Would good to see your BIL how he goes with the results of the AMR500

They as Nick pointed out run at around 14psi and have about 16000rpm redline so as Jmac pointed out wouldnt hurt to change the oil as often as you change engine oil or service your donk.

Im playing with one of these soon, still to finish the manifold but almost there just need time.

Ive been using Dexron 3 and 4 in my manual gboxes with great effect.
The latest Dex4 in my suzuki carry box works better than factory recommended oil.

Now if only we could add some detergents into refined Palm oil for our engines we would be set :)