the ignition switch on and off until a reset is initiated).
-Observe how many revolutions, or how far the sector gear turns for the 60 steps, and observe when the multimeter voltage changes (It should be about 86.7% of the span). Mark the positions adjacent to the sector gear. Start the engine and watch the sector gear movement as the motor decides the oil flow it needs for varying engine states (RPM?). It may move back and forth a little even at a steady engine state.
-Stop the engine, move the stop screw and the sensor an equal amount (by eye). Go through another cycle, make any adjustments required, and see if the sector gear settles out at a higher flow position.
07-25-2007, 07:04 AM
#89
Registered
Oops. I just had another look at the disassembled MOP pictures. It looks like the the sensor will cover the sector gear in operation. Might have to make some mods to observe what is going on, or count the steps electronically.
07-25-2007, 10:26 AM
#90
Got Another Rotary
Maybe, Maybe not.
While I have not run enough miles yet to get a new oil usage read based on moving my position sensor - hopefully soon - there still may be some possibilities here.
From what I can understand from this diagram, there are several possibilities on how the ECM uses this data/routine to operate:
- It could just use the zero point and step 52 as check points to assure OMP is working and not make any program flow adjustments based on these readings - which means we cannot change flow except physically to the needles
- It could use the zero point as the start point for all flow rates and only use step 52 for "check" to assure the OMP is actually working/adjusting - rates could be increased with a zero point adjustment via the set screw
- It could use a combination of the zero point and step 52 to somehow determine flow points as some have stated - which would require both to be adjusted to see any gains in flow
- It could just use the step 52 relative position to the the actual OMP step position, and set the flow rate from there. You see, it is possible that if the ECM senses the supposed step 52 at actual step 46 (from moving the position sensor), then it might adjust all the subsequent flow point positions up 6 steps throughout the range thinking it is not actually flowing enough.
I do think the ECM is making some kind of adjustments based on this procedure, why else would it be called a "learning" function. The question is exactly what readings the ECM using to make these adjustments and how are they made.
I will be taking a long drive this weekend and may have enough miles logged to calculate a new usage rate based on my sensor position changed - stay tuned.
While I have not run enough miles yet to get a new oil usage read based on moving my position sensor - hopefully soon - there still may be some possibilities here.
From what I can understand from this diagram, there are several possibilities on how the ECM uses this data/routine to operate:
- It could just use the zero point and step 52 as check points to assure OMP is working and not make any program flow adjustments based on these readings - which means we cannot change flow except physically to the needles
- It could use the zero point as the start point for all flow rates and only use step 52 for "check" to assure the OMP is actually working/adjusting - rates could be increased with a zero point adjustment via the set screw
- It could use a combination of the zero point and step 52 to somehow determine flow points as some have stated - which would require both to be adjusted to see any gains in flow
- It could just use the step 52 relative position to the the actual OMP step position, and set the flow rate from there. You see, it is possible that if the ECM senses the supposed step 52 at actual step 46 (from moving the position sensor), then it might adjust all the subsequent flow point positions up 6 steps throughout the range thinking it is not actually flowing enough.
I do think the ECM is making some kind of adjustments based on this procedure, why else would it be called a "learning" function. The question is exactly what readings the ECM using to make these adjustments and how are they made.
I will be taking a long drive this weekend and may have enough miles logged to calculate a new usage rate based on my sensor position changed - stay tuned.
Last edited by Jax_RX8; 07-25-2007 at 11:47 AM.
07-25-2007, 12:49 PM
#91
Not to nitpick the details, MM, but the two pieces you refer to as being the apex seal, are they not the apex and corner seal which are joined from the factory with Loctite Blue(or similar)? And wasn't it the corner seal that chipped off at the tip on your engine before the one you are now running? I'm kinda confused by your last post.
MM lost the angled tip of the Apex, the side the wedge goes in.
07-26-2007, 06:28 AM
#92
Registered
Jax RX8
I think you made a key observation by bringing that 'learning function' to the forefront. I had yet another look at that diagram and noticed another important point. It doesn't look for step 52 precisely, it looks for the switch to change state somewhere between step 52 and step 60.
Because of this, it may be that:
These pumps have slightly different characteristics. They are calibrated at the factory by flowing oil through them and positioning the sensor at the position of say, 'average flow'. For one pump it may take 53 steps to get there, for another 56, but all between 52 and 60. On resetting itself, the pump 'learns' where this position is, and then adjusts up and down from there depending on vehicle needs.
If this is in fact how things work, then you would think that moving the sensor away from the stop as you have done, should indeed result in increased oil flow.
I think you made a key observation by bringing that 'learning function' to the forefront. I had yet another look at that diagram and noticed another important point. It doesn't look for step 52 precisely, it looks for the switch to change state somewhere between step 52 and step 60.
