Webras are supercool. i'm running West engines (weston uk), 50V1, 36v1. These are super tuned webras. Weston modify the webra to get more power out it and works.
Look at the success of the MagnumR plane with west 50v1 and their genesis tuned pipe set up. Awesome power plant.
I've run them only on fully high quality synthetic fuel(prosynth). Sometimes on super competition prosynth with only 7.5 oil. The engine after is so cold you could chill your beers on it!!