From: aas7@po.CWRU.Edu (Andrew A. Spencer)
Newsgroups: rec.autos
Subject: Re: Rotary vs. Piston Engines
Date: 7 Nov 1992 18:15:48 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: aas7@po.CWRU.Edu (Andrew A. Spencer)
NNTP-Posting-Host: slc5.ins.cwru.edu


In a previous article, lstowell@pyrnova.mis.pyramid.com (Lon Stowell) says:

>>
>>In a previous article, lstowell@pyrnova.mis.pyramid.com (Lon Stowell) says:
>>
>>>In article <Nov05.024942.84051@yuma.ACNS.ColoState.EDU> cc433336@LANCE.ColoState.Edu (Constantinos A. Caroutas) writes:
>>>>>How is the rotory lubricated?  Does oil get into the fuel?
>>>>
>>>>Yes, by design, rotary engines burn oil.
>>>
>>
>>>   So do piston engines.  I dunno about other owners, but my rotary
>>    ~~~~~~~~~~~~~~~~~~~~~
>>>   uses LESS oil than a Nissan Maxima when both are driven by me in
>>>   the same manner.  
>>
>In article <1dc6m6INNh7k@usenet.INS.CWRU.Edu> aas7@po.CWRU.Edu (Andrew A. Spencer) writes:
>>i do not know how you can claim this. I drive the hell out of my car,
>>admitadly, i would never want to buy a car i had driven.  However, i have
>>driven two four cyl. putmobiles, and neither of  them used a drop of oil
>>ever!  i change oil every 2-3k.(occassionally i let it slip to 5, but not
>   SIMPLE.  I drive both cars regularly and check the oil at least
>   once a week.  Of course it is a complete surprise to me that you
>   consider yourself qualified to comment on either a Mazda RX-7 or
>   a Nissan Maxima.  One is a rotary and the other is a V-6.  
HELLO!!! i am commenting on the fact that you make the claim that piston
motors burn oil, also by design.  This is what i am commenting on, not
that YOUR cars, be they however many cylinders happen to consume oil.
MOST piston motors, by design, are not intended to burn oil.  The 
exceptions are two-cylces, but i will not claim that a four cycle
has never been made that did not use oil in the intake either, i do 
not know of any..but you never can be sure!  what i am saying is that
ROTORIES DO burn oil by design(they have a pump that injects oil into
the intake with the express purpose of lubricating the tip seals and/or
rotor, and, by doing so, consume and burn oil by design). PISTON motors
DO NOT burn oil by design, as they are built with the intent that the
rings(yes, the OIL CONTROL rings) scrape the lubing oil off of the cylinder
wall, and thus no oil is intended to be inside the cumbustion chamber 
at the time of detonation.  Therefore, the piston motor does not use
oil BY DESIGN, unlike the rotary(however the hell you spell it!)



>
>   What that has to do with your 4-banger experience is beyond me?
>   >:-)
>
>>if i can help it!!), have put close to 20k on my car in the last year,
>>well over half of that, i'm sure is at full throttle, either passing,
>>cruising :->, or just trying to get on the freeway.  my car has 98k on
                                                      ~~~~~~~~~~~~~~~~~~
>>it, and uses no oil whatsoever.  not even a touch lower on the ds.(of
>>course, you could use the argument that i haven't gotten out the graduated
>>cylinders and syringes yet, but that'd be silly!..:-)   )
>>
>  20K miles isn't even broken in.  The rotary in question has over
>  100K miles and consumption hasn't changed in the last 70K miles.
>  The Nissan Maxima (actually 2 of them) was an 87 with 127K miles
>  of experience and a 91 with over 38K miles already.   

you are right, 20k is not broken in, but i believe that 98k IS at least
broken in.  I said that i had personaly put 20k on the car in the last 
year, and that they were hard miles. this gives me a basis for the 
assumption that my car does not use oil, even under extreme cases(ok,
so i wasn't in death valley, but close enuff for me to make the assumption)
in fact, i was trying to make my car use oil if it was going to, so that i 
could rebuild it now, and save the time and money later, as i had it at
the time, but knew it would soon go elsewhere if i kept it.  But, i also
could not find any reason to rebuild, and thus put the  money to better
use...if it had consumed oil under my tests, i would have rebuilt it, because
the ARE NOT SUPPOSED to use oil.


>
>  Both Maximas use more oil with a lead foot than the rotary.  

maybe they suck?..maybe you should take them back and tell Mazda
to learn to make a piston motor??...
(semi :-) here, as i think that mazda does a decent job on both types
of motors, but if my v-6 burned that much oil after break in, i would
either get rid of it quiker than you can blink, or the manufacturer
would fix my car!)

>  And so have several 4 bangers I've owned, including a Porsche, MG,
>  TR (well, ok, it leaked most of it), and a flat-6 and a V-8 Chev.

ah..this COULD explain why you seem to think that this is normal...
;-)
>
>
>>
>>
>>BTW.i told how many miles i've put on just in case you thought it might
>>not be getting lubed properly, but i do not see how it could have lasted
>>20k, let alone the rest of themiles, w/o grenading or freezind if it were
>>improperly lubed.
>
>   As noted, 20K is a pretty small sample.  Call back after a half
>   dozen cars or so...or 100K miles of abuse.  
>
shuyeah..right..i don't know where you get your data, but every car
owner that i have known would rebuild or just really bitch if their
car used more oil than the rotary.  that is what oil consumption means,
that your rings are begining to get tired.(with the exception of break in 
period, as they DO tend to use a little during this time, untill things
seat properly)  Now, that does not mean that you should rebuild as soon as
your car burns an ounce of oil, but it does mean that if my piston powered
was burning up to a quart every 500(and was not a porsche, or some other
extremely over-stressed design)i would rebuild it!...it is worn way too far
at that point!(where did i get 500 miles??..out of a Mazda rotary owner's
manual..i do NOT know what yours sez, but that IS what this one says..oil
consumption up to 1qt per every 500 miles is considered acceptable..maybe
for the rotary, but not in a piston powered...with possible exceptions...
but is DEFINATELY NOT the NORM!)
DREW
-- 
??????????????????????????????????????????????????????????????????
??????????????????????????????????????????????????????????????????
?????????????????????????????????-----whatever!