Is this just another rumor???
 

Hey guys,

I keep hearing that the Rx-8's dont have to have rebuilds so soon because they run a quart of oil in a tank of gas every 5,000 miles to keep the seals lubed up?? Is this a total crock of shit??? If its true, should I run a quart through my 7??? Thanks guys!!

There are a few people on the forum who pre-mix their fuel with 2-stroke motor oil. The obvious side effect is a little smoke from the exhaust, but it seems to work.

i put about 4 oz. of mmo in the tank with every fill up.

RX-8's don't generate nearly as much power or heat as FD's, and that is the main reason why their engines should last longer. I doubt that oil consumption has much to do with it.

Where do you keep hearing this, Chunky04?

-s-

Mix it
 

Search for "Pre-mix" or "Premixing". Should be quite a bit out there. Feel free to check the Rx-8 forums too.

I have yet to read a good reason not to pre-mix. :biggrin:

-Rotary4tw

premix or no, the renesis eats side seals.

It sounds like you aren't aware that all rotaries inject oil into the combustion chamber to lubricate the apex seals and to cool the rotors. In fact, the Renesis injects LESS oil than any previous rotary motor.

He's not talking about pre-mixing guys. He's talking about the oil injected into the chamber. It's the same on our cars. The Rx-8s go through less engine basically for the soul purpose that they are not turbo. High heat = detonation or coolant seal failure = death.

Yeah, to sum this up:
1) RX-8s and RX-7s inject oil into the chamber. Assuming your OMP and oil injectors are working properly, it's been happening all along. (Some guys remove the oil injection system and dump the oil directly into their fuel - aka premixing)

2) The reason 3rd gen RX-7 engines die sooner is because of boost. 10psi is a lot more combustion going on in the same space, and this extra heat does cooks the engine a lot more. Boosting a Renesis to 10psi would reduce the engine life to FD levels.

Dave

Thank you

You cleared up at leat 30% of the chaos floating around on different boards.

:)

Wow..Great replys guys...That basically summed it up for me... Thanks for all the input!!! :balls:

Probably reduce it to even less because of the higher compression.

To add to what has been said above----boosted rotaries are much more prone to detonation than normally aspirated ones. detonation spells doom for apex seals, compression, and engine longevity.