1987RX7guy

iTrader: (3)

I do understand and have my doubts about pre-mix but I am confident in it sufficient enough for me to put my engine on the line because of it.

To answer the in my oppinion on why the oil injection was not implemented within the stock fuel injection system: The FC was designed in 1984 or probably earlier but anyways back then they did not have all the advanced types of oil that we have now like the newer synthetics and things like that. Well anyways regular oil was not meant to go in the fuel injection system which is the very reason that we use two stroke oil which is now approved for FI systems. If they would have put regular motor oil then the injectors would clog as oppossed to two stroke that is certified for it not to clog those components.There is an adapter on the market that alows you to run two stroke oil through the stock oil injection system if you really want to keep that. I beleive that there is a link or atleast some mention of it in this very thread check it out.

If my shop gets off the ground soon I will try and contribute to some form of experiment of which has been mentioned so we can effectively compare the MOP system and pre-mix in the tank and two stroke in the MOP that would be a good way to find out more info on this for our selves.

Santiago

PS sorry for getting side tracked there.

Any more???

Bad2ndgen

Ok I am just going to add my two pennys in support of removing the OMP.

First I would like to address the lubricating of the apex seals issue. Some of you think that the two stroke oil is designed to burn away easier, this is not true, the oil that is burnt simply burns cleaner and leaves less residue. But not all the oil is burnt. Also due to the shape of the cumbustion chamber in a rotary motor ( as most rotarheads know ) the fuel mixture near the apex seals is not burned at all and neither is the oil, thus lubricating the apex seals and corner seals very well.

Second as for the deceliration issue. I dont know of any one running zero duty cycle when off the throttle. Please let me know If you know of anyone. Therefore most of us are running more than enough fuel/oil mixture upon decel, especially when you consider the left over fuel/oil mixture from your recent acceleration and the fact the ignition curve is running at full vacume.

Third for those of us running highly boosted motors with nightmare's of detonation, what does motor oil do to fuel?.....It lowers the octane rating! Becouse it burns faster than high octane fuels, posibly causing pre ignition and engine failure. 2 stroke oil does not do this, motorcycles have been running 12:1 compression @ 15,000 rpm's, on pump gas for decades with no worries of detonation......

As for engine life just ask someone like turbostreetracer he has rebuilt all kinds of engines, some that have been fed premix for 100,000 miles. He runs premix in all his cars but only recomends 4 ounces of the magic purple stuff per tank.

thnx.

1987RX7guy

iTrader: (3)

Bad2ndgen


Very nice contribution to the thread.

Santiago

Black13B

iTrader: (1)

wow.. informative bad2ndgen!

Rex4Life

First, Thanks to Aaron Cake and Bad2ndgen (along with others) for sharing their opinions on premixing--great to see some intelligent discussion without flames.

One thing I couldn't find in this thread is whether the OMP drive gear and shaft are removed. I think most people don't remove it because it involves removing the front cover. ReTed has removed it and has had no problems. IMHO if it is removed I would recommend blocking the oil passage that feeds thru the front cover. On my GSL-SE front cover the passage only feeds the OMP shaft/pump and could be blocked off with no problem. The reason I would block it off is because no restriction (the shaft) would be in that path and this would divert oil flow from the rest of the engine components. The amount of flow diversion would be small but I'd still block off that passage.

I'm leaning heavily toward premixing. The stock system IMHO is a hack to get the job done--it does work though.

Now here is my 2 cents on premix:

1) Delivering the oil to the engine seals WILL work properly when using premix. Right now I'm just talking about delivery. Here's why. The 12a engine does not inject oil into the chambers, it is delivered with the air/fuel charge from the carburetor. My old 85 GS had 215k miles and was still running strong when I sold it--AND I don't think it was pumping the right amount of oil. I remember many times going 3000 miles and just needing 1 qt (now I know it should have been more). The two stroke oil is much lighter than conventional oil and will more easily distribute within the combustion chamber and along ALL the engine seals not just the apex seals.

2) The two stroke (TC-W3) oil will burn cleaner than conventional oil, no doubts there. Conventional oil is not made to burn in large amounts within the combustion chamber. But it will still burn. Anyone that follows an old beater on the road that needs new rings will know what I mean. Yea two strokes smoke too, but try putting the same amount of conventional oil in a two stroke and and see what you get.

3) The two stroke oil is made to leave less gum, varnish and deposits within the engine. This has always been a problem with two strokes and the new oils are engineered to leave less crap behind. Using crankcase oil will add the contaminants of the system into to combustion chamber along with what is in the oil to begin with (ash + a mix of other additives). There's a reason the oil gets dark after lots of use (contaminants).

