Colin A Moran wrote:
> 
>  << In all oppsed engines, exceeding 4000 rpm for any lenghth of time will
> heat up the oil and
> >>pound out the main bearings.  This pounding even happens to Waterboxers.
> >>
> >>Dennis H.
> 
> Why then do so many aircraft engines have horizontaly opposed engines? They
> run at that rpm for long periods.  Also why has porsche used horizontaly
> opposed engines for so long if there was an rpm limit so low?  I read in
> Marks Engineering Hand Book that horizontaly opposed engines have the same
> benifits as a v type engine.  A horizontaly opposed engine is a V with
> 180deg between banks.
>     My $0.02 worth :-)
> Colin A Moran
> 
> If you can't dazzle them with brilliance,
> baffle them with bull sh*t.
> 
>  '86 Syncro GL

Most aircraft with HO4C engines run at 2,000 rpm.

Douglas