i dont really know anything about rotary motors. and ive been lookin around on the internet about them cuz i just got one that im gonna start driving them tomorrow. ive seen a few things about 7s and 2stroke oil. i just wanna know if i need it or what? cuz im not trying to mess up my motor. ive got an 86 if that you need that info

 

the 86 to 88 takes oil from the oil pan and injects it. its mechanical pump. its called the OMP ( oil metering pump )

some people dislike the notion of dirty *** engine oil being in the combustion chamber, so they eliminate this system and put the two stroke in the gas tank at every fill up.

 

but its ok to not run 2 stroke through it? cuz id rather have the dirty *** engine oil in my combustion chamber than spending a fortune on 2 stroke oil

 

Test your OMP (procedure in the FSm, or you could probably search up a thread on it)to see if it's functioning the way it should be. If so, it'll be fine.

 

if the omp (oil metering pump) is not broken then you dont need 2stroke oil.....

 

These are you options.

1. Use the factory Oil Metering Pump (The Dirty oil procedure mentioned)
- You'll have to do nothing
- It costs you nothing
- Make sure it's still working

or

2. Remove your Oil Metering Pump Entirely
- You'll have to physically remove the OMP from the front cover.
- Buy the BLOCK OFF PLATE that you'll need to cover the hole where the OMP used to be
- Remove your OMP Lines and OMP Oil injectors.
- Buy the necessary plugs for the holes where the Oil Injectors used to be (www.pineappleracing.com)
- This means your engine will have no oil injection/lubrication in the combustion chamber so you'll have to manually do it (read below)
- Manually 'inject/lubricate' the combustion chamber by putting 2-stroke oil in your gas tank on every fill up.

Really all depends how much you care, and how much work you do. Unless you're planning on turning your car into a money pit (like I've done to mine) I would say, if it ain't broke don't fix it. Now if only I had someone like myself to tell me these things when I was a newbie.

 

It isn't exactly free, as you have to top off your oil roughly half a quart every 1000 miles, but I am just being pedantic.

 

did i mention removing the oil injectors requires removal of the UIM?

 

There are other options. And TONS of threads on this. You'll get some good info searching.

Such as:

-Adapt stock OMP to inject 2 stroke oil from resevoir (~100 dollars for adapter + resevoir, tubing, etc.)
-run supplemental pre-mix (augments stock lubrication)

I ran supplemental 2 stroke on top of a resealed pump; increases longevity of internals and is cheap OMP failure insurance.

 

Ya search for more info. But this kind of thing counts as a special project. Nice to have, but totally unnecessary.

All you need to know is that the combustion chamber of a rotary engine needs lubrication, so a pump injects oil into it. That means you'll lose a quart of oil every 1,000-2,000 miles and need to top it off again.

The best way to convert to 2 stroke IMO is to attach a tank full of 2 stroke to the stock oil pump. Rotary Aviation (google it) has an adapter for this. It's not as even as mixing 2 stroke in your fuel but it's far less trouble than adding 2 stroke every single time you fill your gas tank, or else screwing up your engine royally if you don't. Again, you get better lubrication but it's totally unnecessary.

 

easiest solution is to just keep the OMP on there if it's an 86-88 car and the OMP does in fact still work. it's pretty much the most reliable oiling system of all the 13B's. it injects the most oil and it doesn't have electrical failures like later cars. 89-2008 rotaries (including 04-08 Rx-8's) have OMP related problems much more frequently.

yeah it's dirty oil. so what. dirty oil goes on your bearings too, and they survive. just change the oil at proper intervals. I've made 400+rwhp on the s4 OMP. Modify or pull a working s4 OMP because it makes you feel better, not because you will notice much of a difference. it's not like you are going to drive the car 100k miles anyway.

 

What happens with the pre-86 motors? Is 2-stroke oil in the gas something to consider?

 

All rotaries have some form of combustion chamber lubrication, if not, you get crazy chatter marks and VERY low engine life. Some rebuilds with oiling problems can seize up on the first drive.

Running 2 stroke in an FB/SA is something to consider, but I don't know much about first gens and their ins/outs. If you are having trouble with lubrication, yeah I'd recommend it.

 

Guys. You're forgetting - this is his first RX7.

I wanted to clarify that it's either you stay with the OMP, or you do without it, but not both.

edit: well technically you COULD do both, but that would be excessive.

 

since its your first rx7 I would suggest staying with the stock OMP.

Its far easier with it, and you cant really mess anything up. But you would have to make sure it works. A S4 (86-88) omp is far more reliable then a S5 (89-91). If you get a S4, the omp pretty much works, unless the previous owner did something.

 

Not sure this is true but anyway, one thing the S5 has over the S4 is that if the S5 OMP fails, the ECU goes into limp mode and you know something is wrong.

For the benefit of the OP...
Both the S4 and S5 have essentially the same pump- which is mechanically driven- and only differ in the way the amount of pumped oil is determined. The S4 has a mechanical linkage to the throttle body, the S5 has an electronically controlled valve.

 

yeah. well i'd rather stay with the stock OMP. it sounds like the people that do use 2 stroke pay quite a bit over time.

 

depends on how many miles you drive.
I use a 32 ounce bottle in about 2 months, a little bit less. Thats in my gxl which I only drive to work, 64 miles a month.
Its idemetsu premix so its about $6 a bottle
In my turbo, a 32 ounce bottle only last a month, and I only drive that on the weekend. Miles various.

 

I wouldn't say supplemental pre-mix is excessive if it nets you a longer engine life. walmart tcw3 is cheap and effective. You don't need anything fancy IMO.