4) The TC-W3 oil is made to use with fuel injectors. A fuel injector is a fuel injector, doesn't matter if it's in a boat, motorcycle, or car. Most likely it's other stuff in the gas that causes it to clog.

5) The issue of clogging the cat is still a question to me, but I think if you don't put in an excessive amount you'll be ok. Here's why, the conventional oil would have the same problem of clogging the cat, and no problems have been observed using conventional oil, so two stroke should be OK also--just don't use too much.

It's late and I'll put more in later, rebuttals are certainly welcome. I know I want to hear more about the pros/cons of premix.

Scott

1987RX7guy

iTrader: (3)

This thread is becoming a well rounded discussion. Me like how this is turning out.

Good contributions guy. It is late so I am out. I will be back bright and early so stay tuned for more developements.


Santiago

EDIT: I am sorry for not looking into your question about the oil passage Rex4Life
I will see what I can do for you on that tommorow. Just too damn late for a college student ya know.

Aaron Cake

iTrader: (1)

That's the problem with this (and many other) mods. People do them without thinking of all the consequences. There is so much misinformation and conjecture floating around that it is very difficult for anyone to make an informed decision. Witness all the 5th and 6th port misunderstandings, etc.

Exactly. Since there is such a small market, and since the metering oil system has been proven over 16 years, there has been very little actual scientific research done with regards to premix. Getting 6 new engines and running them in simulation is no small task. Could easily cost a million dollars when all is said and done.

It's good that you pointed out the need for brand new engines. This was something I was trying to stress. Taking a bunch of used engines is pointless, because all have seen different lives and are operating in totally different tolerances. This is a point that many people who like to "prove" the superiority of premix seem to miss.

Many of the venders specifically avoid things like the forum. For good reason too. One thing is that there are very few venders with as much experience as Atkins. Mazdatrix, as well as Mazdaspeed and maybe Rotary Performance and Racing Beat. I know I'm forgetting many, but the point is valid. It is only those who have building several engines a day for 25 years that can truely offer unquestionable evidence as to the effectiveness of premix.

Just another thing to throw out: many of the rotary aviation (ties in with Atkins) guys/gals who constantly run at high RPM are still using the MOP system.

The idea is that the oil spreads accross the seal due to rotating force. Put a drop of oil on a piece of clear plastic, then use another piece to mimic the apex seal. You will see how the oil spreads.

Many don't. They hear "oil injection" and think in terms of pressurized fuel injection. The meterign pump is just that: metering. The oil to the "injectors" (should be called "dribblers") is delivered under very little pressure.

Sorry, I wasen't clear. It certainly does lubricate everything, but I was trying to stress how the metering oil system puts the oil exactly where it is needed: on the apex seals.

Well, it's just just believed, that's what happens. But the major difference is that two stroke oil is used to lubricate bearings in 2 stroke engines, not combustion surfaces. Therefore, it is designed to burn completely, thus not leaving a film like motor oil does. Great for 2 strokes, bad for rotaries which require the actual combustion surface lubricated.

Two stroke oil is not designed for any fuel injection either. Or more accurately, the fuel injectors are not designed to inject oil as well. Both of our points are very valid. Remember that Mazda designed the metering oil system for convenience as well as reliability. We can't expect the average owner to keep a seperated resevoir of two stroke oil full...And think of the bad PR...

I was saying that the stock system pukes out at high RPM, not that premix is better. Premix is currently the only option for running constant high RPMs. The choice is either to get poor lubrication with the stock MOP, or go premix. Personally, I would just bore out the stock oil dribblers and replace the MOP with a higher capacity unit (bore out the cylinder and install a larger piston).

Good idea, but this is not a scientific test. We need a much larger number of engines then 2, and we need to start with known good units and use them in a controlled environment as they would see on the street.

This is exactly correct. Always beating on the engine will prevnt carbon from forming as much as it does on a regular, easily driven street engine.

But the carbon is not what ruins the seals. Carbon buildup is perfectly normal. Take apart any high mileage engine and you will find loads of carbon (I myself have 1.5MM of carbon on Tina's rotors).

Actually, by it's nature I would figure that 2 stroke doesn't leave a film. It is designed to burn easily and cleanly. Motor oil, on the other hand, is designed to stand up to major heat and resist breakdown. Therefore, it should form a superior film.

Nope. Carbon is a normal byproduct of burning gasoline. It's completely normal to build up carbon in any street engine (piston or rotary).

I will throw a wrench into your observations: the 12A and all other carb'ed rotaries had two oil injection lines that would inject oil directly into the venturi so it would be atomized with the fuel. Mazda abandoned this system as they went to fuel injection. Remember that the 2nd gen 13B has 4 oil injectors (dribblers): two apply oil to the apex seals directly, two into the intake airstream. You are getting the best of both worlds: oil in the air/fuel mixture, and oil onto the apex seal. Premix accomplishes only one of those.