Because of this, it may be that:
These pumps have slightly different characteristics. They are calibrated at the factory by flowing oil through them and positioning the sensor at the position of say, 'average flow'. For one pump it may take 53 steps to get there, for another 56, but all between 52 and 60. On resetting itself, the pump 'learns' where this position is, and then adjusts up and down from there depending on vehicle needs.
If this is in fact how things work, then you would think that moving the sensor away from the stop as you have done, should indeed result in increased oil flow.
07-26-2007, 03:02 PM
#93
Got Another Rotary
I think you made a key observation by bringing that 'learning function' to the forefront. I had yet another look at that diagram and noticed another important point. It doesn't look for step 52 precisely, it looks for the switch to change state somewhere between step 52 and step 60.
These pumps have slightly different characteristics. They are calibrated at the factory by flowing oil through them and positioning the sensor at the position of say, 'average flow'. For one pump it may take 53 steps to get there, for another 56, but all between 52 and 60. On resetting itself, the pump 'learns' where this position is, and then adjusts up and down from there depending on vehicle needs.
If this is in fact how things work, then you would think that moving the sensor away from the stop as you have done, should indeed result in increased oil flow.
If this is in fact how things work, then you would think that moving the sensor away from the stop as you have done, should indeed result in increased oil flow.
But, I am still hoping it was intended that a counter-clockwise movement of the sensor would reduce the step reading number (below 52, and avoiding a CEL), possibly increasing flow by making an upward adjustment on the appropriate step number (flow) per setting.
If it does not make an upward adjustment based on the steps to "on", then it likely takes an upward adjustment of the zero point set screw as well, which would be a royal pain to do to an OMP while on the car.
Last edited by Jax_RX8; 07-26-2007 at 03:09 PM.
07-27-2007, 06:08 AM
#94
Registered
I guess this could be interpreted a number of ways. It could for example mean it must be detected at precisely step 53. I now think it means between 53 and 60. I gather you believe it must be detected by step 51 at the latest.
While the position sensor is adjustable - all of them that I have seen stock are fully rotated clockwise (see MM's picture at beginning of thread), with potential movement counter-clockwise. So I have not seen any of them "adjusted" from the factory to account for variances as they all have been fully rotated clockwise.
But, I am still hoping it was intended that a counter-clockwise movement of the sensor would reduce the step reading number (below 52, and avoiding a CEL), possibly increasing flow by making an upward adjustment on the appropriate step number (flow) per setting.
If it does not make an upward adjustment based on the steps to "on", then it likely takes an upward adjustment of the zero point set screw as well, which would be a royal pain to do to an OMP while on the car.
If it does not make an upward adjustment based on the steps to "on", then it likely takes an upward adjustment of the zero point set screw as well, which would be a royal pain to do to an OMP while on the car.
07-27-2007, 10:42 AM
#95
Got Another Rotary
I've looked at it again. Here's what it says: The step number is counted until the position switch turns on ---- The position switch is on above step 52. However, if the on position of the position switch is not detected above step 52....
I guess this could be interpreted a number of ways. It could for example mean it must be detected at precisely step 53. I now think it means between 53 and 60. I gather you believe it must be detected by step 51 at the latest.
I guess this could be interpreted a number of ways. It could for example mean it must be detected at precisely step 53. I now think it means between 53 and 60. I gather you believe it must be detected by step 51 at the latest.
This is really poorly worded, but I think this is right - The position switch needs to be registering "on" by step 53, otherwise the safe-mode will be activated. It can register on anytime before step 53 as it does not matter how soon it registers on as long as it is on before step 53.
Yes I remember you saying this in one of your early posts, and then I did look at the pictures and saw it was the same there. It could be that the mechanical stop is adjusted instead. One advantage of the sensor being positioned completely clockwise is that if it is moved for one reason or another, you can always get it back to its original position.
If I moved my stop screw up some, I would likely have to move the position sensor back some towards the starting position to prevent the fail-safe from activating.
This would mean that the position sensor stock could be reading "on" around steps 40-45, and by me moving it, it would not read on until around steps 50-52 (just under the limit).
That would be why when I rotated it all the way counter-clockwise initially, it set off the CEL as I must have moved it so far that I was at step 53 or above.
I still hope the ECM is making an upward adjustment on the flow rate based on the "on" position of the position sensor, but we'll see - hope to have some usage data soon.
Last edited by Jax_RX8; 07-27-2007 at 11:04 AM.
07-29-2007, 03:05 PM
#96
Got Another Rotary
Well, no such luck. I was able to log quite a few miles late last week and this weekend, and the end result on the OMP oil usage is identical - no change due to moving the position sensor.
