W@nkel motor stopping procedure

[CAPP0]

Serious question:

Lad next door to me recently bought an RX8. Now, every time he comes home, he stops, winds it up to what sounds like about 4000rpm for 5-10 seconds, then shuts it off dead, seemingly without letting the revs drop first.

Now with a conventional piston engine, I always understood that this was a bad thing, where the bores were washed with petrol which caused additional wear on startup. So, is there a good reason why this practice is desirable with a rotary lump? And if so, what is it?

Just curious!

[Stoatman]

http://www.youtube.com/watch?v=h08wd3Q5SdE

http://wiki.answers.com/Q/Why_does_the_Mazda_RX8_f...

Good practice it looks like ?

[Bungleaio]

I believe this is to stop the engine becoming flooded.

[sonarbell]

Modern cars with ecu's dont do bore-wash on switch off as injectors are cut off when switching off ignition.

[JackDaniels]

Bungleaio said:

I believe this is to stop the engine becoming flooded.

This would be true if he had just moved it a couple of feet to get something out of the garage or something as it dumps a load of fuel to start it and if you switch off straight after it doesn't burn off and so dumps more in next time and floods, but if he has just driven home then there is no need to do what he is doing.

[otolith]

That's the cold shutdown procedure, to prevent flooding. It shouldn't flood with a warm shutdown, but it won't do any harm.

[Jimmy No Hands]

Yeah, as a ex-Rex owner this is what they recommend to prevent flooding. Don't think I ever did it mind. Would cost me £11.50 to hold 4k rpm for 10 seconds


Edit: To add, only applicable on short journeys (which they don't recommend at all)

[CAPP0]

Well, interesting! I once got caught out by the cold-flooding issue on a piston engine. Never come across it for a hot shut-off though.

Thanks.