If something burns cleaner, it must burn more easily.

As far as premix getting onto the apex seal, how does it do this? Remember that the apex seal is designed to seal. If it seals, then there is no way for premix to migrate onto it's sealing surface. The only the sealing surface can be lubricated is with the oil film already on the housing (or via the oil dribbler). If you compromise the film on the housing (by running premix, running too rich, etc.) then the sealing surface of the apex seal is never lubricated.

I thought oil raised the octane rating? Remember that ocatane is a measure of resistance to detonation/preignition. Would not mixing oil make it more difficult to burn the gasoline, thus artificially raising octane rating?

Also, a 2 cycle bike engine is a completely different environment then a turbocharged or N/A rotary.

We can't compare like this. We need to compare engines in controlled environments by properly using the scientific method. Too many variables in real life.

Oh, I have no doubt that it will burn cleaner. But that means that it burns easier. And it's not actually oil deposits we are seeing when we disassemble an engine. The deposits we see (carbon) is caused by incomplete combustion of gasoline.

I wonder: what has more impurities, the fuel that you spray in via the injectors, or the oil in the crankcase? Probably the oil for sure, though judging by the carbon on the rotors, maybe not...

Not necessarily true.

My fingers are quite tired from typing, so I think I'll end there...But to answer the question about blocking the passage: there's no reason you can't do it. Removing the driven gear from the front cover will be pain, but it certainly can be done.

1987RX7guy

iTrader: (3)

Aaron I got most of my informaton from fc3s-pro and you and me seem to have different oppinions on what happens when two stroke oil burns. From the website I read that after burning it leaves a lubricating film behind thusly protecting the surfaces when you decelerate quickly. Unfortunately right now I can't continue this discussion because I have to get to my next class at my University so I will need to have some time to respond properly to your latest post.


Santiago

NZConvertible

All EFI systems stop injecting fuel anytime the throttle is closed above ~1500rpm. There is never any fuel being injected during closed-throttle deceleration. There may not be any load on the engine, but all the bits are still moving around inside, requiring constant lubrication. I don't think it's wise to rely on any residual oil coating to do this.

My thoughts on this very interesting (and surprisingly civil) debate:
As has been mentioned, Mazda used to inject oil into the engine via the carb, and only introduced the nozzles on the housings when they developed their first EFI rotary, the 1982 12A Turbo.
Prior to this the system worked similar to the way premix does, with all of the oil being distributed by the intake air. One of the drawbacks of this is that a lot of the oil does nothing becase it's burnt and exhausted before it even hits any metal. I have no idea what percentage of oil is wasted, but it makes sense that if you inject some of the oil directly onto the apex seal where it's required, you won't need to inject as much oil to get the required amount of lubrication for all surfaces. This is why EFI rotaries consume less oil than earlier carb'd ones.
When talking premix the difference is quite considerable. The Mazda OMP system uses (I believe) an average fuel/oil ratio of about 220:1, whereas the minimum recommended premix ratio for a streetcar is 100:1, so that's more than twice as much oil consumed. For a daily driver like mine that would add a considerable amount to the running costs, with questionable benefits and added hassle.
After 21 years of use Mazda still use the combination of direct and semi-direct oil injection, so I find it hard to believe the method is as flawed as some think.

1987RX7guy

iTrader: (3)

Ok I am now unable to find fc3s-pro so I guess that that site got taken down so I now will have to do a search for the material that I need to support my position but for now I will try and give a good response to these comments:

I have had some further thoughts on this since you posted earlier: We all know how sensative the Rotary engine is to bad maintenance schedules right? What I beleive is that as the more neglegent people that own or have owned RX-7's left the oil change schedule slip too far and the oil filter became clogged and is no longer giving the proper anount of filtration therefore contaminants begin to build up in the engine's oil. Now if this was a piston engine it would suffer some but not like the rotary would because the rotary is lubricated by the MOP using engine oil. IF the oil has become highly contaminated because of lack of proper filtration those contaminants thusly end up in your 7's rotor housings being spread around the housings causing internal damage gradually killing the engine from the inside.

This may or may not be one true weaskness of the MOP system because there is no filtering other than that small filter.

