Hi ! For my 13B, I converted the oil injection pump to spray 2 stroke oil inside the engine, instead of having it spray motor oil to lubricate the seals or whatever internal parts the oil injection system was design to lubricate inside the engine.

THIS DOES NOT CONCERNS ME ! But here is the thing> on THIS forum a lot of people clam, that fuel injection cars have their engine management system design so, that during coasting/rolling your car in gear down the hill or approaching to the Stop or red light, and your foot is off the gas pedal during that time, the system automatically turns the fuel injectors OFF, completely. Now , for those who are fuel injected and those who took their oil injection pumps and oil injectors off their engines but instead they premixing their oil in the tank with gasoline. If it comes to the point when their fuel injection is cut off, there is absolutely no more fuel or premixed oil with fuel spraying inside the engine, as it was described "ZIP'' "NO MORE" >>>>


What lubricates engines seals ( engine internals )???

Will it have any effect on the engines internals (wear) in this conditions? And if yes, is that mean that it is better not to mod to premix system but keep it stock???

What would you do or did with your oil injection???


Your opinions PLEASE !!!

 

To prevent any confusions let me rephrase the questions!!

First> Does the engine internals ( apex seals and housings ) get any lubrication during the period of the fuel cut off, since there is no oil metering pump and the only way for it to be lubricated is through fuel witch was premixed with oil ??

Second> Will it wear down any parts ( apex seals housings) during the fuel cut off with a premix setup ??

Third> What would you do or did to your oil metering pump (oil injection system) on your rotary engine?? Why ??

 

Wouldnt cutting the injectors off completly off cause the engine to go all the way lean?
Also, when peoples OMP's fail, some have claimed to drive them many thousands of miles before they noticed so a few seconds wouldnt make a difference...its not like the OMP is constantly pumping **** in there and burning the oil (youd have to fill up your oil every hour lol), Its on a stepper motor I believe.
Correct me if Im wrong of course?

 

to simply answer your questions, fuel never cuts off at all, only a smaller duration of the injectors staying open to inject fuel, IIRC, doing so can cuase serious engine damage. causing to go very lean!!!

so yes they get lubricated, it wont wear as much wear if you premix correctly, depends how you drive the car, i cant say the parts wont wear but not abnormally...

 

read the fsm and see how it works then youll understand a bit about the omp...the single turbo section/race section has good info from my searches...

 

at the situation you describing (coasting)

the engine sees vacuum, so the oil injectors are squirting as they would at idle.

you dont really need to lubricate in these situations anyway.


the biggest concern with seal lubrication is:

1. under load
2. high rpm

premix is better because more load, more fuel, gives you more lubrication.

it's not dependent on your accelerator position and vacuum, thats the biggest difference.

 

search keyword premix ... there are tons and tons of threads that will answer every question you may have on the subject

https://www.rx7club.com/search.php?searchid=6479639

 

OK, listen very carefully people:

Under deceleration, when the engine is drawing vacuum and the TPS is at zero, ALL FUEL IS CUT FROM THE ENGINE until about 1500 RPM. This means that the INJECTOR DUTY CYCLE IS AT ZERO, and thus the injectors are CLOSED. This is called "over run fuel cut", "decel fuel cut", "coasting cut", etc. and is a component of all modern EFI systems.

This seems to keep coming up on this forum again and again, and I don't understand where the confusion is.

Now, as for the premix. During this time of decel fuel cut, the engine is under very little load and is lubricated by the oil film already present on the housings.

Premix has also been covered to death here, so a search for "premix" will turn up thousands of threads.

 

[QUOTE=Aaron Cake;8814066]OK, listen very carefully people:

Under deceleration, when the engine is drawing vacuum and the TPS is at zero, ALL FUEL IS CUT FROM THE ENGINE until about 1500 RPM. This means that the INJECTOR DUTY CYCLE IS AT ZERO, and thus the injectors are CLOSED. This is called "over run fuel cut", "decel fuel cut", "coasting cut", etc. and is a component of all modern EFI systems.



If you didn't know this the TPS is never at zero when the engine is on and is IDLING!! at least, if the TPS is properly set/adjusted l!!!

 

WHat IF... YOu happen to be road racing on premix... ANd you are on the straight and you reach i dunno about 160mph.... ANd from there you have to make a first gear turn at about 15mph. THere will be no gas involved and downshifting hard maintaining high rpms for engine braking.


Could this hurt the engine since it didnt get lubed in such an aggressive situation?


MY bro tunes evos.. and he says injectors never shut off completely under decel.

 

Aaron,

He said "people have their ecu set so when they let off the throttle, the fuel shuts off". That could mean that at 7000rpm, the fuel shuts off. Thats not gonna end good (lol).

 

Going lean is not a big deal at light load.
As for failed OMPs it is often a failure in the position
sensor not the pumping mechanism
Dave

 

understood

 

understood as well...

 

I cannot believe that I am in a discussion trying to convince people on one of the basic functions of EFI that has been known for many, many, many years. I am frustrated by the lack of people to believe a truth, and the lack of effort to just go out and look it up themselves. Lots of basic EFI info out there.

