premix on a rex, im just trying to understand
 

ok i did a search and im pretty cofuse right now about the premix deal. i was reading and somepeople use regular engine oil and some people use 2 stroke oil, with one is better? and about the mix, how many ounces you have to really put in the tank? because some people was puting 4 ouces and some about a quart. and what ratio is, i read that is 100:1? sorry im dont understand. why im asking because im gonna eliminate the OMP on my next engine so i have to do premix. thanks

You don't need to premixes on Rexes. Rexes are 660cc Japan-market Subarus and are not to be confused with RX-7s or any other rotary powered car.

To answer your question as it pertains to rotary engines, you do not want to use motor oil! I've done that in the past but it was because I had nothing else to throw in there. Probably no oil at all is better than using motor oil... motor oil does not burn cleanly. 2-cycle oil does burn cleanly, after all that is what it was designed to do, and it lubricates well when heavily diluted by gasoline, which is also what it was designed to do, and it lubricates well when that fuel/oil mixture is atomized in air, which - surprise! - is what it was designed to do.

Get the picture? :)

The stock OMP on carbureted cars injected oil (well, dribbled oil down the carb) at a rate of 1:150 to 1:400 oil/fuel, depending on running conditions. When you premix, you cannot vary the strength, so you mix for the worst case scenario, which is roughly 1:150.

Now. The more you stress the engine, the more lubrication you need, so you go a bit richer than that. On the other hand, as noted above the 2-cycle oil has much better properties than regular ol' motor oil for the purposes we care about.

What it boils down to is this... 2-cycle oil comes in convenient 8-ounce and 16-ounce bottles. If you have an SA you can use the 8-ounce bottles because the fuel tank holds about 10 gallons before you are on empty (with 2 or 3 gallon reserve). That's about 1:160 or so. If you have an '81-85 you can use the 16-ounce bottles because you are on empty a fill-up will give you about 16 gallons or more, this is closer to 1:120 which is a bit rich but since it burns cleaner it isn't gonna hurt much.

Also, you always put the oil in *before* the fuel. That way when you fill the tank up, the sloshing and flowing around in there helps mix the oil in with the fuel.

Nice! I was just going to ask if you are premixing in a can first and then adding to the tank or if you're adding the oil right into the gas tank and filling up.

Oops, I've been putting it in after I fill up. Guess I'll have to switch around to the othre way. Don't know why I didn't ever think of putting it in first.

I use 1 oz of MMO per 1 gallon of gas.

I use 1.5 oz per 1 gallon of gas. Of course my car is used primarily for AutoXing, so it sees lots of hard use. I use Valvoline high RPM 2 stroke oil.

For getting desired ratio here is a little formula I made:

128 x gal of gas ÷ ratio desired = oz of oil to add to fuel

I run 180:1 but am thinking of changing it to 150:1 like peejay said to do.

It isn't rocket science. Just get the most convenient sized bottle and dump the whole thing in when you fill up.

for my car that is a gslse i have to use 16 ounces of 2 cicle oil, hmm now i understand. thanks

I noticed that Amsoil makes synthetic 2 stroke oil. I've never heard of synthetic 2 stroke oil before. Does anyone know if it's any better than the normal stuff?

how does one remove/disable the OMP?

I was using the Universal 2-stroke at Wal-mart until the other day I found a 16oz bottle that was cheaper than two 8oz walmart bottles. It is TC-W3 or something like that. I know it doesn't answer your question but at 1.07 for 16oz, I thought it was a pretty good buy.

Here are a couple of paragraphs out of HPBooks "How to Modify Your Mazda RX-7" which IMHO everyone should have on their shelves who owns an FB.

The reason they mention octane is that they were running the lowest octane they could find in their Camel Light race-prepped engine. With running premix they found that the octane went down by minimum of another point (ie 87 dropped to 86) while everyone else in the beginning was running higher octane.

BTW, my gas doesn't stay in the tank long enough to settle out of suspension and I haven't had a problem yet using mineral based oil.