Oil coverage in MOP and pre-mix

I understant that the oil will spread as the rotor moves through the housing but: It takes quite a bit of time for the oil to spread to the entire width of the apex seal. Currently I have a rotor housing off of an 88 GXL that used the MOP system and you can observe that there are scuff marks and the general non-shiny surface on most of the housing. I will make some photoshop pics of what I mean after I finish this post. Only about 1/4 or 1/3 of the rotor housing shows a nice shiny surface and the majority of the rest the rotor housing looks like it was sweeped by an apex seal that was not lubricated this car also had a lot of carbon build up and I will also post some pics of that me and wankel7 took when we pulled the engine. Compared to the MOP the two stroke injected via the fuel injectors will cover the majority of the cumbistion camber: rotor face, apex seal, and the rotor housing.


Awareness of what oil injection truely does


I am sure all of us in this discussion want people to find out what is really happening here and dispell any possible myths sorrounding this concept and mod.


Lubricating Film and burning and what happens afterwards with regular oil and two-stroke.

We seem to disagree on what the two oils leave or don't leave behind after combustion:

Motor Oil: From all the things I have read and seen I have noted that oil has chemicals and substances in it that do not burn away when it is combusted in the engine. These substances when burned leave deposits behind but not good ones that lubricate. These deposits are the reason why two stroke was made. Ash is the main thing that I see people talk about in regular motor oil. ICEMARK has posted on the ash content of synthetics before. This is probably why mazda did not recommend using them in our cars.

Now Two-Stroke Oil: This is information that I got directly from FC3S-PRO but unfortunately the site is gone or down at the moment so I can't quote but here goes. Ok on this site it was said that by the very way two stroke oil IS it leaves a film or layer of lubrication when burned behind therefore protecting the housing and seals even after combustion and during deceleration. I always took this as fact but if someone can prove this untrue with some real scientific evidence I would appreciate you showing it or a link to it. From what I have studied up on TCW-3 two stroke oil it contains no ash or not enough to measure it unlike regular oil. In the places that I have so far looked at as far as material for TCW-3 oil they are meant to burn without leaving deposits behind creating less carbon buildup in the engine.



Why didn't Mazda implement the oil injetion into the fuel injection system? Will regular oil or Two stroke oil clog my filter or injectors? Why didn't mazda make a sepparate resivour for pre-mix?


First and second questions question: Like I stated before regular motor oil is thick and will easily clog a fuel injector quickly the same goes for a fuel filter. Implementing the MOP into the FI would have been nearly impossible unless they made some other type of injector and filter that were not clogged easily by the thick motor oil. Two-stroke oil that is TCW-3 certified is safe for Fuel Injection system and is therefore not going to clog your injectors or filter.

Third question: Although now there is an adapter kit that will allow you to use two-stroke oil with the stock MOP system which consists of an adapter plate for the MOP and a tank that you fill with two-stoke oil Mazda did not do this because it would make the car more complex even if just a little more and secondly Mazda was trying to sell cars. Obviously we are people that are very much dedicated to out cars and keeping them healthy but your average Joe or Woman would not bother to put in the two stroke oil so Mazda had to come up with a solution and here came the MOP. I think that if all 7 owners were willing Mazda would have done it with two-stroke and not engine oil.


Well while not a major factor in engine failures carbon is still a bad thing although it is normal in all engines. I would say everyone would agree that the less carbon in our engines the better. People don't always beat on engines and short runs occure all the time and people flood their engines constantly therefore with two stroke oil in the chamber the deposits left by it will be lessend since it contains less ash and other harmful ingredients. Cabon ia also a bigger problem for auto 7's which I hear can not reach 7k RPMs so you can't really beat on it so more carbon builds in these than in a manual transmission RX.

I will be back hopefully with some links to info to back my staements up but no promisses.
If anyone knows what is going on with www.fc3s-pro.com please let me know I need to find information from that site so help my position.

Santiago

PS pictures of some of my explenations COMMING SOON

Black13B

iTrader: (1)

i wish there was an emoticon for applause, because Aaron's last post was a BIG contribution!

well said, Aaron!

andrew lohaus

i dont know $hit about premix but her goes my 2 cents

if you want to extend your engine life (and who doesnt) maybe one should try keeping the tried and true MOP AND using premix. youde probobly want to run a prety low concentration Maybe 1:150-1:250. this way you get both methods working to lune your rotors. as long as the two systems dont counter act each other (i dont see why they would) i dont see any drawbacks and this could even be the holy grail of rotory longjevity. but then again i'm just a noob throwing ideas into the mix (pardon the pun)

Black13B

iTrader: (1)

alot of people i've met run premix and just haven't removed the MOP yet..

1987RX7guy

iTrader: (3)

Yeah many people are afraid their oil dribblers or pump does not work properly so they pre-mix for insurance.


Santiago

Icemark

Only low quality synthetics should be a concern.

