Snox801

So what is the opinion on mix ratios for the rx8 say without a oil pump.
Now keep in mind the ratio is not for the motor. The oil ratio should be followed based on the oil manufacturer not the machine. As we know the metal has no idea what it’s in.
So I’m a typical two stroke it really doesn’t matter if the tank says 32:1 what matter is what the oil itself is designed for. Usually the recommendations are the minimum or what the manufacturer oil is based on.
What I see a lot is people say 8oz per tank. Or something like that. Well that a huge difference. Say a cheap 2stroke oil is rated at 32:1 then 8ounces will have significantly less protection than say a amsoil or redline that is able to provide protection at 100:1. So 8oz amsoil is good for 100:1 in 6gal of gas but say you use 50:1 that 8oz is only good for 3 gallons.
Now the wankle is in fact different than two strokes with pistons so I guess my question is. If no oil pump what oils are people running and at what ratio?
I’m curios if the standard amsoil 100:1 of mixed at 100:1 would suffice or would it need to be a bit more or less. I would say by the way it intakes and travels I would think a bit more as a piston 2 stroke coats the crank first then pushes it back through transfer ports on both side of the piston for a nice even distribution.
Reason I ask is because I saw a guy at the track this year just using ounces per gallon method but never using the same oil. He had the Walmart special that said 32:1 but was putting 8oz in a tank. Not sure if his pump was sohn or not but seems like using that method is wrong always seemed to kill a lot of snowmobiles every year of people using that method over the proper ratio the oil was made for.

RX-8 40th Anniversary

I honestly havent seen a RX8 online running without a OMP while it is possible, I will throw that out, maybe someone else can help me with this or prove me wrong.

Premixing is highly suggested while running with a OMP, it helps the overall engine better. I use the lucas-two stroke oil because its local, but Idemitsu is the best premix you can buy since it is specifically for rotary engines. A quick search says that running without an OMP they recommend 1-1.5 or 2 Oz's a gallon, but thats for the RX7, which I dont think shouldnt be too different. Another factor is.. are you street-driving? or is this gonna be autocross or racing?

Snox801

So that kinda what I’m getting at Idemitsu is great oil but can we say it’s the best. I know it was made for the rotary and of course is great oil. That being said I’m wondering is it really any different that 2 stroke oil. Seem they both accomplish the same thing. If I were to guess Idemitsu is of the very best stock and base that would put it in the 100:1 ratio or higher of oil. Now I may be wrong but the racing verses street has no difference on oil mixture. Now I’m taking this all from many years of two stroke piston engine R&D
if premixing the race and normal mean nothing contrary to belief. In fact less oil tends to create less heat as long as the friction is controlled by the oil.
For example 32:1 oil say Honda will burn hotter than 50:1. Why because oil burns hotter than gas when ignited. so the goal is to get just enough oil to make sure everything is lubricated and no more.
Now my background comes from many years racing at the highest level with two strokes. Most of this R&D was done with large companies like Polaris, arctic cat, and Yamaha. so all these things are true for a conventional two stroke piston. now not saying it’s the same for a rotary but it should at least give us a guideline.
More of a hey how close are rotary to a two stroke. From what I gather they seem to need a bit less ol that a piston two stroke but as you I couldn’t find much to create a good track record.

Snox801

For the sake of it I should mention the only reason that you will see a higher ratio of oil in certain race applications is because oil is carried to small spots in the engine when **** off. It runs to these spots kinda of so on some longer running race engine or a small design flaw like a crank gear pushing oil back (see 04 Polaris factory race sleds) when running they are getting the bare min but when turned off oil will flow back down and bathe the parts. Check out the holes at the bottom of transfer ports in a two stroke that feed crank bearings for examples.
Based on Idemitsu oil recommendations I would say it’s a 100:1 oil with the mixture being very good around 50:1 also very common to see those oils able to be mixed at thicker ratio without cause to much buildup.

