Cool! My next oil change will be with water since it is cheaper and a better coolant than oil.

 

Excuse me? The fact that your interpretation of a technical matter regarding a rotary engine is almost certainly incorrect doesn't affect you?

 

I think some people are taking cooling and lubricating as two separate entities for this matter when in fact oil does both. For those who come from machining experience, what do you think adding oil to a drill bit on a drill press, lathe, or mill does? It cools and lubricates the bit to prevent from excessively heating and reducing or rather ruining the life of the bit as well as reducing friction.

MM's response is technically correct; it's cooling the seals while also lubricating them.

 

Ok so where I can get those hoses for my 05. Anyone have a spare one ?? .

 

No one's arguing that. I think it was the [not so subtle] "..dry-seal..mainly there to cool.." comment that caught us off guard.

"Remember, the Renesis is, essentially, a dry-seal motor. The parts that need lube all the time (bearings) get oil all the time.
Injected oil is mainly there to cool the seals, not lube them." -MM

 

If you have an S1 RX-8 and you aren't premixing, your apex seals aren't properly lubricated where they need it the most. No amount of tweaking the settings can change that. Premix is the answer. For those with the S2, sit back, relax, and enjoy the flight.

 

/\+1
*Word*

 

Correct or incorrect, it does not change the implementation one bit.
Oil is injected and will be regardless of what I know.

 

]

Also having worked as a machinist, there are times when one is more important than the other, "Tap-Free" primarily lubes for example. In other cases, like drilling a 1/2" hole in cast iron, one goes to full-flow smothering the bit in oil to keep the thing cool. In that case however, one is flowing oil in rates many orders of magnitude higher than the MOP. I'm not immediately doubting that the little bit of oil in the Renny has a cooling effect, but am sure it's not being done in a way typical of high-flow situations (like bearings).

 

Why is my engine still running fine, then?

 

Come see me in 100,000 miles.

 

Not really. Prevention of heat is different than removal of heat. and there are multiple ways to remove heat. Since MM made the distinction between cooling and lubrication, it raises the question of what the cooling mechanism is.

Since it seems physically impossible for the small amount of oil to act as a "coolant" by carrying heat away in the fluid (or by vaporization), and MM claims that lubrication is not the major factor, the only mechanism consistent with his claim would seem to be that the oil facilitates conduction of heat from the seal to the housing -- in much the way that a very thin film of "thermal compound" allows heat to be conducted from computer chips into heat-sinks.

This actually makes sense to me because conceptually, this interface seems like a hellish application for lubricants in the normal sense.

Of course, MM could maybe clear things up by explaining what he means but that really wouldn't make any difference to his engine.

 

Hmmm...

 

I don't premix, but maybe that's the right thing to do. My engine craps out at say 90K and it gets replaced. I then pre mix and get say get another 150K miles for a total of 240K. Meanwhile the premixers get their 150K by which time the warranty has run out.

Oh by the way:
No.

 

I think I was closest, my third was put in by Mazda at 96,000 miles I have premixed since the the first tank in that motor.

 

One of the reasons of the S2's third nozzle, that Mazda had to solve the apexes and corner seals lubrication without raising the volume of the injected oil (emission). So if we raise the amount of the injected oil (per injection) in the S1, it can eliminate the need of the third nozzle.
We not only raise the oil volume per rpm, we even raise the volume at every oil injection with this pipe plugging.
I know the MOP is a volume dose pump, but it is not a tightly sealed part, so bigger vacuum can absorb more oil at every oil injection. It is more true, if we have modded pressure regulators, so higher oil pres.


You don't need to change the intake hose, only pull out the vacuum hose of the nozzles from the intake hose, and seal them.

 

Its the direction of the spray that makes it work, not the volume.
The whole point of the third nozzle is to apply the oil uniformly to the apex seal (to reduce "crowning" caused by expansion).

Really bad idea.

 

I still wonder how raising the oil pressure in the system will affect the amount of injected oil.
Given the lack of a third oil injector in our engines and the fact that the 2 nozzles only cover 2/7 or 2/5 of the apex surface i still wouldn't rely on increased OMP settings alone though.

 

I wonder too.
But, since the MOP is a positive displacement pump and oil isn't all that compressible, I imagine the volume difference is negligible.

 

We should see what kind of restriction the pump itself is, and then add the hoses. It is possible that with larger hoses a small increase could be noticed.
Since we are cheap bastards here we usually open the pump and play with the stepper motore to increase the OMP rate so it's always hard to exactly know what's happening, i can't be of any help here.

 

I dunno. The whole thing is moot to me.
If you want to change the injection volume, flash the PCM.

Otherwise, just pre-mix and call it a day.

 

That's fine but we'd miss all the fun of getting our hands dirty
Cranking the OMP up via PCM of mechanically and premixing is still the way to go, I agree

 

i called lubrication and cooling the same for the simplicity sake of it all.Even water has SOME lubrication power for example. Minuscle I know, but if people want details--then yes --it does.
But I understand what you are saying and agree.
Does anyone really think that the small amount of oil that is allowed in the combustion chamber is enough to really lubricate (in a traditional recip like way) both of these LARGE areas? Isnt that the reason Mazda developed the housing coatings/material and the apex/corner seal materials that they have?
If we have the volume of oil in the chambers that a recip has on its rings can you imagine the amount of carbon buildup? Jesus.
Like others have said---its fun to think and brain storm about but premix with adequete amounts of oil withcontinuence of the omp is the way to go?
OD

 

I thought if there are more oil in front of the apex (from the nozzles), it can "spread" better the oil (making almost homogen oil film) on the trochoid wall.

 

Exactly.
There are 42 Seals, 48 Springs, 8 O-Rings and two Rotors.
How do they all get cooled? OIL.
How? The oil sprayed inside the rotor which cools the rotor which cools the oil film between all the seals which cools the seals. This is the ONLY way you can cool the seals. The oil control rings get there oil from the crank case, the side seals get a little from the crank case too. But the apex and corner seals cannot get this oil. This is why we have oil injection and or premix. The oil injected in front of the apex is squished down into the grooves around the seals as the compression comes up on the stroke.
This is why oil temp is so important on a rotary. If you let the oil temp get above 220-240 you will start to kill the seal springs and oil control o-rings.