All I did to stop the omp from pumping oil, was took it off and riped out everything that would come out. Then put it back on and ran a one small tube from one nipple to the other nipple. Still leaks slightly, not noticable on the oil level, but is noticable on the ground if I park in the same spot.

I have heard of people running tubes from the nipples to a "T" connector to a sinlgle tube and then running it back into the engine from the breather on the side of where you pour oil into the engine.

Iam sure their are many different ways to accomplish the same thing.

Is the an OMP on the Fuel injected cars, or what do fuel injected rotaries use?

Can someone do a test for me? I would like to see how 2-stroke oil and gas mix.


Put the 2-stroke oil in a transparent bottle/jar and then fill it up with fuel at the right ratio and close the bottle.

See how well it mixes if you don't shake it. Then shake it and watch if after a while(a day or even a week) if the oil and gas are still mixed.


This would give us some real answers.

All Mazda rotaries have oil metering pumps.

Disable? Mine just wasn't working. :)

Best way is to get a block off plate and just remove it.

im kinda new to the world of rx-7s, but what is an oil metering pump(OMP) and what does it do?

I'm with premix!
 

You guys need to check out this thread on the great "premix" debate:

OMP/Premix writeup

I think it will answer all your questions and give you a few more!

Definitely stick with TC-W3 2-stroke oil. It mixes very well with gas--no need to worry about how well it mixes.

I add mine in about half way during a fill-up.

The TII engine I'm putting in my car will be premix all the way with no OMP--but to each his own.

Either way I think you're OK. With my current FI SE engine I occassionally premix but don't have to. With the TII engine I will.

Nor mine. At least I have never tested it, but I have also never noticed any oil in the tubes or my oil level drop any across 1000 miles. So I pre-mix for safety and piece of mind besides the 2-stroke being cleaner too.

ok, but heres a question for ya, there are diffrent ratios on bottles of 2 stroke... 100:1, 50:1...which am i supposed to use? Or am I just going crazy?
Also, im guessing synthetic two stroke would be best for a TII because of the octane rating? Wouldnt you want to preserve the octane rating in a Forced air car?

Rotary engines have no way to get oil to the apex seals at the tips of the rotors as the ride around the trichoid of the outer housing. So the answer was to inject small amounts of oil into the fuel/air mixture a la a 2 cycle and that would keep the seals nice and lubed.

The oil metering pump is the mechanism by which that was accomplished so owners did not have to dump oil into their gas (and hence feel like they owned a 2 cycle engined car). It works OK except for a couple problems. First, they leak, and leak, and leak and leak. The second is that it needs to be checked and adjusted (who bothers with that - what a pain). The final, and probably most serious problem is that they would fail and the owner would have no way of knowing it - the end result being no oil at the apex seal as they are dragged across the outer housings at a high rate.

I am sure there is more that one could say but that is the basic gist of it.

Yup, with forced induction, you'd want to preserve the octane rating so the synthetic 2-stroke would be better though in my previous post they mention the possibility of synthetic 2-stroke tending to foul out the plugs more often.

As far as mixture, if you keep with the minimum of 150 (I am running just slightly under 120 I think on my NA 12a) you would mix in 12.8 oz of two-stroke for 15 gallons of gas or 0.85oz per gallon.

Regarding synth deposites on plugs, inspecting and cleaning plugs should be part of very routine mainatainance on a forced induction rotary, IMO. You should be paying close attention to things like cracked insulators, ect.

Peejay- Are there any crank oil additives that will help the crank oil be more conducive to being used as an IC lubricant?

It'd be great if you could put 2 cycle in the crank!(I know it's not formulated to do this.) But is'nt there a way you could get the best of both worlds? Are there any other funky crank oils out there that might still do their job as a crank oil, but allow mixing with 2 cycle?

Also, I'm prepping an Rx-4 carb for my Rx-7, and the oil inlet lines are fed directly into the bowls. Pros/cons as compared to Rx-7 oil "dribble" injection?

Picked up a copy of the Rx-3 Haynes, and the OMP output is the same as for the Rx-7, BTW.

As a pro, the gas and oil would be mixed better and should provide better atomization at the inlet to the rotor.

