I bought new rotor housings as part of my rebuild. I figured I would get S2 housings since they were cheaper and why not. I started looking into using the third oil injector hole seeing how there are wear marks on the center of my old housings.
The idea I came up with was to make new oil lines and have a splitter to create 6 connection points from the 4 nozzles on the OMP. I was not sure the pressure and flow would be sufficient so decided to not follow through.
However, after browsing around I found a listing of the S2 housings on RRP and they mention the center oil nozzle hole can be used. I sent a message to ask how but I have not heard yet and I am afraid I will never.
Does anyone have experience with this or have some insights?

 

There's no real pressure in the OMP system, it doesn't inject as much as it dribbles. If I were to do this, I would split left and right, and dedicate one line to the center. I don't think you could make anything worse, the delivery rate is still the same.

Keep in mind that the S2 system activates the 2nd EMOP only under certain conditions. Most of the time it's running on 2 injectors /rotor.

 

The OMP is designed to deliver precisely the same amount of oil to each of the four injectors. The problem is that oil will take the line of least resistance, so Putting a T in any one of those lines opens up the possibility that more will flow through one than the other.

If that happens ..... save up for a rebuild cuz it wont take long.

 

I set up a current rebuild the way Loki described. I put a t between the two side injectors and just ran one line to the center from a modified s1 pump. The t is very local to the injectors with the shortest possible lines of equal length. It might favor one or the other side while running, ( and I wouldn't know it if it did) but using a static gravity test before the engine was installed, both lines flowed the same speed/rate. Under pressure both the banjo bolt valves popped at the same time, at least at the time of testing. The OMP is set to inject vastly more oil than stock. I would not try this with stock settings in my opinion. Too many unknowns. On mine, time will tell if it works and keeps working.

 

mazda maniac did this years ago, had a long chat with him at dyno day

 

I see. That would be interesting. Have you used this?
Also I would think just running 3 all the time would be good too instead of engineering an entire system to have it come in later.

That is exactly what I was thinking. Besides, Mazda put in two oil injectors to cool/aid as part of the side exhaust too iirc. So diverting flow to the center might counteract that too. By keeping the t/y piece close to the rotor housing and the length of both hoses the same the resistance and therefore flow could be as close as possible. But it would be hard to guess if that is sufficient.

That is very interesting! How did you increase the injection amount? I assume either through software flashing or a hardware modification of the omp pistons?
I don't see why you wouldn't recommend trying it with stock settings? It might inject less in the sides but more in the center.

​​​​​​​​​​​​Do you know how he did it? And what did you chat about?


It would be an interesting experiment. I've seen plenty of housings having broken out chrome near the exhaust ports though so I don't know if taking oil away from the sides would do that any favour. On the other hand I would assume the oil is burned up before it can reach that point?
The other downside is that you would need to source 2 additional injectors. Which don't seem to be cheap.
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Thanks for the insights. Keep 'em coming!

 

There is not enough oil stock in my opinion, regardless of 2 injector or 3.

If you then have non standard plumbing with unknown results, it makes sense to add more oil for that reason alone. The factory oil amount delivered in average street driving is miniscule.


This thread may be interesting to you:

https://www.rx8club.com/series-i-tec...cation-268559/

 

I was going to suggest premixing, but then remembered this is the season of the whiney can’t be bothered with it generation that would rather chance eating an engine they can’t even afford in the first place playing this sort of game. Because they’re smarter and have more resources than Mazda ever could.

ps: an S2 engine is no more reliable or longer living than an S1 engine. So why would anyone knowledgeable even attempt this? The answer is right before you.
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