Marcel Burkett

Anyone figure out the connections for the OPM motor , how can the electric OMP be made to work with a haltech.

zullo

Excellent discussion - thanks very much! From a high-level perspective,
1) I doubt it would be called a "pump" if it did no pumping.
2) The OMP would not be gear-driven if it was nothing more than a valve.
3) Since oil is required at vacuum and (especially) at boost, it would not be
practical to engineer this as a vacuum-driven system.

Question: my OMP appears to leak oil. I would like to verify that I can pull
the pump off to check the integrity of the o-ring. Can this be done and
reassembled without opening the front cover, without losing parts inside
the front cover, i.e. without causing a reassembly nightmare? From the
FSM it is difficult to tell if it all comes off as a self-contained, plug-n-play unit.
Thanks

z8cw

It does and it is pretty straight forward. Haven't taken one of while the engine is in the bay, though.

CW

mad_7tist

the pump def pumps. ask someone who cracked a line how fast it pumped oil all over the top of the engine. the omp nozzles are 1 way also. i was under the impression rotary god was talking about the initial vac created by the intake cycle pulling the oil out of the line..

Sgtblue

iTrader: (16)

I had read the FSM, but never had anything close to an understanding of how the OMP worked. Thanks to all.

rotariesrule

the oil metering pump is DEFINITELY a pump. it has a worm gear and several plungers inside of it . it does not use vacuum.

if you are going to check the seal you should just order a new seal now and change it when you check it. the seal sometimes tries to pop out of its groove while mating it to the engine. it helps to stretch the seal a little before assembly and you can also use a little hylomar to hold it in place. there is also two other seals on the omp.

the omp can be removed and checked easily. be EXTREMLY gentle with the plastic omp lines they can get very brittle and break. make sure you lubricate the bolts, washers, and the round metal flanges that the lines have on the ends before reassembling. while you are tightening the bolts for the lines hold the flange for the line still so they don't turn with the bolt or you will crack the line. also tighten the bolts slowly and watch what you are doing.

Speedworks

Great reading this, because I will be opening up my spare FD engine soon and this will be a lot of help investigating.

Just wondering. Vacuum lines are one of the biggest issue on rotary engines and taking them out when possible is aplus.

Reading the above bsically says that the OMp is a pump, engine driven and ECu controlled.
the amount of oil supplied to the injectors is ECu determined and, if I understand correctly, boost/engine RPM related.

boost on itself is also engine RPM related.
Can't the oilflow be engine RPM related? taking out al vacuum lines and ECU controlling? and just find the right gearing related to the drive shaft from the engine (if this is RPM related,which it normally is)
In this way you could authomatically increase oil supply when revving the enginewhether you choose to decide to use the oil supply from the engine or an external source could be an option.

Or am I looking at this the wrong way?

rotariesrule

can you rephrase the above ? i am not sure what you are saying?

Speedworks

Well like the picture of the RA pumps shows... the "OMP" is engine driven one way or the other. As a consequence the amount of oil the OMP is pumping should be related to the engine RPM. Not taking into consideration that the ECU is still regulating the amount of flow through the shaft hole.

Like said before above. When you use an aftermarket ECU, the OMP reduces oilflow to 50%.
Lets assume you can cancel this metering section, make it 100% but let the pump "decide" how much oil it pumps to the injectors...

I'm just brainstorming here. It kinda reminds me of how the turbocicruit is build up.
there is airflow by the turbo's. It goes towards the engine and overboost throught the wastegate.

Basically. you make the OMP receive 100% oilflow from the engine (or external oil feed). I guess the OMP can't be reduced to 0% because it needs lubrication.
Then... as it seems to me, the pump is engine driven so engine RPM related. Oil necessity is related to engine RPM (more RPM->more friction/heat->more oil to cool down and lubricate).

so as the RPM goes up, more oil is needed. OPM is driven by the engine (RPM)
So, theoretically, the pump delivers oil to the engine according to the RPM. and at 100% at full force. so you nee something like an oil return to let go of the unused amount.

