In my opinion, this is the best product available for the subject application

http://www.amsoil.com/storefront/ait.aspx

 

IMHO, the RX-8 is a good example to show that Mazda decision makers are capable of making mistakes. It's possible the engineers made mistakes, it's also possible they warned of the possible failures but were overruled by legal, financial, marketing, or time constraints. Selling a product is rarely as simple as building the best possible product.


Are there any RX-8 owners who are familiar with the engine recalls? I haven't owned one or done much research, but some people claim that the problem was related to the OMP being programmed to inject less oil than RX-7's (and less oil than RX-8's sold in other countries), in order to comply with modern EPA requirements that the emissions systems last for 100,000 miles.

Most of those engines didn't last nearly 50k miles, from what I gather.




He's On Toroids, thanks for posting the rotary Aircraft info.

 

My simple question. Observing that OMP users predate and outnumber premixers:

Who here has a high mileage premixed car?

For bias minimization: we would prefer ones closer to stock.

This is a relevant and useful question right?

 

Yes, that is relevant and useful questions.

All I ask is that before judgement is made, think of what's currently out there and not indirect compare of one engine vs. another. Again, too many variables are hard to compare scientifically.

 

If premix has any lubricative advantage over clean 4 stroke oil applied directly to the friction surface(which it doesn't) it is negated by the absence of lubrication upon throttle closed deceleration.

Rotary aviation is recommending 1oz/1gal premix. Seems to me they take maintenance pretty seriously in the aircraft world. If they're recommending that rate for moderate engine speeds in a stockish N/A application, it logically follows that a high rpm/high horsepower/turbocharged rotary application would require a yet higher premix/fuel ratio.

It should be noted that airplanes don't often encounter throttle closed deceleration. The engine runs above idle until you get out of the plane(or maybe these people are high-altitude-stalling their cesna's). And, the omp is eliminated in this instance simply as a point of possible failure and for the carbon based benefits of 2-stroke, apparently.

2 stroke shouldnt foul plugs in low ratio's, btw. Especially that quality clean burning amsoil interceptor!

 

Here's a thought. Just a thought.

Why don't we run 2-stoke oil in the "crank case"? Do its lubricative properties degrade more quickly? I know it would get dirty, and thats part of the problem with the OMP, but couldn't you just change your oil more often? 1k miles instead of 2k?

I'd love to hear some rational thoughts on this.

 

I couldn't agree more.. I mean, just look at statistics of this matter

Really?? I didn't think this was an argument.. more of can you provide me with facts and more data?? instead of oil company providing you with a statement or comparison pics of an engine that's used on the track mainly vs 15+ year old engine that's driven on average of less than 2,000 miles.

Ahh.. unnecessary and I think you miss the point.

I think you miss what science is... as I kind of get a sense from your previous post. Science in fact is to show proof... and most of this so called proofs are based on in this case statistics. Again, you make it sound like OMP is EVIL... maybe in your term DEVIL. But it has shown statically over 20 years being used engines have lasted 100K plus. And in today's ownership of FD's, there are very few that are being driven as a daily car. I think when someone can't tell me what level of carbon build up is bad and kept pushing its just bad in general makes me think they themselves lack reasoning or doesn't quite understand how things work. Just remember, carbon is not bad... just at excessive. Please think about my '****" ology (someone PM'd me about that lol)

again, its not a win or loose.. Just want better facts. also, do some research about carbon and the level its consider bad. some carbon is reasonable and some consider ok and beneficial. I'll let you search that vs me spoon feeding you.

 

just to add fuel to the fire...

2009+ (S2) RX-8's have a redesigned oiling system which includes not only higher oil pressure but also relocated oil filter and 2x electronically controlled, top of the engine located, oil metering pumps that feed 3 oil metering injectors per rotor housing

 

Looks like they designed it that way to get better oil coverage of the apex seals, without having to inject more oil.

 

To all concerned: I was not suggesting that we should use the seals, I appologize if it appeared that way, I was merely referencing that premix was found to be beneficial by another group using the rotary engine as well. I will find it interesting what he has to say about using it in an automobile. I would be more interested in if he has data too. I'd like to know how much wear was reduced by running the premix.

I agree that, given that they do not rev their engines as often, it won't be very helpful for a direct comparison on carbon buildup. Also it is true that there is not any oil injected into the engine when you are not injecting fuel, I wonder if this is a concern. I know that 2 cycle oil does leave a lubricating residue behind but whether this is enough to mitigate the wear should be tested.

The comment about premix affecting the cats is definately a good one (for those of us that run them). It is my opinion that the true reason that Mazda did not use 2 stroke oil in the car may have been for many reasons, but the nail in the coffin was emissions (it barely passed anyway). Since 2 stroke oil is less combustible than gasoline, some passes through unburnt (HC). This coupled with the volume of 2 stroke oil needed to properly lubricate the engine is just an emissions disaster. Also, the 'ash' that the oil produces when burned is considered Particulate Matter. So in best the best case scenerio, where it is all fully combusted, it still fails. Premix creates more emissions than when oil is inadvertantly burned off (this, BTW only happens during higher RPMs then they dyno when testing for emissions).

This does not mean premixing is 'bad' for the engine. I believe that minimal premix can only help in lubricating the engine and I don't believe anyone has said otherwise.

The question is more about whether it affects carbon build-up. Can anyone produce hard facts for this? So far... No. I agree that if you begin using premix at the start of the engine and you build up a film of oil, it seems logical that carbon would have a more difficult time finding purchase on the surfaces (also 2 stroke oil is lighter weight then 4 stroke so it gets into the small crevices better). To me, it is more likely the excess carbon is due to the AFR ratio being so much lower in a Turbo car as opposed to a NA. The fix: use AI and rely less on extra fuel to keep your engine from detonating.