Cons? Bowls cannot hold as much gas? ;) Are the bowls calibrated then for the added weight of the oil too?

Are you also swapping in the RX-4 intake? One of the 12a intakes during the 1970's had larger ports than the 12a in the RX-7's. The ports were shrunk for emmisions reasons.

i use mine as a daily driver...as most do... it's an FB what is the OMP? i haven't mixing two stroke with my gas.....uhm is this a bad thing? so all you do is buy two stroke oil for the FB it's about 8oz.? add it in before you fill up and you're done? i'm so confused!!! i was fine until i stumbled into this site, joined, learned a few things....and now i'm lost this whole oil thing is a big deal? sombody just give me a simple answer in lamons terms PLEASE! ~signed rotofire (a noob but workin on it)

ill have to find the site again, but a company that dose rotorys for aircraft made an adapter block that goes between the omp and the front cover. it allows the use of a separate oil container for the omp. so, you dont use crank oil, and you can fill the omp suply bottle with 2 stroke oil........ahhhhh...

Rotofire,

1st , you don't have to mix oil in the gas. So don't worry. Just make sure you check your crank case engine oil often and change every 3-5k miles.

2nd, the OMP is an oil metering pump that injects crankcase engine oil into the carb/manifold/intake depending upon what model you have.

Until you learn more about rotaries, it's safe to premix 6-8 oz of two stroke tc-w3 oil into a full tank of gas. Once you determine if the OMP is working you can decide if you want to remove it and do full premix.

Look at the thread in my previous post. It's for 2nd gens but the same principles apply.

Welcome to the club.

Scott

Site that sells an aftermarket metering system
 

http://www.scuderiaciriani.com/rx7/o...ring_pump.html
This site sells the pump that was mentioned above allowing you to use a seperate resevour filled fil 2 stroke to burn in the chamber as opposed to regular 4 stroke oil burning or pre-mixing.

I went outside and checked my plastic gas can of gas and Wal-mart 2-cycle oil that's been sitting since about September. It did not settle out much if any. Plus, it's been stationary. I can't think of any real world case where your RX-7 remained stationary that long unless you couldn't or didn't drive it. If that were the case, then you'd need some gas preservative in it anyway to keep from gumming the fuel path.

.

using the formula provided previously
128 x gal of gas ÷ ratio desired = oz of oil to add to fuel

128 x 16 (gallon tank in my 1983 GSL)
______________________________ = 20.48oz (20oz to make it simple)

100

100:1 ratio desired, number would increase/decrease depending on your chosen ratio)

Mixing 16oz at fill-up will give a 128:1 ratio for my RX-7 which is completely safe weather you beat your car to hell or commute with it (like I do and have had no issues with fuel filters or running conditions). Also 2-stroke usually comes in 8oz or 16oz bottles which makes it an no brainer at fill-up.

I personally have been pre-mixing with MMO (Marvel Mystery Oil) and have not had a single issue. 2-stroke is cheaper and usually easier to find than MMO so use whichever you prefer.

So, how does one determine if his OMP is working? Mine does not leak and I have no reason to doubt it, but after reading this thread I fear what could happen if it were not working! (see -- sometimes too much knowledge is a bad thing)

Pete

Two stroke oil will not truly burn all the way off nor will regular oil thats why a Rotory has problems with carbon buildup.Any oil is cumbustable not flamable,which it has to be put under extreme pressures in order to explode like a diesel does so when oil is injected into a Rotory a little bit of it burns from the fuel explosion but the rest of it stays in the engine. This is also True with two stroke engines thats how they are lubricated. The fuel burns but the oil stays. If you eleminate the OMP i highly suggest you reasearch more than just oil Ratio's and what will burn and not burn. I Used to be a Motor Cycle Mechanic and the same rule applies if you mix oil in gas then you ritchen the fuel mixture because theres not enough air to compensate for it. Reason why is cause the carb is jetted for a certin air fuel mixture if its compromised then tunning goes all to hell Granted the tank is not nearly as big nor is there as much fuel flowing through the Venturies as a two stroke but in high alltitudes it will become an issue its called Volumetric effeciency. Which comes dowm to having the right fuel,air,oil mixture = the most reliable RX7 you can have
if your not having problems then dont fix whats not broke if you Ditch the OMP and have to premix your gonna eventuallly have problems. If its a daily driver then dont do it cause you have to be Religous about putting the same amount and same oil in it every time you Fuel up some thing you guys dont realize is that Synthetic and regular oils dont mix when burned they will actually gelletinize when mixed. When your gonna run a certain oil Run it, not switch to another brand cause its cheaper. I know ratios but not for an RX7 but i do know about jetting carbs and if its not right then its not going to work to your advantage. Oil is heavier than fuel so it will take up more space than fuel if theres not enough compensation for it you will have problems. Its like NITROS too much Boost and not enought fuel youll blow the engine Too much Gas and not enough boost and
the damn thing will just fall on its face hope this helps with all the technical guys. If I am wwrong Please correct me cause I am also still learning
Please if i am wrong correct me JOSH

