Why premix? Here's your answer
 

A recent threat prompted me to post some images to show peopel exactly why you SHOULD premix instead of use OMP. Ok to start, here is a pic of a clean rotor:

http://www.mazdatrix.com/pictures/b-engprt/rotor12a.jpg

Neat huh? Nice and clean.

Here is what a rotor looks like if you use the stock OMP:

http://chris.redmonkeygames.com/RX7/7.jpg

Notice that nice silver spot right in the middle of the apex groove? Thats from where the oil DRIPS onto the rotor. That spot builds up lots of carbon and scores your rotor housing. I've seen so many engines die ONLY because the carbon buildup on the tip of the rotor scored the housing!

So to all your unbeleivers, theres your proof. PREMIX :)

Now you should post a picture of a rotor run in an engine with premix and no omp, a most shocking visual impact it would have.

Hopefully I wont have to take mine apart for a good long time:) Maybe Ted has some pics of one run with premix?

interesting, very interesting *proceeds to check forum for more info on premizing*

Hey guys, I am having trouble with my car getting through DEQ, I am burning too much oil, so If I used premix and took off the OMP, will I have a better chances of getting through?

The problem with yours burning too much oil is probably related to the internal oil seals, not the OMP :(

How about baloney? Have you never taken apart a non fuel injected RX?????? They don't have oil injectors and the carbon builds up in the combustion section of the rotor JUST LIKE A OIL INJECTED RX.

P.S. The oil does not drip into the combustion chamber. The oil is being sucked into a low pressure area on the rotors intake stroke. It ain't being dribbled.

In my opinion, the fuel injected(oil injected) RX's are cleaner inside than the carbed ones. Only rebuilt two carbed ones and four fuel injected ones, so I'm no expert for sure, but that's what I readily observed.

I've premixed from the time I had a rebuilt done and won't go back to stock!

Turned out, 3 of the 4 didn't shoot out/dribble out!

First, fuel injectors were never meant to inject oil. It is thicker than fuel.

Second, oil has a lower octane rating than fuel, you could detonate your motor.

Third, this could only cause a problem if you were to inject too much oil of course.

Re: Why premix? Here's your answer
 

Well, I have heard that too much PREMIX causes mental disorders and makes you look like an ass... supposedly makes you think up real stupid stuff and while actually believing that it's true. I better cut-back on my after hours premix, cause I was thinking them silver spots were hot spots created from the sparkplugs :D

Sensei;)

I would tend to think that the oil injection system that Mazda probably spent millions of dollars developing generally works pretty well (with the exception of the 89+ MOP of course). How many engines with the stock MOP system are running high miles? Probably quite a few. Mine is currently at 258K KM, and still going strong.

Before this topic generates tonnes of questions, I will put down some answers:

1. You cannot remove the metering oil system in the 89+ cars if you intend to still use the stock ECU. If the ECU does not see the metering oil pump, it puts the car into limp mode.

2. Premix usually consists of 2 stroke oil mixed into the gas at a 100:1 ratio

3. Try to find a 2 stroke oil that mentions rotary engines on the label

4. Metering oil pump blockoff plates are available from K2RD and Mazdatrix

5. You can plug the oil injector holes with a bolt

6. It's metering oil pump, not oil metering pump.

I've own a 1st gen and it does inject oil

The nikki carb has oil lines just like a F.I

I have seen what rotors look like after using premix, perfect.

about to be getting me a rebuilt motor here soon. it's for my 87 turbo II. and wanting to go with a haltech. anything i need to be concerned with about the oil?

now as for premix, what's wrong with the stock oiling system? is there problems with only certain year models? personally, i'm not sure that i like the idea of using premix. maybe it's good for when you're filling up, but how bout when you only have about 5 bucks in your pocket or you're on a scrounging spree? then what? not like you can put 5 bucks in and then dump in a bottle ya know? your engine gonna die then cause you don't put in a bottle? just doesn't sound right to me. surely ya'll don't put in a bottle EVERY single time and i'm sure the engine still lives. anyway, being that i'm probably gonna get a haltech, is there some type of oil problem i need to be concerned with for my 87? are there some issues here i'm maybe not aware of? thanks.
scott

If you buy the Valvoline TC-3 (or whatever) certified oil, it USED TO SAY "Safe for use in Rotary engined vehicles." THat certification meanas that it is MEANT to go thtouh FI systems w/o clogging and mixing w/fuel w/o dangerously lowering octane.

... do your homework.

