I got a kit from JHB Performance to block the omp oil supply from the engine and use 2 stroke oil from an external reservoir. The kit uses a plate between the front cover and the omp to block the oil from the oil pan and requires a hole be drilled on the omp body to supply the 2 stroke oil. The oil reservoir is the sub zero assist fluid tank that is modified for this purpose and is the method suggested by JHB Perf.
My problem is that oil keeps flowing (slowly) from the tank through the omp and into the rotor housings through the lines when the engine is off. After 3 days of sitting unused the tank lost about 4 ounces that went into the engine ( no leaks on the floor). The engine has been just rebuilt and runs well but is a bitch to start beacuse of this. It requires the same procedure to start as a badly flooded engine does.

Why does the oil keep flowing into the engine if its off? The omp is in fairly good shape.

Help anyone???


Kenneth

 

series 4 or 5? I'd guess 4 cause I can't imagine the electric OMP liking being drilled into. I'm thinking that the problem you are having is gravity! The cold start assist resovoir is higher up (vertically) than the oil injectors, so that even after the engine is off the OMP is stuck open for some reason and since it was sucking oil previously, it acts like a siphon, so the oil continues to flow into the housings. So either relocate the resovoir to a lower position, or see why the OMP is stuck open.

 

It flows into the rotor housings because.........................the reservoir is located higher than the oil injectors. Water and oil flow downhill..most of the time.

Like tex said in the post above.

 

I have fixed the problem!!!

The OMP is not actually a pump per se. That is a misnomer.
What it actually is, is a metering and distribution valve.
By rotating the input shaft on the OMP there is no pumping action. Only thing that it does is rotate the internal cylindrical valve so that, pressurized oil supplied by the engine`s oiling system, can flow to each individual port and into the intake and housings.

When using an external oil supply the oil must be either pressurized by other means or gravity fed. The intake system provides some suction to the OMP lines, (Suction and amount of oil drawn in, is limited by the size of the metering jet on each oil nozzle. Also there is a vacuum line connected to each one of the check valves on the nozzles, then to a round plastic collector and then to the intake plenum. This keeps constant vacuum on the oil metering lines.) so oil does not really "need" to be pumped into the intake. It is more like allowed to be sucked in, but in a controlled fashion.

The kit`s instructions actually require having the reservoir at a higher level than the OMP for this reason.

Why I was having trouble in my case was because of worn out OMP seals. I took the thing out, disassembled it and replaced all rubber seals with new o-rings. I could not find a source for replacement seals, but the right sized o-rings will perform just as well. It turns out some of the oil went into the combustion chambers and some went into the oil pan. The sealing between the OMP and the front cover has to be perfect or the oil will seep into the oil pan, contaminating the engine oil. This was revealed when the dip stick showed oil to be much higher than the full line. Also my new oil has the blue hue that 2 stroke oils now commonly have.

Problem solved.

I have another question on my hands now regarding the adjustment of the screw on the Air flow Sensor but will start a new thread for that.

Thanks for your reply`s.

 

****I have fixed the problem!!!

The OMP is not actually a pump per se. That is a misnomer.
What it actually is, is a metering and distribution valve. ************************************************** ************************************************** ****************************

Sorry. I stopped reading after those words above and read no more.

It just ain't so. Those words above. I've done everything I know with that omp (series four) except take it to bed and **** it. What I've done is this: blocked off the supply of oil from the front cover completley. Drilled into the cavity where the oil from the front cover enters the omp. Installed a pipe in that drilled hole and attached a hose to it.

I put the other end of that hose in a bottle of oil UNDER the engine. Started the engine up and held the revs to 2000 rpm and at the same time held the omp rod full up. The oil came out of the bottle of oil UNDER the engine.........into the omp.......out the four hoses to the oil injectors. The oil in the bottle was from Wallymart, the blue colored oil. That is what came out the four outlet hose on the omp to the oil injectors.

At one other time I've blocked off three of the four outlets on the omp. I used just regular bolts to do that. With the fourth outlet, I left its banjo bolt in place with a length of hose on that banjo bolt. Then I shoved a hose from a SunPro oil gauge (best 20 bucks spent on this heap of cars) inside that one omp outlet hose.

This was the same omp as described above, but this time there was no blockoff plate b/t the front cover and the omp, so oil was being fed from the front cover to the pump.

But remember that hole I drilled earlier and put a pipe in the hole? And how I had a hose going from it to the oil bottle under the engine? Well that hose was not connected to that new pipe and the bottle played no part in the following, but that pipe was left wide open.

Keep in mind, that new hole I drilled in the omp, and the pipe installed in that hole, go directly to the cavity that is fed oil from the front cover.

Started the engine and the SunPro gauge immediatley started rising. I rev'd the engine to 2000 rpm and the pressure kept rising until at around 40 psi the hose from the SunPro that was inserted into the one outlet hose of the omp, blew out/came apart.

At no time during the above did ANY oil come out that newly drilled hole in the omp. Which means the engine oil pump that pumps oil to the front cover has zippity to do with any pressure in the omp lines other than being a source of oil for the omp. There's no pressure because of the open hole in the omp cavity that spills directly back into the pan. To get meaning of that you have to take the omp off and look at the dump hole and the supply hole from the front cover.

There's a long *** thread on modifying the stock omp , with pictures, out there. The OMP is indeed a PUMP. It also distributes the oil, no qualm with that.

 

Here's that old thread by Patman. I THINK he's the first to drill into the stock omp and use two stroke oil with the original omp.

https://www.rx7club.com/showthread.p...&highlight=OMP

 

Looking at old threads of mine, I find it interesting that my replies to Hailers comments have been deleted.
Hmmm...