Sir Surr

No clue if any of y'all have seen my other posts, but my 12a is blown. I'm planning on getting a new one/finding parts and rebuilding, but I was wondering about the OMP. Preferably I'd rather get rid of it and just run premix because it seems more simple and less of a headache, but I was wondering if I block off the OMP do I still need to add oil? Sorry if it's a dumb question, I couldn't find anything on it and I'm not as knowledgeable on rotaries as I'd like to be, but I'm still learnin

speedjunkie

iTrader: (3)

You mean do you still need to add engine oil or what? You need engine oil, and also the premix in the tank.

Btw, what part of Colorado?

Maxwedge

iTrader: (1)

If you block off the OMP the engine oil won't need regular topping off, but you should still keep an eye on it. I went to premix and my oil pan gasket leaks, so I check the oil level regularly. If you're not leaking then it shouldn't use oil any more than a healthy piston motor car. Can't hurt to check it regularly though.

" I'd rather get rid of it and just run premix because it seems more simple and less of a headache"
No, it's more of a headache. It's an extra step every time you fill up, having to get out your funnel and pre-mix oil, add the right amount, wipe off the funnel and throw the oily rag back in the car. Especially if it's a daily driver. I keep meaning to add a pre-mix tank and modify the OMP (currently on my bench) to pull from the tank only, so I can just top the tank off and have simpler, cleaner fill-ups. I only drive the car on weekends, so haven't gotten around to it yet.

Plus, if you ever let the girlfriend drive the car, or God-forbid it gets stolen, you are guaranteed to get it back with motor damage from lack of lubrication.

*Note - I went to pre-mixing because I was installing an Edelbrock carb, which doesn't have the linkage to attach to the OMP. The stock Nikki and Racing Beat Holley's have the connection points. I am happy to know that my engine is getting plenty of clean lube, but it is in no way simpler than letting the car do it automatically. It starts some conversation at the gas pumps though!

them- "Wait... You need 2-stroke oil AND you have a hand-choke? Haha, WTF lawnmower engine is in that thing?"
me- "Yes, it's an old-school Rotary. Now watch this burn-out" BRRAAAAAAaaaaaaaaaaaaaaPopopopop

chuyler1

iTrader: (1)

I hate pre-mixing. I have to do it on my REPU because I haven't figured out the linkage yet. I might not mind it if I didn't have to also carry around a funnel to prevent spillage...and clean the funnel after each use...and remember to always have premix on hand.

Maxwedge

iTrader: (1)

Exactly. It's a PITA. If you have to do it because you changed intake/carbs, then okay. But don't do it because you think it's "easier" in any way. Letting the car do it by itself is much easier.

Sir Surr

Alright, perhaps I'll keep it and just add a little premix. I premixed before with the OMP and it wasn't too much of a hassle, was also wondering mainly because my brother and I were arguing about the car still needing oil, he thought it wouldn't but I said it did, and couldn't explain why. Anyways, thanks everyone for your input, and for your knowledge. Tons of help!

Sir Surr

Pretty far southwest, Cortez

Maxwedge

iTrader: (1)

I'm still confused about what exactly you're asking. Your car needs motor oil weather or not you pre-mix. You need oil in the oil pan ..... it's not a 2-stroke motor, if that is what you are wondering. Rotaries always need motor oil in the oil pan, just like a piston motor. The pre-mix, or oil provided by the stock OMP , is to help lubricate the Apex seals. This is unique to rotaries, and must be met by either the factory OMP or by premixing.

You need both-
Oil in the pan for motor bearings
&
Oil in the fuel for apex seals, either by OMP or Pre-Mixing.

Sir Surr

Sorry that I was unclear, I was clear about the premixing in the gas tank, but I was questioning if you needed oil in the oil pan, so I now know you need both thanks to everyone's replies.

Maxwedge

iTrader: (1)

Yes you must keep oil in the oil pan. This lubes all the motor's bearings, just like a piston engine. But Rotaries need additional lubes to keep the Apex seals and chambers in good shape. They don't get splashed with oil like a piston does in a piston engine.

The factory setups, for all years/gens of Mazda rotaries, have a pump to spray motor oil into the intake to lube the apex seals. On a piston motor, as I mentioned, this oil splashes up onto the piston rings from beneath. But on a rotary it doesn't, so it is added from the intake fuel.

Carbed 12a's usually pump it into the primary bowl via the stock OMP. Later FI 13B's spray it into the intake runners via a similar OMP.

Regardless, you need oil in the pan. The rotary is NOT NOT NOT a 2-stroke.

rxtasy3

iTrader: (2)

nope, that's how RB does it on the holley. stock nikki has brass looking tubes pressed into the barrel of the carb opposite the boosters. this introduces oil directly into the air/fuel stream going into the engine.

speedjunkie

iTrader: (3)

No way! I'm pretty sure that's where we stopped to get lunch on our way home from SevenStock in November.

And as it's been mentioned, rotaries DEFINITELY need oil in the pan, along with some sprayed onto the apex seals, whether it be by premix or from the OMP.

Maxwedge

iTrader: (1)

Thank you for correcting me, I sold my Nikki a while ago, didn't remember. Regardless, OP needs oil in the pan for bearings. And oil from Somewhere to lube the chambers.

I think the original post could have been titled "Is my rotary a 2-stroke?" The answer is NO.

JOE68

something close to 2 stroke ... taking apart quite a few engines... fuel and engine oil make serious carbon . mazda made it simple for sales how people would pre mix... this is a special engine so the best way to lubricate is 2 stroke oil. so no if ands or butts about it... and u don't need any special oils on the market i use the brand from 7-11 tc-w all good