BTW, Good info on that update for the 2009 rx-8 I have no doubt it was to increase reliability through proper oil injection. From what I've read they reduced the 'extra' oil that was injected into the FDs to help meet emissions restrictions imposed on the rx-8. This caused the engines to fail earlier then expected. And now it seems like they want to do a better job with that minimum oil.

 

but there is ashless 2 stroke available and for quite some time

 

EDIT: Ok, I got a double post. (Must've had 2 tabs of the same page opened)

 

for like 20+ years.



"Since all 2-stroke engines partially burn and expel their lubricant in the exhaust, the resulting exhaust residue must be rendered harmless to the environment (air, water and land). All 2-stroke oil intended for marine use and many intended for land recreational use contain Biodegrading agents. These complex chemical compounds allow the microbes found in water and in the soil to consume the hazardous chemicals and oil from the exhaust as they fall in the water or on the ground. These Biodegrading agents do nothing for the performance of the oil (sometimes they even hinder it), but they help assure us that 2-stroke engines will be around for a while."
http://www.quebecpeche.com/forums/in...-pour-2-temps/

 

I hope someone steps in and corrects me (if wrong) but I believe these Low Ash Oils were created by reducing the amount of metallic detergent in the oil (the stuff that cleans). This caused an issue with the detergency (obviously) and therefore they had to use substitute additives to help clean things up. So yes, low ash oil is improved and could help emissions over conventional oil. It can even be more environmental ...if it is all burnt. The fact is that not all premix is burned (just like fuel). And from what I hear, oil clogs Cats much worse than fuel. If you have no Cats and it is not a street car, it is my opinion that Premix can only help. With the Cats, I am starting to talk myself into just adapting the EOP/OMP to push the 2 stroke oil.

 

They have to be overly conservative, but the fact remains Idemitsu reports racers running 400:1 pre-mix with no ill effects at tear down. RX-7 World runs 1/4 oz/gal and has been for years.

That isn't logic, it's unscientific (religious) extrapolation, the same mistake made by Banzai. 256:1 works fine.

This seems to be your latest side track terminology you're throwing out without any basis, and little bearing on the topic.

Also, when I spoke to Ernst at RX-7 World this weekend, he said that of the hundreds of motors he has torn down, the primary issue is how the car is driven. More carbon build up definitely occurs if you lug the motor. These engines definitely need to have the carbon blown out with a good redline run on a regular basis.

The plugs can be partially coated (wet fouled) when the engine cools down, that's the problem, then it can be hard to re-start.

 

What do you mean racers? Drag racers? Road racers? Auto-x? Thats not logic. They probably tear down their engines far more often than your average modified rx7 owener in stop'n'go traffic. That's logic.


Actually, logic is defined as: "A system of resoning." Because there is less stress on the motor it requires less lubrication. That's logic.



It's relevant. Because rotary aviators do not encounter closed throttle deceleration they do not suffer one of the detriments inherent to the pre-mix system. The pre mix system is at the very heart of this thread, and anyone considering it should realize: when the injectors aren't firing, you're not lubricating your seals.

I agree.

Not a result of too much premix. period. Not at 128:1. That mixture has a scientifically insignificant amount of premix in it(0.8%). 5% is considered statistically significant, btw. That is to say, that if the octane rating of 2-cycle oil is 0(it's not), and you were running 93 octance fuel. You would have an octane rating of 92.256. The burn characteristic would essentially be the same. If anything, it's in your head, your tune is rich, or you're flooding for some other reason.

Here's a moderately relevant 2-cycle comparo regarding carbon buildup, brands, and ratio's
http://www.geistware.com/rcmodeling/...test/index.htm

 

I'll just add that statistical significance is determined by having a reoccurring outcome at 95% or greater (meaning 5% of the time it results in a "negative" and 95% of the time a "positive") -- I use positive/negative here loosely in that you could be trying to find out any type of effects something has. In many medical research this % is even lower at 1%. Meaning that 99% of the time a person takes X pill then this outcome will occur.

SO, what does that mean. It means that the comparison isn't correct. Taking a % of ratio and comparing it to p= +5% doesn't mean much of anything other than one is greater than the other. It's like comparing apples to oranges. Both are percentages but two percentages meaning different things.


I'll just crawl back into my research-geek hole now.

 

Clearance issue of the OMP adapter can be solved in 3 ways:

1. clock the OMP to clear the adapter;
2. clock the oil drain line to clear the adapter;
3. fabricate your own drain line.

For #3, I fabricated a line. I am still pre-mixing 1/2 oz of Idetmitsu oil though. This oil is so clear that it's almost like water. It does not mix well with other 2 stroke oil though.

 

What were the dimensions for the fittings?

 

You're very right. The main point was to provide some point of reference. I didn't mean to imply all that comes along with the experimental terminology and boolean logic.

I'll state it more simply. 1oz/gal of 2-cycle oil/fuel will provide a mixture that is less than 1% 2-cycle oil.
1/2 oz? 0.4%.
And, most of that will be combusted. It's atomized with the fuel and designed to burn, just like gasoline.

 

 

^^^

Looks like you could make a couple bucks fabbing replica lines for TT cars. Hint hint.


What would be super cool is if somebody could figure out how to get a single external 2-stroke oil supply to inject as the MOP does, AND into the fuel supply near the manifold, so you'd never have to manually add oil to the gas, and it wouldn't potentially gum up your fuel pump, tank, or filter.

I'd buy that.

 

+1

I wonder if those new rx8 pumps could be adapted to work with our system.

 

So with your setup here (using the rotary aviation kit) are you drawing 2stroke through the OMP via a seperate tank?
Jono

 

Is there a write up for the omp pulling 2stroke from a separate tank mod?