Malefoda

Hello fellas,
I think I'll go for:
Mobil1 synth 5W40 oil, remove the OMP and go for TCW3 premix around 0.5 liter for a tank refill around 60 liter (1:120 ratio here as I'm half cool half squirel).
My question is: what happens in the RE when the ECU cuts the injectors, e.g. light loads or throttle off? Any danger here as no gas means no oil?

Thx
Matthieu

HAILERS

Let me be the first of probably fifty opinions on pre mix to say it sucks and is a wast of time. FIRST!

theflatlander

iTrader: (3)

^the oil injections sucks just as bad. there are pros and cons to both setups so there really isnt a good argument for either setup. Do what u want.
Malefoda: as long as the car is running there will always be fuel injected

AllMotorRotor

I can see this thread going in the wrong direction very quickly.

the oil injection system is great and is even better when modified to inject 2 stroke instead of motor oil

MaczPayne

iTrader: (5)

Oh no, don't let it start again...

Do whatever you want, you should be getting lubrication as long as the injectors are firing... they do fire under decel too ya know? As long as the engine is running, you'll have gas...

AllMotorRotor

Actually the injectors don't fire at all on decel. This is one of the issues with premix, but because 2 stroke lubricates very well, and that there is no combustion on decel, the oil that was injected before decel stays for a longer period of time. This is where the oil injection system rises above premix.

Malefoda

I said "no weapons allowed"... I see people around are very easy to fight!
Peace!

That's the kind of thing I want to read Very good idea!
I'll start to read this:
https://www.rx7club.com/rotary-car-performance-77/diy-2-stroke-mop-write-up-pics-372329/

texFCturboII

iTrader: (17)

[QUOTE=AllMotorRotor;7225996]Actually the injectors don't fire at all on decel. This is one of the issues with premix, but because 2 stroke lubricates very well, and that there is no combustion on decel, the oil that was injected before decel stays for a longer period of time. This is where the oil injection system rises above premix.[/QUOTE

So that sound of an engine running coming from the engine bay means there is no combustion huh? Oh yea, i forgot about the rubber bands!

K.ronic

This should clear things up a bit....Reted seems to know what the hell he is talking about more than most people around here...... http://fc3spro.com/TECH/FAQ/premix.html

texFCturboII

iTrader: (17)

I stand corrected. Pre-mix still rocks though. Wierd looks from people at the pump, always carrying two stroke in the back compartment, the feel of oil on your fingers, the way you've gotta kinda squirt just a little gas into the receiver at first to clear out the oil. It makes getting gas an event!

K.ronic

If I'm not mistaken, that is one of the drawbacks that Reted states about using premix. It's kind of a pain, especially on a daliy driver. Now if it was a weekend car or a track car then there would be no problems, but I know I'm usually in a hurry to get where ever it is I'm going so premix would not be practical for me.

texFCturboII

iTrader: (17)

tom-AY-to

tom-AH-to

lets call this hold thread off. Either way works safely and fine Malefoda. Do what you want.

AllMotorRotor

I actually used to think the same thing. The sound you hear is the sound of the rotors moving over the ports releasing compression in the exhaust ports
The injectors start to fire again at around 1100rpm on decel.

I have been premixing for about 6 years. From experience, its not to bad the first year, but year after year, especially in the winter.....it is a REAL PITA!

Thats one way of doing it. Search for OMP adaptors at rotaryaviation.com. It would be a much simpler and more reliable way of changing to 2 stroke. Remember that the damage is already done in a high millage engine so swapping to 2 stroke really wont gain you much of anything. I thought it would make my old engine last longer, well I was wrong, 3 years premixing the engine blew at 162K.

Malefoda

I find the mood here funny, in our french owners forum it's soooo cooooool
Here there's so much presure! ...in the MOP of course...
So tonight I'm really in trouble, I think the cheap mods seen here and there to mod the EOM MOP are nice for me, MOP is nice for daily drive, premix also nice...
My engine is 126.000... kilometers (80k) and its past is unknown (former german car). It does start perfectly in any conditions, but idle a bit high most of the time (1100RPM, sometimes 750...).
In fact I just wanted to run synth oil as finding a mineral say 5W30 or even 10W40 is very hard and worst more expensive than a good Mobil1 5W40 synth!!!
And I don't even talk of sourcing oil as Royal Purple here...
The budget is the concern, I'm ready to pay a bit more (maybe the 80$ kit from www.jhbperformance.com) now to use my 30$ Mobil1 after... and 2Stks oil.