The better brands such as Amsoil, Redline, Neo, Royal Purple and Mobil 1 are all perfectly safe, and typically have a lower ash content than many conventional oils. These oils are probably safer to use than convetional oils in a rotary with no concerns about left over byproducts of combustion.

Its the crappy synthetics like Valvoline, Castrol, Havoline, etc that should never ever be used in a rotary as the ash content is considerably higher than a conventional motor oil. These cheaper Oil company brands will result in increased deposits and other issues.

Mazda didn't recommend Synthetics just for that reason, that they couldn't print it was okay to use Mobil 1 but not okay to use Castrol syntec (especially since the Castrol GTX conventional oils are one of the best of the conventional oils for a rotary).

I agree with Aaron on this thread, there really is no reason to disable or remove the MOP/OMP, the system works well and there is no advantage HP or other wise (unless you want to use crappy synthetic oils like Valvoline Synth, etc).

1987RX7guy

iTrader: (3)

I don't want to say or imply that this mod will make your car faster or be done if your MOP system is working properly. The reason I did this was because I broke three of my MOP lines and did not have 75 dollars to spend on them.(not sure how much they cost just guessing) . This was only done out of need in my case. so unless your MOP system is bad somehow you don't need this.

Oh and again if you do this and mess up don't bitch at me its your car and your making the descission.


Santiago

BlackRx7

Damn this thread has Turned out BadASS, good job for posting it Santiago, i have had many question about this mod and I think all of them have been answer, props to Aaron, Icemark and NZ, I mean mazda was smart enough to develop a reliable rotary what makes you think they didn't develop the OMP system on our cars through much scientific effort?

And Also People aren't perfect just cause the majority of the people on the forum think premix is better than the OMP doesn't mean its true...sorry ReTED your going to have to come stand up for what you believe in.

Icemark

off to the archive

1987RX7guy

iTrader: (3)

Santiago

Aaron Cake

iTrader: (1)

Don't archive yet. I still have a reply to post.

pengarufoo

this statement is false. Fuel-cut on deceleration is not always used, and is not always done at a ~1500rpm threshold. I rode in a Superformance S1 a few weeks ago with a ford zetec that didnt do fuel cut on deceleration and shot flames like crazy as a result.

my e6k controlled fc currently does not do fuel-cut on deceleration also.

both of the aforementioned situations were EFI.

Aaron Cake

iTrader: (1)

Sorry I have not replied, but I've been pretty busy, and then forgot about this thread for a while...

This is a major part of my argument against premix. Two stroke oil is not designed to lubricate combustion surfaces. In the two stroke piston engine, the premixed oil lubricates crankshaft and rod bearings, as well as the cylinder walls on the non combustion side of the piston. All the oil that ends up on the combustion side of the piston is burnt off during the combustion process. Thus, the oil is advertised as "clean burning". Although if you pull the spark plug on a two stroke engine, you will see how much carbon has built up. Also take a look inside the (probably half clogged) muffler. Back in my lawnmower repair days, 75% of two-stroke mower problems were caused by clogged mufflers and/or plugs. Though this might be the owner's fault for mixing in too much oil...


This is exactly the point I am trying to make. And with 2 stroke oils being designed to burn alot easier then 4 stroke oils, the problem is magnified.

Hmm, I doubt it. The "contaminates" are mostly chemical, not "solid" and would be so small that they would be trapped in the pores of the housing anyway. This is probably not a great issue. However, over time these contaminates could build up and clog metering oil nozzles. Many engines have at least one clogged nozzle.

Not really. At 3000 RPM, the rotors are moving at 1000 RPM, which is 16 revolutions per second. The apex seal is hitting that oil droplet with considerable force, and I'd imagine that it splatters almost instantly accross both the seal and the housing. Sounds like an excellant lubrication strategy to me. Premix, on the other hand, remains mostly in the "cloud" of vapourized fuel and air. Since the premix droplets are so small, they remain suspended and simply burnt with the combustion process. This might be another disadvantage of premix. The droplets are probably way to small to properly coat the housing. But the only way to prove this would be high speed video...

Again, carbon buildup is not due to oil, it is due to the normal combustion characteristics of the carbon and hydrogen based gasoline.

As I mentioned, comparing random used housings is almost pointless. Yours might be scuffed up, but someone else's might not. In fact, the housings from Tina's engine (250,000 on the clock) are nearly perfect save for the standard corner-of-the-apex mark. I could look at the 10 pairs of housings I have on hand and find that 50% of them are scuffed and scratched, the rest are pretty shiny. We cannot compare engines unless they are broken in and run in labratory conditions.

I should also mention that the cylinders in a piston engine are regularily grooved and scuffed on the oil side. It's part of normal wear inside of any machine.