I run that premix in my S5 NA. Pulled the injectors out recently... NO PROBLEMS.

Search teh 2nd gen form for my usernam and "OMP" and you'll see my MANY posts about premix pros AND cons.

I've seen the internals of my engine after 82,000 miles of no premix. The reason it needed a rebuild, was the apex seals were worn down to basically nothing.
The housings were BLACK except for a nice shiny stripe down the center where the oil was being injected ... that stripe looked as good as a new housing ... everywhere around it was black, burned and scored up.

My mechanic, that has worked on rotaries since he was a teenager (he's in his 50's now), said that's what happens when you DON'T premix. He said to premix every third tank ... however, I premix every tank.

I've noticed that without premix, my engine takes longer to start and doesn't run as smooth.

With premix, my engine starts right up with no "scuffing/scrapping sounds, it idles a lot smoother, smooth/strong acceleration, and I get better gas mileage ... if you can believe that.

Now there are a few downsides ... some smoke on startup, the plugs can get fouled out should you use too much, and it takes slightly longer to fill up. :D

I use 8 oz of Penzoil premium outboard 2 cycle engine oil that is rated TCW3 ... I mix it up with a little gas before pouring it into the tank, then I fill it up with 93 octane. :) I run about a 1/4 tank of non-premixed 93 once a month to clean out the system.


Raise the BS flag if you want ... but after spending as much as I do on this car, not to mention the bill for the rebuild, I figure a few bucks on premix and 5 extra minutes to fill up is a small price to pay.

Seeing how Haltech does not run the OMP ... you'll have to lubricate the seals somehow ... premix is one way.

kabooski.......I never said the first generation did not use oil injection(they get delivered oil with a oil metering pump , but not thru a oil injector, it gets mixed in the carb). The idea is that they don't have oil injectors(pre fuel injection models) and I guarantee that if you tear one down that has some miles on it, you'll find the rotors have a layer of carbon.......just like second generation that have oil injectors.

And not to knock any mechanics out there, but I know a shop here in Texas that's been in business working just on rotary engines over twenty years, and while they are right nice people, think that there is no difference b/t front and rear rotor housings. So while they know a lot do to all their years of servicing cars, there's just a little doubt about how much they really know.

Really wish I had a first generation to pull apart right now to compare the center of the housings with a more recent series.

87s have a mechanical mop. Its not related to the ecu.

so if you are still using the OMP, can you run pre mix through your car every once in a while?

How about this guys with premix:

Youre driving at 7krpm in say 3rd accelerating hard and you let off.

So now your engine is revving at 7krpm but youre injecting enough oil for idle... wont that effect the engine?

I know 2 stroke cars have a freewheeling engine meaning its not able to engine brake at all.

sure, use 1/2 oz. premix per gallon of gasoline.

(make CERTAIN it's TC-3 (orwhatever) certified)

I've been running premix in addition to the OMP (gonna yank it soon) since the summer. Here's my bullet-form report:

- any TC-W3 premix will do. Castrol sells, 'Super Outboard Motor Oil,' in nice big 4 litre containers.

- you want 12-14 ounces of premix per tank of gas. I found that using an empty MMO bottle works perfectly for both measuring and storing 'doses' in my 7. Fill the MMO bottle 'til it's about halfway up the neck.

https://www.rx7club.com/forum/attach...postid=1374762

- I've been burnning about twice the normal amount of oil (OMP and premix) and my exhaust is DEADLY. :D The car is otherwise running normally.

There ya go. :)

(Thread edited for content...In the future please remember posting naked pictures of yourself and/or Richard Hatch is against forum rules)

Obviously, the carbed ones have carbon build-up just like the 2nd gen ones. It's not the delivery system which causes the problem but what you burn in the engine. 2-stroke oil burns a heck of a lot cleaner than motor oil, you have to admit. Whether or not it provides the same degree of lubrication is another issue.

Re: Re: Why premix? Here's your answer
 

And how many engines have you torn apart? Yea thanks ive done 5 now myself. The silver spot just happens to exist right where there is always bad scoring down the middle of the housing. Hm, didnt know a hot spot created from a spark plug could score a groove directly down the center of a housing?

It was the carbon you fool

As far as i know, the spark plugs dont fire right at the apex, they fire in the dish of the rotor.

Besides if you had actually seen these marks, you would see that they are usually about 1/4 inch wide and 1 inch long, with the front bieng the most worn and gradually sloping off. This is a sign of buildup, not a hot spot.