Camrann

I just bought a 91, n/a. Its been rebuilt and only has 8k on the engine and tranny.
The owner before me premixed his gas with two stroke oil with a ratio of .75-.100ounce/ gallon. What is the purpose of this and is it needed and or helpful. Can i just run regular unleaded or will it cause the seals to wear faster.

RotaryEvolution

iTrader: (30)

if the car is setup for strictly premixing then to not premix will kill the engine in a short period of time. i run premix at 100:1 which is about 1 ounce of 2 stroke per gallon of fuel. premixing helps to lubricate the internals of the engine more uniformly rather than the peak of the apex seal causing premature grooving of the rotor housings.

drawbacks of running premix is that it is not good for your catalytic converter and it causes a slight rise in emissions.

a7r

You sure it wasn't 1 fluid ounce a gallon?

Find out if the car has the stock MOP (i.e. oil injection pump), and whether or not it's working. If it doesn't, or it isn't working, then you need to keep premixing or fix the MOP. Not doing so will cause your motor to fail prematurely.

Not to go off topic, but I've never seen this substantiated. TCW3 burns cleaner than most/all lubricating sump oils. I personally passed California's smog tests with amazing results in my TII, while running 100:1.

Camrann

I just bought a 91, n/a. Its been rebuilt and only has 8k on the engine and tranny.
The owner before me premixed his gas with two stroke oil with a ratio of .75-.100ounce/ gallon. What is the purpose of this and is it needed and or helpful. Can i just run regular unleaded or will it cause the seals to wear faster.

RotaryEvolution

iTrader: (30)

not all of the oil will burn completely and it will retain some of the hydrocarbons from the combustion, it is usually not enough to cause a good tuned car to fail but it could cause a borderline car to fail.


it also leaves a nice slimey black residue on the back of my car, lol.

a7r

Hmm, I didn't see anything like this. I tested two weeks ago, and the hydrocarbon output for my car at 966 RPM was 1 PPM, with average being 29 PPM, and the maximum being 120 PPM. At 2522 RPM I had 9 PPM, with 20 being average, and 140 being maximum. This was with a working, near-stock, emissions system.

RotaryEvolution

iTrader: (30)

you sure you didn't pay someone off? even brand new cars i don't see running that clean, lol.

Rxmfn7

iTrader: (4)

Here is a scan from my '86 when it was still N/A. Im not sure why I always hear of everyone having emissions troubles, Ive owned mayn RX-7s , and they all have been very clean cars. This was done with a RB header, single Bonez H-F cat, Greddy cat-back.



Notice the CO ( or lack of ), and very low hydrocarbon readings.

RotaryEvolution

iTrader: (30)

i'm one of the ones having emissions troubles, i'm sure it is a combination of other things as well but i am repeating what our smog tech told me.

sar

iTrader: (1)

Those are amazing numbers. I thought that when gas burned it produced co2.... somehow you appear to be burning non carbon based? It is also really strange that your numbers stayed the same despite the rpm tripling.

I want a car like yours lol.
Mine just barely made the HCs after fixing my alternator which was loading my alternator. I will have to get a cat like yours. Maybe I'll add an electric air pump to completely dilute my mixture too.

My HC numbers were low in the 190s and high in the 350s.



To the subject as to not completely jack the thread....
Supposedly premix will burn more cleanly in our engines that normal oil because it is supposed to burn versus normal oil isn't. I would suspect that if you had your omp fed from 2 stroke oil it would drastically decrease your emissions.

RotaryEvolution

iTrader: (30)

2 stroke oil is made for combustion, regular engine oil isn't so yes i would assume it does burn cleaner but whether it does add emissions still is another matter, i haven't tried comparing one vs the other because i have no OMP anymore.

a7r

I'm positive. I found out after the fact that the smog tech thought I was an inspector, because of the clip-board I had in the car. The car got the book thrown at it and still came out fine.

BTW, I forgot to mention: on top of this, the motor had a pretty agressive intake and exhaust port.

I was wondering the exact same thing. I had heard all of these horror stories, and was expecting my car to fail. I reinstalled the stock ECU and all emissions gear, and then went through the FSM and verified that the equipment checked out. It was no big deal.

Sorry to hijack the thread.

311unity13B

helps clean out the carbon...i put in 4 oz. each tank usually

tecknomage

so happy i dont have to deal with emissions

tecknomage

what waite of pre mix oil ?

and is there a max you can run when you still have the oil injectors functioning ?

RotaryEvolution

iTrader: (30)

i probably wouldn't run lower than 200:1 with the OMP system functional, it would be diluting the fuel mixture too much and lowering the octane.


and 2 stroke oil has no wieght, it is universal but i suggest nothing lower qality than TCW3 certified.

Kenteth

umm... what? How about not.

Try it lubricates the internals with less carbon-after ash then the stock lubrication method.

If I wasn't at work I'd say senerior techs forever underimpose networks...and i'd make a cool acronym for it like.. STFUN

Ricer240sx

iTrader: (3)

yeah, emmisions are the ghey!!

but a question, anyone having any problems with there injectors after premixing?? i am thinking about doing it.

also, i know theres a search button, but if someone has a link or anything of how to properly remove the OMP that would be great

White_FC

Been premixing for the past nearly 3years. Never had injector trouble.

Just make sure you use TCW3 rated stuff.

a7r

I think emission controls are pretty cool actually. They keep your car from smelling like ****. 3" high-flow cats can be had for next to nothing these days.

I'm not.

RotaryEvolution

iTrader: (30)

i would bet premixing is better for your injectors, keeps them lubricated and acts as a cushion for the opening and closing that often wears the seats and causes leaks.

Gene

iTrader: (1)

CO... Carbon Monoxide, not CO2, Carbon Dioxide. CO is bad stuff, major smog component, and if you inhale it it binds to your hemoglobin, meaning the blood can't carry as much oxygen as it should. It eventually works its way out of your system, but you might feel loopy and tired for a while depending on how much you get. Too much can be harmful or deadly, which is why people die if they sit in the garage with the car running.

Since the numbers are percentages, not absolutes, there is no reason they shouldn't stay the same. They might even go down since you get better combustion at higher RPMs.

Aaron Cake

iTrader: (1)

All this is in the archives. Some very detailed premix threads.