Ok, whats the deal with premixing.... on a 79 rx7 does the car automatically burn oil with the gas? Or is it just better on the engine to let a little oil burn with the gas?? Im pretty confused about it, i guess its just because I have never heard of premixing in a car.... Thanks...

 

The 1st gens all have an "Oil Metering Pump" or OMP, which automatically injects a small amount of oil into the carburetor, to keep the apex seals lubed. In effect, it "automatically mixes" oil into the fuel.

The OMP pulls this oil from the engine crankcase, so it's crucial on a rotary to monitor your oil level every fillup. Average useage seems to run to about a quart every 1000 miles or so, but it varies a lot. Since crankcase oil is critical to the engine's life and cooling, letting it get low is very bad.

Like anything else mechanical, the OMPs wear out over time, and some people apparently prefer to disconnect them, block off the opening, and instead mix a measured amount of oil into their fuel with each fillup - - which is called "pre-mixing." Much like what 2-strokers do.

This allows you to control oil loss from the crankcase, makes for one less thing that can break, and allows the use of some oil types that don't burn well, like a number of synthetics.

 

Oh, and thanks for starting with the FAQ. You've already started on the right foot.

 

I ran premix in my 84 for about a year. the simple truth is that yes, premixing is better. Unfortunately premixing can also be a pain in the *** when your have to pour oil in the tank everytime you fill up and get some weird looks from people at gas stations. I recently tore down two engines, one that ran premix and another that ran stock. The motor that ran premix was in better shape and non of the seals were stuck from carbon build up. Premix is ashles burns better than crankcase oil because it was designed to, reducing carbon deposits. In a stock or only mildly modified car, it isn't necessary. My reasoning was there was no place to connect the oil metering pump lines to the weber i installed. http://www.rotaryaviation.com/oil_in...p_adaptors.htm this company sells adaptors to replace with oil metering pump with a unit that feeds off an oil tank that you can put your favorite kind of 2 stroke oil in. Personally, i think this is the best way to go if you don't want to premix and want the benefit of better lubrication for your combustion seals and less carbon build up.