For those interested in the numbers and the details, read on:
- Baseline before position sensor adjustment
3200 miles / 20 mpg =160 gallons x 128 oz = 20480 oz / 32 oz = 640 to 1 ratio
This equates to 2.6 oz per 13 gallons (not enough IMHO and why I started premixing)
- Usage after adjustment
405 miles / 23 mpg = 17.61 gallons x 128 = 2254 oz / 3.5 oz = 644 to 1 ratio
Note that higher MPG was due to more highway miles and 3.5 oz was the amount of oil used. I know a larger sample would be more accurate, that more highway miles may have reduced usage some, etc, but this showed no real improvement.
Thus, this morning I put my position sensor back. Interestingly enough, when I moved it all the way back clockwise, it gave a a CEL again (after an ECU reset), so there might be a minimum position as well. Anyways, I moved it back just a smidgen off of full clockwise, reset the ECU again, and all is fine and it is back to where we began.
Someone else can try moving the stop screw to see if this would add any flow as right now, I am tired of messing with my OMP for while. I am beginning to think that the ECU is going to compensate for whatever we do here, so modifying the needles or an actual ECU program change may be the only way to actually increase OMP flow.
So, I am going to just keep premixing my 3 oz IRP and 2 oz FP Plus per tank as the car is running great, idling silky smooth, and getting decent MPGs as you can see - maybe this is the sweet spot for a while.
For those interested in the numbers and the details, read on:
- Baseline before position sensor adjustment
3200 miles / 20 mpg =160 gallons x 128 oz = 20480 oz / 32 oz = 640 to 1 ratio
This equates to 2.6 oz per 13 gallons (not enough IMHO and why I started premixing)
- Usage after adjustment
405 miles / 23 mpg = 17.61 gallons x 128 = 2254 oz / 3.5 oz = 644 to 1 ratio
Note that higher MPG was due to more highway miles and 3.5 oz was the amount of oil used. I know a larger sample would be more accurate, that more highway miles may have reduced usage some, etc, but this showed no real improvement.
Thus, this morning I put my position sensor back. Interestingly enough, when I moved it all the way back clockwise, it gave a a CEL again (after an ECU reset), so there might be a minimum position as well. Anyways, I moved it back just a smidgen off of full clockwise, reset the ECU again, and all is fine and it is back to where we began.
Someone else can try moving the stop screw to see if this would add any flow as right now, I am tired of messing with my OMP for while. I am beginning to think that the ECU is going to compensate for whatever we do here, so modifying the needles or an actual ECU program change may be the only way to actually increase OMP flow.
So, I am going to just keep premixing my 3 oz IRP and 2 oz FP Plus per tank as the car is running great, idling silky smooth, and getting decent MPGs as you can see - maybe this is the sweet spot for a while.
Last edited by Jax_RX8; 07-29-2007 at 03:08 PM.
07-29-2007, 03:17 PM
#98
Got Another Rotary
07-29-2007, 03:54 PM
#100
Got Another Rotary
I think 2-cycles are definitely easier on the cats than engine oil from a deposit buildup standpoint as 2-cycles burn much cleaner.
However, some 2-cycles could be harder on the cat than some engine oils from high amounts of phosphorous for barrier lubrication versus the new SM 4-cycle standard which has greatly reduced phosphorous requirements.
Unfortunately, it is hard to know which 2-cycles rely on phosphorous as a key lubricity ingredient as most are designed for engines that do not use cats like motorcycles, snowmobiles, trimmers, etc. From the IRP patent application, it does not list it, but that does not mean it does not use some, hopefully just not too much.
IRP and other Ester-based (Group V) Synthetic/Semi Synthetic 2-cycles do have less need for Phosphorous as they have much greater lubricity from the Ester base, requiring less additives. Thus, sticking with Synthetics as Swoop always says is good advice, but you want Ester-based (Group V) synthetics/semi-synthetics.
However, some 2-cycles could be harder on the cat than some engine oils from high amounts of phosphorous for barrier lubrication versus the new SM 4-cycle standard which has greatly reduced phosphorous requirements.
Unfortunately, it is hard to know which 2-cycles rely on phosphorous as a key lubricity ingredient as most are designed for engines that do not use cats like motorcycles, snowmobiles, trimmers, etc. From the IRP patent application, it does not list it, but that does not mean it does not use some, hopefully just not too much.
IRP and other Ester-based (Group V) Synthetic/Semi Synthetic 2-cycles do have less need for Phosphorous as they have much greater lubricity from the Ester base, requiring less additives. Thus, sticking with Synthetics as Swoop always says is good advice, but you want Ester-based (Group V) synthetics/semi-synthetics.
Last edited by Jax_RX8; 07-29-2007 at 04:26 PM.