LittleJohn

Has anyone mixed two stroke oil into their fuel for increase lubrication for the engine?

or is this just a dumb question?

sferrett

This has been covered in another thread - do a seach for premix.

or try this thread as a decent example of a discussion on the topic:
https://www.rx8club.com/showthread.p...ghlight=premix

IMO the stock metering system is plenty sufficient and adding oil to the fuel is not neccessary.

LittleJohn

ok... I'll try the search again..
Bit of a newbie so not sure what keywords to use.

sferrett

For the benefit of plebs like me with a limited vocabulary:

pros·e·ly·tize ( P ) Pronunciation Key (prs-l-tz)
v. pros·e·ly·tized, pros·e·ly·tiz·ing, pros·e·ly·tiz·es
v. intr.
To induce someone to convert to one's own religious faith.
To induce someone to join one's own political party or to espouse one's doctrine.

v. tr.
To convert (a person) from one belief, doctrine, cause, or faith to another.

LittleJohn

ok... I'll try the search again..
Bit of a newbie so not sure what keywords to use.

BasenjiGuy

Stealth - are you kidding about this? I had a a 1st gen RX-7 and learned all about rotaries in 15 years ago. Once Mazda got the oil injection technology and seal composition figured out, it was accepted that lubrication for the rotary was optimized. When folks were getting 200k+ miles on their original rotary engines built from the 70's on up to current models, it would seem that Mazda's rotaries have near optimal lubrication as is. Why add something to the fuel that the fuel injection system is not designed to squirt? Sounds like a recipe for clogged injectors...

Gigolo Jason

MMO all the way. If you are going to use it then this is the stuff to use. It has been a staple in the garadges of third gen owners for quite some time.

rotarygod

There are some things to consider about premixing. Since the factory oil injection system injects oil based on rpm and load, it is constantly varying the amount in the engine. When you premix, you are accounting for the worst case scenario but are overlubricating the rest of the time. Nothing wrong with that. Just something to consider. Typically if you want to run premix, you should disable the factory system entirely. Now you are throwing much more oil than necessary into the combustion chamber. There are many that only use it as a supplement though and don't have issues with it so even this is debateable. The biggest thing to consider is a "what if" scenario. What if you don't premix, the oil injection system breaks yet the computer doesn't shut the engine down? Premix would have saved you. For people that only premix with the stock system diabled, what if you forget to add that 2 stroke oil at the gas station? Not good. Premix in addition to the stock system is more of an insurance. It isn't necessary and isn't helping your engine out any more than the stock system. It definitely isn't hurting though. The biggest problem is with conventional oils getting into the combustion chamber at all. They have no place there and they are what leave carbon deposits. If we use a seperate reservoir for the metering system to pick up 2 stroke oil from, everything would be perfect.

LittleJohn

Thanks for you input RG.. My neighbour, who been a wrench for quite sometime said exactly the same thing about the reservoir. I wonder why Mazda doesn't do this. surely it can't be too hard or costly to implement..

PaulieWalnuts

The oil injection must be made idiot-proof and therefore oil must automatically be drawn from a source that won't run out. The reservoir wouldn't get consistently filled up by the car's owner and the engine would eventually fail or have a shorter lifespan. The current method is the best compromise of the two.

rotarygod

You have a fuel gauge for the fuel tank. Install an oil level gauge for the reservoir along with a warning light and consequently ecu intervention if it runs out. Nothing difficult about that. The ecu controls everything else. If you do it right, you could have a reservoir that is sized so that if you stay at the recommended oil change intervals, you also add oil to it too. If your engine oils gets old and dirty, do you really want this stuff trying to lubricate the inside of the combustion chamber? I don't. I want clean fresh oil designed to burn with fuel to be used.

PaulieWalnuts

I agree with you that the reservoir is the best route from an engineering standpoint. But people are already bitching not only about checking oil, but having to do it so frequently. "I didn't have to do that with my Honda" Add another thing to fill up and owners wouldn't be happy.

And what about the people who ignore the "check oil injection reservoir" for 5,000 miles? Imagine a novice who barely knows how to fill their gas tank stopping at a gas station and asking for "Motul 600". I wonder what percentage of gas stations would actually even carry the required oil? How long would a Renesis run without any lubrication? And how big would a reservoir need to be to provide oil for the life of the car? A quart every 2000 miles is 50 quarts at 100,000 miles. A 12.5 to 25 gallon reservoir is not feasible.

Again, I would have no problem maintaining a reservoir. Too many people who are maintenance idiots would not maintain it properly.

rotarygod

My response to the complainers that say "I didn't have to do that in my Honda" is that "You didn't have to stop driving your Honda". I agree that there are too many people that don't check up on things. That's why I think the ecu should step in and shut it down if it gets too low. A loud buzzer like my RX-7 has for low coolant level really gets the point across before it is too late.

PaulieWalnuts

You are thinking purely from an engineering perspective which is partially what killed the 3rd-gen RX-7. "Let's build an engineer's dream - who cares about luggage space, comfort, and reliability!!!" Well, the buyers do. And if Mazda said kiss off to new buyers so that only rotorheads would be buying the car, sales would be 2000 a year instead of 2000 per month and there no longer would be a profit to justify a rotary engine. 3rd-gen RX-7?

Run out of gas, car doesn't run. No biggie. Let the oil go 15,000 miles before a change, slight reduction in engine life, not much of a biggie. If half of the people let the reservoir go empty, the engine fails and Mazda has a nightmare situation on their hands where people have bad experiences with the rotary and never buy one again.

Shut the engine off??? A couple with their newborn are driving 100 miles through farmland in the middle of nowhere and the car shuts off because of the low reservoir?