Or premix... ahhh I become crazy!!!!!

john ward

iTrader: (7)

ok seriously you think that the injectors are not firing and there is no spark on decell. if so thats funny you must have a diff cas than me and some crazy ecu

dean23

ive been running premix for a while now... not really that bad to deal with. i was forced to run it though (front cover=S5, throttle body=S4... no match) but im getting the front cover switched during my rebiuld and with have oil injection again.. ill still premix a bit though... just a LOT less.

AllMotorRotor

I never said anything about no spark. Fuel does not get injected on decel. It tells you right in the training manual. Mazda did this to prevent the engine from bucking around on decel. Only the front rotor gets fuel cut when you are at partial decel, you know that farting sound when you are at speed and at really light throttle?

If you want to know how the engine acts when there is no fuel cut, disconnect the TPS, atleast on my S4 engine, the engine will buck around slightly and pop like crazy.

ericgrau

iTrader: (1)

1. You should have searched since this has been covered many times before.

2. Mazda injects motor oil b/c most drivers won't want/remember/know to fill up a seperate tank. 2 cycle oil is better b/c it is specifically designed to lubricate combustion chambers, but Mazda figured having a seperate tank wasn't worth the improvement.

3. In your case, you don't even have a seperate tank. You need to add premix at EVERY gas stop, or your engine is in for a heap of trouble. Rotary Aviation sells an adaptor that let's you hookup a tank to your OMP ($80?). That way you just have to fill the tank with 2 stroke every once in a while instead of adding 2 stroke at every stop. You'll also use a lot less 2 stroke this way, though the stock OMP doesn't distribute the oil as well as premixing does. You can also add premix without disabling your OMP, for extra lubrication. Use no more than 1/2 oz. 2 stroke per gallon of gas in that case.

4. You are mainly improving lubrication to the apex seals (and maybe the side seals, I dunno). What that means is less wear on them and better compression longer. That means you can put more miles on your engine before you lose power and fuel economy. It also means less carbon buildup, b/c 2 stroke burns cleaner. It doesn't mean your engine will last any longer, since rarely does an engine need replacing because it has low compression. It only needs replacing if you have almost no compression. That happens if you pop a seal from knocking or overboost. Rarely (never?) does it come from excessive seal wear.

5. Racers like to premix because it's not so much trouble for them, because the stock OMP might not be able to handle their setup, for extra lubrication under intense racing conditions, to give them 1 less part to worry about, etc.

Does premixing help a lot? No. Does it cause any problems? No, unless you forget to add it. If you add way too much, it'll smoke.

SmogSUX

iTrader: (12)

All I can say is I've seen the internals of 2 high mileage 13B turbos...the one that used premix had nice even wear on the rotor housings, the one with the stick omp has uneven wear which you could see where the rotor had most lubrication on the center of the housing, but the sides were a big more worn out where the oil wasn't spread to as much.

Spectator

iTrader: (1)

Why do people with straight exhausts pull backfires on decel?!

AllMotorRotor

Pull backfires? If your TPS is far out of adjustment the fuel injectors will still inject fuel on decel.

AllMotorRotor

How many miles did the premix one have and was it on premix from the beginning of its life. Same questions go for the other motor.

Sideways7

iTrader: (7)

Its the unburnt fuel from right when the throttle is closed.

ericgrau

iTrader: (1)

Ya, the OMP will give you less wear and it'll lubricate more evenly, like I said. But that'll usually only affect compression. Most engines don't fail from it. Not that I have anything against horsepower and good gas mileage, though.

The ECU still injects fuel at decel. Cars backfire when it injects too much, but even on a properly running car it still injects some. There's even something to control the throttle to keep deceleration from being too abrupt. If the ECU didn't inject fuel, controlling the throttle would be pointless. Regardless, losing lubrication for 2 seconds isn't going to affect anything. There is still oil in there.

TehMonkay

iTrader: (-1)

Ever turned the key off while coasting in gear? Same sound.