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Discussion Starter #1
Hmmm....I was wondering about the following the other day....

1) why does the engine always rotate the same way,what controls this ...how ?

2) does the engine always stop/start at the same location ?

3) does the piston actually stop at tdc ?

4) does more than one cylinder fire at the same time ?

Just curious hmmm
 

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GregC said:
Hmmm....I was wondering about the following the other day....

1) why does the engine always rotate the same way,what controls this ...how ?

2) does the engine always stop/start at the same location ?

3) does the piston actually stop at tdc ?

4) does more than one cylinder fire at the same time ?

Just curious hmmm
1: I believe the starter always starts it in the same direction. Interesting though, as with some timing changes I think it can go either way.

2: Nope. It can start/stop in any location

3: Yup. It stops going up and starts going down...although you'd never see it stop.

4: hehe...On the M5, No. On a Viper...Yes. Not sure on the E60 M5, however.

funny questions...
 

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M-Fünf said:
1: I believe the starter always starts it in the same direction. Interesting though, as with some timing changes I think it can go either way.
Which is why it is CRITICALLY important to wire up your starter correctly.

Once time I screwed up in my VW and had 4 backward speeds.

ard
 

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COOL!

ard said:
Which is why it is CRITICALLY important to wire up your starter correctly.

Once time I screwed up in my VW and had 4 backward speeds.

ard
COOL!!!!

And practical too, just think of what Bootlegger´s Turns you could make!

David
 

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The valves would also open in the wrong order if you tried to run an engine in the wrong direction. The exhaust valve would open when the cylinder should be sucking in air/fuel - so the cylinder wouldn't fire at ignition time because there wouldn't be any fuel in it!

Also on the starter motor - I don't think you could use it to turn the motor backwards even if you did wire it up wrong. The reason I say this is that starters I've seen before have a "bendix" gear on them to allow them to only mesh while they're starting the engine. The way that works is that there's a cog seated on a shaft a few inches long with a screw thread - the cog can wind up and down the shaft on the thread. When the starter motor spins up the right way inertia makes the cog wind along to the end of the shaft and it then engages with the engine to start it. When the engine starts it drives the cog too fast, and that causes the cog to spin back up the threaded shaft and unengages it. If you ran the starter backwards the cog would never wind along the shaft because inertia would force it the wrong way, so it wouldn't engage with the engine or start it.

Note: I've not seen the M5 starter, so I'm not sure if it uses a bendix gear, but all the others I've seen do!
 

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Slightly O/T, but that's what makes a rotary (Wankel) engine so ingeneous. In an internal combustion engine, the engine internals have to completely reverse directions (up-down motion) per firing (compression) cycle, putting a lot of wear and tear and stess on the parts. The rotary engine internal parts never reverse directions as the firing/compresssions occur, conserving inertia/momentum as the engine fires.

CP
 

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DavidS said:
Is there a Wankel engine in your Miata?

David
David,

No, the Miata is a standard internal combustion engine.

BTW a littel O/T (again), but did you guys debut in the States yet? As I remember, it's been a littel while since we traded PMs on this matter.

CP
 

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chunpng said:
David,

No, the Miata is a standard internal combustion engine.

BTW a littel O/T (again), but did you guys debut in the States yet? As I remember, it's been a littel while since we traded PMs on this matter.

CP
I´m glad you asked! Yes, Wayfinder Mobile Phone GPS Navigation is up and running in EU, US and Canada.

Nokia will start to sell GSM phones and GPS devices with our software included in the US early 2005. We already sell directly to US consumers on our website.

The software works with top-of-the-line GSM phones from Nokia, Ericsson, Motorola, Siemens and Samsung.

David
 

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David,

Superb. I will watch out for that in early 2005. That is such a logical marriage of technology, I'm glad you guys are the first to deliver.

I'm sure it will be a happy holiday season at your household. Congratulations again.

CP
 
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