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Rotary Basics Question

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Old 10-17-04, 10:40 PM
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The what what?

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Question Rotary Basics Question

Got my first RX-7 on Sunday and the manual I've ordered hasn't come yet. I've a simple question and I think I know the answer but I haven't been able to find a definitive answer yet. When I park on a (very) slight incline without using the e-brake the car often drifts even when in gear. Is this normal due to the different compression (compared with pistons) or should I be concerned that some internals are going bad?
Old 10-17-04, 10:49 PM
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Old 10-17-04, 11:19 PM
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YOu mean park and turn it off? I'm a bit confused.
Old 10-17-04, 11:27 PM
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if you park and turn it off it shouldn't move, if it does you have a serious problem if its on a "(very) slight incline"...if you know it moves why dont you use the ebrake?
if the car is on and its in gear and you dont have the brakes or the ebrake on, of course its going to move, ever car does......

lol, no offence to karken, but you bumped this thread 9 min after it was made, i find that funny
Old 10-17-04, 11:44 PM
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1983 GSL, 1987 323 "GX"

 
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I found that odd too, the bumping

Anyway, I'm still confused about the cause and whatnot of the movement. . . .
Old 10-17-04, 11:58 PM
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yea its confusing, specify a lil....please
Old 10-18-04, 06:43 AM
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The what what?

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Sorry for the lack of detail.

Yes, it's when I've turned the engine off and parked it for the night. With all the other manual cars I've driven you can just put it in 1st gear and not need to apply the e-brake even when on a fairly steep incline. With the RX7 I just bought I always have to use the e-brake even when I have it turned off and in 1st gear or it will roll.

My question: Is this normal behavior for a rotary or do I have compression (or other) problems I should be looking for.

Thanks for the quick replies!
Old 10-18-04, 06:47 AM
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Originally Posted by satoacs
if you park and turn it off it shouldn't move, if it does you have a serious problem if its on a "(very) slight incline"...if you know it moves why dont you use the ebrake?
if the car is on and its in gear and you dont have the brakes or the ebrake on, of course its going to move, ever car does......

My Jetta doesnt when in gear and off. I think that is what he is asking....
Old 10-18-04, 07:13 AM
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might have something to do with the gear ratios, if the 7 has a short 1st gear then it mighnt take much to move the whole engine from the wheels. (is the enghine moving? it'll feel jerky when its moving, no smooth)


other than that i got no idea
Old 10-18-04, 07:14 AM
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other possible is the clutch sucks. I know mine would move because the clutch didnt really grip.
Old 10-18-04, 07:20 AM
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I know that something is moving while it's drifting because it definitely feels different than if I had it in neutral and let it roll. I'm pretty sure it's the motor turning and it does feel a bit jerky (as if going through a compression phase.)
Old 10-18-04, 07:20 AM
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ok. first of all, welcome webmonk. Second, it is normal for your RX-7 to roll a bit on an incline if the ebrake is not on and the car is in gear. Since rotaries build compression from centrifugal and centripetal forces, when they are not spinning, the compression is very low. I would not worry if I were you. However if this were a piston engine, I'd be looking for a rebuild . My GSL-SE has really good compression, and it rolls a bit.. (jerkily) but it still rolls.
Hope that answers your question.
Daryl
Old 10-18-04, 07:32 AM
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Sure does! Thank you very much, Daryl!

It's the subtle differences that makes learning this car and the rotary engine so much fun for me. ;)

Jon
Old 10-18-04, 08:54 AM
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*didn't have time to read the whole thread*

Yeah, the low compression makes it so that you can't just park it in gear on a hill without the e-brake. My friend Eric snapped his e-brake, so he used a "foot brake" (an old boot wedged under the wheel) to keep his car steady!

Welcome to the forum

Jon
Old 10-18-04, 10:55 AM
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If the hill is steep, then it is normal, but if is not steep, start prepareing for a rebuild, because their is low compression? The seals are worn and are not sealing properly. The only negative effect is a loss of power, no major engine damage.
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