Re: [AMC-list] Pacer motor mounts oddities

[adh@xxxxxxxxxxxxxxxxx (Sandwich Maker)]

"   ----- Original Message ----- 
"   From: LarryS 
" 
" 
" 
" 
" 
"   Couple o' things.
"   The wankel rotary isn't a 2 cycle OR a 4 cycle, they are Wankel cycle.

may be, but closely parallels 4-stroke.

"   2 stack rotaries are commonplace.  Even singlestack rotaries are used,
"   but not in cars -- you're talking all of 75 hp or so.

yeah, mazda sized.  iirc someone makes/made 600hp rotors for
stationary industrial power.

"   3 stack are common, racing and road cars, but not domestically.  They
"   are usually ordered in from Australia or somewhere.  Can't make EPA,
"   you know ;-)

i think that's partly a chicken-and-egg.  mazda gave up on us wankels
in anything but the rx7, so they never attempted to epa-rate the cosmo
3-rotor.

"   4 stack are, to my knowledge, not used anywhere except experimentally
"   on stationary applications like their "spark assisted diesel" project for
"   electrical generation.  Yup... a wankel running diesel fuel... except
"   "spark assisted" -- talk about marketing spin.

mazda is the only japanese co to win the lemans 24h, with a 4-rotor.

see also http://cp_www.tripod.com/rotary/pg03.htm - "4 Rotor Engine
info (Mazda factory and aftermarket conversions)"

i've seen pics of a pure-diesel wankel that used a second rotor to act
as pre-compressor and post-expander for the 'main' rotor.  dunno if it
ever made it into production.

"   The 4 stack has a lot of the same kind of crank probs a straight 8 can
"   have.  Too much load over too long a shaft, basically.

2-rotor mazda wankels have only 2 bearings, on the shaft ends.  the
3-rotor cosmo wankel adds a middle bearing.  afaik the racing 4-rotor
also had a center bearing.

imho there's another arg against 4-rotors - unnecessary complexity.  2
and 3 rotors are already plenty smooth, so 4 has no reason unless
you're building a family on modularity.

"   Also, they never did get good mileage.  Ever.  That's why I think of
"   them as a 2 stroke engine -- they chugalug the fuel.

that's b/c while they have great mechanical efficiency, the long
banana-shaped combustion chamber gives them miserable thermal
efficiency.  cummins had an army research program, a no-cooling-system
'red hot diesel' lubed with jet oils that can take 400-500 deg...  the
wankel would need something like that.

"   Oh... and if you run one without a muffler, it makes absolutely the
"   nastiest, loudest, and most-annoying sound I have EVER heard from an
"   engine.  Talk about something that would invoke road-rage... that'd
"   be it.

that partly depends on port location, on the chamber edge or sides.
edge ports are more efficient but louder, and the mazda lemans winner
gave new meaning to the word.
________________________________________________________________________
Andrew Hay                                  the genius nature
internet rambler                            is to see what all have seen
adh@xxxxxxxxxxxxxxxxx                       and think what none thought
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