I have an old rotor sitting on the back of my work bench (I believe it's from an early 10A engine) and I noticed that the center area (behind the gear) is hollow. The passages in the hollow area resemble cooling passages in a conventional cylinderhead. In the case of the rotor, I wouldn't think coolant is pumped through the rotor, so I imagine oil is used for cooling? Just curious.

1.3L

 

you are correct in your assumption. Oil is used to cool the rotor it is pump through the e-shaft and injected into the rotor (as far as my understanding is).

 

Which is exactly why the engine "burns" oil. In a piston engine, oil consumption is seen as a sign of wear - in a rotary it's a sign of life. It means all is normal and fine.

As the oil is pumped through passages in the eccentric shaft and out into the rotor, it also is pumped out under the apex and side seals to lubricate those as well - and that thin film of oil that results between the rotor and housing is consumed by the combustion of the engine.

Anyone who gets their **** in a twist about rotary engine oil consumption doesn't know or understand the basic operation of their rotary. It's NORMAL for a rotary to consume a quart as often as every 600 miles (per the owners manual). Real-world practice and postings here show a quart between 1000 and 3000 miles. My car is running a quart through every 2000 miles.

 

Might I also add, these are the same people who whinge about the fuel consumption on this little "1.3L".

 

So, I assume we are talking about a very small amount of oil? I would think that a large amount (enough to pool) would upset the balance of the rotor as it spins (centrifugal motion). I always thought that the engine had a metering pump, and something similiar to a fuel injector to inject oil into the combustion chamber. How is the amount of oil going through the eccentric shaft's journals measured/metered? Positive crankcase pressure?

 

That's one for the engineers, but I was told by my rotary mechanic when I had my 1st gen RX-7 that the rotary oil pump runs at a significantly higher pressure than that of a non-rotary.

As I understand it, the oil passages out to the apexs and side seals are very minisule and the seal itself and the pressure it exerts back against the rotor acts as a metering valve.

But I just drive and enjoy these things ... so not the guy to ask for the unequivocal technical answer.

 

Can't see where the oil is pumped in to the housing, but interesting pic.

 

Coolant cools the engine block, oil cools the rotors and lubricates them.

 

Oil jets in the eccentric shaft supply oil to the rotors for cooling.

More info:
http://www.rotaryengineillustrated.c...at-eshaft.html

https://www.rx8club.com/showpost.php...2&postcount=10
https://www.rx8club.com/showpost.php...2&postcount=12

 

Good links. Thanks valpac. I am informed

 

My pleasure.