From: aas7@po.CWRU.Edu (Andrew A. Spencer)
Newsgroups: rec.autos
Subject: Re: Rotary vs. Piston Engines
Date: 10 Nov 1992 03:33:31 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: aas7@po.CWRU.Edu (Andrew A. Spencer)
NNTP-Posting-Host: thor.ins.cwru.edu


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

>In article <1dh14kINN7dg@usenet.INS.CWRU.Edu> aas7@po.CWRU.Edu (Andrew A. Spencer) writes:
>>HELLO!!! i am commenting on the fact that you make the claim that piston
>>motors burn oil, also by design.  
>
>   Dear Andrew.  
>
>   After you find a store where you can purchase a clue, see if you
>   can find anyone familiar with the term "blow-by rings".  

i seem to have one..otherwise i would not claim to.
i always tell people when i KNOW that i do not know what i am talking
about.  insults are always nice. 

>   Sorry, but some piston engines--usually those designed to stay
>   in one piece at high rpm--ARE designed to allow small amounts of
>   oil stay on the cylinder walls PAST the upper limit of the rings
>   when the piston is fully down.  

so what?..dragster motors are built at extradordinarily loose tolerances,
this in order to allow them to have less inherent bearing drag.  but does
this have anything to do with longevity??no..they only make one trip down
the strip and are then torn down..ok..soemtimes they run longer, but overall
do not see much in the way of run time.  This has little to do with road
going automobiles. "small amounts" i'll buy, but the proportions you quoted
for your mazdas seem inappropriate to me based on everything i've ever
been told or seen done or personal experiences with motors.

>   Amazingly enough, if you make the oil seal tight enough to
>   prevent this, the engine tends to wear out much faster.  
>
>   Of course that is a matter of a practical engine versus a
>   theoretical "perfect" engine....
>
>   Whether this is "by design" is a semantic distinction...and you
>   obviously nothing better to do than engage in quibbling, but I
>   do.

i do have things to do besided quibbling..like making an attmempt at
giving out correct (or at least acknowledged perhaps incorrect) 
information.  I feel that you are not telling the whole story, and
seem to be overlooking things.  I tell the rest.  No quibbling..
it's a nifty device called a "discussion", something we intelligent
humans beings have devised as a way of sorting through information.

>>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!)
> 
>    NOR is it really for the Rotary.  But since you are so !@#$!
>    well informed, I won't bother to repeat my oil consumption
>    figures on a 107K mile engine....  I'd junk the thing if it ever
>    used that much oil.  Only a Jaguar, and an old one at that,
>    would do THAT bad.   

did i say that it was "normal" or even optimal for the rot?..didn't think 
so..i said that MAZDA sed that it was "acceptable" (ie..within tolerances)
so(but they tell me only to change my oil every
5k too..)(they being my manufacturer)Like i said, this is completely 
unacceptable, to me, in any motor except, maybe for a two stroke..dunno
about them.  and since you too are so well informed, i will not requote my
oil cosumption figure either.

>    But, you, with a single data point, are the expert, so continue
>    to rave on....

who claimed expertise?
rave indeed.
DREW
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Newsgroups: rec.autos