I just bought a rx7 and I was wondering if its bad that the oil injectors that inject oil into the motor and the intake had their lines cut and the 4 to 1 piece was cut out. They were also plugged.

 

Sounds like the PO was pre mixing. They should have mentioned something about putting a thing of 2 stroke oil into it w/ every tank of gas. If they were and you filled it up w/o mixing then you risk damaging the engine do to lack of lubrication.

 

Well wait a minute, here's a more general question that is relevent. If the air bleeds just receive fresh filtered air from the intake (not vac or pressure), shouldn't they work just fine without their lines hooked up, provided there isn't a buildup of harmful particles? Hypothetically speaking here, and I'm not saying anyone should go out and do it, I just want to understand the system a little more. The air bleed lines aren't 100% necessary, it's just plumbing in filtered air. It shouldn't cause a vacuum leak right, as long as you blocked off the nipple on the UIM?

 

if u block off the air bleed lines wouldnt that cause more vacuum to result in the oil feed lines therefore taking in more oil per revolution than stock? i mean yea thats great for lubrication as long as u dont mind burning oil faster. but how much faster i can not say.

 

I assume ALL the lines to the injectors were plugged off. Oil and air. That's the way I read the thread.

IF only the air lines were cut and the oil lines left in place to the OMP, then he'll be sucking a lot more oil thru the OMP than needed. He'll be putting a quart of oil in the pan once a week or more because of that.

 

^ so he'll be consuming more oil. Why is that? What's the difference (in the operation of the oil injectors) between open venting the nipple on them and connecting them to metered fresh air?

 

assuming we are talking about an NA engine for simplicity's sake.
keep in mind that when hailers mentioned if only the air lines where cut he might have implied that they'd also be blocked. if they were simply cut then they would take in less oil and more air because the source of air has changed. now of course your wondering, "whats the difference between metered air and ambient air?" well metered air coming in from the intake tube is always under vacuum with the engine running, ambient air is not. you see the omp system mazda designed is quite intelligent. as the rpm rises so does the vacuum in the air bleed lines netting in more oil into the housing per revolution. so the amount of oil injection per revolution is more proportional to the rpms but not static as many would imagine. that is my theory anyways.

 

The OMP is a pump. It pumps oil into the lines.

The air from the spider to the injectors equalizes the air pressure on either side of the checkvalve in the injector.

IF you close off the path of air from the spider, there is going to be one large suction on the other side of the injector, coming from the rotor intake stroke. Large suction effect that wouldn't be there if the air from the spider was there.

I've proven the OMP is a pump by blocking off three of the four feed lines. Then shoving the other line into a tube connected to a SunPro oil pressure gauge. Start the engine and the pressure showed up right away on the gauge. Rev'd the engine and the pressure on the gauge rose til it blew the injector line out of the SunPro line. At the same time I had a short pipe that I installed into the chamber in the OMP that recieves oil from the front cover. That pipe was open on its end. No oil came out that pipe while the above was taking place.

The picture on the left, below, shows the pipe I installed. It's near the top of the picture. I realize it Might be hard to see/figue out if you have not looked at a OMP lately. The second picture showe that tube from the oil cavity inside the pump. You can see it in the kidney shaped cavity at the top.

In the past I've also blocked off the pump from feed from the front cover. Then attached a hose to the new pipe in picuture one. Ran that tube into a bottle of two stroke oil (colored blue, oil). Then starter the engine and rev'd it to a couple grand. Oil from the bottle (located below the pan, on the floor) rose up into the OMP then out the lines to the injectors. BLUE colored oil, not amber pan oil.

Actually seeing the omp put out over forty psi helps explain how a turbo charged engine under boost gets fed oil to the rotors from the injectors.

Three of the four had to be capped off to see pressure.

On a series four, lifting the omp rod plus the omp turning over faster, is what causes more oil to be injected. Not suction.

 

fascinating. i believe i might have seen you mention this experiment in an earlier thread long forgotten. thanks for taking the time to reiterate that for us.

 

The factory TRAINING MANUAL, Lubrication section, page 2-5 insinuates some of what I said above.

It says, in part: the oil nozzle has a one way check valve, which acts as all airbleed to prevent excessive suction of oil and to atomize the oil.

That Training Manual is out there somewhere for a download. It's only series four non turbo though. NZCONVERTIBELE made that manual available.

The new tube mentioned in the thread above, is shown in the attached jpg. Just drilled a hole and inserted a piece of pipe into the feed cavity of the OMP.