Did you know:
When you shut off your rotary engine, you are recommended to rev your engine slightly for a second (up to about 3k) and while up there turn you engine off and let it naturally stop spinning. (Warm engine)

Why:
The dealer as well as Mazda recommend doing this every time you turn you engine off to keep it well lubed. Why? Since the rotary engine it so compact, the passages are much smaller and harder for the oil to get "up in there". It makes a difference.

 

Yeah, I do that.

Let's the wife know I'm home.

It's also a preventative for flooding if the engine is cold (however the recommended time is more like 10 secs at 3Krpm).

 

Source?

 

exactly how long do you keep it at 3RPM?

 

3K at about a second.

 

Um, no.

Up in where? We don't have a valve train to lube. We don't have nearly the oil passages a piston engine does and we run more oil pressure than most do. That is hardly a system that can't get oil around. Oil moves "up" in the engine a grand total of about 15" from the bottom of the pan to the top of the oil filter which is the highest oil location in the engine. Most of the oil goes in the eccentric shaft and drains through the rotors. From the bottom of the pan to the eccentric shaft is only 8". The oil passages are large enough that an adequate supply of oil is sent through the engine to actually dissipate nearly as much heat as the coolant system. No one recommends to rev the engine because the passages are too small and it helps lubrication. There is always oil flow through the engine when it's running. When you turn it off, it all drains down. It doesn't matter how high you revved it before you shut it off.

This is downright wrong information. The reason why people rev their engine up before they shut it off is because when you shut the engine off at 3K, it gives more revoltions of the engine with no fuel to clear out any excess fuel from the chamber. This theoretically means that it is less likely to flood next time it is started since less fuel will be leftover in the chamber.

Revving it up before shutdown is very bad for a turbo car as you don't want to add heat to the turbo as it could lead to easier oil coking in the turbo after shutdown.

 

... i do it just because i want too ...

 

Agree with RG on this. The rev / shutdown is to prevent flooding.

 

jryeater - if you can post it in writing i'd like to see it. Otherwise, it's freakin b.s. bull crap

 

Ummm, yeah...what RG said. Actually, most of us are aware of this...from way back.

That's what you do if you MUST turn off a cold rotary, not just because.

 

Yes, The dealer told me this would prevent plug fouling.. by spining out all the left over gas? and also prevent flooding. Whenever I turn off the car I just rev. my car up to 3-3.5k let off the gas and turn the car off.

 

I only do this if the engine is not at operating temperature.

 

I was told 6 seconds @3k two weeks ago by the dealership.

 

I never do it. I've never flooded either.

 

You realize that you've just jinxed yourself, right?

 

I do it most of the time, and I find it starts easier.

 

My '05 has never flooded, and I never rev it before shutdown. IMO, it's a waste of fuel. I realize some '04 models have flooding issues, and if it works to prevent that, then that is so. But if you're not having any problems, then leave it alone, no revving needed.

beers

 

I heard the revving at shutdown was intended to set up the right harmonic vibration in the ports, so that the gas molecules get vibrated and aligned properly at the next start up

 

I love these random, mystical "stats". 95% of us don't shut down properly? What data supports THAT deduction?

It's like the infamous "according to a recent survey" statement. WHAT SURVEYS? Who are the people that take these survey's? How come I've never seen or taken one.

I think people make up these "surveys" and fabricated "stats" to lend credibilty to something that otherwise has none.

85% of the people who have read this thread initially asked, "WTF?"

182% of survey takers live in mud flats and drink Yak milk..

 

I heard doing this helps the lifters pre-fill with oil so it's easier on one's cams.

 

Did you know that 8 out of 7 people are bad at statistics?

 

Yes i do that. Thanks to Mr. "Derwankel"

 

Both dealerships I was dealing with told me this b4 I bought, but neither really had any idea why. I assumed it was a flooding issue since I read plenty about it here. But it gave me an excuse to rev every shut down, so it was ok w/me.

mmmmmm . . . yak milk.

 

If you read that handy little booklet on how to operate you vehicle, the MAN-U-AL (I know its a foriegn word for some) it states that one should rev to 3.5k for 1 second and shut off to let excess fuel and emmisions spin out of the engine via enursia, in order to prevent flooding upon next start up. This is also a preventative measure when your engine has not been run long enough to reach proper operating temps.

Its all there in your manual... if this is news to you, you obviously need to go read it.

 

I always love the statisticians who depend on "Yadayada% of Americans believe XYZ." That has far less significance when you realize that 70% of Americans can't find New Jersey on a map.



ps - Source: National Geographic