oops meant Dont know ratios for an RX7

Could you please elaborate. I removed mine for reliability, among other reasons.

It's honestly not that bad. It's really easy up here since were're metric, 40L gas and 400ml oil = 100:1 :eek: They even have the little seight line on the oil jugs so you can see how much you added.
It actually scares me to think of the poor rx7's people own when they think it is too much trouble to premix; I mean come on, these aren't civic's afterall.

I fill a 20oz water bottle full of 2 stroke. Therefor, if I put in 10 gallons of gas, that means 5oz of oil. 5oz of oil means 1/4 bottle, so pour 1/4 in the tank and call it good.

Ok we can go on and on about this premix Q all night and day if you will everyone has their own remedies to fix things. I personally research anything i can. If you take a two stroke and a Rotory and you put them side by side. Both Theoreticaly should not run. reason for this is because they both run in an oppisite manner than a piston engine. first a piston engine has an up and down stroke which in turn has a crank that throws oil up into the galleys of the top end. therefore the top end is lubed by the oil that it throws up. rings separate the compression chamber from the lower crank case preventing blow-by from the compression chamber. much like apex seals help compression (they are both the same things)
rotarys are lubed by an OMP that injects oil into the what you would consider rings which are actually apex seals on the rotors which in other motors are pistons. secondly a rotary runs in a circular motion and has no way of oiling itself without either an OMP or premix. premix is better in a racecar because its not a daily driver. but when dealing with a daily driver premix is the biggest pain in the ass you have ever seen in your life. one you have to have the ratios right and two you have to buy oil every time you fill up. if you are having a problem with the OMP if it's a daily driver its still highly recomended that you fix the problem at hand.

I am just quoting the back of an Idemetsu (spelling) bottle, specifically made for rotaries that have the OMP removed and are running premix.

PS - I bought 2 stroke once in the past 6 months the car has been running, at only $10. Mixing it at the pump is only but 15 seconds max for me :)

You have to be joking right. :wallbash:
I guess if that's your opinion, there is nothing more I need to say.

Jeezus your fast! :) I never timed myself but I think it takes me about 30 seconds on average, I measure from 1 quart bottles of oil and that will usually last me 2 and a half tanks of gas.

God..16 oz bottle of 2 stroke..the Tank is 16 gallons..= one ounce per gallon.. Now 8-oz of two stroke and the 16 gallon tank = 1/2 per gallon..both are sufficient enough to lube the internals .The Two stroke Bottles are usually Marked too.If you Pour the Oil into the Gas filler on the car AT the pump and then add the gas,the Action of the gas being put in at the Velocity it comes out of the Station's Nozzle is more than Enough to Mix the Oil and gas..It's not Like maple Syrup And Water.Besides even the Fuel pump in the tank will create some turbulence along with you Driving the Shit out of your car..the Gas and Oil will mix in the tank.My penny's worth,.,I spent the other penny on Two stroke!

Resurrected from the dead again....

Totally wrong, the OMP feeds oil into the fuel at a mix of about 100:1 to lubricate via the fuel system. This oil then attaches itself to the chrome housing to create a lower friction when the seals run across the face of the housing.

