That is Freakin awesome! Has anybody here done this conversion? If so, how well does it work?

 

I did it about 6 months ago. No complaints yet, just make sure the tank the oil is it doesn't run dry.

I used a tank from AutoZone that was made for "universal" coolant overflow replacments. It gives me about a 1.5 quart capacity. I removed the cold start assist and cruise control and place the tank there.

When you install the adapter, make sure to "bleed" the hose running from the tank. Connet everything up, then fill the tank, then remove the hose from the adapter and let the oil start flowing from the end, then connect the hose back to the adapter. Otherwise you will be running without oil for a LONG time.


Smells kinda neet

 

I ran the adapter with MMO for several weeks following my overhaul. I discovered a few "bugs" about the whole idea that need to be shared for those considering the conversion.

First off, all this adapter does is block the flow of engine oil to the OMP and instead furnish a way for oil from another source to be fed to it. This adapter in NOT a pump and as such requires the oil reservoir to be located at least six inches higher than the OMP. This brought about the problem I had.

With the oil reservoir higher than the OMP (I used my original cold start assist reservoir) the oil is fed by gravity to the OMP. Problem is that when the engine is not running the gravity is still at work and oil will continue to flow into the engine. This problem was especially bad with the relatively thin MMO being used. I then tried some Evinrude two-stroke oil. It was thicker and leaked out at a slower rate than the MMO did but it still managed to flow while the engine was not running.

I ended up using a vacuum operated valve to shut the oil flow off when the engine was not running. My particular valve was a purge valve intended to be used on a Chevy P/U emissions system. To be honest I was afraid that the valve would fail and ruin my enigine. I had no way of knowing it was operating without looking at the injector lines themselves.

I also used a spare oil level sending unit to furnish an alarm if the level in the reservoir went too low. I simply wired the new sending unit into the existing oil level warning circuit. Unfortunately, with the way the cold start reservoir is made, the sending unit could not be placed low enough. It would start going off with the tank still over half full. I could have looked for a different tank or even made one but the cruise control really limits the space there. I ended up taking the adapter off and going back to the stock system. I figured that the original engine lasted for 124K and I will never drive this car that much.

I still may end up trying to fab a different tank with more capacity but that still leaves me with the problem of shutting the oil flow off when the engine is not running. I need something more trustworthy than a plastic vacuum operated valve.

If anyone is interested I would be willing to sell the adapter for 50 bucks.

 

I wish that someone would just do a rite up on this subject already w/pics and all. Hell i'd be willing to pay someone to do a rite-up.

 

Just thinking out loud here, but this sounds like it's fixing a problem that doesn't exist, and in the process, it has the potential to create a problem. If there is/was any kind of genuine problem w/ the stock OMP configuration/operation, wouldn't Mazda, after mass-producing rotary engines for over 30 years, which must equate to literally billions of miles of operation, have addressed it while designing the new engine for the RX8? We all know the stories about the "benefits" of premixing, but so do the engineers at Mazda, so...Why haven't they incorporated a premixing/non-engine-oil system for chamber/rotor lubrication? It would be very easy for them to add a plastic oil tank for the purpose, with an idiot light and buzzer and/or engine shut-off safety switch in case the tank ran dry, to protect the engine. So... Why haven't they done it if it's "better" and makes any kind of improvement in engine longevity? If they knew of a way to improve the rotary engine's durability/longevity at virtually no cost, why wouldn't they use it?
Not looking to get anyone agitated about this, but I'm just curious...

 

Because the engineers are designing a car that the average random moron will purchase, hopefully remember to add gasoline, and might, just might, bother with checking and changing the normal engine oil. If the dealer tells people that they have to check the special auxillary oil bottle, half of them aren't going to buy the car, and half of the remainder are going to forget, idiot light or not, and blow up the engine. I'm sure careful market research was done before they created the system the way it is. I've seen pictures of used rotors from pre-mix engines and normal engines, and the evidence for pre-mix is compelling, since the two-stroke oil burns so much cleaner. Using oil injectors with premix is a nice compromise because you don't have to futz with ratios and pouring oil in the gas tank, but pre-mixed probably provides better distribution of the oil since it's misted in by the main injectors along with the fuel.

Always remember: Engineering is a complex process of compromise; balancing many factors to form what will hopefully be an acceptable product for the price, but not always the "best" product, depending on the application. The factors that go into a race car are very different from those that go into a street car.

 

Damn. I was going to use one of those babies, but after hearing those rather significant problems, I'm reconsidering. Looks like I may have to (gasp!) premix.

 

You do know that MMO is mostly solvents, and not very good for lubrication?

Those adapters are never ever designed to use MMO... you might as well just pour in acetone, and toulen.