RX-8 40th Anniversary

I... am failing to understand what your question is now..

mazdaverx7

iTrader: (6)

The premix in a rotary isn't for lubrication in the same way it is for a two stroke engine therefore you can run much lesser amounts. The ratios for premixing a two stroke don't apply here because the engine internals are not exposed to the gas/oil mixture as they would be in a two stroke. The rotary engine is lubricated by its own crankcase oil sump and fed using an oil pump. Premix does nothing for the engine's rotating assembly bearings.

With a properly working oil metering pump, 1/2oz of premix per gallon of gas is acceptable. Without an oil metering pump, if it were possible on this engine, up to 2oz would be good.

Snox801

So this was not so much a question as to a open discussion about what people feel is the correct oil ratio for the rotary along with maybe some educational info for some. Say why you shouldn’t use oz per gallon as opposed to what the oil states.
Second I know it doesn’t lube the rotating assembly but that is the smallest part the oil does in a two stroke. It’s mainly to lube the rings and piston on cylinder so I bet it is incredibly close to the same purpose. The reason it can pump so little oil with a oil metering pump is two fold one could be because 4 stroke won’t burn as easy this able to spread farther. But I bet the main reason is just like in the modern two stroke it is injected exactly where it needs it the most and the residual covers the rest. Like the new etec.
So I guess I just wanted a open discussion on people’s thoughts to bounce ideas around and see what people thought. Mainly cause my wheels were turning after seeing someone use whatever oil at the same ratio. My guess is his oil pump was still intact and was supplemental oil.

Brettus

iTrader: (2)

People who race rotaries generally premix at 1oz/gal (128:1) .... With the Renesis and no OMP, the race guys here use 100:1 and are getting good engine life with that (so I hear). For my turbo engine (no omp) running an ethanol mix and Motul micro 2T I run 120:1 and up that a little to 100:1 when I'm tracking it. That seems to be working.

Snox801

Awsome this is great info and what I was looki g for some real world. Motul must be good stuff. But could you see my concern of using a oil made for 32:1 at that ratio as opposed to say one developed for 100:1?
I’m thinking of turning down my omp on my series 2 as far as possible and going premix mainly. So I would run 100:1 amsoil at 100:1 for my main lube. Then hopefully just a small amount of 4storke would be pumped, very minimal.
If your running turbo and e at that ratio that will for sure keep my stock One very happy.

Brettus

iTrader: (2)

I guy local to me has been doing much the same thing as you are suggesting for a few years ...seems to be working out just fine.

Snox801

Awsome thanks. Steve from versa tune will be doing my car next month on the dyno and was gonna have him reduce it and then I can toy with it a bit more. I know amsoil 4 stroke doesn’t burn worth the crap but boy is it good on wear.

Brettus

iTrader: (2)

You might find this interesting ...depending on how far down the rabbit hole you want to go

https://www.rx8club.com/series-i-tec...9/#post4872214

Snox801

I have read that great info. My biggest concern was That the amount of 4 stroke might be based on it not burning off as fast and also the possibility of it injecting in the perfect spots. Similar to the etec technology able to go close to 200:1 because oil is exactly where it needs and no where else but if that same motor premix it needs to be mixed at oil recommendation ratio.

CaymanRotary

This car can be run safely without premixing. All premixing does is allow extra lubrication in spots like the middle of the apex seal (in the series 1's) and it also helps because of the detergents in the JASO FD rated 2 stroke oil.

It should make the engine as a whole last longer as long as it is properly cared for. From my experience with people who don't premix their engines, their annual compression test is no worse for wear over people's cars that are premixed. This engine fails primarily from people letting their ignition system, oil levels, cooling system (the stock coolant gauge is useless and you need an OBD2 to properly monitor it), or oil cooling system. As long as those are well maintained, the engine shouldn't give you any real problems. I've had lots of problems on this car but rarely is it the engine.