I premixed by tipping a bottle of 2 stroke into the tank, it was such a pain it took at least 5 seconds. I buy a 4 quart jug and carry a smaller bottle in the hatch along with a rag. This jug lasts me several months.

A rotary engine has very little in common with a 2 stroke motorcycle engine, for a start it is a 4 stroke.

I ran my 12a with premix for the past 50,000 miles with zero reliability issues and with some other mods n average of 23 mpg making about 150 hp.

I highly recommend premixing 2 stroke as it is designed for this purpose in difference to using sump oil which is designed for a complete different useage.

aussiesmg i totally agree with you and am not downing Preemixing for the person that knows about rotorys but if you get a newby here that doesnt know and he starts premixing along with having an OMP then there gonna have problems Two stroke oil has additives in them that help them burn way better than regular oil i am just stating some facts about the difference between them so the newbs to the rotory and Two stroke oil know.

Honestly I think your making things far more complex than they need to be. Premixing is the way to go in my opinion and the omp is one of the 1st things I eliminate from any rotary I get my hands on. I just never liked the idea of burning engine oil. 2 stroke burns clean and its VERY SIMPLE to add at fill up time not a pain in the ass as previously mentioned. Again I've been running omp-less for many years and never had any issues. I'll even throw in a bottle MMO instead of 2 stroke everynow and then just to clean everything up and then go back to my 2 stroke oil..:icon_tup:

^ i agree

but for people who want OMP easiness with 2 stroke oil

do a search with key works like omp diy removal, and there will be a thread that comes up on a diy install a OMP that will meter 2 stroke oil into the engine.

OR buy the kit from rotary aviation (i think is its name)

agreed on Latin270
On I probably am going way to far with this I just read my last post and was wondering to myself if i was getting way to technical. like I said I am a noob myself to a rotory in the sense that I have still not yet ditched the OMP but I am not liking the premix deal because I dont know ratios. I Do know on any two stroke that I work with the oil injector is always taken out for them being unreliable but I still havent heard about any horror storys about a REX having the same problems. I know two strokes Burn hotter and Turn way more RPM than a rotory but why is the ratio only 100:1. It just seems to me that they would need more oil injected into them. And another thing is why the hell would anyone want to burn say 2,000 mile engine oil in one from an OMP is my Question. I use about 1 quart of oil every month and a half with my car but it doesnt smoke so oil changes come way more regular than supposed to. It just seems to me that a mixture of say 75:1 would be better IMOP but like I said i dont know ratios for 7's. LMFAO heres me getting technical again Please dont mind me im just this kind of person and any opinion would be greatly appreciated as long as its constructive

IIRC the factory OMP delivers a ratio of i thought between 100:1 and 160:1 depending on how its adjusted. Therefore for premix, most people fun 1 oz/gallon (which means nothing to me cuz im all metric) and that delivers a ratio of 120:1 which is decent

the ratio is 120 L of gas burned for every 1L of oil burned. The system was in place to use motor oil becuase it worked and then there was less 'stuff' to worry about checking. and it does lube it just fine. As for why that ratio? because that is what the engine requires for this type of engine (being a rotary) better system than pistons which seem to need closer to 50:1

There is SSSSOOOOO much misinformation on here about oils/synthetics/premixing/ 2stroke oils that I finally have to point out a few things to everyone. Facts are facts, opinions are opinions. Let's separate the two.

FACT: All oils burn. There are two The automotive industry measures oil burning by two measures. one is the Flash Point, the other is the Fire Point.

Flash Point: "The flash point of an oil is the temperature at which the oil vaporizes enough for the gas to become
momentarily flammable in the presence of a small flame. There are other conditions and requirements
for this test, but the gist of it is that an oil reaches its flash point when it begins to significantly vaporize.

In today's modern engines a flash point under 400 degrees F is unacceptable. Look for an oil with a flash point of at least 420 degrees F if you want the good stuff. a good quality synthetic should be significantly higher than this.
If this specification is not available, find another oil. This is a specification that no sheet should be without. If it's missing, there's a reason. Look elsewhere for your oil." From the "Motor oil bible" (available @ themotoroilsite.com, everyone needs to download the PDF and read it seriously). What does this mean? The temperature at which oil circulating in your lubrication system will begin to self-vaporize and start to become combustable.