The point I'm trying to make is that this isn't true. Premix will lubricate the face of the rotor, and the housing (a little), but will miss the apex seal for reasons I have already explained. Any lubrication on the apex seal would be from oil that has remained on the housings, but most of this is burnt off at every combustion cycle.

That gasoline we are burning leaves behind alot more deposits then a little oil does. And since 4 stroke oil is of much thicker viscosity, and distinctly not designed to burn, it forms a thicker film that actually survives the combustion cycle.

But wait...if the oil is "clean burning", then how can it leave behind a film? See the comments above about how a two stroke engine is lubricated.

We have also ignored viscosity for the most part. Two stroke, especially after it has been diluted by fuel and atomized, is MUCH thinner then 4 stroke oil. With the high temps of the rotary, it stands to reason that it burns much easier and much more completely then in any two stroke piston engine.

Four stroke oil, on the other hand, lands as a huge drop directly on the apex seal, where very little of that combustion heat is encountered. There is also a certain amount injected into the airstream. The oil injected into the airstream is vapourized by the fast moving air, meaning that it is in larger droplets and therefore has a much greater lubricating capacity when spread over a surface.

Just something to mention as well: maybe I don't want my oil to completely burn up. We still have an exhaust stroke to go through, you know...

Carbon buildup is not caused by incomplete combustion of oil delivered though the metering oil system. That will be the fifth time I have said it.

If Mazda had built the metering oil system to premix oil before the injectors, they would have injected the oil AFTER the filter and provided fuel injectors that are specifically designed to be compatible with the larger oil molecules.

And this is based on your extensive background in designing electronic fuel injection systems? See above.

So is nearly every additive on the market...even the ones that contain PTFE...

This has been around for about 4 years now, and I have mixed feelings about it. On one hand, you have the advantages of the stock oil metering system. On the other hand, you have two stroke oil that has neglegable lubricating (in my opinion anyway) qualities when used inside a rotary working chamber. If anything, I would install this adapter and then run clean 4 stroke oil through it.

The problem is not so much that the car cannot reach 7K (because it can). The problem is that owners of auto RX-7s tend not to drive them hard. Combine this with the short-trip and stop-and-go driving, and you have major carbon buildup. Which, again, has nothing to do with the metering oil pump.

Just one other thing: many people seem to think that higher octane fuel is somehow better for their N/A car. Could this be a major reason for carbon buildup? Probably...

NZConvertible

This discussion is primarily about cars running factory EFI. On every factory EFI system I've seen, this feature is used. Notice I put a tilde in front of the 1500, meaning approximately. Most systems turn the injectors back on around that point. The exact figure is irrelevant, but for FC's it is 1500rpm. Nearly all aftermarket systems have this feature also, but it can be switched off. But what's your point? Nearly everyone in this discussion is using an EFI system than cuts fuel on deceleration, and as a result are not receiving lubricating oil via premix as a result. If your EFI systam has this disabled, you don't need to worry.

RETed

By your argument, a counterargument can be made about why the stock system is so effective?&nbsp I put my statements out there for people to read.&nbsp If you don't believe it, I'm not going to get bent out of shape.&nbsp "You can't please all of the people all of the time..."&nbsp To dispute my finds with a bunch of BS is a whole nother ballgame.&nbsp You're welcome to initiate your own long-term test; I do not have the time nor the resources to conduct a long-term mileage test at the moment.


That very statement implies your regurgitating information - pure and simple.&nbsp It can't be fact, in reference to yourself, unless it's been proven or disproven - the robustness of the proof, as defined by scientific proof.&nbsp Now, we can get into an argument about the earth being round and did you prove it yourself tangent, but that's just pure silliness in my book...

[QUOTE]Fact: the carbon on the rotors that most people attribute to the metering oil system is actually caused by bad gas, short starts, etc.[QUOTE]
Bullshit.&nbsp Run a rotary engine with the same gas you run some other piston engine.&nbsp Pull the spark plugs and look into the engine.&nbsp The rotary engine will always significantly produce more carbon due to the stock oil injection.

I really don't understand this statement.&nbsp Unless the engine is blown, the inside rotor housing surface should be super clean.&nbsp I have never come across a rotary engine that produced a "clean spot" at the oil injection hole.&nbsp If the inside rotor housing surface is covered with carbon, you've got larger issues than worrying about the oil injection system.

As for the oil "slickness" statement, if the surface was covered with carbon, the added detergents in most modern engine oils will cause the carbon to break down.