Anyone who doubts that ECUs cut fuel on decel should just post their question into the Haltech, Microtech, Megasquirt, Wolf or generic EFI forum available on this website.

Zero according to what the ECU reads as zero, not zero according to what you read on your meter. This is why TPS calibration is very important on these cars.

If you are road racing and are at constant high RPM, that is a time when fuel cut should be turned off in your ECU. Or at least adjusted so that all fuel is not cut. Normally there are degrees of cut available and cutting 50% of fuel instead of 90%is probably a better choice.

I don't know a thing about Evos, but I find that highly suspect. All vehicles equipped with a catalytic converter cut fuel on decel to avoid poisoning the cat. Now if your brother is using an aftermarket ECU, it may not have decel cut enabled by default. In that case I suggest he explore those settings as they represent a major increase in mileage and drivability.

At no load, it's irrelevant.

Oh, and fuel cut has been used for years as a rev limiter. It's far safer for a catalytic converter to cut fuel instead of ignition as a rev limiter. Cutting ALL FUEL is perfectly safe as when you have no fuel, you can't have detonation.

At any rate, I've wasted enough of my time trying to convince people that the sky is up and the Earth is down. I've laid out the information necessary to be informed, so now I'm done with this thread.

 

I am under the opinion that if you premix there should be Enough Lubrication in the housings anyways to cover IF the Engine gets fuel Cut off,and therefore the engine should survive any Momentary fuel cut.
I've noted that when some engines are Disassembled that there is a Line inside on the housing where you could actually see the Path of the oil injected into the Housing.
and when I see that,I think that it would be better "in my opinion',For me anyways,to run an engine with premix.
That way the Whole internal area is Coated with Fuel and oil and not just a Small spray off the oil injector.
It all comes down to Preference.

 

and you're correct in thinking so ...

some people seem to take the general idea of lubricating the seals too literally and propogate the idea that any lapse in metered oil (or premixed oil) - no matter how momentary - leads to immediate and complete engine destruction. i can say for sure that it doesn't. obviously the motor was designed to consume oil for seal lubrication and obviously it's to your benefit to make sure that it gets it, but if you're premixing, you're not going to grenade it on deceleration fuel cut.

 

People who freak out about apex seal lubrication have not done their research. They don't realize that in many ways, the seals are self-lubricating and that the rotor housings have a porous chrome coating that stores oil...

 

SO my big WHat IF. IS completely safe on STOCK ecu?

 

Yes, it's safe.

 

I have a friend who premixing his car, according to his experience> not only it is a pain on the *** but also a wast of two stroke oil, I think the coolest way is to convert your O.M. pumps to inject two stroke oil instead. like I did, even for those who don't premix two stroke oil would be better lubricant at that point but also reduces the carbon build up and decrees in octane, and when you racing, premix just a little bit in your tank as well, just to be on the safe side, but this is just in my perspective !!!

 

It's funny, same discussion about the premix for rotary and premix for 2 stroke motors ...

In 2 stroke, small motors are not lubricated by oil pump, and this is not a problem ... When you cut off, you haven't a great explosion like under load = the motor can run lean.

Same issues, same fixes !

It's BETTER when the lubrication is all the time like our 7 and OMP, but in most case this is not a problem ...

(sorry for my english ...)

 

Con, I am leaning toward your setup vs pre-mix but I have'nt decided which way to go. (fyi I bought a Rotary Aviation fd OMP pump adapter. Of course it will use a separate tank to hold 2-stroke, TWC-3 oil, and inject using the stock oil injectors, but not yet installed).

Background: I bought a single turbo fd, it had the stock omp connected, but with oil injector vacuum lines plugged, PFC, and he also ran 0.5 oz per gal premix in the fuel tank. I was concerned that this is not the best solution.

Couple thought starters and question.

According to Richard Sohn, designer/fabricator of the RA omp adapter, "the oil injector check valve just acts to prevent oil from backing up into the intake manifold, also the vacuum connection, from the oil injector, to the intake acts like a mini intake manifold, allowing the injector to vaporize oil droplets before they are injected toward the apex seals".

Potential benefits to this system:
1. Clean and no fussing with measurements as with premix
2. Eliminates the fuel cut, lack of oil flow, mentioned (could be a problem during hi rpm decel if using a stock ecu)
3. Potential better "cooling" of the apex seal (ie oem Mazda design)
4. As you mentioned, better lubrication, higher octane in the fuel mixture than engine oil

My question "What's the best vacuum connection point for a single turbo FD? I need to research this since my car is not stock. Also, the FD oem vacuum diagram is hard to follow, and I am not sure how the vacuum source is plumbed to the intake (ie is there a vacuum check valve in the line or not, best point to connect the vacuum lines)

Any thoughts on this???

 

ps I've been reading the rx7, rx8 and aviation forums for ideas

 

If you still have all your emission controls in tacked, than you should run the vacuum from the stock source. The principal of vacuum for the oil injectors should be the same, regardless of the set up.

On FCs it should connect to one of the larger vacuum ports on the manifold by the throttle plate.

Maybe you can refer to this, this is FD, light blue color lines, is what you should look at, > http://www.fd3s.net/turbosystem.jpg,