Fire Point: "Fire point is similar to flash point. However, this test determines the point at which an oil gives off
enough vapor to provide a continuous flame as opposed to a momentary one. Expect a fire point of at
least 420 to 450 degrees F for petroleum oils and near or over 500 for a synthetic oil." - Motor Oil Bible.

How do these apply to rotaries? They are instructive to know because oil is already vaporized, or close through it, by the time is reaches the combustion chamber. So it is easy to assume the oil will "burn" or " combust" at the flash point or even lower. Remember, flash point is where fluid starts to eveaporate and become flamable. In therotary combustion chamber we are already have vaporized oil and there is a BIG spark being applied.

If you look at some of the ratings of flash points of top grade petroleum oils and synthetics, they range from 420 F to 470F. (You can do so by downloading the bible and comparing flash points and several other measures in a great chart at the end of the motor oil bible PDF. I would post it here but the publisher specifically requests you dont, he gives you this great doc for free but wants to drive traffic to his site in exchange.) In fact, some pretoleum oils have higher FPs than synthetics. The range for FRP is similarly from 450 to 500 for both. Similarly, some top petro oils have higher FRP than synthetics. All relatively similar. There are of course cheap crappy oils that burn at very low FPs and FRPs, but your engine will not last long enough for you to worry about carbon buildup if you use them.
TRANSLATION: It is a MYTH synthetics do not burn as well as Petro oils. They both burn similarly relative to the combustion temp created at spark: Around 750*F at IDLE! around 930*F at high RPMs!!!

Another myth is that synthetics cause carbon buildup because they dont "burn" or dont "burn as well". Wrong. Carbon building up is due several factors. One source is from incomplete burning of gasoline, mostly from the fuel additives and low quality fuels. Another is from additives in the oil as well as oil itself. Another is the temperature at combustion: The lower the combusiton temp, the more carbon deposits and vice versa. Synthetic oils are more consistent in their molecular weight and have much less impurities. Petro oils have a much less consistency and need more additives to yield necessary properties for engine oils. A thought experiment: Which oil will likely yield more carbon deposits: One with more impurities, more additives, inconsistent molecular weight, OR one created with taylored hydrocarbon chains, which require fewer additives to perform under the variable conditions required? I have my opinion, you can have yours.

Now let's look at 2cycle oils. Look at the top-of-the-line Amsoil synthetics. Their Flash point is listed from 180* to 237* F!!! This stuff really burns quickly! Almost too low a temp! The whole purpose of putting Oil in the rotary is to lubricate the apex seal tip as well as the area where the rotor and irons meet. This lubrication reduces heat and friction.

Lets take a step back and think of how oil is working in the rotary. In the 2 stroke engine it is being added at every other stroke, it enters during intake stroke, ignited, leaves in exhaust stroke, then right back in comes more oil to lubricate the piston chamber. There is a realtively small surface area realtive to volume the oil is lubricating and lubed every other stroke so it can afford to burn off almost instantly. The rotary engine receives the vaporized oil at the intake port and goes along to get compressed halfway through the combustion chamber until it gets burned. The oil in theory does a good job from intake to right before spark since it has not been burned yet. Not only that, the from intake to right before spark you have a cooler half of the rotary, less heat, less friction there anyway. So then you spark. If you use a 2cycle oil, you do a real good job of burning most of it off. Such a good job, what is left to lubricate the combustion chamber for the seond half of the rotor housing from where the spark occurs to exhaust port? I dont know whether 2 stroke is good or not at lubing the second part or the chamber, but I do know it was NOT designed to do so. Think about how much distance is covered from the point of spark to entry of new fuel/oil mixture. I know that you have three sides, three seals, gas coming into each etc, but focus on the housing itself and the two halves that are fixed. I also know engine oil , with more than twice the FP temp of 2 stroke oil, WAS designed specifically by Mazda engineers to do the job. This doesnt even begin to get into other factors Mazda designed into the oil such as weight/thickness/flow etc.