I haven't been sleeping enough this weekend so I might be talking BS here... :-)

You would need some kind of a solenoid to regulated the excesive pressure...

What do you think?

DamonB

This is exactly why the third gen OMP has the stepper motor to control the amount of oil the engine receives. If the output is based strictly on RPM (as I assume the first and second gen are) you end up injecting more oil than is needed. The third gen ecu through a combination of engine rpm and manifold pressure (and maybe other things I'm not aware of) decides how much oil is to be injected by controlling the stepper motor on the valve. The OMP pump is always pumping all the oil it can for any given rpm, it's just a question of how much oil the ecu decides to actually let through the stepper motor controlled valve and into the engine.

If you read the first post this is exactly what Eric Michel was talking about. He went Haltech, removed the stepper motor from the OMP and added a "set it and forget it" mode of manual adjustment to the OMP by means of a screw on the valve. In that case the volume of oil injected would closely relate to engine rpm only. Note that he did not do this because it's improves the OMP system over stock, he did this because the Haltech has no means of driving the OMP stepper motor. His only other choice would be to completely remove the OMP and premix instead.

rx7tt95

The oil injectors themselves have a valve (actually a diaphram) in them, no? Hence the reason for a vacuum line coming off of them in the first place. It allows oil to flow when the engine is running and none when it is not. If you cap them off, much of the oil in the lines runs down into the engine and upon startup, poof, a puff of smoke out the tailpipe. They also get vacuum from the turbo inlet on the stock car, not from the throttle body, where there is always vacuum and never boost

Could it be that the stepper motor regulates flow much as the "valves" inside of a shock? It either restricts or increases flow but doesn't actually do the pumping?

Speedworks

Ok, so basically I'm getting this right.

BUT, the stepper motor is the weak part of the assembly, vacuum and ECU driven so reliability is relative. So taking it out and replacing it with another kind of steering would be a more reliable alternative.

What I'm saying is... let the pump give all what it can, run an oil line to the injectors and have the pressure regulated by something else than vacuum.

I guess in the stock setup there is no return line for the oil before or after the one way valves?
What about creating an oil return to the engine or external reservoir when the injectors are overpressured?
I guess a better comparison would be the fuel system.
You let the pump give all it can, make a certain pressure on the circuit (regulated) and a return to the tank.

In any case you could take out the stepper motor, the vacuum I don't know.

Or am I missing something here?

Or am i missing something here?

vellj001

I had mine installed by my specialist as my first realibility mod. It is quite tricky to regulate the quantity of oil the it pumps in. In fact he already applied one restriction to its tank and tommorow it should be in for another one.

To much oil going in might dirty thing up after a long period of time that's why. My specialist say you should fill the pump's tank some 3 maximum 4 time every service and I already filled mine up twice.

I have a photo of it installed on my website but it is not that clear.

clayne

Can someone move this to AT please?

RotorJoe

Now I am reading in a few places that the OMP does not use vacuum. People say to hook it to the TB which would be under vacuum at idle but would have boost pressure any other time. I thought this way was wrong?

When I looked at the FSM the OMP vacuum tube was hooked up before the turbos and at that location they will always see vacuum. I also saw that other people did it this way (mainly some top dogs on the forum).

So which is correct?

RotorJoe

Never mind, I got it.

patman

iTrader: (3)

It is a pump, but it does not pump oil the way you are thinking-- there is no 'squirt' of oil....it merely keeps a positive flow. rotarygod is right in the the engine's vacuum is what causes the oil to actually inject into the engine. If you guys want something else to think about, check out this write-up I just did on my own version of the 2-stroke MOP setup:

https://www.rx7club.com/rotary-car-performance-77/diy-2-stroke-mop-write-up-pics-372329/

Note that mine is a s4 TII, but that there is really not much difference and the basic idea would be the same on all models. Also, for someone with a bit of skill, you could easily put the s4 mechanical MOP on a later model car, thus eliminating any problems with standalones or just to simplify the system and save yourself 300 bucks for a new one.

