I've searched and couldn't find anything recent about what the RX8 is doing for oil mixing. Anyone know?

The basic idea I got was that for sure premix burns cleaner in the engine and leaves less residue. The "line" of oil spray people find when taking the engine apart might have been attributed to drip from when the engine is off.

Does the RX8 do anything differently as far as distributing the oil?

And while I'm on the subject, any quick link directions to disabling the S5 OMP? Bad choice? If I was running premix I'd want to stop the extra oil consumption in the engine.

EDIT: I realized exactly 1/8 of a second after pressing Submit that I was in the 2nd gen section. Sorry.

--Bob

 

That's the wrong question to ask.. . Here comes the 13 page long debate on premixing.

 

For the S5....

To run pre-mix you need to take out the MOP... and yank the gears out or something... just so the MOP motor can still operate, and the position sensor still works. But the motor won't actually be pumping anything.

 

OR you coudl run premix on top of the OMP. not neccicary but also can be done that way if you don't have time right now to do all that.

Matt

 

That's what i do. 4 oz per tank.

 

You know, I used to think the oil metering system design was at fault for the rotor housing wear also, because of the number of times I'd heard it mentioned. I payed particular attention to housing wear and apex seal wear during the teardown on my rebuild. The housings were worn along the edges as expected, but the apex seals weren't worn into a "horn" shape along their running edge like I had heard they would, to match the housing wear.

I came to my own warped conclusion that the apex seals are "rocking" back & forth during normal operation. When the rotors move forward & aft very slightly during transient power events, clutch application, etc, the seals will rock at their pivot point ever so slightly, which is the spring contact area on the rotor itself, or about at the center of the apex. This rocking throws the edge (corner) of each end of the apex seal against the rotor housing, at the edges, causing the wear we see.

Makes sense to me; you are of course free to demand a psyche evaluation for me, and I'll add it to my list of things to do during my life

 

Someone was making an adapter plate which went inbetween the OMP which let it run off an external oil source (like a windshield washer bottle filled w/ 2 stroke). It mightve been rotary aviation.

 

It is Rotary Aviation. They run something like $88 or so.

The RX-8 does have electric oil metering. It is still done the same way. What differs is the rotor housings. Instead of one oil injector per housing, it has 2 per housing pointing a little diagonally towards the side housings. They don't have any oil injectors on the manifold anymore.

 

I've been told that the RX-8 OMP mixture is leaner than the previous generation cars though. I realized it had 2 per rotor housing but not that they were angled... I guess that makes sense.

With a S5 or 6 electric MOP, to completely switch to premix you need to remove and block off the pump mounting surface on the front cover, and plug the pump back into the harness and mount it somewhere out of the way. The stock ECU goes to limp-home mode when it doesn't have a good feedback signal from the pump.

If you just need to beef up for a track day or autocross weekend, toss in some 2-stroke oil into the tank and call it good.