i noticede some people talked about premixing the oil and gas.......... does the rotary burn oil gas mix??? or is it just to cool the engine and provide extra lubrication.... im kinda lost on this one. so could someone clear this up for me. thanks

 

I have heared about that but not really sure what it does sorry.

Steve

 

You guys are in for It ! Hell yea they burn oil got a owners manual? If not you might want to do a search on the Oil Metering Pump. Good Luck

 

Not to get to technical, all rotary engines have a OMP (oil metering pump) that pulls motor oil out of the engine and injects with the fuel/air mixture. Either into the carburetor or into the intake on fuel injected motors.

Why, to lubricate the engine rotor seals. Some people choose to disconnect and block off the OMP and pre-mix their own 2-stoke oil with their fuel. Just like you would if driving a 2-stoke motorcycle.

I personally never saw a OMP fail, but I have seen they leak though.

NOTE: Note sure how they accomplished this feat with the RX-8

John

 

i dont see anything like that in the haynes manual ???

 

Will it hurt anything if I leave the omp hooked up and still had 1 oz of 2stroke oil per gallon? Or can I get away with that safely.

 

If you are referring to the OMP, my Haynes manual has talks about it on pages 61-62. Chapter 2 cooling and lubrication section.

If you are referring to pre-mixing then you need to visit Mazda Competition site.


John

 

I've been running the OMP and premixing for about 8k miles now, no problem. If you don't want to go through the hastle of removing the OMP, you can simply disconnect the rod that goes from the carb to the pump. Or.... at the bottom end of that rod by the pump, you can set the cotter pin down a hole or two, this way the pump will only come on at WOT.

 

If your OMP is working correctly, adding 2 stoke oil may cause blue smoke out the exhaust, damage to the converter. When my old Rx-2 was getting tired, I used to add redline 2 stoke oil to the tank just to get the compression up, but boy did she smoke on hard thottle and de-accelleration.


John

 

I add about 10-12 oz of MMO in the gas tank every fill-up. I think I need to adjust the oil metering pump, cause it is either not working, or something... my oil level never goes down.

 

oil is used in all engines to cool, lubricate, and seal regardless of pistons or rotors. I personally have my 6port motor on my street car with the stock omp, my dragcar on the other hand is a 12a jbridge and I removed the omp and I add 2stroke synthec in the fuel cell. For street use pettit racing makes and additive that they claim is what you should use for street applications. I didn't say that I read it

 

It's a very small amount. Infact, if your oil seals are old, enough oil will probably leak down to the apex seals to lube them even if the OMP were disconnected/malfucntioning. I think peejay had a car like that.

 

does it not burn the oil up???? does it just go back in the pan???

 

You need to cut back to 4 oz.s, effendi...

 

Yes it burns it up. At least that is the idea behind using 2-stroke oil as it is meant to be completely burned off. I is exactly what the stuff was made for. Synthetic on the other hand is meant for whole different application.. sorta both are there to keep stuff lubed but pretty much one is meant to burn and the other aint.

 

I believe haynes manuals call it the metering oil pump. So thats probably why you cant find it...Also, it is completly your decision to premix or not, I remember a poll on this a while back, and many people ran OMP, some ran Premix, some ran both. It just depends on your setup and if you can remember/afford to add 2-stroke with every fillup.

The reason for using 2-stroke oil in your gas, is because some claim(although i have never seen a study done on this) that 2 stroke oil will burn completly and leave an oil residue behind, like it was designed to do.(Makes sense to me)

Your OMP injects engine oil, from the pan, into your engine. While this oil will also burn, some claim it may leave carbon deposits in the engine, because it will not burn completly like 2-stroke will.

An alternative to both premix and OMP would be this... http://rotaryaviation.com/oil_inject...p_adaptors.htm ... This is an adaptor that will use your OMP to inject 2-stroke held in a seperate resivour.

Premix, and the OMP leads to the argument about synthetic oil ... Some believe synthetic oil, in a OMP car, will leave even MORE carbon behind, simply because synthetic is designed NOT to burn. This again, is all talk and rumor, as I dont believe anyone has seen a real study conducted on this.

Furthermore, if you decide to run 2-stroke premix, use a non-synthetic 2-stroke on a N/A engine, and synthetic 2-stroke with a Turbo or Supercharged car. Why? Synthetic will not lower the octane rating of the gas put into the car, while a normal 2-stroke will actually lower your octane rating one point.

In a N/A rotary, lower octane is actually better. It doesnt resist ignition as much as a higher octane fuel, giving the engine a more complete burn ( N/A rotary race cars used to bring their own low octane gas for this reason). In a forced air car you run the risk of detonation with a lower octane. So, you would want to preserve your octane rating and synthetic 2-stroke is the way to premix, and preserve octane rating at the same time.

There is more to it, but keep searchign and keep reading, this board is full of information about premix and octane ratings.

 

wow im learning so much.....

 

One of the other threads says that if the OMP is bad the car will run like a limp noodle. It makes the ECU make the car run bad like what mine is doing. There is a little hesitation from idle and then the car bucks badly throughout the rpm's, its very slow compared to what it was. My coil packs and plugs and wires are good. So if I disable the OMP and use premix will that fool the ECU and make the car run better or will I be SOL and have to replace it? Oh yeah this is a 88' GXL.

 

Synthetic oil has an octane rating now? That's news to me...

 

No, but as i understand it(or as it was explained to me) the ingredients in a synthetic 2-stroke will not combine with the gasoline the same way a normal 2-stroke would. A normal 2-stroke will actually lower the octane rating by one point because of the way it combines with the gas... possibly it breaks bonds in the gasoline or something. I am not 100% sure on this. But that is how it was explained to me, and it makes sense to me... Can anyone help me out on this one?

 

I would think that ANY oil added to gas would reduce octane. Dilution is dilution, whether you're using dino oil, synth or water, for that matter.

 

I agree, however 2 oz of this will hurt more than 2 oz of that is basically how i understand it... or it coudl all be bullshit

 

That really has more to do with the aged oil control rings bypassing oil from inside the rotors under high-vacuum conditions than with the oil that you pre-mixed.

 

my lack of knowledge (stupidity) always creates such long threads