I first became aware of these engines when I was asked to go and
borescope them for someone who intended to purchase them as a lot
from the RAF.
Fortunately this gave me the heads up on the better engines amongst
them and enabled me to select the best one to purchase when the
original buyer decided against the idea. The
engine that I selected must have been the last enigne off of the
test bed, as the engine came with most of the test bed still attached.
These engines were a modification
of the standard 200 series Viper. Modifications included a fuel
system set up to permit greater fuel flow, the propelling nozzle
area was altered, and the govenor was adjusted to permit a greater
rotational speed. These (amongst other minor alterations) enabled
the engine to be operated at a significantly higher power than the
engine from which it was derived. This of course was at the expense
of a reduced TBOH.
These engines were started
by 120psi air impingement onto the turbine blade tips. Please
click the images to enlarge