ON another side note.... If someone with an FD were interested, I could be talken into making a MOP 'simulator' that would allow later model cars with the stock ECU to use the mechanical MOP as well (or premix).

pat

pat

rotariesrule

pat, you are wrong about the vacuum you just have to look at the 1985 mazda factory workshop manual on page 2 - 8. it says if you disconnect the oil metering lines from the carb and put a measuring cup under the lines to catch the oil. the lines should pump out 1.8~2.2cc in six minutes at 2000 rpm. this means it is pumping oil up against gravity without any vacuum. the stepper motor on the newer cars is merely controlling the control pin in the pump thus controlling the amount of oil flow.

omg, patman, that seems like a complete waste of time to do. mazda's original omp does a fine job using the regular motor oil. your mod adds weight to the car and creates one more thing you have to fill up. also, if there is too much oil on the rotor housing or a cylinder wall in a piston engine, the seal either a piston ring or apex seal will not seal as well. that is why recip pistons have whats called an oil scraper ring, it removes excess oil from the cylinder wall as the piston travels down.

patman

iTrader: (3)

since you copied your pose over to here, i may as well copy my reply, too:

#1) they do pump out oil. that's what I said. but they do not pump it with any appreciable pressure. the engine's vacuum supplies the pressure for the oil to be 'injected'. if you will rememeber correctly, my words were something to the effect of " provides a positive pumping pressure" sorry you didnt get that, but what i meant is that they push the oil without letting any flow backwards..therefore filling the tubes. then the engine sucks the oil in at velocity high enough to atomize it (or at least partially)

#2) if you think it is a waste of time, you have a lot to learn. the merits can be argued, but saying 'complete waste of time' is ignorant. here's why:

1) 2-cycle oil lubricates much, much better than motor oil. therefore less wear on the apex seals/rotorhousings.
2) 2-cycle oil does not take part in the combustion process to nearly the extent that engine oil does, therefore much less carbon.
3) engine oil is dirty and nasty, especailly towards the end of an oil change cycle, the 2-cycle from a tank is always fresh and clean.
4) many synthetic engine oils leave nasty deposits when burned. since i am no longer burning crankcase oil, i can use synthetic, which has many,many advantages over conventional oil.
5)since everything is external, i can always be sure the MOP is working.
6) motor oil lowers the octane rating of gas when mixed. 2-cycle oil does too, but not nearly as much.

#3) there is not going to be any more oil on the housing than there was before, i am using the same system, just different oil. also, too much oil on the housings is not a problem for rotaries like it is for piston engines. the oil scraper ring catches oil that is sloshed up from the crankcase. in rotaries no such thing can ever happen, as the apex seal is completely seperate.

#4) total weight is very little...maybe 5 lbs... tank only weighs a pound or so... oil is the main weight.

pat

patman

iTrader: (3)

oh, by the way, the answer to some people's forced induction thing a ways up:

yes the chamber is pressurized WHEN the intake port is open. since the oil is injected before the rotor gets to the intake port, and before the compression 'stroke' begins, there is always vacuum for the injectors.

i wish i was at home i'd go grab a rotor and housing and take a pic for you guys, but oh well...

DamonB

You're off your rocker and have absolutely no idea what you're talking about. We agree that turbos build positive manifold pressure, right? Regardless of where and when you feel the oil is injected every spot in the motor is under positive pressure if boost is present. Since the turbos create positive manifold pressure there is in fact no vacuum present anywhere in the motor. There is no vacuum present during the intake stroke when under boost as the air is already under pressure due to being compressed by the turbos. The air merely gets compressed even more once it gets to the compression stage. The pressurized air does not enter the engine and then somehow turn into a vacuum. If there was a vacuum present inside the motor you would never be able to build postive manifold pressure!

All you guys insisting that engine vacuum has anything to do with pulling OMP oil into the engine go home and perform a little experiment. Remove the OMP tubes from the injectors and hold them above the motor (with the tubes removed from the injectors we have now isolated the OMP from the intake and engine). Start the car. Watch oil squirt out of the tubes and make a mess. Rev the engine and make a bigger mess. This is a direct result of the OMP pumping the friggen oil everywhere!!!