In fact, there are a Variety of 2-stroke oils designed speficically for specific types of engines: OUtboard vs. snowmobile engines vs lawnmowers vs scooters. Why do they bother making different types of 2 cycle oils? Different engines require different oils. Yes, 2 stroke is designed to be burned in the combusiton chamber, but the rotary isnt a two-stroek engine. It may well be 2cycle oil is better than conventional or synthetic, but it would be strictly by chance, not design. Mazda spent millions of dollars desgning the lubricating system, including how they would lube the combustion chamber. If someone can point to me where Mazda says 2 cycle is more effective at lubing than engine oil, Id be convinced. Otherwise, anyone using 2cycle is conducting and experiment. I cant tell you of you are right or wrong, I dont know, but I am NOT going to be experimenting with my rotary. I'll wait until some contrete reasearch gives a verdict.

Back to the synthetics though. Synthetics will in all likelyhood create much LESS carbon buildup than convetional oil and burn at about the same rate. The big question is how do they behave on the oil seals and gaskets? When synthtics first came out they were notoriously hard on engine seals in piston engines. Especially on older engines that were converted from petro to synthetics. This is partially because synths actually help clean the engine and caused leaks by removing gunk that was keep the engines from leaking in the first place. Nowadays the synths are better designed and the additives in top quality oils are similar. BUT AGAIN, unfortunately Mazda has not revealed the research on how synths behave on something like the flourinated oil seals. So running synthetic is AGAIN experimentation in the rotary.

At least for me, running synthetic is a lesser gamble than 2cycle. If you think about it, petro and synth oils BOTH are drastically different today than what they were when the flourinated oil seals were first created. Putting in a name brand petro oil designed for 21st century piston engines in a 12a is probably just as experimental as putting a high quality synthetic.

The purpose of this isnt to burst anyone's bubble. I just wanted to put some facts against statements like "Synthetic oil doesn burn" or "2cycle oil is made to burn therefore better than engine oil". Not to mention the other factors like what the effect of adding 2 cycle has on the fucntioning of the carb or fuel injection system. The issue is even more complicated the more I think about it: effect on the octane rating...

Happy new year!!!

Damn,

i thought my comments would cause SOME discussion!

Are you saying Mazda designed a specific oil brand for a rotary?


This is simply for discussion, no flamming allowed.
Here's my logic.
I thought engine oil was, for the most part, designed for piston engines but just so happens to also work well for a rotary. The oil injection on a rotary was designed to use engine oil because it was cheaper for mazda and gave the owner one less thing to worry about checking; if mazda had used a remote 2stroke oil tank. I'm sure Mazda could very well have designed our cars to run with 2 stroke oil injection if they wanted to.

Here is a warped analogy for you.
I have a toothebrush, it's really nice. After 3-4 months of use, it's not so nice. This toothbrush was DESIGNED to clean my teeth BUT I also found out it works very well at cleaning the little nooks and crannys of the interior of my RX7. Was it designed for this, no, but it works good. JUST like 2stroke oil was not designed for use in the rotary it sure works good, at least in my experience.

This is NOT to argue with anyone, If i'm completly or even half wrong correct me nicely so I can learn and not be veiled in this cloud of darkness the rest of my life. :)

I am just stating the fact that Mazda designed the rotary to lubricate itself with engine oil. Millions and millions of dollars have gone into the development of it. Many scientists and engineers involved in this. 2cycle oil was DESIGNED for a totally different purpose and the properties are also VERY different from engine oil. That is what I am saying. I welcome anyone to give me some facts as to why 2 cylce should work better in a rotary. Even anecdotal experience is welcome. My biggest problem with 2 cycle is that it burns so quicly and easily it may cause a higher temp and friction in the housing from the point after spark until intake. This could mean shorter life of apex seals and housings. Like I said, the conventional logic for using 2cycle is just plain flawed. It may turn out to be perfectly fine or even better. But those premixing are doing their own expreiment and research on behalf of Mazda.

I agree, this is just for discussion purposes. Anyone who has an egenda and believes this stuff is like a religious belief that cant be questions needs a life.