 

I just ordered a case of 12 bottles of redline racing 2-stroke for myself. It's kinda pricey, but I beat the hell ouf of my car at track days, so I figure it's worth it.

 

i just dont think that it would get enough oil into the engine, thats one of the things i wonder about as far as what ratio to mix when i premix. right now im just using 1 ounce per gallon but the normal OMP operation doesnt use 1/4 of that. figure normal OMP uses 1 quart per 1000 miles(I dont think it uses that much). so thats like 3-3.5 tanks of gas roughly 50 gallons of gas and 32 ounces of oil. so thats like a 200:1 ratio right? i think i did the math right.
copandengr how much oil do you think the system was using while you had it in?

 

how exsactly do you change the OMP for I need to do one on my 88 it leaks some.

and how do you setup the premix I would be willing to do it
Ben racing dirt bikes for years on end and i sugest klots r50 oil or redline if it makes any difference on the rx7. can you run a castrol based 2 cycle oil like blensoil? whats the ratio 40-1? or 1 quote per 4 gallons?

 

If it leaks on a pre-89 then it is probably the O -ring between the MOP and the engine. A $2 part that is easy to change.

Normal ratios are around 100:1 to 150:1 (about one ounce for every gallon of gas) if you are not running a MOP, or you are running a MOP with pre-mix only (as shown above); and 200+:1 if you are running with the stock setup and just want a little extra protection.

<edit< and Mazda calls it a MOP as in Metering Oil Pump... often mis-called the OMP by people that don't know better.>end edit>

 

do you disconnect or plug up the oil spray noselz when you do this? I assum we are just poring it into the gas tank.

 

Arg why do people keep saying one oz per gallon is 100:1!? A gallon is 128 ounces, so 1 oz per gallon is 128:1, a difference of 28%. That's not even close!

OK I'm done ranting now.

iceblue: yes if you convert to premix you disable the stock OMP. On series 5 the engine computer gets mad if you do that however, and puts you in limp mode (fuel cut as soon as you reach zero manifold vacuum) so you don't break anything. That's why my OMP is bolted to the fender next to the engine.

 

nice! thx for the ratio correction and all. allright deal is im gona do it on my 88 S4 since i will ither be turbing it to or selling it for an fd. Is there a wright up on how to do all this since the OMP i realy dont know anything about.
I am asuming as well if you went standalone ECU that would solve the freekign out ishue but is it only s5? why did u bolt it to the side of your fender?

 

https://www.rx7club.com/rotary-car-performance-77/diy-2-stroke-mop-write-up-pics-372329/

my take on this. works great.

pat

 

why are people so reluctant to premixing? mixing the oil with the gasoline before it enters the combustion chamber ensures that it is uniformly spread over all the parts during the combustion process. though i didn't post this to cause a discussion, it's already been discussed i still wonder why it's such a hassle for people to pour a bottle of oil in the tank before filling up, it is a habit for me now and doesn't bother me a bit.

 

The S4 is mechanical, the computer doesn't look for it. The S5 is electric and has a sensor. You can just block the place on the block and block the holes and you're all set. The reason I have it bolted inside the fender is because that way the computer sees it's there and doesn't pitch a fit.

 

I think the reson is the same that was for me. they dont know the ratio and for some people not knowing where to get or what brand of oil to use.

 

12 oz per 10 gallon sounds good?

 

1 ounce per gallon of gas is a good rule of thumb if you are not using your OMP anymore, you can get a gallon jug of TCW3 2 stroke oil at Wal mart for about $6. i just carry several 12 ounce bottles of 2 stroke oil in my storage bins and add a bottle to my tank before each fill up.

 

I am probly going to run klots R50 its 49$ a gallon
its what i run in my race bikes nad burn great. you cant run castrol based no more it puts carbon build up in the power valve and locks them up I asum this is probly a bad mixture with a rotary

 

i have used the best grades of synthetic 2 stroke oils in my T2 and i have run the wal mart crap, there was little carbon buildup after 4k miles, no scarring, minimal wear for basically 0 break in after i assembled it to the time i started boosting the motor and the carbon wiped off with a single swipe of a shop rag.

using an expensive 2 stroke oil is a waste of money.



but for dirt bikes, i don't stray much from the upper end of the synthetic range.. 2 stroke dirt bikes are almost always at the redline and pushing their limits through their whole life, i won't run anything less than a premium synthetic 2 stroke oil in my KTM 250MXC.


if you plan on running a rotary through extreme conditions like redlining alot then a good grade synthetic couldn't hurt.

 

I see posibly a mid grade.
yea i race 125 pro my motors are full pro circuit motors im easly at 17grand non stop.
pro circuit yz125 and 250f
weve found klots r50 to be great for us in MX
thx for the budget saver