I think he's way ahead of you.

patman

iTrader: (3)

so, in your turbo engine, after the exhaust has exited, and before tho rotor spins back around to the intake port, you still have compressed air/fuel mixture? guess again, bro.

there is no compressed air left in the engine between after the exhaust port and before the intake port. there is also no engine compression being built until right at the intake port.

what you need to see is that the engine is 'divided' by the rotor. what is on one side of the rotor is not the same as what is on the other side. this is how you have vacuum on one face and boost on the other. think about it this way: if the turbo fill the whole engine with compressed air/fuel, why doesnt it just push it straight through without ever combusting it? the answer is because it doesnt compress the whole engine, just the area sectioned off by one face of the rotor.

and dont tell me to perform expiriments with my MOP, did you read my other thread? I have just spent a week completely learning everything about how the MOP works. YOU try what you have said. what you will find is that the oil does not squirt out, it drips out. the engine vacuum is the only thing that causes it to move with any velocity at all.

as far as my other thread, i would like to point out that it is a seperate thread, and if you don't want to do it, that's ok with me.... i know it is a better system, if you disagree, fine, to each his own.

rotariesrule

patman, actually your need to read a couple books. it is called an oil metering pump as in OMP, not MOP, it is not something you clean your floor with. you even got the abbreviation wrong. haahahahahaahahahahahahahahaaah. lmao..roflmao..

kenn_chan

Damon B is correct and sombody (no names) is out in left field and I mean way out there!



The OMP is exactly what it says, an Oil Metering Pump IE: an item that takes oil (Oil), measures it (metering) and pumps it (pump).

end of discussion.

the electronic OMP is controlled through a stepping motor to adjust the amount of flow, there is no "vacumm pulling the oil through the pipes" WTF look at your freaking boost gauge man!

If there was a vacumm source under boost, why would they put a one way valve right before the brake booster, Hmmmm maybe to maintain vacumm under low vacumm circumstances (like boost)

How would a dual stage fuel pressure regulator work if it always had a vacumm source,

How would a external wastegate work if it always had a vacumm,

need I say more? i really don't like to flame a person this hard but makes me wonder a tad about somebodies mechanical abilities

The OMP's for early non turbo's were a mechanical pump driven by the engine, and controlled off of a linkage to the carb, the later injection ones for the NA 13b's i personally haven't disected to figue out, but the ones on the my 20b's are identical to the FD's OMP and its driven by the little tang on the back, and controlled by the stepping motor and its sensor pack. no vacumm, no straw in a bottle (Osmosis?) and no other crazy stuff, just a mechanical pump.

Ken

patman

iTrader: (3)

it is sad that all of you guys are so sure about what you say, sure enough to insult me fairly often, yet quite a bit of it is obviously wrong.

here are a few examples:
1) one-way valve: this does not maintain vacuum, it simply blocks positive pressure to keep it from destroying the brake booster. the only way to get vacuum from boost is with a diaphragm pump.

2) it is NOT OMP, it is MOP, metering oil pump. see attatched excerpt from fsm.

3)all of the examples you post get their pressure source from the MANIFOLD. no one is talking about the manifold, we are talking about the MOP injectors on the rotorhousings. the injectors on the manifold do not get a vacuum source, but do to the velocity of the air flowing past, they don't need it to atomize the oil.

4) as stated a bunch of times before, i never said that it wasnt a pump. it is a pump, but it does not pump oil the way you guys are thinking... maybe moves is a better word than pump. all it does is keep a steady stream of oil flowing, the speed of the stream is controlled by the pump, hence metering. however, this stream is not flowing fast enough to 'squirt' out. it merely dribbles. see other excerpt from fsm, notice hos the oil is dripping out. not to mention that unlike you guys, i have actually DONE this many times, and know that it drips rather than squirts.

is it possible that some of your ire stems from the fact that you keep getting this nagging feeling that i am right and you are not?

pat