In all the years of people premixing their rotaries, has there been any report or forum members experiencing problems with their rotary engines as a DIRECT result of Premixing? I mean: either engine failure, carbon lock, fuel pump replacement, spark plugs fouling, etc

I mean, there's a thread on Premix that's 76 pages long and growing! and every single person that uses premix says its good for the engine. But is it SAFE to conclude that in the absence of negative reports, Premixing is positive and good for the rotary engine?

On that note, I am thinking coming up with a survey for people who wish to participate so that I can compile a more representative report (based on statistical analysis of people who premix and those who don't, looking at how much they add, why they premix and why they don't, etc)Working on it now but will start a thread with the survey once I finish. That way, we can get a sense of Premix and how it is being done, rather than 76 pages of anectodal information which is still hard to draw any conclusions from. Will get cracking on this if I can find time from my work!

 

Early rotary engines didn't have oil injection and the seals didn't last. Mazda designed oil injection (at first mechanical, next electrical and now computer controlled) to solve this problem. The driving public doesn't want to be bothered to adding oil to their gasoline every time they fill up. Early racers found the mechanical oil injection lacking. They disabled it and started premixing oil in their racing fuel to make their engines last longer. Performance oriented street drivers simply add a small amount of oil to their gasoline as assurance that they won't be destroying their engines while being run hard.

Have there been any official studies done on premixing? I doubt it. It isn't officially sanctioned by Mazda. If it was, that would be an admitting that there were deficiencies on how the OMP system works in the engine in high performance situations. It is sold as a street car after all.

So, I think all you are going to get is anecdotal evidence from the owners and engine rebuilders on the effects of premixing.

On my GSL-SE, the first time I started premixing, I blew a apex seal during a race. I don't blame premixing on the engine failure and have started premixing on my RX8 (3 oz/tank).

 

I go back and forth on premixing.
I have done it but I'm not now.

When I did do it I used 8oz on a full tank but now I think that may have been too much for how I drive.
I don't track or auto-X and only redline on the on ramp to the highway.
My car did not run better.
My gas mileage was about the same or lower and the engine did not feel "smoother"

After reading that people were getting 100k plus on 5w-20 and no premixing, I've thought more about it.

I will still use heavier than 5-20 but I'm not sure if I'll go back to premixing.

I do use a combo of BG-44k at oil change time an 11oz of Techron a tank between oil changes and my car runs much better than when I premixed.
Smoother, a tiny bit better gas mileage and it feels like the power is there when I need it. Like new not extra hp I mean........

I don't know but count me as a "use to premix" carbon fighter.

 

Ya I know what you mean. I don't expect it to be scientific because if it was scientific, we would need alot of $$, 2 rotaries, 1 with premix, 1 without, and run it for tens of thousands of miles in a lab, open the engine up and check the seals..

It's more to see why people premix, how they feel about premixing, and if they have run into any problems with premixing.

Somewhere in that exercise, I'm pretty sure we will find some interesting information

 

I believe in pre-mixing, but i don't believe in pre-mixing on the RX8.

Pre-mixing is a must for most Rx7 people because after 20 something years, the stock teflon/rubber oil injection lines simply fall apart, so instead of spending 100+ dollars on the OEM replacement, they pre-mix, which is mechanically free.

Does it work? You're sure as **** it works. I used a ratio of 1oz/gallon in my GTUs, most of the time i had that car it was in the 4-5k RPM range, while hovering around redline for extended periods. No problems at all.

With the MSP-16 PCM re-flash, i see no reason to pre-mix on the RX8, unless you are doing a track day or something and feel the need for some extra protection.

The damage has most of the time already been done on the early model RX8's, pre/MSP16, and pre-mixing will not bring life back into the engine.

 

So basically, if premixing works on an RX7 rotary, so technically it would also work to lubricate a rotary engine on an RX8. The way I see it, the question then becomes one of non-necessity because:

1) it is costly and therefore not something you would want to spend on long term on premixing for an RX8, given that it's gain is hypothetical and minimal at best

OR

2) because adding premix would somehow affect the rotary (carbon lock for example) and/or other parts of the engine (such as fuel pump, spark plugs, Cat convertor) and premixing would then become a liability.

If COST of premix is out of the equation, meaning I am OK to spend on the premix, fix the plugs, the pump AND the Cat (all adding up to less then a replacement engine I should think), ALL in the interest in prolonging my engine life, then does it then become a question of: will it cause any detrimental effects on my 8 engine and the fuel system.

Am I right to see it this way? And if so, then it's back to my original question:

Has anyone experience ANY problems traceable to premixing?

 

The first 20,000km no premix and the past 14,000km till now I have been premixing. Not much of difference, just thought is a good thing to do for our rotary...

 

I pre-mixed (4oz a tank) on my 1st engine from 70,000 - 110,000 and I am doing so on my 2nd which has about 25,000 on it. My CAT has 134,000 miles on it and I never had any issues on the street with my fuel pump. The tear down of my 1st engine was documented HERE, Premix was not an issue. Premix does do one thing that is quickly noticed, reduce tailpipe soot so something is going on.

The only other thing I wish to add is if the oiling system on the 04-08's was adequate why did Mazda make such a major change to it on the 09's? Hint see the above mentioned tear down thread.

 

My non-technically inclined brain tells me 2 possibility:

1) Premixes help burn off the soot generated in the combustion chamber that otherwise would have been blown out of the tailpipes

2) the premix makes the soot stay in the rotary engine and is accumulating..

 

premix generally prohibits the formation of carbon or soot

 

I think that the only negative is the fuel pump filter clogging due to bad quality of premix.

No problems or downsides if you use proper quality premix. Proper quality is for example Idemitsu and Amsoil saber pro

 

are the amsoil and idemitsu premix safe on cats and injectors?

 

idemitsu premix claims that it actually clean the injectors

 

I've been premixing for about 20k miles and no problems here...50k on plugs and still look good.....but I still have the same amount of carbon "dust" comin out the tailpipes

 

really?

care to share where you got that?

beers

 

"Keeps Fuel Injectors Clean For Reduced Maintenance "

http://www.idemitsu-usa.com/page_207.htm

"Special detergent/dispersant additives keep you fuel injectors clean to reduce maintenance."

http://www.idemitsu-usa.com/page_210.htm

 

pwned!

 

Based on the Pre-mix thread, I decided that pre-mix was the way to go. Started premixing around 50K on my 04. I have used Idemitsu exclusively at 4 oz per fillup (13 gal), less on partial fills. I felt that the 8 seemed smoother with pre-mix but this is purely seat of pants observation. Yes, less tailpipe soot. Say what they will, I have not had any problems with premixing and I turned over 100K two weeks ago. Still running strong. Next up another set of plugs and will be replacing coils and wires.

 

Pre-mixing doesnt change the way your stock oil system works, it simply provides more lubrication.

 

Congrats on 100k

 

thx,

those were not the details that i got with my case.. different color bottles. about a year ago..

i really wonder what changed?

beers

 

yep i asked for info and got if for the many that are reading this thread..

i really wished i had not asked that question now..

whatever.

beers

 

Amsoil Saber Pro and Idemitsu Premix are both safe for the cats and injectors

 

hell, if dem boys over at mazda run premix and synthetic oil in the 787b then i can too. anything to help my apex seals last longer.

 

What differentiates the two from 2 Stroke Premixes that are unsafe for Cats and Injectors? I am using Castrol Racing 2T which is fully synthethic. Is that going to cause problems with injectors and cats? I use at 200ml for a full tank of gas.