1). What do you think of dry vs wet oil sump? All comments and
suggestions
welcome
2). As it is impractical, if not impossible, to make a fully
aerobatic
rotary engine on the basis of a Mazda block, what level of
"limited"
aerobatics capabilities is acceptable/wished for? I am especially
concerned
with vertical or near vertical manoeuvres... tricky situations for
rotaries...
Thanks in advance for the feedback.
Francois Badoux
Francois,
1) Dry sump gives you much greater flexibility. I plan to use dry sump
on my 20B from the start. With respect to inverted operation, a
pickup with a dedicated scavenge segment can be placed at the top of the
engine to scavenge inverted. You have probably thought of this but I
must offer the thought.
2) Your concern with vertical maneuvers is drain back problems? This
could be the tougher of the problems to surmount. But since so few of us
are Sean Tucker it is probably the least often used acrobatic mode for
most of us. (straight and level is fine with me for the most part)
For crankcase pickup most of the auto applications use pickups at the
front and rear of the pan anyway. (for acceleration and braking) Your
concerns about filling the rotors is a much more serious item. With dry
sump you do have the option of placing more scavenge pickups in critical
areas. I have seen V8 engines with 6 or 7 scavenge segments; in addition
to the oil pan they have pickups at the back of the valve covers and the
back of the intake valley. Tests in the past by Chevrolet showed the
more oil you could remove that wasn't in the bearings (drainback oil)
the more HP you could generate. There is a point of diminishing returns
on this of course. We need to concern ourselves with weight of the added
plumbing too. Dry sump does give you these options though, wet sump doesn't.
Bill Jepson
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