Are the original Allison/Rolls 250 engine a thing anymore? It was revolutionary for its time - under 400 lbs, 300-400 shp, 30 gph. But now easily below par performance wise.
Edit - supplanted by the 300 SHP Rolls-Royce RR300 and used in the R66.
Edit - supplanted by the 300 SHP Rolls-Royce RR300 and used in the R66.