Snox801

I understand it’s not needed. But as you stated it’s more about how clean the two stroke can be over the 4cycle oil being injected. Id have to believe premix had to help on some level or mazda would not have added more injectors to series two engine.
My goal is to back off my omp as far as I can and supplement with premix. This using the bare min 4cycle oil and more premix hopefully to a a dded benefit of less carbon. And oil quality can make a huge difference in wear. A top oil like Idemitsu or amsoil I’m sure helps but you may indeed see far less benefit from cheap oils. It’s a stark contrast in engine longevity in snowmobiled using cheap oil versus high end stuff.
Plus this is more for a discussion on what ratio the wankle can or like to run.

10KRPM

I'm no expert, this is all from my reading, and mostly on this site:

Using Jaso FD is the only way to go for premix or Sohn. I've read enough discussions to believe that "just any" 2 stroke is a mistake. Don't try to save money, use Idemitsu or similar.

I get it that dirty 4 stroke seems like it can be a mistake. But how dirty is it, if you change oil often as recommended by anyone familiar with the Renesis? My oil tends to look like I could put it back in the bottles when I drain it. I've gone back and forth about whether to add a sohn adapter on my 8, still haven't decided. My OMP isn't injecting enough, or possibly at all, I need to look into that first but I'm catless and adding .75 oz./gallon premix with Idemitsu.

BigCajun

iTrader: (1)

A more descriptive thread title would've been helpful.
We already have beaucoup premix threads.

10KRPM

More descriptive? The title is "Premix ratio". He's asking about premix ratio.

Snox801, I meant to ask, why turn down the OMP rate? I just don't see how that could improve things at all. If you really don't feel right about the dirty oil issue, add a sohn, but reducing/removing one lubrication source (and the factory one at that) doesn't seem to be a winning strategy to me. BTW I'm saying this right after admitting my OMP isn't working well, but I do intend to dig into that and fix it.

Snox801

So dirty was the wrong term. I meant how dirty it burns in comparison. Deposits left after burn. Plus have you. Ever tried to burn a high quality 4 stroke in a fire it doesn’t burn well in comparison. The idea would be replace it with 2 stroke similar to sohn but I have not found anyone offering that for the s2 engine. Is that available? Thanks

Snox801

As for the premix threads they are all the same people saying use x amount per gallon which is part of the topic x amount of 32:1? Big difference in an oil at 32:1 adding 1oz per gal vs a 100:1 at 1oz a gal.

10KRPM

Maybe I'm missing something about 2 stroke oils. I think of the 32:1 or 50:1 or 100:1 being the ratio determined by the engine manufacturer, not a description of a type of 2 stroke oil. In other words, the same 2 stroke oil can be used for all of those ratios, the oil doesn't change, the mix does.

BigCajun

iTrader: (1)

My point was "Premix Ratio Without An Oil Pump" would've garnered more attention maybe as opposed to possibly assuming it was another noob starting the 89th premix thread that would likely be ignored by many.

Snox801

That is the big issue. The engine manufacturers is the wrong way to do it. I actually at one time had a statement from two major oil companies stating this because all to often people thought like you.
It’s always based on what the oil is made for.
Say you have a engine that says 50:1 but you run it on 32:1 oil bad things are more than likely going to happen. But if it says 32:1 like almost all Honda two stroke you can easily run 50:1 and 100:1 oils no issues. The problem lies in the oil is developed to protect at a certain ratio. Those engine has no idea what it is just metal parts. And I can say for the most part after years of building race engines at the highest level for snowmobiles and bikes. That they are all very similar in design and function.
It’s similar to 4 cycle oil. The manufacturer can state oil change at 3,000 but that’s based on the lowest base oil or the manufacturer oil. Mobil one and amsoil can go 15,000 miles or more. I in fact have had 9 vehicles run to 300,000 plus miles on the 15,000 mile amsoil change interval.
Always use the mix recommend by manufacturer.
You can use more or change it early but never run oil designed for 32:1 at 100:1

10KRPM

Interesting, I never knew that.

kevink0000

I don't agree with some of this, but yes, 2 stroke oil is a very different animal than 4 stroke. Spending time in that world is an eye opener.