All rightey,Here's a question that may have already been answered, but I
must have missed it the first time.It seems to me that the 13B would be a
perfect candidate for a dry/external sump system.  I was looking at a 2006
Aston Martin this weekend and it too has a dry sump - which I have always
associated with inverted flying, not driving.  Anyway, does anyone on this
forum have some insights and thoughts about removing the oil pan on a 13B
and replacing it with an external tank/dry sump?

Kevin in Denver

Mazda Sport has a dry sump system but it is designed for car racing.
Looks like you will have to build your own.

Paul Lamar



kevin in denver, Doing a dry sump you can use the current oil pan to
collect the oil and easily scavenge it out of the oil pan with an
aftermarket gerorotor pump such as moroso sells (parker hannifin internal
parts).This adds firewall forward weight due to the tank which should be
larger than the pan capacity particularly on the smaller RX8 pan, a minimum
of two more hoses which present a place to leak, a third vent hose back to
the engine and weight of the oil pump and drive.

There is an upside to this
IMHO in that you would be filtering and then cooling the much hotter  temp
oil returning from rotor cooling and end housings and only this hotter oil.
Also you will add the pressure pump bypass oil and be cooling as well as
filtering it on each pass. the stock syster has the oil fall into the oil in
the pan mix up with it avaraging the temperature then pumping it back to the
engine without any heat removal.

After the engine pressure pump their is a
relief valve which maintains a set oil presure and flow into the engine. The
oil which is surplus at the relief valve is directed to the engine mounted
filter and thru the oil cooler back to the pan. Therefore we are filtering
less of the oil and cooling with less delta T at the cooler. These engines
reject A larger percentage of heat to the oil than a recip because the
hottest parts (the rotors) are oil cooled.

The  extra 18 pounds of hardware
would be on the accessory end of the engine and firewall area and lessen the
impact on the firewall forward CG. Add the new one piece front mount/ PSRU
adapter Paul is developing and get the weight back.As far as inverted
operation goes, take a  look at the internal structure of the
center  housing found in photos of housings sawed in two as  seen in this
newsletter.

Notice that the oil path  up thru the engine from the eccentric
shaft is of a similar size to the oil return to the pan. IMHO one could
collect the oil from the filler tube, the top of the accessory housing  with
some tedious drilling and tapping, or just brute force drilling and epoxy a
steel tube from the top of the rear housing down to the oil  relief ring
inside the rear oil seal part of the housing.

The overflow from the engine
pressure pump relief valve woild be sent (check valve) through this
collection header to a separate scavenge pump so that the pump would be
lubricated with this oil when flying with the rubber down. I have not done
this scheeme but plan on doing so, if anyone on the news letter sees
something  I am missing don't be shy.

george grimes