[QUOTE][B]Fact: most people don't understand the stock metering oil system. They are under the false impression that it is supposed to inject oil under pressure. This is exactly opposite of how it is designed. The system is designed for form a drop of oil at the injection hole. As the apex seal sweaps around, it catches the drop which then flattens out along the seal. Thus, the apex seal is lubricated throughout it's travel. Oil is applied exactly where it is needed...[QUOTE][B]
True, most people don't know the exact nature of the stock oil injection system...so let me try to describe it.&nbsp The Zenki FC3S mechanical oil injection system has a linkage that is connected to the throttle body.&nbsp This means the oil injection is dependent on how far you mash the gas pedal.&nbsp The mechanical OMP has 4 levels of oil flow.&nbsp Depending on how much you mash the throttle, you get 4 different rates of oil flow.&nbsp Keep in mind, on high RPM lift-off you're off the pedal, which means this system will default to the lowest rate of oil injection - keep that in mind.&nbsp Now, Kouki FC3S models have an electronic system.&nbsp This bi-polar stepper motor also has 4 levels of oil injection.&nbsp Since this is controlled by the computer, the oil injection rates can be tweaked by computer control.&nbsp We haven't cracked the ECU code yet, so we can't confirm how different the oil injection rates are with the Kouki electronic OMP.


Wrong.&nbsp You obviously don't know the dynamics of the intake charge when it enters the rotor housing.&nbsp The intake charge is actually tumbling.&nbsp Couple a tumbling intake charge with an atomized fuel delivery, and you get complete coating of all internal surfaces.&nbsp The stock oil injection is primarily designed to coat the apex seal.&nbsp Pre-mix (in the fuel) no oil is able to access the apex seal, but it also hits the side seals due to slight blow-by of the rotor face.&nbsp Whatever the case, we are interested in the trailing apex seal anyways...due to combustion chamber "squish", the trailing apex seal gets most of the lubrication form the fuel/pre-mix charge.&nbsp Since trailing apex seal turns into leading apex seal due to engine design, it's safe to say ALL apex seals are adequately lubricated.

I do no profess to have substantial knowledge of two-stroke engines, but I do know 2S engines have significant blow-by.&nbsp By my previous statements, your theories are moot.

Now, this is an interesting assumption.&nbsp These pre-mix chemicals have been used by water craft and snowmobiles for years now.&nbsp Some of these pleasure craft are fuel injected.&nbsp I don't hear them complaining about clogging fuel injectors.&nbsp As for "foul plugs", that's total nonsense.&nbsp Anyone who is running pre-mix with no stock OMP can confirm their spark plugs come out CLEANER than before.&nbsp As for the fuel injector fouling issue, the TCW3 certification virtually guarantees this won't happen.&nbsp Go take it up with them if you've got a problem with a TCW3 certified pre-mix is screwing up your fuel injectors.

[QUOTE]Also, to much will clog exhausts, smell bad, cause smoking, etc. Again, probably not a concern here. Just something to be aware of.[QUOTE]
This is a problem if you're running too rich of a mixture.&nbsp We haven't seen the above mentioned problem unless you run under 100:1 pre-mix ratios.&nbsp I really prefer the smell of pre-mix burning in my car - of course that's a pretty subjective statement.&nbsp I'd like to see proof of those claims you've just made it.

Answer:&nbsp Mazda engineers have decided that running pre-mixing was too much of a hassle for your typical automobile consumer.&nbsp If a consumer forgot to add pre-mix, then your engine is gone.&nbsp Why add the hassle of adding another chemical the consumer would have to worry about if they can get away burning motor oil.&nbsp So it came down to convenience.&nbsp That is the "unofficial" reason.

Pre-mix is an alternative to the stock system.&nbsp If you're satisfied with the stock oil injection, then that's fine.&nbsp I figure the majority of us are hear to listen to alternatives that might offer better performance and longevity.&nbsp If you didn't want more power, then I don't know why you're reading this.&nbsp After all, there are people out there who are adding turbos to non-turbo FC3S engines...right?


-Ted

RETed

By your argument, a counterargument can be made about why the stock system is so effective?&nbsp I put my statements out there for people to read.&nbsp If you don't believe it, I'm not going to get bent out of shape.&nbsp "You can't please all of the people all of the time..."&nbsp To dispute my finds with a bunch of BS is a whole nother ballgame.&nbsp You're welcome to initiate your own long-term test; I do not have the time nor the resources to conduct a long-term mileage test at the moment.


That very statement implies your regurgitating information - pure and simple.&nbsp It can't be fact, in reference to yourself, unless it's been proven or disproven - the robustness of the proof, as defined by scientific proof.&nbsp Now, we can get into an argument about the earth being round and did you prove it yourself tangent, but that's just pure silliness in my book...