Look at this a bit more from a business standpoint.

lafrad

imagine all the owners that take the car to a "quick lube" place... "uhh.. we are suppose to check WHAT oil?!?! hmmm... "

Racer X-8

The new sensor of the new reservoir could trigger the same alarm as low oil level does today. Those who know their car would check the engine oil as well as the new reservoir. Those who don't know their car would take it somewhere to be checked. A decal or some embossed thingie could alert the ignorant garage mechanic about the separate reservior, that also needs to be filled above minimum level with 5-20 engine oil. The reservoir only needs to be 1 quart. That's plenty if it should be routine procedure to top it off during oil/filter changes.

There. No more "check the oil every time you fill the gas tank" jargon, which is what is going on right now, and the ex-honda owners will be happy. Me too, too.

edit: Having re-read my post here, it came across a tad heavy on the nuisance side of the whole thing. OK, it really is a nuisance and just a bit of a mental strain on really being infatuated with the car. But, that's all really ok. There are two bigger issues that are not ok with the current design, and it is those two things that really are the drivers for this new reservoir thing to be brought to fruition:
1) The injected oil should be perfectly clean and in good condition, not used oil from the sump. (Already discussed, yes. Just reiterating it here, cuz it's true.)
2) The injected oil should not be taking engine oil out of the engine and subjecting the engine at times with a lower-than-desirable level of its' life blood of lubricant.

Seems quite silly to me. The first guy to mention the current design as a possible approach, back in one of those Mazda think tanks many years ago, probably got laughed right out of the room. Deservedly so, in my opinion. Oh well...

PaulieWalnuts

You missed something. This is about using 2 stroke oil in the reservoir. I doubt many places outside of a Mazda dealership would be carrying 2-stroke oil and most independant mechanics and Jiffylubes would have no clue of what to do.

Racer X-8

Well, I know I didn't discuss the kind of oil to be used in the reservoir, but I didn't miss the point. I just left it there for y'all to think on. Mazda will want to specify regular engine oil to be used for injection. That makes things real easy. Oil conniseurs can modify that to mmo, or whatever. The main thing is going to the separate reservoir though.

PaulieWalnuts

And here's a couple of points to consider. What is better:

1. Uninterupted lubrication 100% of the time with somewhat imperfect oil, or
2. Lubrication with fresh oil only 50% of the time?

If you're so conviced, try #1 and run your car for 10,000 miles without changing the oil. Then try #2 by disabling your oil injection for 10,000 miles. Let me know what happens.

In a perfect world where everyone is an RX-8 fanatic who sleeps with their factory shop manual, I would agree 100%. I AGREE that the reservoir is superior IF USED ONLY BY GEEKS LIKE YOU, ME, AND RG. In our current world where there are too many people (novices, fools, or just idiots) who think cars are appliances, they would not be willing or able to handle the reservoir. Forget to fill the reservoir for a long enough period of time and the engine fails. I doubt Mazda would be willing to put the success or failure of the Renesis in the hands of the consumer. With the current system, Mazda has control.

rotarygod

Since I obviously need to explain with much more detail let's try this again. When the reservoir gets below a 1/4 of a tank, a light blinks. When it gets below 1/8 full a buzzer sounds continuously. If you hear this, you'll only let it happen once! It is too damn annoying. If it runs completely out, the ecu steps in and shuts it off. If it gets this far, you shouldn't own a car of any kind. Another option is that we could have it switch over to regular oil from the pan instead of shutting off completely and then just sending the car into limp mode. This will still make it drivable but not very quickly. Since that is overly complex, the best thing to do is if it gets below 1/8 of a tank, it goes into limp mode. Just call the 1/8 full mark 0 on the internal gauge. This is why we have idiot lights in the car. Complete idiots alradey run the risk of running the car out of oil due to the injection system. You can't protect against everyone with this type of engine anyways so why not do it better for those that can change their oil more often tha every 50000 miles? This is the best way to do it. 2 cycle oil isn't rare and can be found at any autoparts store. If someone runs low on oil now, they have to go there anyways. What's the difference? You don't need to have it coincide with the regular oil change.

When you quote someone, instead of hitting reply and then quote, try just clicking on the quote icon under the person that you wish to quote's avatar. This is how everyone else does it. It saves you the trouble of typing it all over again.

dannobre

iTrader: (3)

SO......Is it possible on the Renesis to tap into the intake for the oil injection system, and add a reservoir that uses 2-cycle oil?? I assume that the ECU would need to make allowances for the different type of oil used....so is this a pipe dream, or can it be done reliably, and be an improvement in reliability for those of us that are willing to ensure that the oil level is kept up?? RotaryGod?

T-von

I agree 100%. My coolant buzzer went off once in my Fc. Talk about annoying!


PaulieWalnuts, I'm with RG on this one. I know for a fact that Toyota has a similar engine shut down feature. Example: My sister was driving my parents 91 Toyota Previa mini van. On the highway the coolant started leaking out and before the temps got to high, the computer shut down the engine to keep it from over heating. To this day the van has over 200k miles and runs perfect. There are reasons some manufactures have that reputation of reliability because they are willing to go the extra mile to make their products reliable. Heres another example, same sister was driving a 93 Mercury Sable that developed a coolant leak in the lower radiator hose while on the highway. This car overheated do a lack of a warning system. Again, Toyota went the extra mile and Ford didn't. The end result, the Toyota is still driven while the Sable is collecting dust with a fried engine.



dannobre, RotaryAviation.com sells a reservior kit for 2-cycle oil on rotarys. I believe it could work for the Renesis as well but I'm not sure.

PaulieWalnuts

That's a good idea

That's an emergency situation that has little to no chance of happening to a new car. The reservoir shutdown would have the potential to happen every couple thousand miles or every month or two because the oil is used regularly and needs to be replentished. That's a huge difference.

Xystas

Now that would be a project a would partake!!!