The JT300 has a T63-A-700 Allison engine installed upside down. One reason for this installation was to enable relatively easy alignment of the tail rotor drive with the aft end of the free wheeling unit. However, there is a problem created here. The oil drain on the sprag unit is now on top which causes the unit to be constantly flooded with lube oil. A design manual I found on sprag units doesn't like flooding the sprag. Further, the Bell design uses the same turbine oil in the gear boxes and engine which enables the sprag to be lubed off the same source, pumps, filters and sump. The JT300 main rotor gear box is a unit from a Ford 4wd car and needs gear oil with the EP additive. Sprag clutch design manual doesn't like the EP additive in the sprag unit. In an attempt to have just one lube system, a separate experiment has been reported where turbine oil was used in the main rotor gear box (Ford 4wd unit). Heavy gear wear was noted in a short period of time. At the present time, I'm designing and building a separate oil supply for the sprag unit. Adapting to the the engine oil system would leave the sprag un-lubed during any lengthy engine off auto rotation. Also the separate lube system would keep the engine oil from seeing any particles generated by the sprag. Also the sprag system does not want to see oil pressures that exceed 10psi. Experimental aviation is designed to create a learning environment. There is also a small amount of actual aviation in there somewhere.