[QUOTE]Fact: the carbon on the rotors that most people attribute to the metering oil system is actually caused by bad gas, short starts, etc.[QUOTE]
Bullshit.&nbsp Run a rotary engine with the same gas you run some other piston engine.&nbsp Pull the spark plugs and look into the engine.&nbsp The rotary engine will always significantly produce more carbon due to the stock oil injection.

I really don't understand this statement.&nbsp Unless the engine is blown, the inside rotor housing surface should be super clean.&nbsp I have never come across a rotary engine that produced a "clean spot" at the oil injection hole.&nbsp If the inside rotor housing surface is covered with carbon, you've got larger issues than worrying about the oil injection system.

As for the oil "slickness" statement, if the surface was covered with carbon, the added detergents in most modern engine oils will cause the carbon to break down.


[QUOTE][B]Fact: most people don't understand the stock metering oil system. They are under the false impression that it is supposed to inject oil under pressure. This is exactly opposite of how it is designed. The system is designed for form a drop of oil at the injection hole. As the apex seal sweaps around, it catches the drop which then flattens out along the seal. Thus, the apex seal is lubricated throughout it's travel. Oil is applied exactly where it is needed...[QUOTE][B]
True, most people don't know the exact nature of the stock oil injection system...so let me try to describe it.&nbsp The Zenki FC3S mechanical oil injection system has a linkage that is connected to the throttle body.&nbsp This means the oil injection is dependent on how far you mash the gas pedal.&nbsp The mechanical OMP has 4 levels of oil flow.&nbsp Depending on how much you mash the throttle, you get 4 different rates of oil flow.&nbsp Keep in mind, on high RPM lift-off you're off the pedal, which means this system will default to the lowest rate of oil injection - keep that in mind.&nbsp Now, Kouki FC3S models have an electronic system.&nbsp This bi-polar stepper motor also has 4 levels of oil injection.&nbsp Since this is controlled by the computer, the oil injection rates can be tweaked by computer control.&nbsp We haven't cracked the ECU code yet, so we can't confirm how different the oil injection rates are with the Kouki electronic OMP.


Wrong.&nbsp You obviously don't know the dynamics of the intake charge when it enters the rotor housing.&nbsp The intake charge is actually tumbling.&nbsp Couple a tumbling intake charge with an atomized fuel delivery, and you get complete coating of all internal surfaces.&nbsp The stock oil injection is primarily designed to coat the apex seal.&nbsp Pre-mix (in the fuel) no oil is able to access the apex seal, but it also hits the side seals due to slight blow-by of the rotor face.&nbsp Whatever the case, we are interested in the trailing apex seal anyways...due to combustion chamber "squish", the trailing apex seal gets most of the lubrication form the fuel/pre-mix charge.&nbsp Since trailing apex seal turns into leading apex seal due to engine design, it's safe to say ALL apex seals are adequately lubricated.

I do no profess to have substantial knowledge of two-stroke engines, but I do know 2S engines have significant blow-by.&nbsp By my previous statements, your theories are moot.

Now, this is an interesting assumption.&nbsp These pre-mix chemicals have been used by water craft and snowmobiles for years now.&nbsp Some of these pleasure craft are fuel injected.&nbsp I don't hear them complaining about clogging fuel injectors.&nbsp As for "foul plugs", that's total nonsense.&nbsp Anyone who is running pre-mix with no stock OMP can confirm their spark plugs come out CLEANER than before.&nbsp As for the fuel injector fouling issue, the TCW3 certification virtually guarantees this won't happen.&nbsp Go take it up with them if you've got a problem with a TCW3 certified pre-mix is screwing up your fuel injectors.

[QUOTE]Also, to much will clog exhausts, smell bad, cause smoking, etc. Again, probably not a concern here. Just something to be aware of.[QUOTE]
This is a problem if you're running too rich of a mixture.&nbsp We haven't seen the above mentioned problem unless you run under 100:1 pre-mix ratios.&nbsp I really prefer the smell of pre-mix burning in my car - of course that's a pretty subjective statement.&nbsp I'd like to see proof of those claims you've just made it.

Answer:&nbsp Mazda engineers have decided that running pre-mixing was too much of a hassle for your typical automobile consumer.&nbsp If a consumer forgot to add pre-mix, then your engine is gone.&nbsp Why add the hassle of adding another chemical the consumer would have to worry about if they can get away burning motor oil.&nbsp So it came down to convenience.&nbsp That is the "unofficial" reason.

Pre-mix is an alternative to the stock system.&nbsp If you're satisfied with the stock oil injection, then that's fine.&nbsp I figure the majority of us are hear to listen to alternatives that might offer better performance and longevity.&nbsp If you didn't want more power, then I don't know why you're reading this.&nbsp After all, there are people out there who are adding turbos to non-turbo FC3S engines...right?


-Ted